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Broad-band spectra of Cyg X-1 and correlations between spectral characteristics

Broad-band spectra of Cyg X-1 and correlations between spectral characteristics
Broad-band spectra of Cyg X-1 and correlations between spectral characteristics

a r X i v :a s t r o -p h /0502423v 2 19 A u g 2005

Mon.Not.R.Astron.Soc.000,1–17(0000)Printed 2February 2008

(MN L A T E X style ?le v2.2)

Broad-band spectra of Cyg X-1and correlations between spectral

characteristics

Askar Ibragimov,1,2?Juri Poutanen,1??Marat Gilfanov,3,4Andrzej A.Zdziarski,5and Chris R.Shrader 6

1Astronomy

Division,PO Box 3000,FIN-90014University of Oulu,Finland

2Kazan State University,Astronomy Department,Kremlyovskaya 18,420008Kazan,Russia

3Max-Planck-Institut f¨u r Astrophysik,Karl-Schwarzschild-Str.1,85740Garching,Germany

4Space Research Institute,Russian Academy of Sciences,Profsoyuznaya 84/32,117810Moscow,Russia 5Centrum Astronomiczne im.M.Kopernika,Bartycka 18,00-716Warszawa,Poland

6Laboratory for High-Energy Astrophysics,NASA Goddard Space Flight Center,MD 20771Greenbelt,USA

accepted,received

ABSTRACT

We present the results of spectral analysis of 42simultaneous broad-band Ginga –OSSE and RXTE –OSSE observations of Cyg X-1carried out in 1991and 1996–1999.The broad-band spectra from 3to ～1000keV can be well described by thermal Comptonization model with re?ection from the cold disc,with an additional soft component visible below 10keV .The relative contribution of this component to the total energy ?ux appears to be higher in the spectra with larger re?ection amplitude and steeper photon index of the thermal Comptonized component.We consider a number of physically realistic models to describe the shape of the E <～10keV excess.The additional soft component can result from thermal Comptonization by electrons with a low Compton parameter,or can be a part of a nonthermal,power-law like emission extending above 1MeV .

We study correlations between parameters obtained from the spectral ?ts with different models.We con?rm a general correlation between the photon index Γand the amplitude of re?ection R .We ?nd that simple phenomenological models (like power-law plus Compton re?ection)applied to the narrow band (3–20keV)data overestimated the values of R and Γ,although the simple models did rank correctly the spectra according to R and Γ,as it was demonstrated in the original publications on this subject.

The dynamic corona model provides a satisfactory description of the observed correla-tion,while the hot inner disc models have problems in reproducing it quantitatively.On the other hand,in the context of the dynamic corona model it is dif?cult to understand correlations with the timing characteristics,which seems natural in the hot disc scenario.We do not ?nd signi?cant correlation between the electron temperature and other spectral parameters,while the optical depth of the hot medium seems to decrease when the spectrum becomes softer.It is also shown that spectral parameters are well correlated with the timing characteristics of the source.

Key words:accretion,accretion discs –black hole physics –gamma-rays:observations –stars:individual:Cygnus X-1–X-rays:binaries

1INTRODUCTION

Matter accreting onto a black hole,whether supermassive in Seyfert galaxies or stellar mass in Galactic X-ray binaries,releases most of its gravitational energy in the form of X-rays deep in the po-tential well.Accretion may proceed in a number of regimes.The accreting gas can approach the black hole in a disc-like con-?

E-mail:askar.ibragimov@oulu.?(AI),juri.poutanen@oulu.?(JP)?Corresponding Fellow,NORDITA,Copenhagen

?guration (Shakura &Sunyaev 1973)if the gravitational energy is effectively transported away in the form of radiation,or in a form of an almost spherical ?ow if the energy exchange mech-anism between protons (carrying most of the energy)and elec-trons is inef?cient (Shapiro,Lightman &Eardley 1976;Ichimaru 1977;Narayan,Mahadevan &Quataert 1998).Magnetic ?elds can play an important role transporting large fraction of the total avail-able energy and dissipating it in a rare?ed medium (corona)above the disc (Galeev,Rosner &Vaiana 1979;Tout &Pringle 1992;Svensson &Zdziarski 1994;Beloborodov 1999a;Miller &Stone

2 A.Ibragimov et al.

2000).However,every model is based on a number of assumptions that include prescriptions for the viscosity,the vertical distribution of the energy release through the?ow,the energy transport mecha-nisms,etc.Given the dif?culties in the accretion physics,observa-tions should help in choosing among the different possibilities as well as guide theoreticians in the right direction.

Cygnus X-1,one of the best studied black hole binaries (BHB),served as an accretion disc laboratory since the end of the 1960’s.The most dramatic observed phenomena are the spectral state transitions occurring every few years,when the source,typ-ically emitting most of its energy at about100keV in the hard state,switches to a soft state consisting of a prominent～1keV black-body and a power-law-like tail.The hard state spectrum was believed to originate from thermal Comptonization in a hot elec-tron cloud(Shapiro,Lightman&Eardley1976;Ichimaru1977; Sunyaev&Tr¨u mper1979;Sunyaev&Titarchuk1980).The black-body looking soft-state spectrum was associated with the optically thick accretion disc(Shakura&Sunyaev1973),while the origin of ～100keV emission in that state was not discussed much,because the detailed spectrum was not available.

During the last decade,the quality of the X/γ-spectra in-creased dramatically improving our knowledge as well as pro-ducing many new questions.In the hard state,the spectrum turns out to be rather complicated containing a number of compo-nents.Thanks to the broad-band coverage by Ginga and CGRO (and later by ASCA,RXTE and BeppoSAX),and advances in modelling of Comptonization at mildly relativistic temperatures (Coppi1992;Poutanen&Svensson1996),the parameters of the electron cloud where Comptonization takes place were deter-mined to a high accuracy.In Cyg X-1,the electron tempera-ture of kT e?100±50keV and Thomson optical depth of τ?1?2were found to be typical(Zdziarski et al.1996, 1997;Gierli′n ski et al.1997;Poutanen1998;Di Salvo et al.2001; Frontera et al.2001;Zdziarski&Gierli′n ski2004).Compton re-?ection bump,a signature of the presence of cold matter in the vicinity of the X-ray emitting source,was discovered(Done et al. 1992;Ebisawa et al.1996;Gierli′n ski et al.1997).The black body associated with the cooler accretion disc(Ba?uci′n ska&Hasinger 1991;Ba?uci′n ska-Church et al.1995;Ebisawa et al.1996)and an additional soft excess at a few keV of unknown origin further com-plicate spectral decomposition(Di Salvo et al.2001;Frontera et al. 2001).A high energy excess at>500keV discovered by CGRO (McConnell et al.1994;Ling et al.1997)gives some clues about presence of nonthermal particles in the source.

The X/γ-ray soft state spectrum has been studied exten-sively by simultaneous observations with ASCA,RXTE,Beppo-SAX,and CGRO during summer1996.In addition to the dom-inating black-body,a long power-law like tail extending up to10MeV was discovered(McConnell et al.2002).The high-energy spectrum could be well described by single Compton scattering off electrons having a nearly power-law distribution (Poutanen&Coppi1998;Poutanen1998;Gierli′n ski et al.1999, hereafter G99;Frontera et al.2001).The Compton re?ection was stronger than in the hard state,which was interpreted as a change in the geometry of the system,from the hot inner?ow in the hard state to the standard Shakura-Sunyaev disc with a nonther-mal corona in the soft state(Bisnovatyi-Kogan&Blinnikov1977; Ichimaru1977;Poutanen,Krolik&Ryde1997;Li&Miller1997; Esin et al.1998;Poutanen&Coppi1998).Evaporation and con-densation of the gas can provide a physical basis for the change of the transition radius between standard disc and hot inner ?ow(Meyer,Liu&Meyer-Hofmeister2000;R′o˙z a′n ska&Czerny 2000).A smaller re?ection fraction in the hard state,how-ever,can be explained by a beaming of the primary emis-sion away from the disc due to mildly relativistic motion of the emitting plasma(ejection model,see Beloborodov1999a,b; Malzac,Beloborodov&Poutanen2001,hereafter MBP01).In or-der to distinguish among different possibilities,one needs to com-pare model predictions with other observational facts.

A few,well separated in time,broad-band spectra do not give us a good picture about relations between different compo-nents such as,for example,Comptonized continuum and the re-?ection bump.One can study these relations on a larger data set in a narrower energy band.Zdziarski,Lubi′n ski&Smith(1999) (hereafter ZLS99)and Gilfanov,Churazov&Revnivtsev(1999) (hereafter GCR99)analyzing data from Ginga and RXTE,re-spectively,showed that the photon spectral slope of the Comp-tonized emission,Γ,is strongly correlated with the ampli-tude of Compton re?ection component,R=?/2π,where ?is the solid angle the cool material covers as viewed from the source of primary X-rays.This correlation exists for in-dividual BHBs and Seyfert galaxies as well as in a sam-ple of sources(see also Gilfanov,Churazov&Revnivtsev2000; Revnivtsev,Gilfanov&Churazov2001).Zdziarski et al.(2003) studied possible statistical and systematic effects and concluded that the correlation exists beyond any reasonable doubts.Similar correlation also exists for Fourier-frequency resolved spectra,i.e., those corresponding to the variability in a given range of Fourier frequencies(Revnivtsev,Gilfanov&Churazov1999).

The observed correlation provides extremely important clues to the geometry of the accreting material and can be used for testing theoretical model.The fact thatΓand R are correlated is a natural consequence of co-existence of the cold media(accretion disc)and a hot Comptonizing gas in the vicinity of the black hole.The cold material acts as a source of seed photons for Comptonization and,at the same time,re?ects and reprocesses the hard radiation produced in the hot gas.

The cold disc with the hot inner?ow model naturally produces the correlation if there is an overlap between hot and cold phases (Poutanen et al.1997;ZLS99).However,theΓ–R dependence ob-served in BHBs can be quantitatively reproduced only if the ratio of the seed photon temperature,kT seed,to the electron temperature is about10?4(ZLS99;Gilfanov et al.2000).For kT e～100keV this gives kT seed～10eV which is an order of magnitude smaller than the disc temperature in BHBs and closer to that expected from Seyferts.For kT seed～300eV,the spectra are too hard for the given re?ection fraction.In this model,the spectral slope is an ex-tremely steep function of the overlap between the corona and the disc,while the re?ection varies very little(Beloborodov2001).In-trinsic dissipation in the disc can make spectra softer for the given re?ection,but then the spectral slope will be even steeper func-tion of the overlap.Values of re?ection larger than1sometimes observed in Seyferts also cannot be explained.On the other hand, all the data can be well described by the ejection model with the correct kT seed(Beloborodov1999a,b;MBP01).

The problem is that theoretical models try to reproduce the best-?ttingΓand R which are subject to a number of system-atic effects.The photon index and,especially,the strength of the Compton re?ection depend crucially on the spectral shape of the underlying continuum and description of the re?ection physics (see detailed discussion in Zdziarski et al.2003).All the papers above,where this correlation was studies,assumed the underly-ing spectrum to be a power-law.Since the Comptonization spec-trum has a cut-off at high energies it gives fewer incident pho-

Broad-band spectra of Cyg X-1

3 Figure1.Broad-band spectra of Cygnus X-1as observed by RXTE and OSSE(with the respective observation number from Table1)and the best-?tting

models.Theoretical curves represent model1for observations6,25and31(see Sect.3).

tons that are available for re?ection(Weaver,Krolik&Pier1998;

Perola et al.2002;Malzac&Petrucci2002),and thus the?tted R

would be larger.Fitting an exponentially cut-off power-law to the

broad-band data(e.g.Matt2001;Perola et al.2002)does not im-

prove the situation,since this model does not reproduce well the

shape of the Comptonization continuum(Malzac&Petrucci2002;

Zdziarski et al.2003).Approximate treatment of ionization could

be another source of errors.

As we discussed above,the spectra of BHBs are rather com-

plex having number of components,and it is not possible to re-

solve different spectral components(e.g.thermal Comptonization

and soft excess)in the narrow energy range of an instrument such

as RXTE/PCA or Ginga/LAC.There is a danger that different com-

ponents overlap in that energy band producing effectively a power-

law of one index while in reality the slope of the primary emission

could be rather different.The resulting re?ection amplitude could

be also in?uenced signi?cantly.Thus,in order to obtain actualΓ

and R to be used in theoretical models,analysis of broad-band data

with physical models(such as Comptonization)is absolutely nec-

essary.

Additional sources of information are the width of the?uores-

cent Fe Kαline at6.4keV and the frequencies of the quasi-periodic

oscillations that were also observed to correlate with the re?ection

fraction and the spectral slope(Gilfanov et al.2000,GCR99).This

seems to be consistent with the variations of the inner cold disc ra-

dius.Not much data exist on the variability of the electron tempera-

ture and Thomson optical depth of the Comptonizing source which

can provide information about the nature of the emitting plasma

(electron-proton or electron-positron).It would be of interest to de-

termine how the optical depth changes with the bolometric?ux,

because this can help in distinguishing the accretion mode the?ow

is in.

In this paper,we analyze a large set of simultaneous broad-

band spectra.Four observations of Cyg X-1by Ginga/LAC and

CGRO/OSSE from1991as well as38observations by RXTE/PCA,

RXTE/HEXTE and CGRO/OSSE from1996–1999are studied

in details.For the spectral analysis,we use physically motivated

Comptonization models and study correlations between model pa-

rameters such as spectral slope of the primary Comptonization con-

tinuum,re?ection amplitude,the width of the Fe line,electron tem-

perature of the hot gas,and its Thomson optical depth.

2OBSERV ATIONS AND DATA ANALYSIS

The observation log is presented in Table1.Data reduction for

RXTE has been carried out using LHEASOFT5.3.1software;PCA

responses were generated using pcarsp v.10.1and HEXTE re-

sponses were used from2000May26.In PCA data reduction,all

5PCUs were taken into account,when possible.If not all PCUs

were turned on,we use PCUs0,2and3.Judging from the Crab

data,these two PCU con?gurations produce similar spectral slopes.

Systematic errors of0.5%were added in quadrature to the PCA

data.CGRO/OSSE spectra were prepared by adding per-orbit data

(average exposure2–5ksec),with total exposure up to12hours

and contemporary PCA observation in the middle of the period.

The systematic error in OSSE spectra varies from3%at50keV

to0.3%at300keV.Stability of OSSE spectra was checked using

hardness ratios(154–282/52–154keV)for per-orbit spectra being

added.If orbital spectra within12hours were apparently different,

we lowered the total integration time to include only similar data.

We used PCA data from3to20keV,HEXTE data from20-

25to200keV and OSSE data from50to1000keV.In addition,

four Ginga/LAC and OSSE simultaneous observations from1991,

previously studied by Gierli′n ski et al.(1997),were also analyzed.

The Ginga/LAC data are available from1.7keV,but we decided to

use exactly the same energy interval as covered by the PCA.For

the spectral analysis,we use XSPEC11.3.1k(Arnaud1996).

The spectra may be separated into two groups based on the

difference of their photon index(see Fig.1).Spectra from1991

and1997,represented by observation6,haveΓ～1.6(usual for

the hard state)and ones from1999(observations25and31)have

Γ～1.8–2.2,and hereafter we call the corresponding state?at

(because the spectrum is nearly?at in the EF E plot).The spectra

from1996and1998are close to the hardest ones from1999.We

do not consider here the broad-band soft state spectra,for which

the similar analysis has been performed by G99and Frontera et al.

(2001).

4 A.Ibragimov et al.

Table1.Observation log

1991hard state

G12304June600:18–02:1002412100:03–02:11 G2888June604:43–06:2902404004:29–06:51 G32828June611:03–14:2502597510:43–14:32 G41272June620:22–20:4402162920:02–20:33

1997hard state

510239-01-01-009095–Feb220:13–02:03612.54786416:53–04:52c 610238-01-03-0064411938Feb319:30–22:06612.54453014:38–02:36c 730158-01-01-001175809Dec1007:08–08:30705755202:55–12:46 830158-01-02-002012823Dec1107:06–08:457051200404:11–14:05 930158-01-03-002027706Dec1408:48–10:207051159903:09–11:35 1030158-01-05-002614901Dec1505:26–07:097051672123:31–11:18c 1130158-01-06-003210941Dec1700:40–02:0570********:13–07:32d 1230157-01-02-002309784Dec1807:07–08:16706992401:49–08:46 1330158-01-07-002275766Dec2007:11–08:297061184702:46–12:52 1430158-01-08-002581878Dec2105:28–07:0570********:51–12:31c 1530157-01-03-002846860Dec2421:24–23:0370********:36–03:18c 1630161-01-01-000132444136Dec2813:56–21:0370********:33–00:24c 1730158-01-12-002836916Dec3003:52–05:00707897923:49–07:57d

1999?at state

2440101-01-09-002405665Oct518:39–19:45831.52960515:04–01:12c 2540101-01-11-00731165Oct619:22–20:03831.52596014:39–00:50c 2640101-01-12-00865–Oct707:10–07:40831.52838903:08–12:55 2740101-01-15-00741218Oct808:07–08:48831.53101404:20–14:35 2840101-01-16-00757215Oct909:41–10:22831.53377003:55–15:48 2940099-01-20-011228354Oct1217:33–19:56831.53718612:11–01:23c 3040100-01-11-014300–Oct2810:46–15:128321955906:16–17:46 3140099-01-22-001444520Nov814:44–15:258321750409:52–21:28 3240099-01-23-0130841453Nov2315:26–17:32834.5873415:14–21:54 3340100-01-13-01770–Nov2420:08–20:59834.51965214:51–02:13c 3440100-01-14-02479–Nov2520:05–20:56834.51668314:24–01:47c 3540100-01-15-031729–Nov2621:40–22:32834.52437217:11–04:33c 3640100-01-16-021448–Nov2719:59–20:50834.51906315:13–02:34c 3740100-01-17-031902–Nov2821:32–22:27834.51030919:19–00:28c 3840100-01-18-031961–Nov2921:29–22:25834.51999916:03–03:19c

Broad-band spectra of Cyg X-1

5 Figure2.Correlations between parameters for the model0(pexrav).(a)The re?ection amplitude,R,vs.the photon spectral index,Γ.(b)The relativistic

smearing Gaussian widthσvs.re?ection R.(c)The Fe Kα6.4keV line equivalent width EW vs.R.

3SPECTRAL ANALYSIS

In order to describe the observed broad-band spectra we use the

following models:

(0)Power-law(without or with an exponential cutoff)and

Compton re?ection(pexrav model,Magdziarz&Zdziarski1995);

(1)two thermal Comptonization models and re?ection,with

the soft excess also modelled by thermal Comptonization;

(2)thermal Comptonization with re?ection plus a nonthermal

Comptonization corresponding to the soft state spectrum.

We use the eqpair code(Coppi1999;G99)for modeling ther-

mal and nonthermal Comptonization.All models include also a

Gaussian line at6.4keV and interstellar absorption with column

density N H which we?nd often larger than the value of0.6×1022

cm?2(derived from the reddening towards the companion star,see

Ba?uci′n ska-Church et al.1995).To avoid unreasonably low values

of this parameter,its low limit was set to0.5×1022cm?2.The pre-

sented uncertainties are given at a90per cent con?dence level for

a single parameter(?χ2=2.71).Fluxes,unless stated otherwise,

correspond to the range covering all the model emission.

3.1The power-law and re?ection model in the3–20keV data

The spectra of Cyg X-1clearly show correlations between re?ec-

tion amplitude and the spectral index(GCR99,ZLS99).Detailed

analysis con?rms(Zdziarski et al.2003)that the extend of correla-

tion is much larger than typical errors in the best-?tting parameters.

However,since the PCA spectrum falls in a quite narrow energy

interval and it is dif?cult to distinguish between various spectral

components that may form an“effective”power-law.Therefore,it

is not certain that the values forΓand R obtained from the simple

power-law/re?ection?ts indeed correspond to the actual physical

situation.

Still,in order to compare our results with those of previ-

ous analysis,we have performed?ts similar to those presented in

ZLS99and GCR99.We later compare them to the results obtained

with more physical models(see Sect.4.4).We use the XSPEC

model phabs*(pexrav+gaussian)(model0),i.e.,a power law

with the photon index,Γ,and Compton re?ection with the rela-

tive strength,R(Magdziarz&Zdziarski1995),accompanied by a

Gaussian?uorescence Fe Kαline(characterized by the relativistic

smearing widthσand the equivalent width EW),all absorbed by

interstellar material of column density N H.Hereafter,we assume

the disc inclination of i=50?and neutral re?ector.

The?t results are presented in Table2.Only the low-energy

3–20keV(RXTE/PCA and Ginga/LAC)data were?tted,and there-

fore we did not apply any high-energy cutoff to the power law.We

?nd that the correlations between spectral parameters(see Fig.2)

are similar to GCR99results.

As shown in Sect.3.2below,there is a likely overlap of dif-

ferent spectral components in the PCA energy range.Therefore,

the model0cannot represent a good approach for physical inter-

pretations for the spectra.Taking into account also the OSSE data

and including an exponential cutoff in the model,we can model the

joint data only very roughly,withχ2/dof～2.This is likely to be

due to the the shape of the exponential cutoff(which is assumed

in pexrav)being substantially different from the shape of the cut-

off of thermal Comptonization(see e.g.Zdziarski et al.2003).This

provides an argument against utilizing simple phenomenological

models in the analysis of BHB spectra.

3.2Comptonization model and broad-band spectra

The hard state spectra are well described by thermal Comptoniza-

tion(Gierli′n ski et al.1997;Poutanen1998;Frontera et al.2001),

with a weak soft excess.To describe Comptonization we use the

XSPEC model eqpair(see Coppi1999;G99).The spectrum of

seed photons is from a pseudo-Newtonian accretion disc,see G99.

Parameters of emission are expressed through the compactness,

?=

LσT

6 A.Ibragimov et al.

Table2.The best-?t parameters for model0(?tted to the low-energy Ginga and RXTE/PCA data only).

1991

G10.5+1.2

?01.63+0.09

?0.03

0.39+0.19

?0.08

0.46+0.81

?0.46

134+47

?66

3/11

G20.5+1.2

?01.62+0.09

?0.03

0.37+0.18

?0.09

0.58+0.93

?0.58

152+54

?73

4/11

G31.3+1.3

?0.81.60+0.10

?0.07

0.26+0.17

?0.13

0.60+0.95

?0.60

142+77

?75

3/11

G41.4+1.2

?0.91.69+0.09

?0.08

0.41+0.19

?0.16

0.42+0.97

?0.42

82+36

?60

5/12

1996

011.2±0.21.80±0.020.51±0.050.68±0.1696±1924/43 020.6±0.21.79±0.020.48±0.050.80±0.12148±2020/43 030.7±0.21.80±0.020.48±0.040.72±0.12138±1920/43 041.2±0.21.89±0.020.66±0.050.87±0.16112±1924/43

1997

051.3±0.31.65±0.020.25±0.040.40+0.22

?0.40

66±2019/39

061.2±0.31.65±0.020.24±0.040.38+0.19

?0.33

76±2027/39

071.0±0.31.71±0.020.35±0.050.52+0.21

?0.26

79±2216/39

081.0±0.31.69±0.020.29±0.040.44+0.19

?0.24

86±2135/39

091.2±0.31.71±0.020.36±0.050.56+0.21

?0.25

82±2226/39

101.2±0.21.69±0.020.32±0.050.43+0.20

?0.27

77±2022/39

111.2±0.21.70±0.020.32±0.040.35+0.20

?0.35

69±1915/39

123.1±0.21.72±0.020.38±0.050+0.42

?0

32±1223/39

132.1±0.31.71±0.020.37±0.050.30+0.55

?0.30

56±1921/39

141.1±0.31.70±0.020.37±0.050.43+0.20

?0.29

78±2121/39

152.1±0.31.70±0.020.35±0.050.15+0.53

?0.15

41±1817/39

162.1±0.21.69±0.020.41±0.050.17+0.43

?0.17

57±1622/39

172.7±0.31.71±0.020.36±0.050.03+2.79

?0.03

37±1719/39

1998

181.2±0.21.87±0.020.54±0.050.73±0.1699±2019/39 191.2±0.21.84±0.020.48±0.050.71±0.1795±2019/39 201.2±0.21.85±0.020.50±0.050.71±0.1796±2017/39 211.1±0.21.83±0.020.47±0.050.71±0.1793±2014/39 220.7±0.21.83±0.020.47±0.050.69±0.14123±2120/39 230.7±0.21.82±0.020.46±0.050.72±0.13135±2117/39

1999

240.5+0.1

?0

2.09±0.010.89±0.070.93±0.12203±2328/33

250.5+0.1

?0

2.30±0.021.38±0.161.12±0.16249±3448/33

260.5+0.1

?0

2.23±0.011.15±0.101.09±0.13247±2743/33

270.5+0.2

?0

2.05±0.010.81±0.080.95±0.14188±2514/33 280.7±0.32.05±0.030.84±0.100.82±0.15161±2632/33

290.5+0.1

?0

2.01±0.010.74±0.070.91±0.15185±2522/33

300.5+0.1

?0

2.20±0.011.07±0.071.03±0.11237±2227/33

310.5+0.2

?0

1.94±0.020.61±0.060.82±0.13170±2225/33 321.1±0.31.85±0.030.50±0.060.54±0.2379±2220/33

330.7+0.3

?0.2

1.87±0.030.53±0.070.63±0.19113±2630/33

340.6+0.3

?0.1

1.86±0.030.47±0.080.61±0.19125±2814/33

350.5+0.2

?0

1.88±0.020.52±0.050.65±0.13141±1825/33

360.5+0.2

?0

1.88±0.020.55±0.060.72±0.14156±2225/33 371.2±0.31.92±0.030.62±0.070.68±0.18109±2427/33 381.2±0.31.98±0.030.77±0.080.78±0.16125±2439/33

Broad-band spectra of Cyg X-1

7

(similar to that analyzed here)

by Frontera et al.(2001)in Beppo-SAX data.This component,that nature we address below,however,is relatively weak in case of 1991and 1997(observations G1–G4,05–17)hard state data.The spectra observed in 1996,1998and 1999(observations 1–4,18–38)appear similar in the overall shape to those of hard state,but are signi?cantly softer (see Fig.2).The soft excess in the ?at state is stronger.

We stress that the requirement of an additional soft excess is implied only by the joint PCA/HEXTE/OSSE data,since the PCA data cover a too narrow energy range.Even if the actual spectrum in the PCA 3–20keV band is not a power-law but is e.g.concave,a good ?t with a power law plus re?ection (model 0)can be still achieved.However,the real strength of Compton re?ection can be signi?cantly different.

Since the data require an additional component only in a rela-tively narrow,～3–10keV ,range,the parameters of the soft excess cannot be constrained accurately.Below we consider a number of physically realistic scenarios of its nature.In each of the considered models,we restrict the parameters controlling its spectral shape to values that makes its ?ux signi?cant only at low energies,and we ?t only its normalization.These ?ts allow us to completely describe the broad-band spectra and to constrain the parameters of main con-tinuum.

3.2.1High temperature of the optically-thick disc

The additional component may,in principle,be emitted by the hottest part of the optically-thick disc provided its temperature is high enough.We ?nd that the spectra of the observations 1–4,18–38can be well ?tted with kT max ～1keV .But Di Salvo et al.(2001)showed that the spectral decomposition of the BeppoSAX data of Cyg X-1in the hard state requires the presence of both the soft blackbody disc photons (with kT max ?0.1–0.2keV ,and an additional soft excess component.Therefore,we consider this model to be not appropriate.3.2.2Hybrid model

We also tried to apply hybrid thermal+nonthermal eqpair model to the spectra.Most of the data require nearly nonthermal injection and the resulting spectrum becomes a power-law directed by PCA part of the spectrum.Because the observed hard tail is not power-law,large re?ection appears to mimic the cutoff region,but it is still not enough to describe both the soft excess below 10keV and the hard tail,in which the systematic difference between the data and the model remains.Therefore,we ruled out this model.3.2.3Two thermal Comptonization components

The soft component can be described by additional thermal Comp-tonization (Frontera et al.2001;Di Salvo et al.2001).We use the model 1,phabs(comptt+eqpair+gaussian),where eqpair gives the main Comptonization and comptt (Titarchuk 1994)–the addi-tional soft component.Since the parameters of the soft excess are rather weakly constrained by our data,we ?xed the parameters of comptt at kT e =20keV and τ=1.Such a model produces a soft power law that does not extend to very high energies.This model ?tted to the data of the observation 24is shown in Fig.3.In spite of its simplicity,it yields a relatively good description of the data.

The ?t parameters are given in Table 3,and the dependencies between various model parameters are shown in Fig.4.We also

Figure 3.The model spectrum with two thermal Comptonization compo-nents (model 1,Sect.3.2.3)?tted to the RXTE +OSSE observation 24(from 1999).The spectral components of the ?t are shown by the dotted (green),dot-dashed (red),and dashed (blue)curves,which correspond to the main thermal-Comptonization continuum,the additional thermal Comptoniza-tion with kT e =20keV and τ=1,and the Compton re?ection including the Fe line,respectively.The solid (black)curve shows the total spectrum.The lower panel shows the residuals of the ?t.

quote the values of the spectral index Γof the power law obtained from the least-square ?tting of the logarithm of the intrinsic model ?ux at a logarithmic energy grid in the 2–10keV range (chosen to enable comparison with results of other papers).

The meaning of the normalization of eqpair is described in Sect.3.2above.Substituting f c =1,M =10M ⊙,i =50?,D =2.0kpc (see references in G99,Frontera et al.2001)and βc =1.7(Shimura &Takahara 1995),we expect the normalization of ?1.92.The lower normalization of the obtained ?ts (see Table 3),is caused either by a larger βc ～1.77–1.98or by a smaller covering factor f c .A slightly smaller,than the assumed disc temperature of 200eV ,can also reduce the normalization.On the other hand,some ?at state normalizations are larger than the expected value of 1.92.This cannot be explained by changing f c (smaller covering factor can only reduce the normalization),but could be a result of somewhat larger inner disc radius or larger temperature.The largest observed normalizations correspond to kT max ～220?245eV .

We see that there is a clear anti-correlation between the strength of the soft component and hardness of spectrum expressed in terms of ?h /?s .There is also a correlation between τand ?h /?s .The re?ection amplitude is correlated with the Fe line equivalent width EW and anti-correlated with ?h /?s (while at high values of ?h /?s the anti-correlation possibly breaks down).

The electron temperature kT e is a calculated parameter and no errors on it can be obtained from ?tting.However,we estimated its 1σlimits using its extremal values within the uncertainties of the parameters controlling spectral shape,i.e.,?h /?s and τ.This esti-mation gives us a possible conservative error on kT e of about 15keV for both models 1and 2.Taking this into account,no correla-tions between kT e –?ux and kT e ??h /?s are apparent.

8 A.Ibragimov et al.

Table3.The best-?t parameters for model1.

a Hydrogen column density,in units1022cm?2.

b Normalization of the eqpair model component.

c The unabsorbe

d total model?ux,in units of10?8erg cm?2s?1.

d Th

e unabsorbed model?ux o

f the comptt component,in units of10?8er

g cm?2s?1.

e Temperature o

f the emittin

g plasma in keV(for the eqpair component).

f Photon spectral index of the eqpair component in the2–10keV range.

Broad-band spectra of Cyg X-1

9

Figure 4.Dependencies of the spectral parameters for model 1

(Sect.3.2.3)?tted to the 1991and 1997(blue ?lled circles)and the 1996,1998and 1999data (red ?lled squares)on Compton ampli?cation factor of the main Comptonization component ?h /?s .(a)The re?ection fraction R ;(b)the relativistic smearing Gaussian width σat 6.4keV;(c)ratio of the additional thermal Comptonization ?ux to the total ?ux;(d)Thomson optical depth of the main Comptonization continuum component τ;(e)electron temperature of the main Comptonization component kT e ;(f)total luminosity of the Comptonizing cloud (assuming D =2kpc).

Figure 5.The model spectrum with the thermal and nonthermal Comp-tonization components (model 2,Sect.3.2.4)?tted to the RXTE +OSSE ob-servation 24(from 1999)together with the COMPTEL (McConnell et al.2002)hard-state data (marked by squares).The spectral components of the ?t are shown by the dotted (green),dot-dashed (red),and dashed (blue)curves,which correspond to the main thermal-Comptonization continuum,the additional nonthermal Comptonization,and the Compton re?ection in-cluding the Fe line,respectively.The solid curve shows the total spectrum.The lower panel shows the residuals of the ?t.

3.2.4Thermal continuum and nonthermal Comptonization

component As an alternative to the second thermal-Compton component,we consider here addition of a nonthermal Comptonization compo-nent.We ?nd that such a nonthermal component can describe both the soft excess and the MeV nonthermal tail observed in hard states by COMPTEL (McConnell et al.2002),while neither of these components can be described by the main thermal-Compton emission.This model ?tted to the spectrum 24is shown in Fig.5.Note that the COMPTEL data are shown for illustration only and were not taken into account in the ?tting.The used model 2consists of phabs(eqpair+eqpair+gaussian),in which the second eqpair component produces the nonthermal spectrum.In eqpair ,the avail-able power is supplied in part into heating electrons and in part into their acceleration,with the resulting steady-state electron distribu-tion calculated self-consistently.The compactness corresponding to the acceleration is hereafter denoted as ?nth .Then the relative fraction of the input power going into the nonthermal acceleration is ?nth /?h ,where ?h (as before)corresponds to the total rate of energy dissipation in the plasma.

For that additional component,we assumed that all the avail-able power goes into nonthermal acceleration,i.e.,?nth /?h =1.Note that the resulting self-consistent electron distribution is not purely nonthermal but hybrid,i.e.,it does contain a low-energy Maxwellian heated by Compton and Coulomb interactions.We further assume R =0,the power-law index of the acceler-

10 A.Ibragimov et

al.

Figure 6.Dependencies of the spectral parameters for model 2

(Sect.3.2.4)?tted to the 1991and 1997(blue ?lled circles)and the 1996,1998and 1999data (red ?lled squares)on Compton ampli?cation factor of the main Comptonization component ?h /?s .The meaning of the axes is the same as in Fig.4,except (c)ratio of the additional nonthermal Comptonization ?ux in model 2to the total ?ux.

ated electrons of Γinj =2.4(see McConnell et al.2002;G99;Frontera et al.2001;Poutanen &Coppi 1998),the minimum and maximum Lorentz factors of the power law of γmin =1.3and γmax =1000,respectively,kT max equal to that of the main com-ponent,?h /?s =1,and τp =1.No pair production is required,and τis found to be equal to τp .

The best-?t parameters are presented in Table 4and correla-tions between them are shown in Figs.6and 11.The normalization of the thermal eqpair component corresponds to βc =1.63–2.01,the values similar to those obtained with model 1.The strength of the additional (non-thermal)component is again clearly anti-correlated with the spectral hardness.The anti-correlation between R and ?h /?s is apparent and corresponds to the R ?Γcorrelation that we discuss in Sect.4.4.The values of R and the Fe line equiv-alent width EW are well correlated and can be approximated by a linear function passing through zero (see Fig.11c).Again,there is a correlation between τand ?h /?s .The electron temperature does not seemingly depend on the hardness,but the spread becomes smaller at larger ?h /?s where kT e ～90keV .

4DISCUSSION 4.1Absorption

As noted in Sect.3,the hydrogen column density N H was free in our ?ts.We ?nd that our data require absorption signi?cantly larger than 0.6±0.2×1022cm ?2which is derived from the reddening towards the companion star (Ba?uci′n ska-Church et al.1995).

Figure 7.(a)Fitted value of absorption column density N H for model 1

vs.orbital phase of the binary system.(b)Same,for model 2.Distributions are repeated twice for clarity.N H is in units of 1022cm ?2.

Broad-band spectra of Cyg X-111 Table4.The best-?t parameters for model2.

G10.9+0.5

?0.414.2+1.1

?0.9

1.41±0.080.40±0.040.61+0.32

?0.38

182+59

?52

1.29±0.09 5.320.2190 1.6249/73

G21.0+0.5

?0.616.4+2.1

?1.2

1.62+0.17

?0.08

0.37±0.050.78+0.34

?0.32

210+68

?60

1.50+0.12

?0.20

8.230.9381 1.5856/74

G31.4+0.4

?0.214.0+0.9

?1.7

1.35+0.08

?0.21

0.26+0.07

?0.03

0.58+0.93

?0.58

144+57

?50

1.12+0.10

?0.06

4.190.0193 1.6253/73

G41.6+0.5

?0.613.8+2.9

?1.9

1.37+0.34

?0.30

0.30+0.09

?0.08

0.56+0.95

?0.58

122+55

?48

0.97+0.13

?0.15

3.810.2391 1.6253/73

012.0±0.211.4±0.31.39+0.02

?0.040.34±0.020.85+0.13

?0.14

148+19

?21

1.63+0.07

?0.05

7.55 1.9883 1.66498/478

021.4±0.210.5±0.21.36±0.020.35+0.02

?0.010.95±0.10203+21

?19

2.12±0.069.00 2.3083 1.67528/493

031.6+0.1

?0.211.1+0.2

?0.1

1.55+0.03

?0.04

0.32±0.020.85±0.11182+22

?17

1.81+0.05

?0.04

8.28 2.3473 1.66527/506

042.1+0.1

?0.29.86+0.19

?0.24

1.49+0.03

?0.07

0.41+0.02

?0.03

0.93±0.12167+23

?17

2.16+0.09

?0.06

10.45 3.8673 1.69515/493

051.7+0.2

?0.313.0+0.5

?0.6

1.21+0.05

?0.04

0.21±0.020.51+0.21

?0.23

81+18

?17

1.17+0.05

?0.02

4.620.31101 1.6360/73

061.6±0.213.0+0.4

?0.51.29+0.03

?0.07

0.20±0.010.47+0.18

?0.20

90+18

?16

1.01+0.04

?0.03

4.020.2995 1.63372/402

071.5+0.2

?0.312.5±0.41.27+0.13

?0.08

0.25±0.020.64±0.18108±211.42+0.06

?0.08

5.850.7695 1.64366/415

081.6±0.212.2+0.4

?0.31.42±0.030.23±0.020.56+0.18

?0.19

106+20

?19

1.37+0.04

?0.05

5.450.6584 1.64401/415

091.9+0.2

?0.312.7+0.3

?0.2

1.44+0.03

?0.07

0.27±0.020.72+0.20

?0.19

110+27

?18

1.40+0.06

?0.04

6.110.9884 1.64348/415

101.4+0.4

?0.311.5+0.7

?0.4

1.17+0.13

?0.03

0.26+0.02

?0.03

0.55+0.19

?0.25

103+21

?26

1.37+0.05

?0.08

4.970.40101 1.66301/334

113.7+0.1

?0.312.3+0.4

?0.7

1.22+0.10

?0.05

0.27+0.03

?0.02

0.07+0.56

?0.07

43+19

?10

1.38+0.07

?0.06

5.820.9099 1.64193/236

123.6+0.4

?0.212.3+1.1

?0.4

1.22+0.18

?0.04

0.27±0.030.21+0.62

?0.21

46+21

?12

1.38+0.04

?0.06

5.780.8599 1.64201/238

132.5±0.813.4+0.6

?0.51.47+0.06

?0.03

0.25±0.020.50+0.21

?0.22

88+21

?22

1.31+0.06

?0.07

5.960.9183 1.62365/411

141.7±0.213.0+0.5

?0.41.37+0.13

?0.03

0.28±0.020.61+0.18

?0.19

109+20

?19

1.42+0.05

?0.06

6.350.9689 1.63391/415

152.8+0.2

?0.414.6+0.6

?0.8

1.32+0.09

?0.08

0.23±0.020.42+0.34

?0.40

62+27

?17

1.14+0.07

?0.04

5.630.9296 1.61198/244

162.8±0.214.0±0.31.49+0.02

?0.030.30+0.01

?0.02

0.41+0.17

?0.22

85+16

?15

1.38±0.04 6.67 1.0284 1.62436/402

173.3±0.213.7±0.51.42+0.08

?0.130.22±0.020.37+0.30

?0.37

58+19

?15

1.11+0.05

?0.04

5.160.8387 1.62342/415

182.0+0.1

?0.39.53+0.40

?0.23

1.59+0.04

?0.03

0.33±0.020.83+0.13

?0.12

150+32

?16

1.70+0.07

?0.06

7.34 2.4767 1.69481/489

192.0+0.2

?0.310.4+0.1

?0.3

1.66+0.01

?0.05

0.29±0.020.86+0.13

?0.15

148+22

?21

1.34+0.06

?0.03

6.10 1.9966 1.67455/502

201.9±0.29.93+0.43

?0.181.49+0.03

?0.06

0.31+0.01

?0.02

0.85±0.13151+19

?20

1.47+0.04

?0.05

6.30 1.9573 1.69467/502

211.7±0.29.73+2.14

?1.381.31+0.25

?0.36

0.30+0.04

?0.06

0.82±0.14139±201.64+0.30

?0.46

6.47 1.7384 1.6947/73

221.3±0.28.70+2.75

?1.411.08+0.32

?0.26

0.34+0.05

?0.06

0.76+0.13

?0.12

160+30

?20

1.98+0.39

?0.47

6.82 1.5999 1.7144/73

231.2±0.37.25+2.36

?0.560.97+0.31

?0.42

0.39±0.040.80±0.12171+22

?21

2.29+0.34

?0.46

6.32 1.11103 1.7543/73

240.7+0.3

?0.16.61+0.37

?0.31

1.42+0.09

?0.05

0.49+0.06

?0.04

0.89+0.08

?0.11

301+22

?39

1.15+0.06

?0.09

5.03 2.5566 1.78379/409

250.5+0.2

?06.06+0.73

?0.67

1.47+0.20

?0.22

0.63+0.12

?0.09

0.88+0.08

?0.07

346+26

?27

1.17+0.07

?0.14

4.28 2.2262 1.80354/409

260.5+0.2

?05.29+1.47

?1.15

1.30+0.38

?0.29

0.59+0.08

?0.06

0.93±0.07348±271.32+0.35

?0.28

3.69 1.7067 1.8352/67

271.0+0.3

?0.26.86+0.98

?0.78

1.28+0.23

?0.17

0.46+0.06

?0.05

0.91+0.10

?0.11

263+28

?29

1.48+0.21

?0.14

4.21 1.3976 1.77380/409

280.8±0.26.63+0.36

?0.311.43+0.08

?0.05

0.50+0.05

?0.04

0.90+0.08

?0.11

299+23

?35

1.14+0.07

?0.09

3.31 1.2066 1.78379/409

290.9±0.26.51+0.77

?0.391.14+0.05

?0.06

0.47+0.04

?0.05

0.91±0.10264±271.51+0.13

?0.17

3.74 1.0183 1.78388/409

300.6±0.13.68+0.81

?0.790.86+0.49

?0.14

0.75+0.09

?0.07

0.93+0.08

?0.07

324+26

?23

2.17+0.65

?0.73

3.91 1.5889 1.9149/67

311.0±0.27.26+0.47

?0.411.15+0.14

?0.12

0.38±0.040.85±0.11228+26

?25

1.53+0.11

?0.15

3.860.8487 1.75388/409

321.8±0.210.4+0.3

?0.61.47+0.04

?0.13

0.29±0.020.69+0.15

?0.16

128+22

?21

1.19+0.11

?0.04

4.030.7576 1.67388/409

331.4+0.2

?0.48.26+1.38

?0.82

1.24+0.19

?0.20

0.35+0.04

?0.05

0.69+0.18

?0.15

151+38

?21

1.63±0.21 4.440.8183 1.7262/67

341.0±0.37.18+1.54

?0.831.08+0.25

?0.16

0.34+0.03

?0.05

0.66+0.17

?0.16

160+30

?26

1.66+0.10

?0.30

3.650.4692 1.7542/67

350.9±0.27.48+1.20

?0.871.13+0.21

?0.15

0.36+0.05

?0.04

0.70±0.11189+23

?22

1.74+0.23

?0.24

4.150.6389 1.7541/67

361.1±0.48.15+1.22

?1.331.16+0.17

?0.29

0.38+0.07

?0.05

0.78+0.12

?0.11

203+26

?25

1.56+0.31

?0.21

4.210.7489 1.7358/64

372.3+1.0

?0.97.27+2.05

?1.28

1.14+0.35

?0.24

0.45+0.08

?0.06

0.79+0.19

?0.18

149+29

?27

1.54+0.35

?0.18

5.72 2.1688 1.7541/62

382.2±0.97.26+1.12

?1.021.11+0.20

?0.19

0.49+0.08

?0.06

0.79+0.16

?0.13

169+25

?24

1.60+0.34

?0.25

4.58 1.3289 1.7545/62

12 A.Ibragimov et al.

lation of N H with the orbital phase,which indicates that variable absorption indeed can be caused by the companion’s wind obscur-ing the X-rays from the black hole.

We note that since our models are relatively complicated in the range of3–10keV(consisting of absorption,Comptonization together with the seed photon emission and a soft excess),and also, the PCA energy range is affected by absorption rather weakly,it

is dif?cult to determine the exact values of N H.Even though,the derived values of the parameter are in the range quoted by other authors and its relative changes are quite remarkable.

4.2Spectral variability patterns

Using CGRO/BATSE and RXTE/ASM

data,Zdziarski et al.(2002) showed that Cyg X-1has two types of variability–changes of?ux without spectral slope change and pivoting at～50keV which pro-duces anti-correlation of the?uxes in the soft and hard part of the spectrum.However,those instruments do not provide detailed spec-tral information giving?uxes only in some energy intervals.The effective photon spectral indices using?uxes in two energy bands and calculated in the wide(20-300keV)energy interval,where real spectra experience a cutoff,should be treated with caution.Now we have a possibility to check the results of Zdziarski et al.(2002)us-ing our set of observations,on which we have a detailed spectral information in the wide energy range.For this purpose we are us-ing the model spectra obtained from model1.

In Fig.8we present the spectra related to different time peri-ods.It is possible to see that1991,1996–1998spectra only change their normalization.However,spectral slope is different for various years and forms two groups:1991+1997spectra and1996+1998 ones.In the1999data,we again can see normalization changes (see pairs of red solid curves)as well as pivoting behaviour.

TheΓ–?ux correlations are shown on Fig.9.It is clearly seen that the1991and1996–1998data do not show dependence between ?ux andΓ.The1999data show clear anti-correlation betweenΓand?ux on low energies(3–12keV)and correlation on high ener-gies(20-100,100-300keV),that indicates the pivoting behaviour with the pivot energy between12and～50keV.On Fig.9d(see also?g.8in Zdziarski et al.2002),it can be seen that spectra from 1996and1998are somewhat softer at high energies than the hard state spectra from1991and1997,but the?uxes in all energy in-tervals generally correlate with each other.The1999spectra show clearly different dependence:the high energy?uxes are correlated, but there is a clear anti-correlation between3–12keV and100–300 keV?uxes due to pivoting.The timing behaviour has also changed its nature in late1998,as was pointed out by Pottschmidt et al. (2003).

4.3QPO frequencies

Among the data sets we have studied,there are timing data for33observations available from the recent paper by Axelsson,Borgonovo&Larsson(2005).This allows us to check the relation between the characteristic frequencies in the power density spectra and the spectral parameters.In the work of Axelsson et al.(2005),several values of QPO frequenciesνQPO might be determined during one observation,and for these data points we assume the averaged middle frequency and consider the uncertainty from lower to higher of obtained values.In agreement with earlier results of GCR99,we?nd a clear anti-correlation be-tween the characteristic frequencies of the aperiodic variability and Figure8.Sample of the spectra from different periods.Lowest and highest spectra from each time period are shown.Red solid lines–1999;blue dotted lines–1991(the1997spectra are similar to them);black dashed lines–1996and1998.The1991+1997and1996+1998data form two groups with slightly different spectral slopes.

?h/?s(Fig.10),indicating an apparent connection between QPO frequencies and the parameters of the Comptonizing region.This provides an argument(but not a proof)in favour of the presence of a hot inner corona and a variable inner radius of the surrounding disc.

The frequency–hardness correlation can be described by a power-lawνQPO∝(?h/?s)?αwithα=?1.48±0.04.The best ?t is shown by the solid curve on Fig.10.Similar correlation was observed by Pottschmidt et al.(2003)and Nowak et al.(2002). 4.4Comparison between phenomenological and physical

spectral models and R?Γcorrelation

Fig.11compares the results obtained with the simple phenomeno-logical model of power law+re?ection in the3–20keV energy range(model0)with those from our model2applied to the3–1000keV range.More elaborate and physically justi?ed models utilizing the full energy range of our data do not change the pic-ture qualitatively.On the quantitative level we?nd that the simple power law+re?ection spectral?ts to the3–20keV data overesti-mated the amplitude of the re?ected component R and the slopeΓof the primary Comptonization continuum.We con?rm,however, that the simple models did rank correctly the spectra according to the strength of the re?ected component and slope of the Comp-tonized radiation,as it was demonstrated in the original publica-tions on this subject(ZLS99;GCR99).It is also illustrated by the lower three panels of Fig.11.The difference of the obtained pa-rameters comes from the fact,that for wide-energy observations the main thermal Comptonization component that describes well the hard energy tail may lie well below the observed?ux in the2–10keV range(see Fig.3and5)and has a different slope in this band.The difference is largest for1996,1998and1999data,while in the1991and1997cases the soft excess is weak and parame-ters obtained with the physical models are similar to those obtained with the phenomenological ones.

On Fig.11a,we see a clear correlation betweenΓand R. For comparison,we also show the dependencies predicted by the plasma ejection model of Beloborodov(1999a,b)and MBP01 (cylindrical geometry with h/r=2),using the geometric param-eter of that model ofμs=0.4and0.5,i=50?,albedo of the re?ecting medium of0.15andτ=2.We used the dependence between the ampli?cation factor A of Comptonization andΓfrom

Broad-band spectra of Cyg X-1

13 Figure9.Flux–spectral index(3–12keV)and?ux–?ux correlations.Respective energy intervals are indicated along the axis.The1991and1997data indicated by blue?lled circles,1996and1998–by red?lled squares and1999–by red open squares.All?uxes are in units of keV cm?2s?1

.

Figure10.Dependence between QPO frequencies and?h/?s.The?h/?s

are best?t values from model 2.The QPO frequencies are from

Axelsson et al.(2005).The solid curve shows the best power-law?t

νQPO∝(?h/?s)?1.48.

MBP01.We also compared our data with the dependence expected

in the model of ZLS99,assuming the black body temperature of

0.2keV,appropriate for Cyg X-1,with one minor change.In the

original paper,all the re?ection luminosity was assumed to reach

the observer.Re?ection amplitude is an integral that consists of

two parts,from the disc inside the corona and from the outer part

of it.We multiplied the part of luminosity coming from the former

part by e?τ,to approximately take into account scattering of radi-

ation in the corona(τ=1was chosen).We see that this model

cannot quantitatively describe the presented data.Moreover,taking

into account intrinsic dissipation in the disc(see Appendix A for

details)will further increase the slope of the dependence making

the discrepancy larger.Intrinsic dissipation becomes important for

a small inner disc radius(when re?ection is relatively large)and the

increase of soft seed photon?ux in that case makes the spectrum

softer(see Beloborodov2001).

4.5Physical scenario

The hard spectral state of black hole binaries is commonly de-

?ned as the state in which the spectrum is dominated by the

hard Comptonization component,without signi?cant contribution

of the blackbody-type emission from the optically thick accre-

tion disc.Naturally,the hard state is not characterized by a single,

uniquely de?ned spectrum,but rather includes a continuum of spec-

tral shapes with the major spectral parameters vary in a rather broad

range.The diversity of the hard state spectra re?ects the position of

the source with respect to the“bottom hard”state and the soft state.

Quantitatively,this position can be characterized by the strength

14 A.Ibragimov et

al.

Figure11.(a-c)Correlations obtained using model0(green open circles),model1(blue?lled circles)and model2(red?lled squares).(a)The spectral slope Γvs.re?ection scaling factor R correlation.For model0,Γis a?tting parameter,for model2–index of a power-law?tted to the spectral model in the2–10 keV range.The solid curve shows the dependence predicted for the ejection model(Beloborodov1999a;MBP01)with the parameters of i=50?,the albedo of0.15,μs=0.5andτ=2,the dotted curve–the same forμs=0.4.The dashed curve shows the dependence predicted by the model with a hot spherical corona and cold overlapping disc(Poutanen et al.1997;ZLS99)with the black body temperature of0.2keV,see Sect.4.4for details;the dot-dashed curve shows the same model with the dissipation effect taken into account(dissipation parameter L int=1,L int/4π=1at r<1,see Appendix A for details).(b) The relativistic smearing Gaussian widthσat6.4keV vs.R.(c)The equivalent width of the6.4keV line EW vs.R.The straight line is EW[eV]=500R. (d–f)Γ,R and EW obtained from model2vs.those from model0.

of the re?ected component(re?ection scaling factor R or Fe line

equivalent width EW)or properties of the main Comptonized

component(Comptonization parameter,or Compton ampli?cation

factor A=?h/?s,or the photon indexΓin the low energy limit)

or characteristic frequencies of the aperiodic variability.Existence

of good correlations between all these quantities suggests that they

all are an equally good measure of the source position within the

hard state.The results found in earlier work(ZLS99;GCR99;

Gilfanov et al.2000;Gilfanov,Churazov&Revnivtsev2004)and

presented in the previous sections of this paper suggest the fol-

lowing pattern of spectral and temporal variability.Increase of the

strength of the re?ected component is accompanied by the increase

of the width of the Fe line,increase of the characteristic QPO fre-

quencies and softening of the Comptonized component observed as

increase of its photon indexΓin the low energy limit.

We?nd from our spectral analysis that in the“bottom hard”

state the broad band spectrum(3-1000keV)is mostly described

by the single thermal Comptonization spectrum with superimposed

component due to re?ection of the primary emission from relatively

cool and neutral,or partly ionized,optically thick matter(the ac-

cretion disc),with an additional relatively weak soft component.

As the source moves towards the soft state,the strength of the

re?ected component increases,and the soft component becomes

more signi?cant.Considering the3–1000keV energy range cov-

ered by our data,this spectral component reveals itself most clearly

in the E<～10keV energy domain as the“soft excess”.Another

independent indication of spectral complexity is the gamma-ray

power-law tail detected at MeV energies by the COMPTEL tele-

scope(McConnell et al.2002).

From the point of view of the formal?t quality,the E<～10

keV excess can be described equally well by an additional thermal

Comptonization component due to low temperature,low Comp-

tonization parameter plasma or by non-thermal Comptonization

with the power law index of accelerated electronsΓinj～2?3.Ow-

ing to the complex shape of the continuum at these energies de?ned

by the superposition of several spectral components,these two pos-

sibilities can not be easily discriminated based solely on the low

energy data.The task is further complicated by the rather limited

low energy coverage provided by the PCA instrument,E>3keV.

However the above possibilities predict very different behaviour in

the～MeV energy domain,where the main thermal Comptoniza-

tion component diminishes and the power law tail due to the non-

thermal Comptonization should reveal itself.As the OSSE sensitiv-

ity and energy range are insuf?cient to probe existence of the MeV

tail correlated with the E<10keV excess,we can not,strictly

speaking,give preference to either of these two models.

There are however several additional considerations to be

taken into account:(1)COMPTEL detected a weak MeV tail in

Broad-band spectra of Cyg X-115

the averaged hard state data for Cyg X-1(McConnell et al.2002). The slope and amplitude of this tail is qualitatively consistent with the extrapolation of the non-thermal Comptonized component,re-quired to explain the E<～10keV excess(Fig.5);(2)in the soft state the non-thermal power law is the dominant(the only)high energy component;(3)the E<～10keV excess is more pronounced in the spectra characterized by large re?ection and rather steep slope of the main Comptonized component,i.e.in those suf?ciently close to the soft state.Its strength seems to increase with increase of the re?ection.These arguments suggest that the non-thermal origin of the E<～10keV excess is more plausible.We note,that the1991 and1997data show much weaker excess.This may be explained by the lower relative luminosity of the non-thermal Comptonization component which therefore reveals itself at lower energies,below the E=3keV threshold of the PCA instrument,but can be de-tected by instruments which have response at lower energies,i.e. BeppoSAX(see Frontera et al.2001;Di Salvo et al.2001).

The overall qualitative picture can be outlined as follows. The overall geometry of the accretion?ow is adequately repre-sented by the truncated disc model with the inner radius of the standard optically thick geometrically thin disc varying from～3 R g to～several tens R g.Inside this radius the accretion?ow proceeds via quasi-spherical optically thin hot?ow.The plausi-ble mechanism governing the transition from the disc accretion to the coronal?ow is the disc evaporation process as proposed by Meyer&Meyer-Hofmeister(1994).The geometrically thin disc gives rise to the soft black body type component.In addition,due to dynamo,solar-type magnetic?ares can be produced above the ac-cretion disc(Galeev et al.1979).The electrons there can be acceler-ated and form non-thermal https://www.sodocs.net/doc/3e9685656.html,ptonization of the disc emission on these electrons results in the power law-like Comp-tonized emission.The inner optically thin?ow gives rise to the thermal Comptonization component.The relative contributions of non-thermal and thermal Comptonized components are de?ned by the fractions of the gravitational energy released in the disc(i.e. outside R in)and in the inner hot?ow(inside R in).The position of the transition radius is de?ned by the mass accretion rate and is modi?ed by the irradiation-related effects.The transition radius decreases as the mass accretion rate increases.

The QPOs are due to some processes in the transition region near R in and approximately scale with the Keplerian frequency and other characteristic time scales of the coronal?ow and standard accretion disc in the transition region.

The con?guration with the large inner disc radius,probably R in>～50?100R g,corresponds to the classical hard state.The main features of this“bottom hard”state are low strength of the re?ected continuum,relatively narrow?uorescent Fe line of small equivalent width,large Comptonization parameter of the thermal Comptonized component(hard spectra with the low energy photon indexΓ～1.6),low frequencies of QPOs.As only small fraction of the gravitational energy is released in the disc,the contribution of the non-thermal component is small and the spectrum is adequately described by thermal Comptonization.

As the mass accretion rate increases,the transition radius de-creases,the disc moves towards the compact object.This results in increase of the re?ection,broader?uorescent Fe line,larger QPO frequencies,smaller?h/?s,i.e.smaller Comptonization parameter in the inner hot?ow.The contribution of the non-thermal compo-nent increases.The optical depth of the thermal plasma of the inner ?ow decreases due the shrinking of the inner hot?ow as the disc extends towards the compact object.

The classical soft state(we ignore all the complications and sub-states here)corresponds to the accretion disc extending all the way towards the last stable orbit or very close to it.Correspond-ingly the inner hot?ow disappears and the dominant or the only hard component is the one due to non-thermal Comptonization of the disc emission on the non-thermal electrons accelerated in the magnetic loops/?ares above the disc.

The behaviour of the temperature of the thermal Comptoniza-tion component is unclear.It seems relatively constant,which sug-gests of possible presence of electron-positron pairs(see MBP01).

The physical scenario qualitatively outlined above is based on the truncated disc picture and on the assumption that the spectral evolution is governed by the change of the transition radius be-tween the standard accretion disc and the hot inner?ow.In this picture many of the observed correlations can be explained natu-rally.However,the R?Γcorrelation is signi?cantly better quan-titatively explained by the non-stationary corona model(MBP01), in which the governing parameter is the velocity of the blobs of emitting plasma relative to the accretion disc.We note that both models are geometrical in their nature and the predicted qualita-tive relations between the physical parameters are obtained with a number of simplifying assumptions.Therefore results of quantita-tive comparison of the model predictions with the observed pattern of the spectral variability should be interpreted with caution and any conclusions regarding validity of either model based on such a comparison would be premature.

5CONCLUSIONS

Based on the broad band(3–1000keV)data from simultaneous observations by Ginga and CGRO/OSSE in1991and PCA and HEXTE instruments aboard RXTE and OSSE in1996–1999we studied the spectral variability of Cyg X-1.

(i)We con?rm earlier results on R?Γcorrelation.Consider-ing the3–20keV data we?nd very tight one-parameter relations between re?ection,spectral index and the width of the Fe line. (ii)More elaborate and physically justi?ed models utilizing the full energy range of our data do not change the picture qualita-tively.On the quantitative level we?nd that the simple power law +re?ection spectral?ts to the3–20keV data overestimated the am-plitude of the re?ected component R and the slopeΓof the primary Comptonization continuum.We con?rm,however,that the simple models did rank correctly the spectra according to the strength of the re?ected component and slope of the Comptonized radiation, as it was demonstrated in the original publications on this subject (ZLS99;GCR99).

(iii)Based on the analysis of the broad band data we found that the spectra in our sample can be adequately described by the ther-mal Comptonized component with superposed re?ection from the optically thick disc and a soft excess.This excess is relatively weak in case of hardest spectra of our sample(Γ～1.7).As the strength of the re?ection increases,the excess becomes much more signi?-cant.Presence of this excess was the primary reason for the simple spectral approximations of the3–20keV data to overestimate both R andΓ.The nature of this excess cannot be unambiguously de-termined from our data.Based on the circumstantial evidence we suggest that it is the lower energy part of the non-thermal Comp-tonized component with the power law index of accelerated elec-tronsΓinj～2?3.At higher energies this non-thermal component reveals itself as a power law detected by COMPTEL at MeV ener-gies in the average hard state spectrum of Cyg X-1.

16 A.Ibragimov et al.

(iv)We note the variability of the absorption correlated with the phase of binary system.These results con?rm previous?ndings of the X-ray dips in the source.

(v)The overall pattern of spectral and temporal variability can be summarized as follows.Increase of the strength of the re?ected component is accompanied by the increase of the width of the Fe line,increase of the characteristic QPO frequencies and softening of the Comptonized component observed as increase of its photon indexΓin the low energy limit or,equivalently,decrease of the Compton ampli?cation factor?h/?s.Simultaneously,the optical depth of the thermal Comptonization decreases and the fractional contribution of the non-thermal component to the total energy?ux increases.The exact behaviour of the electron temperature in the hot inner?ow is not constrained by our data.

(vi)We suggest a qualitative physical scenario naturally ex-plaining the observed behaviour.In this scenario the evolution of the spectral parameters is governed by the value of the transition radius between the standard optically thick accretion disc and the inner quasi-spherical hot?ow.The thermal Comptonized compo-nent originates in the inner hot?ow as a result of Comptonization of the soft photons emitted by the accretion disc.The origin of the non-thermal component is related to the optically thick disc,for ex-ample it can be produced due to non-thermal electrons accelerated near the surface of the optically thick disc in the solar-type mag-netic?ares.The relative contributions of non-thermal and thermal components to the total energy?ux depends on the fractions of the gravitational energy of accreting matter released in the optically thick disc and in the hot inner?ow. ACKNOWLEDGMENTS

We are grateful to Bryan Irby(NASA/GSFC)for help with con-verting the Ginga data,and to Magnus Axelsson for sharing the results of the timing analysis.This work was supported by the Cen-tre for International Mobility and the V¨a is¨a l¨a foundation(AI),the Academy of Finland grants201079and204600and the Wihuri Foundation(JP),and the NORDITA Nordic project in High En-ergy Astrophysics.AI was also supported by RFFI02-02-17174 and presidential program for support of leading scienti?c schools NSH-1789.2003.2.AAZ was supported by KBN grants PBZ-KBN-054/P03/2001,1P03D01827and4T12E04727. REFERENCES

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APPENDIX A:DISSIPATION AND ATTENUATION IN

THE DISC-HOT FLOW MODEL

ZLS99have considered an idealized geometrical model for thermal

Comptonization,reprocessing and re?ection in an accretion?ow

consisting of a central hot sphere surrounded by a?at cold disc,see

?g.2in ZLS99.The sphere has a unit radius,and the inner radius

of the disc can assume any value,d.For d<1,there is an over-

lap between the two components.The hot sphere Comptonizes soft

seed photons emitted by the disc.In the original model of ZLS99,

the disc reprocesses and reemits only the photons emitted by the

sphere incident on the disc.

Here,we generalize that model to include intrinsic dissipation

in the cold disc(as expected in an accretion?ow).Also,we take

into account scattering of the Compton-re?ected photons in the hot

sphere,which was neglected in ZLS99.For completeness,we give

here the full set of relevant equations,but refer the reader to ZLS99

for details of the derivation.

The hot sphere has a unit luminosity and emits isotropically.

The total?ux incident on the disc at a radius,r,is then given by

(ZLS99),

F inc(r)=3h(r)

1?L inc

.(A4)

Another effect not included in the treatment of ZLS99is the

intrinsic dissipation in the disc.Far away from the center(so any

effect of the inner boundary condition is negligible),the dissipated

?ux per unit area is∝r?3,and we assume it for r>1.On the

other hand,the dissipation in the part of the disc inside the hot

sphere,r<1,is reduced due to the transfer of the power to the

hot plasma.We assume here that dissipation either to be null or

constant matching that of the outside disk,

F int(r)=

L int

4π2 ∞d d r rh2(r)+L int r2

+

L int

圆的面积计算练习题

一、填空 1．一个圆形桌面的直径是 2米，它的面积是（）平方米。 2．已知圆的周长，求d=（），求r=（）。 3．圆的半径扩大2倍，直径就扩大（）倍，周长就扩大（）倍，面积就扩大（）倍。 4．环形面积S＝（）。 5．用圆规画一个周长50.24厘米的圆，圆规两脚尖之间的距离应是（）厘米，画出的这个圆的面积是（）平方厘米。 6．大圆半径是小圆半径的4倍，大圆周长是小圆周长的（）倍，小圆面积是大圆面积的（）。 7．圆的半径增加，圆的周长增加（），圆的面积增加（）。 8．一个半圆的周长是分米，这个半圆的面积是（）平方分米。 9．将一个圆平均分成1000个完全相同的小扇形，割拼成近似的长方形的周长比原来圆周长长10厘米，这个长方形的面积是（）平方厘米。 10．在一个面积是16平方厘米的正方形内画一个最大的圆，这个圆的面积是（）平方厘米；再在这个圆内画一个最大的正方形，正方形的面积是（）平方厘米。 11．大圆半径是小圆半径的3倍，大圆面积是平方厘米，则小圆面积为（）平方厘米。 12．大圆半径是小圆半径的2倍，大圆面积比小圆面积多12平方厘米，小圆面积是 （）平方厘米。 13．鼓楼中心岛是半径 10米的圆，它的占地面积是（）平方米。 14．小华量得一根树干的周长是75.36厘米，这根树干的横截面大约是（）平方厘米15．一只羊栓在一块草地中央的树桩上，树桩到羊颈的绳长是 3米。这只羊可以吃到（）平方米地面的草。 16．一根 2米长的铁丝，围成一个半径是30厘米的圆，（接头处不计），还多（）米，围成的面积是（） 17．用一根 10.28米的绳子，围成一个半圆形，这个半圆的半径是（），面积是（）

儿少分章节重点考试资料缩印版

名词解释 儿童少年卫生学：是保护和促进儿童少年身心健康的科学,是预防医学的重要组成部分。 生长（growth）：指细胞繁殖、增大和细胞间质增加，表现为组织、器官、身体各部分乃至全身的大小、长短、重量的增加和身体成分的变化，为量变。 发育（development）：指细胞、组织的分化和功能的不断完善，心理智力的发展和运动技能的获得，为质变。 成熟：指生长和发育达到一个相对完备的阶段，，标志着个体形态、生理功能、心理素质等方面都已达到成人水平，具备独立生活和生养下一代的能力。 成熟度：专指某一特定生长发育指标当时达到的水平占成人水平的百分比。 生长发育可塑性：指人体结构、功能为适应环境变化和生活经历而发生改变的能力。 生长发育指标体系：体格发育指标，体能发育指标，心理行为发育指标 儿少卫生学的研究对象是从出生后的婴儿到发育成熟的青年，年龄范围为0~25岁。重点对象是中小学生群体，在此基础上向学龄前儿童和大学生群体延伸。三个鲜明的发展特征：1.高度重视主要服务对象——中小学生的三大特点：正在旺盛生长发育；生长的同时在接受教育；集体生活在学校这一特殊环境里。2.制定工作目标和提出干预措施时，不仅关注生长发育及其影响因素，学生常见病和伤害防治，而且充分考虑其心理-情绪-行为发展特征和实际需求。3.核心任务是针对青春期少年的身心发展过渡性特点和特殊问题，提供良好的教育、保健和医疗服务。 主要研究内容：生长发育、疾病防治、心理卫生、教育过程卫生、学校健康教育、学校卫生监督和学校建筑设备卫生。 生长发育的一般规律：1.遗传与环境的交互作用。2.生长发育的阶段性和连续性的统一：阶段性：婴儿0-1，幼儿前期1-3，幼儿期3-6，童年期5-12，青春期10-20 女孩比男孩早1~2年，青年期18-25。3.生长发育速度的不均衡性：整个生长期内个体的生长速度有时快，有时慢，是不平衡的。第一突增期：胎儿4个月开始至出生后一年，身长（胎儿中期4-6个月）体重（胎儿后期7-9个月）；第二突增期;青春期（女9-11至13-15 男11-13至15-17）； （1）突增期意义：1补充适当的营养2保证充足的睡眠3保证足够的锻炼。4各系统生长模式的时间顺序性与统一协调性：生长发育过程中，各组织、器官的生长模式在时间进程上是不同的。（2）程序性：1头尾发展律（胎儿期和婴幼儿期，由上至下、由近而远） 2近侧发展律（瘦的精细动作，近-远，粗-细，简单-复杂）3向心律（童年期和青春期，下肢先于上肢，四肢早于躯干）。（3）Scammon生长模式：1一般型：肌肉、骨骼脏器等，两次突增；2神经系统型：发育最早，一次突增，先快后稳；3淋巴系统型：发育最旺盛，一次突增，有升有降；4生殖系统型：发育开始最晚，一次突增，先慢后快。5.子宫型：子宫，肾上腺发育在出生时较大，其后迅速变小，青春期开始前才恢复到出生时的大小；其后迅速增大。（4）生长轨迹现象和生长关键期：1生长轨迹现象：在外环境五特殊变化的条件下，个体儿童的发育过程比较稳定，呈现一种轨迹现象，其中遗传基因起关键作用；2赶上生长：因某种因素生长发育受阻的儿童，在阻碍生长的因素被克服后表现出的加速生长，并恢复到正常轨迹的现象；3生长关键期：生长关键期是器官和组织的快速生长期，此时受到干扰，常导致永久性的缺陷和功能性障碍。 体能：是指人体具备的能胜任日常工作和学习而不感到疲劳，同时有余力能充分享受休闲娱乐生活，又可应付突发紧急状况的能力。（体能发育过程的不均衡性、阶段性、不平衡性和性别特征） 体成分（身体成分）：指人体总重量中不同身体成分的构成比例，属化学生长的范畴。（体成分的两成分模型由体脂重和去脂体重） 青春期（adolescence）：是个体从童年向成年的逐渐过渡的时期，是生长发育过程中的一个极其重要的阶段。青春期的年龄区间为10~20岁，WHO把青春期定义为这样一个时期：1.是个体从出现第二性征到性成熟的生理发展过程；2.是个体从儿童认知方式发展到成人认知方式的心理过程；3.是个体从社会经济的依赖性到相对独立状态的过渡。女性青春期的时间跨度一般为10~18岁，男孩为12~20岁。 青春期的发育特点：1.体格生长加速，以身高为代表的形态指标出现第二次生长突增；2.各内脏器官体积增大、重量增加，功能日趋成熟；3.内分泌功能活跃，与生长发育有关的激素分泌明显增加；4.生殖系统功能发育骤然加快，迅速成熟，到青春晚期已具有繁殖后代的能力；5.男女外生殖器和第二性征迅速发育，使两性的外部形态特征差异更明显；6.青春期心理发展骤然加快，产生相应的心理-行为变化，可能出现一些青春期特有的心理-行为问题。 青春期发育类型：早熟型（盆宽窄肩的矮胖体型，突增维持1年左右）、晚熟型（瘦高，维持2年以上）、一般型（介于二者之间，维持两年左右） 矮身材：身高低于其性别--年龄组正常值的第三百分位P3。垂体性侏儒症、甲状腺功能低下症、遗传代谢性疾病、生长迟缓、家族性矮身材、体质性生长迟缓。高身材指个体的身高高于其性别年龄相应标准的第97百分位数以上。按原因分：家族性高身材、体质性生长发育加速、巨人症。 性早熟（sexual preiocity）：是一种以性成熟提前为特征的性发育异常，一般指男9岁以前出现睾丸增大，女8岁前出现乳房增大活10岁前出现月经初潮。一般分真性性早熟，由下丘脑-垂体-性腺轴过早启动引起；假性性早熟，多因性腺或肾上腺皮质肿瘤等导致性激素分泌过多，环境污染物种的激素成分，外源性性激素药物，含性激素制剂的不当应用也可引起；部分性早熟，患儿仅有某一方面的单独提前发育现象、不伴随其他异常表现；体质性性早熟，女孩8~8.5岁前出现第二特征指标一项以上发育或10岁前来初潮男孩9~9.5岁前出现睾丸增大或阴毛生长，本质上属健康人群。 青春期性发育障碍(delay puberty)：一般指男童14岁未出现睾丸增大，女童13岁未出现乳房发育为判断标准。 影响生长发育的因素有：遗传和环境因素，其中前者决定了生长发育的可能性，即决定了生长发育的潜力。后者决定了生长发育的现实性。即在不同程度上影响该潜力的正常发挥，决定发育的速度以及最终可达到的程度。①遗传因素：遗传的家族.种族影响：如家族聚集性和种族差异，是遗传影响的具体表现，身高、 性成熟早晚、生长突增模式、月经初潮年龄，都与家 庭遗传有关，种族影响对个体的体型、躯干、和四肢 的长度的比例等作用很大；双生子研究。②环境因素： 1）营养2）体育锻炼3）疾病4）生活作息制度5） 气候和季节6）环境污染7）社会家庭因素。 双生子研究：MZ同卵，DZ异卵 遗传度：是衡量遗传、环境因素各自对表型性状总变 异相对作用大小。越接近1，遗传作用越大。 生长发育调查方法含义以及特点：1）横断面调查； 在某一较短时间和一定地区范围内，选择有代表性的 对象对某几种指标的一次性大标本调查。特点：通过 其，可在短期内获得大量的资料。在一个较大地区范 围内通过调查得出某项指标的正常值，建立该地区儿 童少年生长发育的标准；也可将本地区本人群的调查 结果与其他地区人群结果作比较，以了解本地区儿童 少年的生长发育水平，并作为评价本地区儿童少年保 健工作效果依据；对同地区同人群的连续多次调查， 可比较不同时期的动态变化，分析生长长期趋势。调 查规模达时间短，需较多测试人员，调查前应该有详 细的计划严格的人员分工和测试程序，调查项目不宜 过多，根据调查目的确定调查对象具有代表性，对所 处的内外环境属性有明确规定2）追踪性调查；是一 种动态观察，通过选择一定数量的对象，在较长一段 时间内进行的定期，连续多次的调查，观察儿童少年 的生长发育动态。制定生长速度正常值，揭示生长发 育规律性，系统深入的观察分析某些内外因素对生长 发育的长期影响。调查对象自始至终是同一组人群， 故反应的生长发育规律较横断面调查更加准确，更能 确切的反映人群或个体的生长速度。费时长，调查中 人员和对象都容易流失，从调查开始即应采取措施保 证其稳定性，最大限度减少样本流失。尽量使用同一 型号的测试器材，技术标准保持一致，使前后结果有 可比性。3）半纵向调查；将横断面和追踪调查两种 方法混合，克服追踪调查所需年限太长，研究样本易 流失的缺点。节约时间和工作量。只具有部分的追踪 性质，获得生长发育速度是近似的，将会出现两组不 同对象的重叠，产生差异，需利用适当的统计方法修 匀。 生长发育的评价的实际意义：1.了解个体、群体的生 长发育现状，处于什么等级、发展趋势如何；2.为评 价遗传--环境影响因素，考察学校卫生工作实效、开 展保健干预提供依据；3.筛查、诊断生长发育障碍。 生长发育评价既针对个体也针对群体，由生长发育水 平、生长速度、发育匀称度（指标间相互关系）和体 质综合评价报告等四类内容组成。 生长发育评价方法：一：等级评价法和离差曲线图法 （正态分布的计量资料）；二：指数法：利用数学公 式，根据身体各部分比例关系，将两项或多项指标相 连，转化成指数进行评价。身高坐高指数：根据人体 躯干与下肢的比例关系，从纵截面角度反映体型，分 为长躯型、中躯型、短躯型（坐高cm/身高cm*100%）； 反映生理功能指数：身高肺活量指数和体重肺活量指 数=肺活量/身高或体重；BMI营养状况指数。三：Z 分法：Z标准差法，是一种特殊类型离差法。它不以 均数加减标准差表示，而是以中位数为中心，将资料 从偏态分布大体转换为正态分布，再取＋－1Z、＋－ 2Z、＋－3Z为界值点，建立正常值。通过正态转换过 程，实测值即被转换成Z分，由此确定发育等级。四， LMS法：三大优势：1.对百分位数法、Z分法既沿袭 又修正。2.只要使用的样本量达到要求，所制成的正 常值或标准课精确到个位。3.各相邻百分位数值间不 会出现交叉、颠倒或重叠，从而使所定正常值或标准 的精确性显著提高。五：发育年龄评价法：是指用某 些身体形态、生理功能指标和第二性征的发育水平及 其正常变异，制成标准年龄，评价个体发育状况。（四 种：形态年龄，第二性征年龄，齿龄，骨龄） 心理卫生（精神卫生）：是研究如何维护和促进人类 心理健康的科学。包括一切旨在改善心理健康的措施， 使人能按自己的身心潜能进行活动。（对儿童来说， 就是促进心理健康发展、培养健全性格、提高儿童对 环境的适应能力、预防精神方面的各种问题） 儿童少年心理健康的标准：心1.智力发展2.情绪反应 适度 3.心理行为特点与年龄相符。4.行为协调，反 应能力适度5。人际关系的心理适应。6，个性的稳 定和健全 心理障碍:儿童在心理健康方面存在的偏倚称心理卫 生问题，若其严重程度、持续时间超过相应年龄的允 许范围，称心理障碍。（20%） 儿童期心理行为问题的表现主要有： 1、学业相关问题学习困难、注意力障碍、自控力 差等，多发生在小学阶段，特别是初入学儿童。注意 有些属于学龄前期向学龄期过渡时出现的暂时性适 应不良。 （ADHD注意缺陷多动障碍：俗称儿童多动症，是以 注意力不集中、情绪冲动、过度活动、学习困难为特 征的综合征。通常起病于7岁之前， LD学习障碍：是指学龄儿童在阅读、书写、拼写、表 达、推理、计算能力等学习过程中存在一种或一种以 上的特殊性障碍，包括阅读障碍、数学障碍、书写障 碍、非特定性学习障碍等。） 2、情绪问题紧张焦虑、孤僻、强迫行为、恐怖。（焦 虑指突如其来出现的、无明显躯体原因的恐惧感，若 经常反复出现，已形成儿童焦虑障碍，是儿童期最常 见的情绪障碍之一。强迫行为：指儿童以强迫观念和 强迫动作为主，伴焦虑情绪和适应困难的一类症候群。 恐惧：当参与某项活动或面临某种情景式产生过分强 烈、持续的紧张、恐惧和回避情绪。心境障碍：又称 情感性障碍，是一组以显著而持久的心经高涨或低落 为主要症状的精神障碍，伴有相应的思维和行为改 变。） 3、品行问题如偷窃、经常撒谎、攻击性行为。 4、 不良习惯如习惯性抽动、吮指、咬指甲、口吃、遗 尿。5、广泛性发育障碍：孤独症谱系障碍ASD：也 称自闭症，是由脑发育不良引起的，以社会功能、语 言沟通缺陷为主，伴异常狭窄的兴趣和行为特征的儿 童期发育行为障碍。表现：交流障碍、言语发育障碍、 行为刻板重复、智力落后、感觉异常。 青春期心理咨询：专指处于青春发育阶段的少年（尤 其是那些存在心理问题者），运用心理商谈的技术、 程序和方法，帮助其对自己与环境形成正确的认识， 矫正其心理上的不平衡，以改变其态度与行为，并对 社会生活产生良好的适应。原则：保密、限时、自愿、 情感自限、延期决定、伦理规范。 生长发育指标：发育水平、营养状况、智力。 生命指标：婴儿死亡率：IMR是指在所给定的年份内 每1000名活产儿在0~1岁期间的死亡人数，反映活 产儿一年内的死亡概率。它是国际公认的衡量一个国 家/地区社会经济文化、居民健康状况、卫生保健事业 发展的重要标志。 疾病指标：因病缺课率：以月为单位计算因病缺课的 人时数或人日数占授课总时数的比例。反映学生健康 状况的重要指标。 生命质量指标：包括日常功能指标、心理社会功能评 定、专门性生活质量评定量表、综合性生活质量评定 量表。 六、视力不良：视力低下，是在采用远视力表站在5m 远处检查时，裸眼视力低于 5.0 。（近视不能仅凭上 述检查而必须通过眼科的散瞳验光才能确诊）。 近视：是指眼睛辨认远方（5米以上）目标的视力低 于正常，但视近正常，它是由于屈光不正所致。严 格定义是在不使用调节功能状态下，远处来的平行光 在视网膜感光层前方聚焦。 预防近视的措施：1.限制近距离用眼时间：预防近视 眼的基本措施是限制过多的长时间近距离视近活动， 每日可3~4次向5m以外的远处眺望，远望时宜选择 固定目标，每次5~10分钟，避免刺眼的强光刺激； 2.重视读写卫生：阅读、书写时坐姿要端正，眼书距 离保持在30~35cm左右，避免在光线过强或过弱的地 方读写；3.开展体育锻炼，增加室外活动，认真做好 眼保健操：活动有助使眼压下降；4.合理饮食，注意 营养：合理营养是预防近视眼的综合措施之一；5.改 善学习环境6.定期检查视力：学校应每年两次进行视 力检查；7.健康教育：开展用眼卫生的健康宣教。8. 加强围生期保健，减少早产儿。低体重儿的发生。 七、龋齿：龋齿是牙齿在身体内外因素作用下，硬组 织脱矿，有机质溶解，牙组织进行性破坏，导致牙齿 缺损的儿童少年常见病。患牙不能自愈。患龋后不仅 引起疼痛，而且影响食欲、咀嚼和消化功能，对生长 发育造成不利影响。 流行病学特点：1.龋患率：幼儿园儿童高于小学生， 小学生高于中学生；城市高于农村，大城市高于中小 城市。2.龋均（总龋牙数/受检总人数）和患者龋均（总 龋数/患龋总人数）都是反映龋齿患病程度的重要指标， 防龋工作重点在幼儿园儿童和小学生人群上。3.5岁 乳牙无龋率，12岁恒压龋均。4.好发牙和好发部位： 乳龋的好发牙是第1、2乳磨牙（第4、5乳牙），尤 其第2乳磨牙；恒龋的好发牙是第1、2恒磨牙（第6、 7恒牙）尤其第1恒磨牙（俗称“六龄齿”）；恒龋的 好发部位相同都以咬合面为主。 四联致病因素论：1、细菌和菌斑，是根本原因。主 要的致龋菌是变形链球菌，可合成葡糖基转移酶，使 蔗糖转化为高分子细胞外多糖，使牙齿内的酸度增加， 有利于菌斑的形成。2、食物因素，是物质基础，碳 水化合物（尤其蔗糖）是致龋的主要食物，不仅可以 酵解产酸，降低菌斑的PH值，而且参与菌斑形成和 作用，流行病学调查显示，蔗糖消耗量和龋齿发病率 间存在高度正相关。3、宿主，是重要条件。指牙齿 对龋病的抵抗力或敏感性。。4、时间因素是发生过程。 儿童系统防龋法：1.定期检查、早期诊断。2.控制牙 菌斑。3.讲究饮食卫生，增强宿主抗龋力。4.健全学 校口腔疾病防治网。 八、缺铁性贫血：是由不同程度缺铁引起的以小细胞、 血红蛋白低下为特征一类贫血总述。防治要点：一般 治疗（饮食），病因治疗，铁剂治疗，针对性防治综 合措施，预防铁中毒。 九、肥胖：肥胖是在遗传、环境的交互作用下，因能 量摄入超过能量消耗，导致体内脂肪积聚过多，从而 危害健康的一类慢性代谢性疾病。 肥胖的两种类型：一种是单纯性肥胖，主要因摄食量 过多、“以静代动”的生活方式、缺乏运动等原因引 起；另一种是继发性肥胖，因神经-内分泌功能失调或 代谢性疾病引起。 男女18岁时都分别取BMI值24和28为超重和肥胖 界指点。体脂率男超过20%，女14岁以下超过25% 或14岁以上超过30%为肥胖。肥胖的防治：养成良 好的饮食习惯，纠正偏爱高糖、高脂、高热量饮食的 不良习惯。限制过量进食，对体重定期检测，加强体 育锻炼与户外活动。 体育锻炼的卫生要求？1适合年龄、性别和健康情况 2培养体育锻炼的兴趣和习惯3体育教学必须遵循的 基本原则：①循序渐进②全面锻炼③准备和整理运动 ④运动与休息交替 体育课的结构：开始部分2-3min，准备部分6-12min， 基本部分25-30min，结束部分3-5min 体育课的运动负荷决定于课程强度，密度，时间三大 因素 靶心率：达到最大运动强度60%—70%的心率，是判 断体育课运动负荷的常用指标，是运动时需要达到的 目标心率，是判断有氧运动的主要指标。健康人 130-180。=安静心率+（最大心率-安静心率）×60% 评价体育课的运动负荷指标还有脉搏（心率）曲线图、 平均脉搏、脉搏指数（=平均脉搏/安静脉搏）（中学生 1.6~1.8） 学生一天应有至少1小时的体育锻炼时间。注意饭前 饭后一个小时不宜剧烈运动。运动时大量排汗，必须 少量多次饮水，适量补充水分和盐分。在补充水分和 电解质的同时，还应注意适当补充钙等无机盐。 预防运动性创伤方案？1安全防范法2保护帮助法3 量力适应法4准备活动法 体育锻炼的自我监督：1主观感觉，包括运动时的排 汗量，运动后的心情，睡眠食欲等方面的自我感觉， 其他身体疲劳感觉、睡眠、食欲、运动情绪等2客观 评价：内容包括测试脉搏，监测体重，分析运动成绩 的变化、进行体能和其他形态、功能的测量等。 健康监测体系（三部分）：健康体检、检测结果报告、 建立健康档案。 健康教育基本内容：健康行为与生活方式，疾病预防， 心理健康，生长发育青春期保健，安全应急与避险。 大脑皮层功能活动特性及卫生意义：1始动调节：大 脑皮层的工作能力在刚开始时，因脑细胞和其他相关 器官、系统的功能尚处于较低水平，需要一定的起动 时间。伴随工作时的能量消耗，工作能力将逐渐提高， 该现象称~。据此，在学日、学周、学期开始时规定 的学习难度、学习强度都不宜太大，应逐渐增强。2 优势法则：各种脑、体力活动内容，在大脑皮质上各 有其代表区域。皮质能从机体受到的大量刺激中，选 择最符合自身目的和兴趣的一些刺激，在脑皮质引起 强烈的兴奋区域，即优势兴奋性。其兴奋性高于其他 区域，而且能将皮质其他部位的兴奋性吸引过来，加 强自身的兴奋性，又使那些部位处于抑制状态。因此， 优势兴奋性的形成可明显提高学习效率。所以，组织 教学内容时，一定要注意该内容的持续时间应适应受 教育者的年龄特点。3动力定型：如果儿童体内外的 条件刺激按一定顺序多次重复后，在大脑上的兴奋、 抑制过程及与此相关的神经环路将相对固定下来，形 成动力定型。因此，有规律的生活作息、良好的学习 态度、健康的行为方式应从小培养。4镶嵌式活动： 伴随学习性质的变化，脑皮层的功能在定位上（兴奋 区与抑制区，工作区与休息区）相互轮换，称为~。 因此，教学安排中应注意课程性质的轮换，脑力与体 力活动交替，以确保脑皮层在较长时间内保持旺盛的 工作能力。5保护性抑制：一旦大脑皮层的活动超过 其功能限度，皮层反馈性的进入抑制状态，称为保护 性抑制。~是一种生理状态，也是早期疲劳的表现， 对保护脑皮层免受功能衰竭发挥重要作用。因此，教 育过程中如果能注意到学生的早期疲劳表现，适当组 织休息或安排其他活动，脑皮层功能活性将很快恢复； 如果任其发展，不采取劳逸结合措施，学生的疲劳状 态就会持续下去并逐步加重，甚至发展成病理性的 “过劳”状态。 影响脑力工作能力的因素？年龄；性别；健康状况； 遗传；学习动机和兴趣；学习生活条件；养育和生活 方式。 疲劳：在过强、过猛的刺激或刺激强度虽不大但持续 长时间的作用下，使大脑皮层细胞的功能消耗超过限 度，所产生的保护性抑制。是一种生理现象，出现早 期疲劳是学习生理负荷达到临界限度的指标。 试述学生学习疲劳的表现和评价学习疲劳的意义。第 一阶段又称早期疲劳。机制是优势兴奋性降低，不能 实行对周围区域的抑制（内抑制障碍）。表现为上课 时坐立不安，小动作多；注意力转移。条件反射实验 出现错误反应增加。有些人的早期疲劳内抑制表现不 明显，主要反应是兴奋过程出现障碍。早期疲劳的重 要特点是：兴奋过程或内抑制过程中的一个方面有障 碍性表现。第二阶段又称显著疲劳。机制是大脑皮层 的保护性抑制加深、扩散，特点是兴奋过程和内抑制 都减弱或发生障碍。具体表现：上课打呵欠和瞌睡； 对条件刺激的错误反应增多，反应量减少，反应时延 长，有时甚至出现后抑制现象。 学校的作息制度符合哪些原则？1、符合皮层的功能 的特点和脑力工作能力的变化规律，使学习活动与休 息的交替安排合理化2、对不同年龄阶段，不同健康 水平的儿童少年应区别对待，分别制度3、既能满足 学习任务，又要保证学生德智体美全面发展4、学校 与家庭作息制度相互协调统一5、制度一经确定，不 要轻易改变 一日生活制度：1课业学习：小学1、2年级不超过 4h，3、4年级5h，5、6年级6h，初中7h，高中8h； 2、每节课持续时间:小学40分钟；中学45分钟；大 学50分钟3、课外活动：小学生不少于3-3.5h，中学 生2-2.5h，其中至少有1h体育锻炼时间。中学生每周 参加课外体育活动不宜少于3次，每次45min。4、睡 眠：小学生10h，中学生9h，大学生8h。5、休息： 每节课休息10min，第2、3节课间休息20min。炎热 夏季保证短时间午睡。6、自由活动：每天看电视或 课余上网时间不宜超过1h。7、进餐 青少年健康危险行为：凡是给青少年健康、完好状态 乃至成年期健康和生活质量造成直接或间接损害的 行为。特征：1.明显偏离个人、家庭、学校乃至社会 的期望。2.对健康的危害程度各异。3.有个体聚集性 和群体聚集性。4.有鲜明的后天习得性。5.青少年行 为有良好的可塑性。导致的危害：危及健康和生命， 产生潜在危险，引发性传播疾病。分类：易导致非故 意伤害的行为、致故意伤害行为、物质滥用行为、精 神成瘾行为、危险性行为、不良饮食和体重控制行为、 缺乏体力活动行为。 伤害：是由各种物理性、化学性、生物性事件和心理 行为因素等导致个体发生暂时性或永久性损伤、残疾 或死亡的一类疾病的总称。分为非故意伤害和故意伤 害。 儿童青少年意外伤害的危险因素有：宿主因素（年龄 性别种族心理行为特征生理缺陷与特征），家庭因素， 社会因素，物理因素（地区因素），其中伤害事故出 现的两个高峰在婴儿期和青春期 儿童青少年意外伤害的预防控制干预包括教育干预， 技术干预，工程干预，经济干预，称为“四E策略”。 暴力是指蓄意滥用权力或躯体力量，对自身、他人、 群体或社会进行威胁或伤害，导致身心损伤、死亡、 发育障碍或权利剥夺的一类行为 校园暴力：发生在校园内、上下学途中、其他与学校 活动相关的所有暴力行为。分为躯体暴力、言语/情感 暴力、性暴力三种形式。 教学楼的卫生原则：1.保证教学顺利进行。2.光线好、 通风好。3.方便师生课间休息和户外活动。4.保证师 生安全。 教室内部设计的卫生要求？1 足够的室内面积 2 良 好的采光照明和室内微小气候 3防止噪音干扰 4 便 于学生就座和通行，便于清扫和养成良好的卫生习惯。 采光系数：或称自然照度系数，为综合评价教室的采 光状况，指室内某一工作面的天然光照度与同时室外 开阔天空散射光的水平照度的比。一般最低采光系数 不低于2.0% 教室课桌面的平均照度不应低于300lx，黑板面平均 垂直照度不应低于500lx，照度均匀度不低于0.7 教室人工照明的卫生要求：保证课桌面和黑板面上有 足够照度，照度充分均匀；不产生或少产生阴影，没 有或者尽量减少眩光作用；不因人工照明导致室内温 度过高而影响空气的质量和安全性。 桌椅高差：为桌近缘高与椅高之差。1/3坐高+1~2cm 课桌椅尺寸有11个型号，不同身高不同型号，桌椅 配套，同号搭配。 教室自然采光的卫生要求：满足采光标准，课桌面和 黑板上有足够光照；照度分布均匀；单侧采光的光线 应自学生作为左侧射入，双侧采光也应将主要采光窗 设在左侧；避免产生较强的眩光作用，创造愉快、舒 适的学习环境。 玻地面积比不低于1：5 黑板反射系数<20% 投射角不小于20~22°，最小开角不小于5°。 室深系数不小于1:2。 采光方向：南北向双侧，左侧 学校卫生监督：是指卫生行政部门依据国家相关法律、 政策和学校卫生标准，对学校建筑设备、学校生活环 境、学生用品、学校卫生服务工作等进行监督检查的 系列性执法活动。

半导体激光器驱动电源的控制系统

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古诗词翻译

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古诗文名句解释 1、他山之石，可以攻玉。攻：琢磨。【译文】别的山上的石头，能够用来琢磨玉器。原比喻别国的贤才可为本国效力。后比喻能帮助自己改正缺点的人或意见。 2、靡不有初，鲜克有终。【译文】事情都有个开头，但很少能到终了。多用以告诫人们为人做事要善始善终。（诗经·大雅·荡） 3、祸兮福之所倚，福兮祸之所伏。【译文】祸与福互相依存，可以互相转化。比喻坏事可以引出好的结果，好事也可以引出坏的结果。（老子） 4、合抱之木，生于毫末；九层之台，起于累土；千里之行，始于足下。【译文】合抱的大树，生长于细小的萌芽；九层的高台，筑起于每一堆泥土；千里的远行，是从脚下第一步开始走出来的。（老子） 5、言必信，行必果。【译文】说了就一定要守信用，做事一定要办到,不拖拉。（5到16选自论语） 6、朝闻道，夕死可矣。【译文】早晨闻道，晚上死去。形容对真理或某种信仰追求的迫切。 7、不愤不启，不悱不发。【译文】不到他努力想弄明白但仍然想不透的程度不要去开导他；不到他心里明白却不能完善表达出来的程度不要去启发他。 8、人无远虑，必有近忧。人如果没有长远的谋划，就会有即将到来的忧患。 9、工欲善其事，必先利其器。【译文】工匠想要使（他的）工作做好，一定要先使工具锋利的。比喻要做好一件事，准备工作非常重要。 10、往者不可谏，来着犹可追。【译文】已往的事情不可挽回，未来的却还来得及。 11、君子坦荡荡，小人长戚戚。【译文】君子心地平坦宽广，小人经常局促忧愁。 12、三军可夺帅也，匹夫不可夺志也。【译文】三军之帅的职务由不得我本人，个人的志向却能由我做主，是不可改变的。（你可以撤我三军之帅的职务，却不能改变我的志向，吾志所向，一往无前） 13、人谁无过？过而能改，善莫大焉。 14、知之为知之，不知为不知，是知也。 15 、知之者不如好之者，好之者不如乐之者。 16、其身正，不令而行；其身不正，虽令不从。【译文】当管理者自身端正，作出表率时，不用下命令，被管理者也就会跟着行动起来；相反，如果管理者自身不端正，而要求被管理者端正，那未，纵然三令五申，被管理者也不会服从的。 17、凡事预则立，不预则废。【译文】不论做什么事，事先有准备，就能得到成功，不然就会失败。（礼记·中庸）

儿科名词解释

【下载本文档，可以自由复制内容或自由编辑修改内容，更多精彩文章，期待你的好评和关注，我将一如既往为您服务】 【儿科名词解释】 1、功能性腹痛：是由于肠管蠕动异常或肠管壁痉挛引起的腹痛，如婴儿阵发性腹痛和功能性再发性腹痛(肠痉挛症)。前者与饮食不当有关，表现为夜间阵发性哭闹。后者多见于儿童，有周期性发作，其发病原因与精神因素和植物神经功能紊乱有关 2、高渗脱水：水的丢失多于电解质的丢失，血钠>150mmol／L时称为高渗脱水。多见于腹泻伴有高热、饮水不足，或输入电解质液体过多。由于细胞外液渗透压高，细胞内水分向细胞外流动，出现细胞内脱水，表现口渴明显、高热、烦躁不安、肌张力增高、甚至惊厥。 3、等渗脱水：是水和电解质成比例丢失，维持血钠浓度在130~150mmol／L。临床上最常见，出现一般的脱水症状。2、低渗脱水：电解质的丢失大于水的丢失，血钠<130mmol／L时称为低渗脱水。多见于营养不良小儿伴较长时间腹泻者，或腹泻时口服大量清水、静脉滴人大量非电解质液体，以及因心、肾疾病长期限盐等情况。细胞外液减少相对较重，临床上除脱水体征较重外，易出现外周循环衰竭，严重低钠者可致脑水肿，出现嗜睡、惊厥、昏迷等。 3、食欲不振亦称厌食：是指患儿缺乏进食欲望，常见于急慢性疾病。突然食欲不振往往是疾病的先驱症状，长期食欲不振可能是某些慢性疾病的症状。此外，小儿情绪变化、不良的饮食习惯也可引起长期食欲不振，造成营养不良，以致影响小儿的生长发育。 4、呼吸性酸中毒：由于呼吸系统器官疾病、呼吸中枢疾病、呼吸肌麻痹或心功能不全致肺水肿，造成通气换气障碍，导致体内C02潴留、碳酸增高、血pH降低，而C02CP增高，血钾也增高。 1、维生素D缺乏性手足搐搦症：由于维生素D缺乏，引起血钙降低，神经肌肉兴奋性增高，导致全身惊厥、手足抽搐或喉痉挛等。多见于4个月—3岁小儿。 2、(猩红热)巴氏线：猩红热患者出疹期在皮肤皱褶处，因皮疹密集或因摩擦出血而呈紫色线状，称巴氏线。 4、高热惊厥：是颅外感染伴有高热时在年幼儿常有可能引起的惊厥，急性上呼吸道感染时尤为常见，其特点是：①年龄多在6个月至3岁之间；②多在病初突然高热时；③发作呈全身性、次数少和时间短；④神志恢复快，预后好，无阳性神经体征。 1、血钾<3．5mmol／L时称为低钾血症。表现为神经肌肉兴奋性减低，精神萎靡、肌肉无力、腱反射减弱或消失、肠鸣音减弱或消失，严重时出现肌肉弛缓性瘫痪。心音低钝、血压减低，心电图可见T波低平、双向或倒置，S-T段下降，Q-T间期延长，出现U波，心律失常，严重者可发生猝死。 3、百日咳:痉咳期为百日咳第二期，约在起病后7-10天即由卡他期进入痉咳期，此期体温恢复正常，较大婴儿及儿童突出阵发性痉挛性咳嗽。每次发作连续数十声，集中在呼气期，患儿面红耳赤，张口伸舌，涕泪粘痰交流，十分痛苦。在咳至憋气濒于窒息时，突然急速深长吸气，发出鸡鸣样吸气声。每次阵咳末常伴有呕吐，夜间影响睡眠。剧烈阵咳使颜面、眼睑浮肿，并使眼结膜、鼻粘膜毛细血管破裂出血，持续2-6周或更长。6个月以内婴儿症状不典型，表现为憋气和窒息。 4、急性颅内压增高:简称颅内高压，是由于颅内容物体积增加，超过代偿范围，即导致颅内压增高。 1、感应性腹痛：常与内脏性腹痛同时存在或相继发生，当内脏病变使痛觉神经纤维受刺激，发生冲动，传人相应的脊髓节段的脊髓神经支配的皮肤部位，而引起体表感应性腹痛。例如阑尾病变的体表感应区是右下腹；小肠的体表感应区在脐周；胃的体表感应区在上腹部；肝胆的体表感应区在右上腹和右肩胛；肾和输尿管的体表感应区在腰和腹股沟部。此种疼痛比较尖锐，伴皮肤过敏和腹肌痉挛，定位较明确，常位于腹部两侧。此外，腹外病变也可引起感应性腹痛，例如胸膜炎可引起前腹壁疼痛。 2、代谢性酸中毒：是由于碱性物质丢失过多或酸性物质过多堆积，为[H+]增加或[HCO-]减少所致。血pH<7．35。轻度酸中毒症状不明显，仅呼吸稍快。较重酸中毒可出现呼吸深长、口唇樱红、恶心、呕吐、疲乏无力、烦躁不安、嗜睡、昏迷、心率增快。严重酸中毒时心率转慢、血压下降、心力衰竭、心律紊乱，可致生命危险。小婴儿呼吸变化不典型。 3、麻疹粘膜斑(柯氏斑)：在麻疹前驱期发热2-3天后，在下磨牙相对应的颊粘膜上，可见散在小沙粒状黄白色小点，周围有红晕，为麻疹特征性粘膜斑。此斑持续仅1-2天即完全消失，但粘膜粗糙充血可持续数日。 4、结核半杀菌药：是指在碱性环境中能杀灭细胞外的结核菌的药物如链霉素，或能杀灭在酸性环境中细胞内的结核菌和干酪病灶内代谢缓慢的结核菌的药物女口吡嗪酰胺。 1．新生儿硬肿症：是指新生儿期内由于寒冷、早产、感染、窒息等多种原因引起的皮肤及皮下组织变硬与水肿，常伴有低体温和多器官功能受损。

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