Chandra Studies of Millisecond Pulsars in Globular Clusters
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Binary Radio Pulsars ASP Conference Series,Vol.TBD,2005F.Rasio &I.H.Stairs Chandra Studies of Millisecond Pulsars in Globular Clusters Jonathan E.Grindlay Harvard-Smithsonian Center for Astrophysics,60Garden St.,Cambridge,MA 02138Abstract.The high resolution X-ray imaging and broad-band moderate res-olution spectra enabled by the ACIS cameras on the Chandra X-ray Observatory have opened a new window in our study of millisecond pulsars (MSPs).Given the large excess of MSPs in globular clusters vs.the ?eld,globular clusters are the favored sites for MSP study.Globular clusters (GCs)o?er advantages of both known distance and likely MSP formation mechanisms but are complicated (or made more interesting!)by the complexities of subsequent MSP dynamical interactions.Here I review recent X-ray studies,focusing on our recent deep Chandra study of 47Tuc,which provide new constraints on both the spectra (thermal and non thermal)and evolution of MSPs and their encounters with both cluster and ?eld stars.1.Introduction and Overview It is ?tting that the oldest stellar systems in the Galaxy contain the oldest pulsars,the millisecond pulsars (MSPs),but not always in the oldest binary systems.Most MSPs in globular clusters (GCs)likely predate most of those in the ?eld of the Galaxy given that the requisite neutron stars (NSs)in GCs were formed primarily from PopII massive stars which predated NS production from massive stars in the disk.At the same time,some of the MSPs in GCs (e.g.PSR B1821?24in M28)are clearly younger,as evidenced by their spindown ages P/2˙P (however approximate these may be).These suggest either recent spinup of old NSs,or more recent NS production from accretion induced collapse
of
white dwarfs in cluster binaries,or possibly ˙P values enhanced by mass transfer
in a retrograde second exchange of an old MSP (see below).In fact it has become clear that some MSPs in GCs (e.g.47TucW;discussed in more detail below)have had at least one swapped binary partner and thus more complex histories than any in the ?eld.
New clues into the nature,formation and evolution of MSPs have come from the additional constraints that ～0.3–8keV X-ray observations of their in-tegrated or pulsed emission provide.The high sensitivity,spectral resolution and bandwidth of the Chandra and XMM-Newton X-ray Observatories have enabled great progress in studies of MSPs.The great increase in angular resolu-tion with Chandra has been essential for studies of MSPs in crowded GC cores.The ?rst moderately deep Chandra observation of 47Tuc (Grindlay et al.2001a;hereafter GHE01)provided a dramatic view of GC-MSPs and enabled (via X-ray to optical boresites)the optical identi?cation,with HST,of the ?rst MSPs in globulars.Accordingly,in this review we shall focus on Chandra (and some
1
2Jonathan E.Grindlay
HST)results and only discuss brie?y some recent XMM(and earlier ROSAT) studies.
The?rst optical identi?cations of MSPs in GCs,two in47Tuc(Edmonds et al.2001,2002)and one in NGC6397(Ferraro et al.2001),have provided direct evidence that some GC-MSPs have swapped their binary partners.The main sequence or somewhat evolved binary companions now found in two such systems(PSR J1740?5340in NGC6397and MSP W in47Tuc,as discussed below)are not expected for systems that have evolved directly from their parent LMXBs.Post-LMXB secondaries are He white dwarfs(He-WDs)or very low mass degenerate remnants in?eld MSPs and most GC-MSPs.The nature and evolution of both of these systems is further constrained by their X-ray spectra and variability.The recently derived spectrum for MSP W in47Tuc(hereafter either47TucW or MSP W)shows hard emission,possibly from gas near the L1point shocked by the pulsar wind(Bogdanov,Grindlay and van den Berg 2004,hereafter BGvdB04)and similar to that reported(Grindlay et al.2001b, Grindlay et al.2002;hereafter GCH02)for the Chandra source and MSP in NGC6397,PSR J1740?5340(hereafter6397A).Even more important is that the spectra,luminosity and X-ray vs.optical variability of47TucW show re-markable similarities to the accreting MSP J1808.4?3658,thus providing the crucial missing link between radio MSPs and LMXBs(BGvdB04).
Recent Chandra studies of MSPs in GCs,as reviewed here,have now es-tablished that MSPs can show three di?erent spectral components:very hard non-thermal emission(magnetospheric;with power law photon index～1)vs. hard(with PL index～1.5and probably due to shocked gas)vs.soft(ther-mal emission from the NS polar caps,with typical kT～0.1keV).In this review we focus on the hard and soft components.Whereas both the very hard mag-netospheric and soft thermal(polar cap)emission were evident from ROSAT spectra and timing(cf.Becker and Trumper1999),the Chandra detection of the shocked gas component has required the high resolution imaging of Chan-dra to both isolate the source from neighbors and to enable HST identi?cation of a heated stellar companion as the likely source of gas.It has also required su?cient temporal coverage to establish spectral variation with binary phase (for47TucW).Although pulsation spectra and pulsed light curves are also both highly desirable,spectra are arguably more important for a?rst investigation of MSP properties and have meant that the ACIS(with～150–200eV resolution), rather than the HRC(with virtually no energy resolution),Chandra cameras have been used in most GC-MSPs studies to date.Thus pulse-phased spec-tra for multiple MSPs imaged with Chandra are not possible(although this could be done in principle for a single MSP observed with the LETG grating and HRC-S),and HRC-S imaging pulsed light curves are only available for one MSP(J0437?4715,in the?eld;Zavlin et al.2002).As discussed by BGH04, such“grey”pulsed light curves can constrain MSP emission and neutron star properties.
Chandra Studies of Millisecond Pulsars in Globular Clusters3 2.Brief Overview of X-ray Studies of MSPs in Globular Clusters
2.1.The Brightest and Hardest
The X-ray brightest MSP in a globular cluster is the source in M28,PSR B1821?24,?rst detected and resolved with the ROSAT HRI(Danner et al.1997)and for which high quality spectra(but with no temporal resolution for pulsations) have been obtained with Chandra(Becker et al.2003).If this were the only MSP studied in X-rays,our view of their properties would be very di?erent: its predominantly non-thermal emission and narrow pulse pro?le in X-rays is very di?erent from that now inferred(GCH02,Bogdanov et al.2004,hereafter BGH04)for the bulk of the MSP population in47Tuc with their predominantly thermal spectra(GCH02).Unambiguous X-ray spectra for even this apparently brightest GC-MSP require the spatial resolution of Chandra,given source con-fusion(Becker et al.2003),although RXTE hard X-ray spectra for the(narrow) pulse peak(Kawai and Saito1999)are in reasonable agreement.
Upper limits have been obtained with RXTE for hard X-ray emission from the integrated population of MSPs in47Tuc(Ferguson et al.1999),and RXTE has been able to provide spectra and timing constraints on the brightest nearby MSPs in the?eld.Atγ-ray energies,the very?at non-thermal spectrum(with photon index～1)is detectable for B1821?24and may have been detected with EGRET(cf.Zhang and Cheng2003).MSPs in the?eld,which are gener-ally much closer than the GC-MSPs,have been detected atγ-ray energies(e.g. J0218+4232,detected convincingly with EGRET by Kuiper et al.1998).Its broad soft X-ray pulsed light curve suggests a thermal component,con?rmed by its combined thermal plus PL spectrum detected with XMM-Newton(Webb, Olive&Barret2004).Detection of the non-thermal components of nearby thermally-dominated MSPs in the?eld(e.g.J0437?4715)may constrain the evolution of the magnetospheric spectra with the B?eld at the light cylinder, which may be correlated with non-thermal X-ray luminosity,as shown below. 2.2.vs.the Dim and the Soft
As suggested above,most MSPs in GCs are not bright and hard;B1821?24 is the exception.Rather,as our initial studies of the MSPs in47Tuc have shown(GHE01,GCH02),the norm is relatively low X-ray luminosity,primarily in thermal emission and distributed in a relatively narrow band:～2–8×1030 erg s?1.This was not apparent to ROSAT and the pioneering studies,and review,of Becker and Trumper(1999)since again the samples were dominated by nearby or by extreme objects.The virtue of the GC-MSPs is,again,that they can de?ne MSP parameters for entire populations in a single observation, given(of course)the required angular resolution and sensitivity.
This population-view,a?orded by Chandra,can not only de?ne the role of MSPs in binary evolution and thus cluster evolution,but in MSP or NS evolution as well.One of the key questions posed in GCH02was:if MSPs are indeed swapping partners,as evidenced by6397A or47TucW(see below), then what must be the fate of i)the P and˙P history,if matter accretes with randomly aligned angular momentum vector J from the new secondary onto the “old”MSP during the re-exchange,and ii)the B?eld,both surface and at the light cylinder,if B?eld evolution on NSs has anything to do with the accretion
4Jonathan E.Grindlay
history of the star,as is commonly believed?We address some of these issues here and in more detail in forthcoming journal papers.
2.3.From Hard to Soft(and back)?
As shown below,the hard-bright MSPs have young ages(P/2˙P)vs.the opposite for the dim-soft(reminiscent of other aging populations!).Does re-recycling restore youth?If so,could some of the apparently young MSPs(e.g.B1821?24) be masquerading youth after re-spinup in a second exchange,as the B?eld is ampli?ed by the di?erential rotation between a newly-accreted outer layer that is misaligned with the original J and B vectors?Or,more likely,is its NS a relic of the cluster formation and been able to maintain its stronger B?eld without internally driven decay until its recent?rst-time accretion episode when it was exchanged in a binary encounter to acquire its?rst partner?
On the other hand,the soft-dim MSPs,like those which predominate in 47Tuc,may be resurrected(as for MSP W)with a“new”main sequence com-panion apparently heated by the pulsar wind to produce mass loss through L1 that in turn is shocked by the pulsar wind to produce hard X-ray emission.This renewed hard emission phase for an MSP would be characterized by a lack of hard X-ray pulsations,though soft and sinusoidal pulsations are still expected from the polar caps.Resurrected MSPs would likely show a smooth modulation with binary phase if(as for47TucW)part or all of the shocked-gas emission region is eclipsed by the companion.Such a doubly-recycled MSP can thus be hard but old(both chronologically and as measured by its new P/2˙P).On the other hand,given the bizarre torques that must occur when a randomly aligned “old”MSP exchanges its(usually)degenerate secondary for a main sequence star and then has renewed mass transfer and spinup,the deceleration accretion torque from a retrograde second capture could cause the P/2˙P age to appear young despite a previously reduced B?eld.
These are representative questions raised by the fascinating demography of GC-MSPs.Let us look again at the MSP population in47Tuc,but now with the additional perspective of a much deeper Chandra observation.
3.Chandra Probes Deeper into47Tuc
Over a13day interval(September29–October11,2002,we observed47Tuc with four65ksec ACIS-S pointings and matched short(5ksec)sub-array ex-posures(to deal with bright sources).Simultaneous HST/ACS images were obtained in three?lters(B,R and Hα)for3HST orbits on each of Chandra observations2–4.This Large Chandra Program was motivated in part by the MSP population,detected for the?rst time as soft X-ray sources with the less sensitive(at low energies)ACIS-I imager in our single70ksec observation in March2000(GHE01).The overall source catalog for the ACIS-S observations is reported by Heinke et al.(2004a):some300sources are detected within the cluster half-mass radius of2.8′.In Figure1we show a representative color im-age constructed from the summed exposures in the0.3–1.2keV(red),1.2–2keV (green)and2–6keV(blue)bands.
All16MSPs located with timing positions(Freire et al.2001),and47TucW which was identi?ed by the discovery(Edmonds et al.2002)of its optical coun-
Chandra Studies of Millisecond Pulsars in Globular Clusters5
Figure1.Representative color image(from Heinke et al.2004a)of central
2.5′×2.5′of the deep ACIS-S exposure(270ksec)on47Tuc,with all17 MSPs with known locations detected as marked.MSPs F and S,separated
by0.74′′,are partially resolved but G and I,separated by0.12′′,are not.The Chandra positions are much more accurate than the large circles shown,with
rms deviation from the MSP positions of only～0.2′′.(NOTE:this image compressed for astro-ph size limits;original to appear elsewhere.)
6Jonathan E.Grindlay
Figure2.X-ray color-color diagram for the MSPs in47Tuc(from Bogdanov
et al.2004)vs.model tracks folded through the detector for?xed cluster col-
umn density NH and blackbody emission or neutron star atmosphere(NSA)
temperatures,or power law spectra with photon index values shown.
terpart with photometric periodicity and phase identical to the radio values,are clearly detected(though G and I,with0.12′′separation,are not resolved)in this deep Chandra image.Several MSPs,particularly C and T,were marginal detections in the original ACIS-I image but are now well detected.The total counts recorded in the summed Chandra images for each MSP range from38–306 over the0.3–4keV band.This has allowed new studies(Bogdanov et al.2004, hereafter BGH04)of the spectra and variability of this largest MSP sample in a single GC.We preview several key results from this work and provide some additional constraints on the X-ray spectra and properties of MSPs.
3.1.Colors,Spectra and Luminosities of MSPs in47Tuc
First,the>～5×better count statistics as well as improved soft response of ACIS-S(despite its low energy degradation with time)allow the X-ray colors and thus spectral characteristics of even the faintest sources to be better determined. Figure2shows the color-color diagram,derived in softer bands appropriate for ACIS-S,and comparison of the MSPs with tracks for blackbody(BB),neutron star atmosphere(NSA;Lloyd2003)and power law(PL)models derived for the ACIS-S response and latest measurement(Gratton et al.2003)of the cluster reddening from which we derive NH=1.3×1020cm?2(Heinke et al.2004a). Whereas the ACIS-I color-color plot,with larger errors,suggested that all but MSP J(MSP W was not yet identi?ed)were consistent with pure thermal emis-sion(GCH02),Figure2suggests that most MSPs are a mixture of thermal and power law models,or possibly a two temperature thermal model and ad-ditional hard component,as derived by Zavlin et al.(2002)for the?eld MSP J0437?4715.
Chandra Studies of Millisecond Pulsars in Globular Clusters7
Figure3.Spectral?ts(Bogdanov et al.2004)for two MSPs bright enough
to clearly require hard spectral components in addition to a soft thermal component.MSPs O and,especially,W also require such a two-component model.The?ts shown here are for a NSA+PL model but are?tted for NSA temperature only with PL photon indexΓ=1and NH=1.3×1020cm?2held
?xed.The derived NSA temperature T(106K)and radius R(km)values,(T, R),for J and L are(0.89±0.18,1.59±0.76)and(1.25±0.16,1.07±0.30).
Figure4.Spectral?ts(single temperature NSA model only;from Bogdanov
et al.(2004))vs.data for fainter MSPs showing excess?ux above NSA model
in highest energy bin.
8Jonathan E.Grindlay
Figure5.a)Left,temperature distribution for NSA model?ts to MSPs
in47Tuc;b)Right,thermal luminosity distribution(solid histogram)derived
from R,T values from NSA model?ts vs.X-ray luminosity derived from
total?ux in0.01–8keV band(dashed histogram;see text).The non-thermal
(PL?)luminosity may be estimated from the di?erence between the total and
thermal components.
The improved statistics now allow direct spectral?ts for NSA models(BB ?ts,with larger kT but smaller radii,are equally acceptable)and an additional PL component.Spectral?ts were done by requiring at least15counts(or10 counts for the faintest MSPs)per spectral bin and were thus limited by statistics: the highest energy bins included in the?t exceeded2keV only for the brightest-hardest4MSPs:J,L,O and W.Spectral?ts for these four were done for a NSA+PL model by holding the photon index?xed at1for the PL component. Only MSP W was bright enough to?t the NSA and PL components separately, giving a photon indexΓ=1.3±0.2.Spectra are shown in Figure3.
For the remaining11MSPs(the unresolved and partly resolved MSP pairs, G+I and F+S,were each?tted as if one object),the?ts were done for an NSA model only.However these typically showed an excess above the soft NSA?t at energies above2keV,as shown in Figure4for MSPs N and Q.Thus we now conclude that although the soft-thermal emission is dominant,it is likely that most of the47Tuc MSPs also contain an underlying harder component.It is interesting then to examine these thermal and hard components separately.
3.2.Spectral properties vs.MSP properties
The distribution of thermal temperatures,for an assumed neutron star atmo-sphere(NSA)model(we use the Lloyd(2003)model),is surprisingly narrow as shown in Figure5a.All of the MSPs have their thermal emission?t by NSA models with mean temperatures(in units of106K)T6=1.18±0.22.In fact all of the MSPs except U,with T6=1.83,have their polar cap temperatures within the narrow range of0.9–1.3×106K.This presumably re?ects a nearly constant heating rate,despite the>～10×range of MSP ages.
Chandra Studies of Millisecond Pulsars in Globular Clusters9 The?tted polar cap radii are also relatively narrowly distributed,with mean value R=0.91±0.46km,and–given the NSA model–is larger than the
BB radii discussed in GCH02as evidence the B?elds may be multipolar.The corresponding thermal emission luminosity,derived from a Stefan-Boltzmann application of the NSA-derived R,T values,is shown in Figure5b.We have
assumed the thermal emission is from two polar caps,each of radius R(both R and T are evaluated at the NS surface),and have approximated their combined luminosity as2πR2σT4,whereσis the Stefan-Boltzmann constant.This is an
approximate upper limit since it ignores the unknown projection e?ects of the polar caps due to the B?eld inclination,and also ignores the exact e?ects of
gravitational bending near the NS.While exact photon bending corrections are not known,they nevertheless ensure that both caps are seen at least partly. The thermal luminosity distribution(solid curve)has mean value log L thermal=
30.64±0.25whereas the luminosity derived from integrating the total?ux in the0.01–8keV band(dashed histogram)has mean log L tot=30.80±0.32.The
latter luminosity was derived from the detected counts over this band for the two-component model(NSA+PL)spectral?ts derived over the0.3–8keV band and then integrated over the broad band(0.01–8keV)in XSPEC for an estimate
of the total?ux.
The fact that the MSP spectra can be decomposed into thermal and to-
tal components(Fig.5b)suggests that the underlying hard component(here approximated by a PL)might be extracted by simple subtraction.If this hard component is indeed non-thermal and a PL,then this would allow constraints on
the evolution of this magnetospheric emission vs.fundamental MSP properties such as magnetic?eld or age.In Figure6we show the possible dependence of the hard luminosity component(i.e.the excess above the NSA thermal?ux)
on a)magnetic?eld at the MSP light cylinder,B lc,and b)the dependence of this same hard luminosity of spindown age.The intrinsic˙P values required for either B lc or P/2˙P are corrected for cluster acceleration as derived in GCH02.
The MSPs display a weak(85%con?dence level from a Spearman rank correla-tion)correlation between the PL luminosity,L PL,and magnetic?eld at the light
cylinder,B lc,and suggest a possible anti-correlation between L PL and spindown age.Both correlations are suggested by the data presented in GCH02and Bog-danov et al.(2004)but are more apparent in the attempted decomposition of
the PL or hard luminosity presented here.
Note that this“PL Luminosity”may not be magnetospheric non-thermal
emission,though this is plausibly at least partly the case.Instead,some MSPs could have their hard component due to their pulsar winds shock heating gas driven o?from their binary companions,as is the case for MSP W(BGvdB04).
At?rst this seems unlikely since none of the MSPs in Figure6have binary mass functions and constraints on inclination(e.g.eclipses)which require main
sequence companions as is the case for MSP W.Freire(2004,in this volume)dis-cusses the distinction between the low mass binary pulsars(LMBPs),for which mass functions require secondaries with masses>～0.1M⊙and which are usually He white dwarfs,and the eclipsing LMBPs(ELMBPs)such as MSP W for which the main sequence(and thus massive)secondaries are required from their optical identi?cations.These ELMBPs are much less common than the very low mass
(secondary)systems,the VLMBPs,with secondary masses usually<～0.05M⊙.
10Jonathan E.Grindlay
Figure 6.Plot of “PL luminosity”(=L 0.01?8keV -L NSA )for each MSP in 47Tuc with measured ˙P using the luminosities for each plotted in the distributions shown in Figure 5b)vs.a)left,magnetic ?eld at the MSP light cylinder and vs.b)right,spindown age,P/2˙P
.However,some of these VLMBPs are eclipsing (e.g.MSP J,which Camilo et al.(2000)note is eclipsed at 70cm and 50cm,but not at 20cm,for about a quarter of its orbit)and have luminous hard components.A magnetospheric vs.pulsar wind shocked gas origin for the hard component would both likely scale with B lc .
The magnetospheric vs.shocked gas origin for the “PL”component could be tested by (much)more sensitive spectra which would also distinguish PL from a hot thermal bremsstrahlung component,though brems is surely ruled out by dispersion measure constraints,as pointed out by GCH02.Pulsation analysis would provide a de?nitive test since the shocked gas origin should not be pulsed due to the emission region having size (much)larger than the characteristic pulse period length scale,c ·P ～108cm.Unfortunately,detailed spectral ?ts are not possible with the present Chandra data given the limited statistics,and pulsed pro?les vs.energy are not possible with Chandra-ACIS (or Chandra-HRC).Thus we cannot prove the “PL”component is of magnetospheric origin on these old,weak-?eld MSPs.
Another test can be done,however:plot the hard X-ray luminosity,L x (PL),vs.˙E
and compare with the soft X-ray luminosity L x (NSA)vs.˙E (as in GCH02).If the hard component is magnetospheric,it will likely fall closer onto the roughly linear L x ～˙E relation shown for ?eld MSPs and luminous GC-MSPs (Becker and Trumper 1999,GCH02)than to the L x ～˙E 0.5relation for the soft component that is likely due to polar cap heating (GCH02).Using the ˙E values for the 47Tuc MSPs corrected for cluster acceleration (GCH02),we plot L x vs.˙E
in Figure 7for the two components of L x .The L x (NSA)–˙E relation has slope 0.3±0.2,which is marginally ?atter than the slope 0.5±0.2relation found in GCH02for the dependence of the 0.5–2.5keV luminosity measured with ACIS-I for a mean BB spectrum with kT =0.22keV.The L x (PL)–˙E
relation appears steeper,with slope 0.6±0.3from ?tting all the points.However a slope 1relation is also consistent and in fact approximately “bisects”and is parallel to the two apparent groups of points (the lower of which is formed by MSPs G,I,N,U,Q,F,E;this grouping can also be seen in Figure 6a).
Chandra Studies of Millisecond Pulsars in Globular Clusters11 Thus within the scatter,a linear relation between log(L x(PL))–˙E is con-sistent with the data.We suspect the“PL”component lies in a broad band, bounded by the upper and lower groups on either side of the linear correlation line.As suggested above,it is possible that some of these on the more luminous side(e.g.J and O)are a mixture of magnetospheric and shocked gas compo-nents.It is thus interesting that MSP O is similar to J in Figure8,since it is so similar in its binary properties(cf.Figure5in Freire,in this volume).Con-versely,the“lower group”of MSPs in the log(L x(PL))vs.˙E plot are dominated by single MSPs(F,G,N,U),wide binaries(E,Q)or those with extremely low mass companions(I,with M c～0.01M⊙;Freire,in this volume).
3.3.47TucW and Total MSP Populations
We have already hinted at the special role MSP W in47Tuc has assumed.As an eclipsing(3.1h)radio MSP with a main sequence(MS)companion discovered with HST(Edmonds et al.2002),it is similar in many respects to the1.3d binary-eclipsing MSP6397A with MS(or evolved)companion in NCG6397.As noted in Edmonds et al.,the X-ray spectrum derived with the original Chandra ACIS-I observation is also similar:a hard spectrum(?t with a PL with photon indexΓ=1.8±0.6,with L x(0.5–2.5keV)=7.8×1030erg s?1vs.values1.6±0.3and4×1030erg s?1for6397A.
The deep Chandra observation of47Tuc has greatly expanded our view of MSP W,with more than7×the total number of counts.The X-ray spectrum and variability,as well as the simultaneous HST/ACS-WF data and archival ACS-HRC data,are described in detail in BGvdB04.As included in Figure 5,we now?t W with an NSA model with T=1.03×106K and radius(at the NS)of1.4km for a thermal luminosity of L NSA=7.8×1030erg s?1and a PL component with photon index1.3±0.25and non-thermal luminosity L PL= 2.8×1031erg s?1.From comparison with the qLMXB J1808.4?3658,we conclude that MSP W is the long-sought missing link between MSPs and qLMXBs in its properties and that it constrains the origin of the hard PL component seen in many qLMXBs to be due to the shocked gas due to an underlying pulsar wind, as recently suggested by Campana et al.(2004)and references therein.
Here we simply comment on the implications for?nding an X-ray population of hard(“PL emission”)MSPs,like W,for the total population of MSPs in 47Tuc or in other clusters.Freire(in this volume)notes that there are now6 such eclipsing MSPs known in GCs(including the three with optically identi?ed MS like companions:47TucW,6397A and PSR B1718?19in NGC6349;and3 additional likely candidates in other GCs)out of some80total MSPs known in GCs.This of course is based on a radio-selected sample(all MSPs were originally discovered as radio objects).However these objects as well as the EVLMBPs (e.g.J)are all subject to eclipses and variable absorption in the radio.We note that47TucW was only detected for4h(Camilo et al.2000),thus precluding a timing measurement for its apparent˙P and therefore our including W with a derived B lc or age in Figure6or˙E in Figure7.Our Chandra spectra now also indicate that at least two of these(6397A and47TucW)are similar in their PL-component X-ray spectra,which are likely also due to pulsar wind shocked gas rather than magnetospheric emission in hard X-rays.Thus the Chandra deep images can detect these objects regardless of their radio detectability and
12Jonathan E.Grindlay
Figure7.Log-log plot for X-ray luminosity vs.spindown luminosity,˙E, for thermal(NSA)component(?)vs.power law component(+).The linear regression lines shown are for the thermal luminosities(log(L x)=19.5±4.6 +0.33±0.13log(˙E),solid line),PL luminosities(log(L x)=10.6±11.7+
0.57±0.35log(˙E),dashed line),and a linear relation for the PL luminosi-
ties(log L x=?4+log(˙E),dash-dot line),which bisects the upper and lower tracks of PL points and would be consistent with the linear Becker and Trumper(1999)relation for more luminous pulsars dominated by magneto-spheric emission.
Chandra Studies of Millisecond Pulsars in Globular Clusters 13inclination;MSP W is dominated by hard emission that would not be eclipsed
if the system were at inclination i <～40?but in fact is eclipsed for part of the binary orbit since it likely arises from shocked gas near the L1point (BGvdB04).
This suggests that some of the hard source population in 47Tuc and other GCs could be additional MSPs that are permanently “eclipsed”in radio by the winds driven from their secondary companions by pulsar wind shock heating.Thus the ～8%fraction of ELMBPs inferred by Freire (in this volume)must be a lower limit;all those that are permanently eclipsed in radio are not counted.These hard X-ray sources would be variable (on binary phase timescales)and could appear as blue objects due to pulsar wind-heated stellar companions or possibly heated accretion streams,prevented from accreting by pulsar winds.We note that heating e?ects (and moderately blue companions)are only expected for the shortest orbital period systems like W;those which have second-exchange
captured companions in to >～6–8h periods (like 6397A,with 1.3d orbital day period)would likely not show heating e?ects (though H αmay still be detected).
As hard sources with otherwise main sequence type optical counterparts,they could then be confused with active binaries or BY Dra systems,which is precisely what happened with our initial identi?cation (Taylor et al.2001)of the optical counterpart of 6397A before the discovery (D’Amico et al.2001)of the MSP in NGC 6397and our identi?cation (Grindlay et al.2001b)of it as a Chandra source.The total number of MSPs in 47Tuc must then include some of these and be larger than the revised estimate of ～30–60MSPs and ～400NSs derived by Heinke et al.(2004a)in part from the 8%estimate of Freire (in this volume).
4.Are the MSPs and qLMXBs in 47Tuc Anisotropic?
We note that the spatial distribution of the 15MSPs in 47Tuc with timing positions originally reported by Freire et al.(2001)as well as that of 47TucS (Freire 2001)and now also 47TucW (Edmonds et al.2002)are suggestive of anisotropy:all but 4(E,O,L and M)are on the north side of the cluster center,over a range of position angle (PA)bisectors through the cluster center.Interestingly,all 5of the qLMXBs in 47Tuc (Heinke et al.2004b)are on the same (N-NW)side of a bisector through the cluster center as the MSPs.In Figure 8we show the positions of the 17MSPs and 5qLMXBs with precise positions in 47Tuc.The binomial probability of only 4(MSPs D,E,L and M)of 22objects that are themselves likely drawn from the same parent distribution (LMXBs)being on the SE side of the cluster center is 4.2×10?4;this increases to 2.2×10?3for 5objects (over a wider range of PAs).
The signi?cance of this result is thus only ～3σand of course less if all possible “bisectors”are considered.However,the possible anisotropy direction may be “preferred”:the MSPs (and qLMXBs)are approximately on the side trailing the direction of proper motion (PM)of 47Tuc,which is towards PA =233+12?9?,as derived by Odenkirchen et al.(1997)by referencing to Hipparcos data.The a-posteriori binomial probability of the 7MSPs (and no qLMXBs),namely MSPs Q,D,E,T,G/I and W being “below”the bisector line through the cluster center and perpendicular to the PM vector (double-dot-dash drawn in Figure 8)is 0.026.On the other hand,the more accurate PM vector at PA =250±2?reported by Anderson and King (2003)does not suggest this
14Jonathan E.Grindlay
Figure8.O?sets from the cluster center(de Marchi et al.1996)of all 17MSPs(?)with known positions and the5qLMXBs(+)in47Tuc com-pared with the proper motion(PM)vectors and±1σuncertainties250±2?
and233+12
?9?of the cluster as reported by Anderson and King(2003)and
Odenkirchen et al.(1997),respectively(we show both for comparison since the more accurate value is derived as an o?set from the SMC proper motion which may still be subject to systematic uncertainties,though its quoted er-rors were included).The core radius of the MSPs and qLMXBs in47Tuc, r c=15′′as derived by GCH02,is shown as the circle.The dot-dashed lines are perpendicular to the PM vectors and are similarly uncertain.The Odenkirchen PM vector suggests the MSPs and qLMXBs may be trailing the cluster(7of22are leading);the Anderson-King PM vector suggests they may be o?set perpendicular to the cluster motion(7of22are”below”the PM vector).The binomial probabilities for either are about3%and so only marginally signi?cant(see text).
Chandra Studies of Millisecond Pulsars in Globular Clusters15 but instead has a similar number(7)of MSPs(E,O,L,M)and qLMXBs(X7 and X5)o?set to one side of the PM vector.This PM determination,while statistically more accurate,is measured relative to the SMC for which the value reported by Irwin(1999)contributes the dominant error and which may still contain systematic e?ects.Thus,overall,the anisotropy may be associated with the cluster proper motion at the～2σlevel.
Regardless of any association with the cluster PM,if the MSP-qLMXB distribution is anisotropic,it is unlikely that selection e?ects could introduce azimuthal anisotropy in the Chandra source distribution(indeed the overall X-ray source distribution in Figure1is isotropic),and no dispersion measure (DM)gradients are present in the DM values given by Freire et al.(2001)that could give rise to a lack of radio detections of MSPs in the SE quadrant.In contrast,the comparable numbers of Chandra sources optically identi?ed by Edmonds et al.(2003a,b)with CVs(22)and active binaries(29),which are chromospherically active main sequence binaries,appear to be isotropic in the deep HST images used for their identi?cation.
Why should the MSPs/qLMXBs,predominantly,be a?ected by the cluster motion if the trailing or perpendicular associations are signi?cant?We note that if the MSP/qLMXB o?sets are real,they would not be expected to show up in the present PM measures for the MSPs(four are given in Freire et al.(2001))vs. the cluster PM since the di?erence must be negligible for the MSPs to remain bound to the cluster.As the oldest compact binary population,with(typically) degenerate secondaries,the MSPs(and qLMXBs)may have accumulated the largest net recoil de?ections by weak encounters with soft main sequence binaries in the galactic halo and disk.An MSP(or qLMXB)will have weak encounters with wide?eld binaries(with semi-major axes typically a f=100AU)in the disk and galactic halo,which are(much)too soft to survive in the cluster core,at a rate R f～n fσf v f.Adopting a weak encounter impact parameter as b f～100a f, which would typically Rutherford scatter a cluster MSP to induce a～1%velocity perturbation on the typical～10km s?1velocity of the MSP in the cluster,a ?eld binary density n f～10?3pc?3,and cluster velocity relative to the?eld v f～100km s?1,the time between such encounters isτf=1/R f～108?9y.This
is comparable to the weak encounter time for an MSP with cluster binaries in the core of47Tuc,which as hard binaries have a c<～1AU,n c～103pc?3(for an assumed1%binary fraction for such wide binaries in47Tuc),and relative velocity in the cluster v c～10km s?1.These weak encounters will be isotropic in the cluster frame for cluster binary perturbers but anisotropic for?eld binaries, which will impart(small)recoil momentum transfer to the MSPs and qLMXBs. Since the maximum transfer is at closest approach,it would seem the recoil velocities would be preferentially in the perpendicular direction.Note that such recoils would occur preferentially when the compact binaries are near apastron in their largely radial cluster orbits(where they spend the most time),so that relatively small?v values imparted to the binary can have the largest e?ect. The length of the PM arrows are drawn in Figure8for the two di?erent PM values and show the approximate motion of the center of mass of the cluster and MSPs over104years.The comparable o?sets of the MSPs,if acquired over their ～109year lifetimes,thus represent a net drift velocity of only～10?2km s?1,or comparable to the induced velocity perturbation by scattering o??eld binaries.
16Jonathan E.Grindlay
Single cluster stars have smaller cross sections than binaries for scattering o??eld binaries,and without the internal degree of freedom provided by the binding energy of a cluster binary,scattering of single stars are likely perturbed more isotropically by their encounters.Cluster CVs and ABs have binary evolution lifetimes generally(much)shorter than MSPs and may also absorb their recoils in tidal distortion of their non-degenerate secondaries(absent for all the known MSPs in47Tuc except W).Detailed simulations and a full di?usion analysis are of course needed to test whether disk and halo binary encounters can scatter the orbits of compact binaries in a cluster preferentially and not alter(signi?cantly) their radial distribution(GCH02),which is consistent with an isothermal King pro?le with core radius r c=15′′(cf.Fig.8)as expected for～1.5M⊙objects in dynamical equilibrium with predominantly0.7M⊙stars in the core.
Clearly both a larger sample of MSPs and/or qLMXBs is needed to test the reality of this(marginal)anisotropy as well as speculative interpretation. Based on X-ray luminosity and spectral colors and absence of variability or CV/AB optical counterparts,additional MSP candidates in the original ACIS-I data have been given by GCH02and Edmonds et al.(2003a)but have been reduced by Heinke et al.(2004a)to just4or5in the ACIS-S data:W5,W28, W34,W142and possibly W6.All of these additional MSP candidates are again perpendicular(and on one side)of the Anderson-King PM vector but only two (W34and W142)are on the“trailing”side.This would support the picture of preferentially perpendicular(to the PM vector)scattered velocity perturbations, though it is puzzling these are not symmetrically distributed about both sides rather than just the north side.In addition,of course,there are at least5radio MSPs in47Tuc still not located with radio timing,and as noted above,Heinke et al.(2004a)estimate there are an additional～10–40additional MSPs likely present in47Tuc(likely a lower limit;see above).Thus MSP/qLMXB possible anisotropy and di?usion e?ects will be testable.
5.Conclusions
MSPs in GCs remain a treasure to be mined further with high spatial resolution X-ray imaging as well as high throughput spectroscopy.They are low luminosity objects which must be resolved,cleanly,from comparably bright CVs and ABs. It is clear that Chandra and future higher throughput telescopes,with compa-rable or(ideally)better angular resolution(<1′′)are needed.With Chandra, very long observation times are required to make signi?cant new progress on MSPs.Accordingly,we have concentrated here on X-ray spectra derived from our300ksec observation of47Tuc and have shown that they are generally all con-sistent with a combination of soft thermal emission from their polar caps plus a harder PL component.The thermal temperatures(derived for a NSA model) are in a surprisingly narrow range:1.1±0.2×106K.The“PL component”can only be?tted as such in the four brightest MSPs;for the others we can only say there is an excess of?ux above the thermal?ts at>～2keV which is consistent with a PL origin.
We note that this hard X-ray component could be either magnetospheric or pulsar-wind shocked gas or both.Shocked gas is certainly the case for the brightest“hard”MSP in47Tuc,MSP W(BGvdB04).MSPs,generally,may
Chandra Studies of Millisecond Pulsars in Globular Clusters17 have all three components–polar cap,magnetospheric and pulsar wind-induced, with the latter most prominent for the doubly-exchanged systems with main sequence companions(47TucW and6397A).
It is interesting that the luminosities separately derived here for the thermal (NSA or BB)and PL components have correlations with˙E consistent with log-log slope0.5and1,respectively.The PL component decreases in luminosity with MSP age and?eld at the light cylinder,both of course due to variations in ˙P.We note again that all˙P values are the same intrinsic values corrected for the MSP acceleration in the cluster as described in GCH02.
We have called attention to a puzzling,though marginally signi?cant,ap-parent anisotropy of the MSPs and qLMXBs in47Tuc:this may(or may not) be associated with the cluster proper motion.Weak encounters the oldest clus-ter compact binaries,the MSPs and qLMXBs–NSs with(typically)degenerate binary companions–with soft binaries in the?eld(both halo and disk)may provide an explanation,but detailed simulations are needed and,of course,more MSP/qLMXB precise positions are required to con?rm the e?ect.
X-ray pulse timing and pulse-phased spectroscopy is the obvious new do-main which would provide crucial tests.The soft thermal component emission should show up as broad quasi-sinusoidal emission,which can test the polar cap geometry(and presence of multipoles;cf GCH02).The magnetospheric com-ponent is beamed(at least partly)and will generally produce narrower pulse pro?les dominated by PL emission;whereas the PL component from the pulsar wind and shocked gas from the binary companion will be unpulsed.It is unfor-tunate that the only pulsar timing capability on Chandra is the HRC-S with its limited sensitivity above2keV,high internal background,lack of any spectral sensitivity and limited response above～2keV.Nevertheless,the800ksec HRC-S observation to be conducted in Cycle6by Rutledge et al.will make an impor-tant start on measuring these predicted components(though the sensitivity for the PL component will be limited)and may enable Chandra identi?cation of the remaining5radio MSPs by detecting their soft pulsations from among the ACIS-S sources.
I thank Craig Heinke and Slavko Bogdanov for many discussions and for preparing Figures1and2–4,respectively,and Andrew Lyne for discussions about the puzzling possible MSP anisotropy.This work was supported in part by NASA grants GO2-3059A and HST-GO-09281.01-A.
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返至筒体内壁，以筒体下端面为基准，距下端面100 mm处的筒体内表面划出一条基准环线，以心线及基准环线作为划塔内支撑圈、接管开孔及分段口处用于现场组对的基准环线的基准。现场组对基准环线距下端面的理论距离为100mm。在各分段口处分别测量圆度、平面度及外圆周长并作好记录，以便进行现场调整组对。 2.塔内件的制作与安装：a)塔内件一般均采用焊接连接形式。此焊接至关重要，直接影响内件的顺利安装及工艺操作，故应严格按照焊接工艺卡和施工图纸的要求去施焊组装，塔体分段处留一层塔内件在塔体内不焊，现场合拢缝组对后再在塔内组装焊接。b）焊接完要进行焊渣清理。 3.塔器的预组装：塔体分别制造检验完毕后，在制造厂内按JB／T4710的规定进行无间隙预组装，对分段口处的超差圆度和总体直线度进行调整，预组装后的尺寸应满足图纸及相关标准的要求，预装检验合格后 每段塔体分段端口外表面处的0°、90°、180°、270°四条心线位置用白色油漆划出，并点焊现场组对定位工艺板，以便现场组对。 4.现场组对：a）塔体运至现场经复验合格后，将环缝从下至上一次进行空中组焊。b）检验基础是否满足安装要求，确定后把基础上表面清理干净。c）将裙座下段吊装到基础上，利用工艺垫铁进行主体找平、找正等相关工作。可采用经纬仪检查塔体的垂直度和其他要求。d）检验合格后做好检验记录，拧紧地脚螺栓、螺母，通过搭建的工装进行装配组对。e）采用经纬仪检查筒体的垂直度，利用钢尺检测塔体对口间隙和错边量，并复查管口方位。f）以上检测结果符合设计要求后点焊固定，焊缝的强度至少能够承受风载荷等其他外力。g）塔体周围应布置安全防护措施保
北大应届女生自曝面试经历
北大应届女生自曝面试经历 北大应届女生自曝面试经历 女生曹煜，北京大学历史系应届本科毕业生。 上个星期三参加广州日报的面试。我们系一共去了六个人，四名男研究生，一名女研究生，我是惟一的本科生。第一次得到面试机会，我有点紧张，事前想了很多问题，人家可能会怎么问，我该怎么回答，等等，又向一些朋友咨询了一下。去之前专门去洗了个头，认认真真梳洗了一把。 我去得比较早，不过到了那里发现已经有很多人了。一问，都是人民大学学新闻的学生，参加面试的总共有一百多人。 等了一会儿，面试正式开始了，大家一个一个轮流进去，由广州日报的社长、总编和副社长分头谈。给我面试的是广州日报的总编。 我进去了之后没大在意，心想：面试嘛，就是随便问两句，没什么大不了的。没想到总编看了一下我的简历，问题就来了。他说，你是学历史的呵，你们历史跟我们报纸好像不太对口吧，你觉得怎么样？我就跟他讲了一下，大概是说文史相通，我们学历史的做报纸编辑、记者没什么问题，等等。其实这些话都没什么意思，但是我当时很紧张，也找不出更好的解释。他就说：你能不能在短时间内给我证明一下，你确实适合干报纸。我想了半天，也没证实出来。不过我也不是完全乱了章法，大概还是表达了一下自己的才干，譬如学习能力强，学习速度很快，能很快熟悉报社的业务，等等。他又问了几个问题，面试就结束了，时间很短。我出来的时候，那个女研究生还没有面试完。后来听说，给她面试的人基本上不问问题，就让你自己说，风格跟我这个完全不一样。 我出来之后，跟那几个研究生探讨。我说这个总编很厉害嘛，提这么尖锐的问题。他们说这就是考你的应变能力。 全部面试完之后，大家都认为总编提的问题比较难回答，不像社长挺和气的。不过遇到这样的考官确实挺锻炼人的。我们总结经验的时候就说，其实那些问题有没有道理你先不去管他，就看你怎么反过来难倒他。譬如他问我们一个研究生陈林的问题是：你觉得你们历史系谁秀？陈林说：都优秀。他说：你是不是秀的？陈林说：各有各的长处嘛。他说：那我怎么知道我应该选择那个呢？陈林说：那你就看着办呗，我也没有办法。挺搞笑的。他们研究生跟我们不一样，他们有工作经验，对面试根本无所谓，就当成锻炼。他们跟我说，你不要怕，双向选择嘛，他不选你你还可以不选他呢！你一定不要怕，对自己要有绝对的自信，相信自己什么都能干。 通过面试，我觉得学到的东西挺多。一是积累了经验，懂得面对一些尖锐的问题怎么回答，我就跟他说我虽然没有上研究生，没有硕士文凭，但是我比他们年轻好几岁，这几年青春就很宝贵，对吧？二是要有自信，不怕那些人，对他们的态度要不卑不亢，不是说我求着他非要这个工作，也不是说他求着我，我们是平等的。我觉得当时我还不够自信，下次要注意这一点。三是可以做一些必要的准备，但是临场时一定要随机应变，轻松自如地表现自己。 跟那些研究生的交流，也增加了我的自信。不就是工作吗？！找不着满意的工作，还可以考研究生，出国，其实路子挺多的，并不是说现在找着一个好工作你将来就怎么着了，现在没有一个特别满意的工作，也不代表你的路就走不开了。更何况，现在看起来，去哪儿工作并不重要，不是说非要留在北京，关键是要找一个有发展前途，有挑战性的工作。生活过得丰富一点，很充实，但是也不要为了一点钱一天到晚拼死拼活的，还能有自己的生活空间。我相信我的要求不算太高，能找着一份有前途的工作就行了。 不管怎么说，我现在就是一颗平常心，没什么大不了的，一切顺其自然，对自己自信就行了。
大直径塔器裙座结构设计
大直径塔器裙座模板结构设计 摘要：本文以实例介绍大直径塔器裙座模板的结构和设计方法，提出了防止模板变形应采取的加强措施。 关键词：大直径塔器裙座模板结构设计 1.前言 塔器是化工、石油化工和炼油等生产中最重要的设备之一。一般塔设备的高径比较大，要承受地震、风、偏心以及内压等载荷，为保证塔设备的安全可靠运行，其安装基础非常重要，必须进行可靠、合理的设计。但目前国内外有关塔设备基础设计的文献较少，有的只是定性介绍[1]，有的虽然有定量的介绍[2]，但不全面，特别是针对大直径塔器的基础设计几乎没有。为此，本文以实例介绍一种较为完整的大直径塔设备裙座基础模板的设计方法。 2.裙座模板 塔设备的基础一般由三部分组成：模板、混凝土地基及地脚螺栓。混凝土地基由土建专业设计，地脚螺栓一部分埋入混凝土地基中，裙座支撑的塔设备要用地脚螺栓固定在地基上。而裙座模板在地基之上，起到固定地脚螺栓位置的作用。模板制造材料一般为Q235-A。 现在以某公司的DN6000塔器的裙座模板为例，介绍模板结构，请看图一。因为直径比较大，无法整体运输，所以分为两部分，相互采取螺栓连接结构。为了防止运输时变形，设置了支撑角钢。 截面Z-Z请看图二。每个地脚螺栓外均套有一根定距管，定距管为标准钢管。此外，每间隔三个地脚螺栓间有一块支撑板，它和定距管一起，对模板起加强作用。
图一 图二
图三 A-A截面请看图三。上下支撑角钢与上下模板焊接，相互之间采用支撑板连接，同时在支撑板和支撑角钢上面打孔，采用螺栓连接使两部分模板联为一体。 C-C截面请看图四。此图进一步表示出上下支撑角钢和支撑板的关系。 E-E截面请看图五。此图表示出上下支撑角钢和上下模板的连接关系。 图六是I处放大图，更清楚地表示出定距管与上下模板的连接结构。 图四
塔器设计时应具备那些知识点.doc
一、塔器的分类及用途 1.塔设备的作用： 2.塔器的分类:①按操作压力分②按单元操作分③按内件结构分：填料塔和 板式塔 3.填料塔的结构：①塔体②支座③人孔或手孔④吊柱及扶梯⑤操作平台 ⑥填料⑦除沫器，等等 4.板式塔的结构：①塔体②支座③人孔或手孔④吊柱及扶梯⑤操作平台⑥ 塔盘等。 5.填料塔使用场合：①分离程度要求高的情况②具有腐蚀性的物料的情况 ③容易发泡的物料的情况 6.板式塔使用场合：①液相负荷较小时②含固体颗粒，容易结垢，有结晶 的物料等。 二、填料塔 1.填料塔的特点： 2.填料分类：散装填料和规整填料 散装填料的分类：（1）环形填料（2）开孔环形填料（3）鞍形填料 （4）金属环矩鞍填料 规整填料分类：（1）丝网波纹填料（2）板波纹填料 填料的选用： 3.液体的分布器分类：（1）管式液体分布器：重力型和压力型（2）槽式液体 分布器（3）喷洒式液体分布器（4）盘式液体分布器 4.液体的分布器作用： 5.了解填料支撑的种类，结构 三、板式塔的种类 1、泡罩塔的结构 优点： 缺点： 2、浮阀塔的结构 优点： 缺点： 3、筛板塔的结构 优点： 缺点: 4、无降液管塔 5、导向筛板塔 6、斜喷型塔 四、板式塔的塔盘 1、板式塔的塔盘分类：溢流型和穿流型 2、板式塔的塔盘结构分类：①整块式塔盘：定距管式塔盘和重叠式塔盘 ②分块式塔盘 3、塔盘支撑结构种类，结构 五、塔设备的附件 1、除沫器的作用： 2、常用的除沫装置：丝网除沫器、折流板式除沫器、旋流板除沫器
3、吊柱的结构： 六、塔设备的计算 塔设备的各种载荷，计算中需要知道设计哪些载荷 塔设备标准的适用范围，什么样的设备，才算是塔设备 设计压力，设计温度如何考虑 材料的选择，负偏差，腐蚀裕量，最小厚度 1.了解塔设备的受力模型，塔设备受力模型的理论基础 地震受力模型 地震水平力如何计算， 地震垂直力如何计算；什么情况下考虑地震垂直作用力 地震弯矩如何计算 多质点的地震弯矩是如何叠加的 风载受力模型 风作用力的计算 风弯矩的计算 地震作用和风载作用是如何叠加的 2.塔设备强度计算包括哪些步骤 3.塔的固有周期，振型的概念是什么，又是如何参与到塔设备计算中的 七、塔设备零部件 1.裙座 1.1 裙座材料的选择，地脚螺栓的选择，许用应力的确定 1.2 裙座的类型，每种类型适用场合，每种结构有何要求 1.3 裙座与塔壳的连接形式，焊缝有和要求 1.4 排气孔，排气管和隔火圈的规格数量的确定 1.5 裙座上面引出管的结构如何设计 1.6检查孔规格，数量的确定 1.7地脚螺栓座的结构有哪些，每种结构尺寸如何确定的 2.塔壳 通常包括的元件有哪些，塔壳结构有哪些 3.静电接地板如何设置 4.地脚螺栓模板的用途，结构如何考虑 5.设置吊柱的目的（分段塔可不设置吊柱），结构尺寸的确定 6.塔设备吊耳如何选择，如何计算 八、设备法兰（专题讨论） 1）设备法兰的类型，以及各种类型的优缺点，各适用什么场合 2）设备法兰的标准号，在选用标准设备法兰需要注意什么 3）非标设备法兰如何计算，结构尺寸如何确定，怎样才算是最优设计 4）设备法兰材料有哪些，如何选择 5）设备法兰的制造，法兰的制造技术要求有哪些 九、螺栓和螺母， 1）螺栓材料选择，标准的选择，载荷计算
塔类设备检修标准
塔类设备检修标准 000 检修前准备 001 B-[ ] 检修施工的时间安排已经确定。 002 B-[ ] 所有参与检修的人员已了解设备的结构、图纸及检修方案等有关技术资料，熟悉检修内容、检修技术要求和注意事项。 003 B-[ ]凡对设备进行施焊修理的焊工，已持证上岗。 004 B-[ ]按有关规定进行焊接工艺评定，合格后指定焊接工艺规范，检修中按此规范作业。 005 B-[ ]准备好各种检修用机具和劳动保护用品；对备品备件、材料的型号、规格、数量和质量等进行检查、核实，并应符合检修技术要求。 006 B-[ ] 准备好最新版本的检修作业规程。 010 办理施工作业票 011 B-[ ] 施工作业票已经按规定程序办理审批好。 B-< > 确认施工作业票规定的内容已经全部落实。 签字：（） 020 B-[ ] 与塔连接的所有管线已加盲板隔离。塔内部已吹扫、置换清洗合格，并符合有关安全规定。 021 B-[ ] 设备内部存有的可燃性或有毒介质已彻底清洗吹净，且周围现场气体化验分析合格，达到安全检修要求。 022 B-[ ] 确认塔已经具备安全拆卸的条件。 B< >-C< >-J< > 确认塔体及附件已安全交出，具备安全检修条件。 签字( ) ( ) ( ) 100 拆除螺栓 101 B-[ ] 设备上的各人孔盖、卸料口盖吊杆及塔顶部吊装用吊杆进行检查和修理，使其处于完好状态。 102 B-[ ] 人孔应自上而下逐只打开。 103 B-[ ] 法兰螺栓拆卸时须对称分两轮进行，首轮松开约1/4~1/2圈。 104 B-[ ] 拆卸的螺栓、垫片放在指定地点保存好。
200 塔的清洗、检验、检查 201 C-[ ] 清洗、除垢。 202 C-[ ] 检查、修复塔体腐蚀、变形以及焊缝的裂纹、表面损伤等缺陷；检查塔内积垢情况并清理；检查、修理塔体附件（如压力表、安全阀、放空阀、温度计、单向阀等），使之灵活、准确。 203 C-[ ] 检查除沫装置。 204 C-[ ] 检查液体分布器。 205 C-[ ] 检查填料支承板、液体再分布器的填料支承板、压板及篦子板。 206 C-[ ] 检查塔板各部件(如出口堰、受液盘、降液管)的尺寸是否符合要求，并进行修复或更换。 207 C-[ ] 检查塔板各部件的结焦、污垢、堵塞等情况，并进行清理；检查踏板、鼓泡构件和支承结构的腐蚀和变形情况，并进行修复或更换。 208 C-[ ] 对于浮阀塔板应检查浮阀的灵活性，是否有卡死、变形、冲蚀等现象，浮阀孔是否被堵塞，并修理或更换。 209 C-[ ] 检查垫片和螺栓完好情况。 B( )-C( ) 对检查发现的问题进行确认。 签字( ) ( ) 300 壳体裂纹、腐蚀的修理 301 B-[ ] 对于壳体表面的裂纹或是轻微的腐蚀，若裂纹或腐蚀深度小于壁厚的10％，且不大于1mm时，可采用角磨机打磨修复消除，修磨区应与原塔壁的金属表面圆滑过渡，并按要求检查。 302 B-[ ] 对于壳体上深度大于壁厚10％的裂纹以及穿透性裂纹，可先在其两端各钻出一个直径大于裂纹宽度的止裂孔，然后沿裂纹用角磨机彻底清除裂纹，并加工出焊接坡口，进行补焊修复，并按检修质量要求进行检查。 303 C-[ ] 塔由于结构不良，局部应力过高而产生疲劳裂纹，不应继续使用。 304 C-[ ] 内壁若发现有晶间腐蚀、应力腐蚀裂纹，一般不宜继续使用。若腐蚀程度轻微，可根据具体情况改变原有操作条件使用。 305 B-[ ] 局部腐蚀深坑长度不超过40mm，并且相邻两个腐蚀坑面间的距离在120mm以上，任何腐蚀深度都可采用堆焊处理。
女生面试：如何应对敏感问题
女生面试：如何应对敏感问题 女性在求职时，常会碰到一些敏感的问题，总觉得如何回答都不妥，很难让自己和别人都满意。那么，究竟该如何应对这些让人感到尴尬的问题呢？ 问题一、你认为家庭与事业之间存在着难以调和的矛盾吗？ 这是一个老问题，也是一个难题。招聘单位自然非常希望你以事业为重，但也希望你拥有一个幸福美满的家庭。后院不失火，才会使人无后顾之忧，集中精力干工作，才能发挥出你的聪明才干。显然，直接回答事业与家庭之间存在难以调和的矛盾或根本不存在矛盾，都是不合适的。建议你这样回答：我以为无论在工作上还是在家庭中，女性的最大目标都是要使自己活得有价值。虽然我是一个很想通过工作来证实自己的能力、体现活着的意义的人，但谁能说那些
相夫教子培养出大学生、博士生的农家妇女就活得没有价值呢？这样回答，能恰到好处地体现出女性特有的刚柔相济的特征。 问题二、你如何看待晚婚、晚育 别以为这个问题与工作没有多大关联。你对此的回答是否得体，可能会直接关系到你的应聘能否通过。招聘者之所以提出这个问题，是想知道你在工作与生育的关系问题上持一种什么态度。女性求职为什么普遍比较难？这就是症结之一。为了工作晚结婚、晚生育，当然是用人单位所希望的，但如果真的这样做了，恐怕也会令人产生疑惑：一个连孩子都可以不要的人，如果再有其它利益驱动，会不会抛弃一切，包括她曾经为之自豪的工作呢？ 谁都希望鱼和熊掌能够兼得，当二者不能同时得到的时候，在一段时间内我会选择工作，因为拥有一份好的工作，将来培养孩子就会有更为坚实的经济基础。我想总会有合适的时候让我二者兼得。这样回答，或许真的能提醒上司在你生孩子休息时仍把原来的位置给你留着，而不让别人取而代之。
常用塔器制作安装施工方案
常用塔器制作安装施工方案
塔器制作安装施工方案: 我公司承建贵公司的塔器的制作安装工作，已进入施工准备阶段，根据目前现场基本条件和设计要求，特编制施工方案如下，请审议。工程概况：我公司主要负责现场制作安装项目，总重量为Kg，_--年月日止年月的工期日，塔内件为不锈钢和碳钢组合件。 一、现场制作安装基本程序 1、塔体下料和预制按照设计和设计标准进行下料。筒体料预制，预制前视管口位置对钢板进行排列。取筒体直径展开长度，加工艺留量下料，并单边开设30 坡口，预制的单片弧板应与筒体的弧度相同。 2.下料时应保证每块板的两边要平行，对角线相等。 3、安装正装工具对基础进行放线，检查对角螺栓的位置，用经纬仪测°量标高是否正确，用标高为依据调整基础的水平度，并打出基础基准十字线。所有塔器现场安装采用正装，由底座
逐步向上制作安装，采用每4-6 米为一段向上组对主筒体。在空中作业进行组对和焊接时，汽车吊作为主要的施工工具，现场施工的台塔用25 吨吊车将筒体吊之塔高20 米左右，然后再用50 吨吊车进行吊装工作，距塔顶10 米左右时用110 吨吊车进行起吊，施工临时工作平台与工位祥见附图。 二.吊装注意事项 在每段筒体制作完成后，用吊车把上部塔体吊装到下部塔体上，由于起重重量较大并且是高空作业，在吊装前应做好以下工作： a、对下部塔体的上口水平找正，以确保整个塔体的垂直度，并焊接导向板，使上部筒体正确就位。 b、下部塔体的上部搭焊临时平台其标高应低与腰缘1100mm 左右，宽度不小500mm 便与施焊。 c、吊耳，吊耳厚度不小于40mm，宽度应大于300mm，四点吊装，保证吊装安全。超过额定负荷不吊（必须吊的物件，经有关部门研究审批，采取有效措施，方可吊运）； d、信号不明，重量不明，光线暗淡不吊；
常用化工设备标准规范
常用化工设备标准 第一部分： 1 《压力容器安全技术监察规程》 2 《压力管道安全管理与监察规定》 3 钢制压力容器（GB150-1998） 4 钢制管壳式换热器（GB151-1999） 5 钢制化工容器设计基础规定（HG20580-1998） 6 钢制化工容器材料选用规定（HG20581-1998） 7 钢制化工容器强度计算规定（HG20582-1998） 8 钢制化工容器结构设计规定（HG20583-1998） 9 钢制化工容器制造技术要求（HG20584-1998） 10 钢制低温压力容器技术规定（HG20585-1998） 11 塔器设计技术规定（HG20652-1998） 12 钢制压力容器焊接工艺评定（JB4708-2000） 13 钢制压力容器焊接规程（JBT4709-2000） 14 钢制塔式容器（JB/T4710-2005） 15压力容器涂敷与运输包装（JB4711-2003） 16 压力容器无损检测（JB4730-2005） 17 钢制卧式容器（JB/T4731-2005） 18 钢制焊接常压容器（JBT4735-1997） 第二部分 1 机械搅拌设备（HG/T20569-94） 2 塔盘制造安装技术条件（JB/T1025-2001）
3 钢制管法兰及垫片选用规定（HG20593-98） 4 不锈钢－硫酸铜腐蚀试验方法（GB4334.5-1990） 第三部分 1 化工管道设计规范（HG20695-1986） 2 化工装置管道布置设计规定（HG/T20549-1998） 3 化工设备、管道外防腐设计规定（HG/T20679-1990） 4 管架标准图（HG/T21629-1999） 5 石油化工企业设备和管道隔热设计规范（SH3010-2000） 6 化工装置设备布置设计规定（HG20546-92） 7 石油化工管道布置设计通则（SH3012-2000） 8 石油化工企业蒸汽伴管及夹套管设计规范（SHJ40-91） 9 石油化工企业管架设计规范（SH3055-93） 10 管道常用数据表（TC42A1-93）
关于女朋友的面试问题
考官∶你有男朋友吗？ 应聘者∶有。 考官∶他在本地吗？ 应聘者∶不是，他在外地。 考官∶对不起，我公司不能用你。 应聘者∶为什么？ 考官∶你不会安心在这里长期工作的，另外，本公司也不希望因为你而使长途电话费大幅度增加。 （二） 考官∶你有女朋友吗？ 应聘者∶没有。 考官∶你追过女孩吗？ 应聘者∶追过，可是没追上。 考官∶你工作后准备再追女孩吗? 应聘者∶先努力工作，暂时不考虑个人问题。 考官∶对不起，本公司不能用你。 应聘者∶为什么？ 考官∶你公关能力欠佳，况且缺乏自信。 （三） 考官∶你有女朋友吗？ 应聘者∶有。 考官∶她漂亮吗？ 应聘者∶不算漂亮。 考官∶对不起，我们不能用你。
应聘者∶难道女朋友不漂亮也会影响贵公司的形象？ 考官∶那倒不会。不过，本公司是经营艺术品的，你的审美情趣似乎不适合本公司的业务需求。 （四） 考官∶你有女朋友吗？ 应聘者∶有。 考官∶她漂亮吗？ 应聘者∶很漂亮。 考官∶她是你的初恋吗？ 应聘者∶是的。 考官∶对不起，我们不能用你。因为你缺乏不断追求的进取心。 （五） 考官∶你有女朋友吗？ 应聘者∶有。 考官∶她是你的初恋吗？ 应聘者∶不是，以前还谈过几个。 考官∶对不起，我们不能用你。因为你很快会跳槽的。 （六） 考官∶你有男朋友吗？ 应聘者∶有。 考官∶他很有钱吗？ 应聘者∶不是。 考官∶对不起，我们不能用你。因为你的工作要和钱打交道，我担心你经不起诱惑。
（七） 考官∶你有男朋友吗？ 应聘者∶有。 考官∶他很有钱吗？ 应聘者∶是的，他有一家自己的公司。 考官∶对不起，你男朋友的公司都不用你，我们就更不能用你了。 应聘者∶可是，他的公司里没有适合我的职位呀。 考官∶那你是学什么专业的？ 应聘者∶秘书。 考官∶对不起，我们还是不能用你。漂亮姑娘会影响我们经理工作的。 应聘者∶可是，我并不漂亮呀？ 考官∶那就更不行了。如果你长得不漂亮，经理不会对你有兴趣的 问题：奔三大龄男在找工作中，如果面试者问“现在有没有女朋友”该怎么回答？ 82年的老男人，因为工作环境的问题还没找到女朋友，现在想跳槽但面试时老是被问这问题，然后就不了了之。 我一个哥们意见是说有女朋友，说没有的话面试者会认为你这么大龄了还没女朋友肯定心理有问题，所以会PASS你。 现在搞的我都不知道怎么回答了，大家有没有什么意见可以提供参考下？谢谢了 答案：我长期招聘面试别人,有一些自己的看法,供你参考. 说没有没关系,面试问的问题主要是看你诚实不诚实,还有你的反应能力,你的语言组织能力,你是否是个可以很快融入公司文化的人.至于答案没有多少人会关心,除了专业知识,一般问这种问题,都是随便问的,不要在意答案. 如果对方还追问,那就告诉他.,你现在没有,一是自己事业还没有成功,不能给对方一个良好的生活环境,男人要肩负自己的责任,你不忍心自己的爱人以及自己的孩子生活的清苦,还有你要表示,感情不是随便的,不是随便找个人就可以的,要找到一个适合自己的,可以过一辈子的人.这样面试的人就会觉得你有责任感,可以信赖,同时你不是个随便的人,是个坚持自己原则的人. 问题：我面试中被问到"你女朋友是成都的吗"该怎样回答？
化工设备课程设计计算书(板式塔)
《化工设备设计基础》 课程设计计算说明书 学生姓名：学号： 所在学院： 专业： 设计题目： 指导教师： 2011年月日 目录 一.设计任务书 (2)
二.设计参数与结构简图 (4) 三.设备的总体设计及结构设计 (5) 四.强度计算 (7) 五.设计小结 (13) 六.参考文献 (14) 一、设计任务书 1、设计题目 根据《化工原理》课程设计工艺计算内容进行填料塔（或板式塔）设计。
设计题目： 各个同学按照自己的工艺参数确定自己的设计题目：填料塔（板式塔）DNXXX设计。 例：精馏塔（DN1800）设计 2、设计任务书 2.1设备的总体设计与结构设计 （1）根据《化工原理》课程设计，确定塔设备的型式(填料塔、板式塔)； （2）根据化工工艺计算，确定塔板数目(或填料高度)； （3）根据介质的不同，拟定管口方位； （4）结构设计，确定材料。 2.2设备的机械强度设计计算 （1）确定塔体、封头的强度计算。 （2）各种开孔接管结构的设计，开孔补强的验算。 （3）设备法兰的型式及尺寸选用；管法兰的选型。 （4）裙式支座的设计验算。 （5）水压试验应力校核。 2.3完成塔设备装配图 （1）完成塔设备的装配图设计，包括主视图、局部放大图、焊缝节点图、管口方位图等。 （2）编写技术要求、技术特性表、管口表、明细表和标题栏。 3、原始资料 3.1《化工原理》课程设计塔工艺计算数据。 3.2参考资料： [1] 董大勤.化工设备机械基础[M].北京：化学工业出版社，2003. [2] 全国化工设备技术中心站.《化工设备图样技术要求》2000版[S]． [3] GB150-1998.钢制压力容器[S]． [4] 郑晓梅.化工工程制图化工制图[M]．北京：化学工业出版社，2002. [5] JB/T4710-2005.钢制塔式容器[S]． 4、文献查阅要求
女生面试的着装案例分析
女生面试的着装案例分析 面试，是每个求职者必须要面对的一个环节，尤其是女士面试，需要注意的事项也非常多，例如好多女士都不知道自己面试时该穿 什么好?什么样的面试着装更得体?下面是干货资源社小编给大家搜 集整理的女生面试的着装案例分析。希望可以帮助到大家! “我前几天去华夏银行面试被BS了，说我穿得太随意.郁闷了，在回来的路上下定决心去买套职业装。可后来查了很多资料却糊涂了。关于服装有的说最好穿套装，有的又说穿太正式了不好，毕竟 还是学生呢.我还特意看了金正昆的求职礼仪，他也说用不着穿得太 正式，说你比人家考官还专业可不行呀.再就是头好，有的说要扎起来，有的说无所谓.我现在是直发可以扎起来，原计划是开学弄卷的，想打扮成熟些找工作，现在又犹豫了，害怕弄卷了头发扎不起来了!唉.真不知道怎么弄了哦!” 根据上述女大学提出的问题，可想而知，面试着装在面试当中 的重要性。那么女生在面试时怎样才能给面试官一种好的第一印象呢?下面是鹏程万里汕头人才网的小编剖析的几点面试着装技巧，希 望可以帮助广大女生更自信的去面试。 第一点：套装成套不成套 女式套装在选配方面较男士西装更为讲究，也更为繁复。男装 要求同色配套，而女士套装可以在不同套之间进行搭配，不同颜色 之间也可以互相映衬。但总的原则是以深色为宜。不同季节和不同
的区域可以适当变通，秋冬季节宜选深色，春夏颜色可稍浅，南方 可穿浅色，北方深色更适宜，但不论什么季节和地区，如果只买一 套正装，深色套装是最稳妥、保险的。可以在招聘会及平时多观察 正规公司的职业女性如何穿着。 第二点：妆的浓淡 一般去正规中外企业面试，女性需要稍微化一些淡妆，显得更 有朝气，如果素面朝天地去面试，很容易因为“面黄肌瘦”、“灰 头土脸”的本色而丢分。通常，女性至少应该在眉、唇、颊三个部 位上稍下功夫。面色红润、朝气蓬勃才显得更有亲和力，更加干练，也更会受到同事及客户的尊敬。 切忌浓妆艳抹，那不是职业女性尤其是年轻女性应该有的精神 风貌。一来与崇尚效率的公司风格不相符，你很可能因为每早“刷墙”而在早上迟到个把小时;二来万一碰上挑剔的女上司，你的浓妆 艳抹加上青春的朝气有可能会招致她的嫉妒和排挤;三来作为尚未毕 业的学生，带有朴素学生气质的淡妆既符合自己身份，也与面试的 要求很吻合。 第三点：长发还是短发 近年来，在很多商业企业中都能够看到一些精明、干练的职业 女性，她们具有的共同特点之一就是“一头短发”。当然，也不是 所有的优秀职业女性都留短发。这里没有必要强调每一位准备参加 面试的女生都去剪断长发，只是将较为普遍的情况提供给大家作为
塔器设计计算要点
塔器设计要点 1.筒体分段原则: 1.1.计算自振周期和地震载荷时的计算分段 1.1.1.对于不等截面的塔(包括等直径不等厚或不等直径塔),在计算基本振型自振周期 和地震载荷时,将其视为多自由度体系(多质点),因此将塔沿高度分解为若干计算段,各段的质量可处理为作用在该段高度中以处的集中质量.考虑到足够高的计算精确度,宜将塔分为10个等高段. 1.1. 2.对于等直径等厚度的塔,计算自振周期无需分段,但在计算地震载荷时仍需将塔分 为若干等高段(10段为宜). 1.2.计算风载荷时塔的计算分段 1.2.1.对于等截面塔(等直径,等厚度),一般将距地面高度10m以下作第一计算段,其它 的计算段一般取每段小于或等于10m; 1.2.2. .对于不等截面的塔(不等直径,不等厚),宜按截面变化情况分段(即相同直径,相同 厚度为一段),当然也可取与自振同期地震载荷计算时相同段数. 1.3.壁厚分段 1.3.1对于塔壁厚取决于压力载荷(内压或外压),且为同一材料时,塔体(裙座除外)可取 同一厚度。但对满液操作的塔，需考虑液柱静压力。因此应根据不同高度处的计算压力决定是否采用同一厚度段。 1.3. 2.当塔壁厚是由风载荷或地震载荷控制时，由于风或地震载荷引起的弯矩随塔高 自上而下递增，因此从等强度及结构设计的合理性考虑，应将塔体分为自上而下逐段递增的厚度段。 其不同厚度段的划分原则如下： （1） 从制造、经济合理等因素考虑，不同壁厚段数不宜太多，以最多不超过5个壁厚段（不包括裙座） （2） 相邻段的壁厚不宜过大，碳钢和低碳钢塔体厚度差一般为2~4mm；不锈钢为1~2mm （3） 在保证强度和结构设计的前提下，同一壁厚段的长度宜控制在5~10m范围内，同时应尽量考虑钢板宽度规格，且是钢板宽度的整数倍。 （4） 有变径段（锥体）时，变径过渡段的锥壳厚度不得小于与其连接的上下圆筒的厚者。 2.裙座 2.1.当符合以下条件之一时，裙座应设与塔底封头（或筒体）材料相同的过渡短节。 （1）塔釜设计温度大于250℃或低于-20℃ （2）裙座筒体与塔釜封头相焊后，将影响塔釜材料性能（如不锈钢、铬钼钢、低温钢等） （3）过渡段的长度规定：当塔釜设计温度大于350℃或低于-20℃，过渡段长度是保温厚的4~6倍，且不小于500mm；当塔釜设计温度在-20℃~350℃之间时， 过渡段长度不小于300mm。
女性求职者在面试的时候必问的问题
具研究表明，现在的职场普遍是女性成为高管，掌握职场的话语权，而仅有少部分男性是公司的创始人。 其实对于职场来说，女性一直处于劣势的，天生存在一些避免不了的劣势。 所以经常在面试的时候都会被问道的话题： 未婚的职场女性会被问的奇葩问题： 你有男朋友吗？ 你打算分手吗？ 已婚的女性会被问到：什么时候要baby？什么时候生二胎？ 这类奇葩的问题。 这些问题真的都奇葩吗？其实不然，这个是作为女性在职场生存无可避免的问题。 大学毕业，在你面试的时候经常会被hr很随意的问，你有男朋友吗？你这么漂亮肯定有男朋友了吧？ 如果你研究生毕业，毕业的时候都25岁以上了，被问道这么奇葩的问题的概率就更高了？ 如果你到了28岁，作为职场女性去面试的时候，基本都会被问这样的问题。 为什么面试官会问这样的奇葩问题，尤其是你的面试官还是一位女性的情况下？ 记住此时的“她”不在是跟你同类“女性”，千万不要被她随意、和蔼、亲和的“你有男朋友吗”就一脸小女人的状态甜蜜的回复“我有男朋友”。
记住作为面试官，他们不关心你的情感生活，你是不是有男朋友，你们感情如何，根你在不在一个城市，做什么工作。他们都不care的。 记住每位面试官所有提出的每个问题，都有她自己的关注点，它们关注的是背后的事情。 比如说对于应届毕业，其实企业是知道应届生没有经验的，能力是不可能跟工作几年的人来比的，之所以招聘应届毕业生。 他们看重的是什么？？ 你值不值得培养 但作为企业它也会担心，我培养了你，录用你，但会因为感情问题，不稳定，不值得培养。 毕竟我们女性天性比较感性，遇到一些感情问题会反应比较大。 如果出现问题的话很容易影响到工作；而男生在这些事情上处理则比较理性，多数会把工作和个人生活分开，不容易影响工作。” 更不用说“总有那么几天......”， 可以说这是所有“恋爱”女人的通病。 作为企业当然会把这方面作为考察我们“女性”的一个重要的要素的。
面试提问问题库
面试提问共性问题罗列 一、责任 1、家庭责任 以下必问： 请简单介绍一下你的家庭成员？（了解员工家庭背景） 以下选问： 父母的生日是什么时间？ 如果你有女朋友或老婆，请问你们平常沟通和交流最多的是什么？（了解家庭是否支持他的工作） 请问你配偶是做什么工作的？小孩多大了？ 平常是怎样辅导和教育小孩的？平常是怎样培养孩子的劳动习惯？ 2、企业责任 以下选问： ●团队意识 （团队管理）请说出你作为团队者所遇到的最困难的事情。是怎样解决这个困难的？你在解决这个困难中起了什么作用？ （团队成员）若某位员工经常迟到、早退、旷工，或不愿意干活，会给整个团队带来什么样的问题？这些问题该怎样解决？作为团队的一员，你是怎样改善这种情况的？
●自我评估（推荐问，性格决定服务） 你为什么认为你很胜任这个工作？ 你认为自己最大的优点是什么？最大的缺点是什么？ 你的好友怎样评价你？ ●目标 你为什么对我们的工作职位感兴趣？ 哪些原因导致你考虑离开你目前的公司？ 你想在我们公司找到哪些在你原来公司找不到的东西？ 对你来说，什么样的工作氛围才是非常适宜的？ 在什么情况下你才不会离开你现在的工作岗位？ ●是否追求上进，有进取心 你在工作中遇到困难是如何处理的？（就具体的一件事情讨论） 若你自己来写你的职位描述的话，你会写些什么？ 在原来公司提出过什么合理化建议？ 在这个公司，你个人希望取得什么样的成绩？ 请告诉我，你曾经从事的最好的工作是什么？你为什么认为那是最好的工作？你开始是怎样获得那份工作的？ 个人近期打算和长远打算是什么？ ●处理矛盾和冲突能力，能否和同事友好相处
请讲一个你和其他部门因部门间工作协调而发生冲突的经历。问题是怎样解决的？你在解决这个问题中起了什么作用？ 请讲一个这样的经历：为了完成某项工作，你需要另一个部门提供十分重要的信息；但另一个部门认为，为你的部门收集信息不是他们的工作重点。你该怎样解决这个问题？ 你和同事们怎样相处？（推荐问） ●服从意识 假如直接上级对你的工作进行了调整，但是在调整之前，直接上级并没有向你通气，假如调整后的工作很难做，你该怎么办？ 你认为和你未来的直接上级建立和保持良好关系的最主要的因素是什么？（推荐问） 3、社会责任 平常参加一些什么公益活动？ 有没有捐助过希望工程？ 对乞丐这种社会现象是怎么看的？（推荐问，价值观的体现） 二、习惯（以下选问） 1、学习习惯 你喜欢的一句话是什么？ 是否看过公司网站、宣传资料，了解到什么内容？（推荐问，特别是对行业的了解度） 2、工作习惯 ●计划性 你是怎样计划每天（每周）的工作的？（灵活多变性及工作是否有计划）
典型塔器设计与选型
1、概述 塔设备是化学工业、石油工业、石油化工等生产中最重要的设备之一。它可使气（汽）液或液液两相之间进行充分接触，达到相际传热及传质的目的。在塔设备中能进行的单元操作有：精馏、吸收、解吸，气体的增湿和冷却等。 在化工、石油化工及炼油厂中，塔设备的性能对于整个装置的产品质量、质量、生产能力和消耗定额，以及三废处理和环境保护等各个方面，都有重大的影响。 2、设计依据 3、设计原则 塔设备除了应满足特定的化工工艺条件（如温度、压力及腐蚀性）外，为了满足生产的需要还应达到下列要求： （1）生产能力大，即企业处理量大。 （2）高的传质、传热效率，即气液有充分的接触空间、接触时间和接触面积。 （3）操作稳定、操作弹性（最大负荷对最小负荷之比）大，即气液负荷有较大的波动时任能在较高的传质效率下进行稳定的操作，且塔设备应 能长期连续运转。 （4）流体流动的阻力小，即流体通过塔设备的压力降小，以达到节能降低操作费用的要求。 （5）结构简单可靠，材料耗用量小，制造安装容易，以达到降低设备投资的要求。 事实上，任何一个塔设备能同时达到上述的诸项要求是困难的，因此只能从生产需要积极经合理的要求出发，抓住主要矛盾进行设计。 4、塔结构尺寸的确定 塔设计依据于Aspen plus软件模拟结果。经灵敏度分析，得出最优塔板数和回流比，然后根据塔设计标准方法计算出各个塔径与塔高。 5、塔的分类与总体结构 （1）塔的分类 ①按操作压力分：加压塔、常压塔和减压塔； ②按单元操作分：精馏塔、吸收塔、解析塔、萃取塔等； ③按相际接触面的方式分:固定相界面和流动过程中形成相界面； ④按塔的内部结构分:板式塔和填料塔（最常用） a、板式塔中，塔内装有一定数量的塔盘，气体自塔底向上以鼓泡喷射的 形式穿过他盘上的液层，使两相密切接触，进行传质。两相的组分浓度沿塔高呈阶梯式变化。 b、填料塔中，塔内装填一定高度的填料。液体自塔顶沿填料表面向下流 动，作为连续相的气体自他爱地向上流动，与液体进行逆流传质。两相的组分浓度呈连续型变化。 （2）塔的总体结构 ①塔体：是塔设备的外壳。常见的塔体由等直径、等壁厚的圆筒及作为顶盖 和底盖的椭圆形封头所组成。除了满足工艺性条件下的强度外，还应校核风力、地震、偏心载荷所引起强度和刚度，以及水压试验、吊装、运输、开停工的情况。另外，对于塔体安装的不垂直度和弯曲度有一定的要求。 ②塔体支座：是塔体安放到基础上的连续部分，一般采用裙座。
石油化工塔器设计规范
中华人民共和国行」卫标准 SH 3098-2000 石油化工塔器设计规范 Specification for the design of petrochemical column 2000-06-30发布2000-10-01实施 国家石油和化学口巨业局发布 中华人民共和国行业标准 石油化工塔器设计规范 Specification for the design of petrochemical column SH 3098-2000 主编单位: 中国石化集团兰州设计院 主编部门: 中国石油化工集团公司 批准部门: 国家石油和化学工业局 国家石油和化学工业局文件 国石化政发(2000) 239号 关于批准《石油化工企业污水处理设计规范》 等 10 项石油化工行业标准的通知 中国石油化工集团公司: 你公司报批的《石油化工企业污水处理设计规范》等10项石油化工行业标准草案，业经我局批准， 现予发布。标准名称、编号为: 强制性标准: 序号标准编号标准名称 1. SH 3 095-2000 石油化工企业污水处理设计规范 2. SH 3 097-2000 石油化工静电接地设计规范 3. SH 3 098-2000 石油化工塔器设计规范(代替SYJ1 049-83) 4. SH 3 099-2000 石油化工给排水水质标准(代替SHJ1 080-91) 5. SH 3 100-2000 石油化工工程测量规范 6. SH 3 010-2000 石油化工设备和管道隔热技术规范(代替SHJ1 0-90和SYJ1 022-83) 7. SH 3 502-2000 钦管道施工及验收规范(代替SHJ5 02-82) 8. SH 3 513-2000 石油化工铝制料仓施工及验收规范(代替SHJ5 13-90) 9. SH 3 518-2000 阀门检验与管理规程(代替SHJ5 18-91) 推荐性标准: 序号标准编号标准名称 1. S H/ T3 511-2000 乙烯装里裂解炉施工技术规程(代替SHJ5 11-89) 以上标准自2000年10月1日起实施.被代替的标准同时废止. 国家石油和化学工业局 = 000年六月三十日 前言 本规范是根据中石化(1998) 建标字159号文的通知，由中国石化集团兰州设计院对《炼油厂塔 器设计技术规定》SYJ1049-83进行修订而成。
面试的十三个经典问题 答案
面试的13个经典问题及参考答案 选自《挑战500强面试官》 面试按其操作方式可分为结构化面试和非结构化面试两种。结构化面试是指面试时按照预先确定的程序和题目来进行，组织严密、层次分明、评价标准明确，面试官会根据事先拟好的提纲逐项向面试者提问。而在非结构化面试中，面试官可以自由决定提问的内容和方式，谈话层次交错，有很大的偶然性和不确定性。结构化面试涉及的问题，一般是常规性问题，比较容易准备；而非结构化面试的则往往是随机的，需要应聘者临场发挥多一些。 下面列出的是一些最常见的面试题，以及对这些题的分析和参考回答，希望能够起到抛砖引玉的作用（对答案的点评汇集了众多人力资源经理的智慧）。 1. 做一个简短的自我介绍好吗？ 这是在面试中出现频率最高的问题。通过这个问题，面试官可以在很短的时间内考察你的表达能力、性格特征和自我表现能力。自我介绍实际上就是一个自我推销广告，你应该把面试官当成你的"客户"，投其所好，将自己适合应聘职位的一面淋漓尽致地表现出来。 错误回答： 有的求职者喜欢把简历上的内容背诵一遍，其实这种做法是完全错误的，因为如果是一模一样的内容，面试官是没有兴趣再听一遍的。等到他（她）打断你的背诵，要你重来一遍时，面试已经失败一半了。另外，自我介绍要短小精悍。有些应聘者把准备的所有内容都一股脑地说出来，长篇大论，滔滔不绝，殊不知面试官已经在偷偷看表了。这样的自我介绍，即使感情丰富语言生动，也会让你的表达能力和沟通能力大打折扣。 正确的做法是，在介绍完自己的姓名、毕业院校和专业后，应该充分表达你对这个职位的理解和渴求，同时要让面试官看到你的自信心。 2．为什么来应聘我们公司？ 这是面试官非常关心的问题，主要考察应聘者对公司的兴趣及求职动机，所以你应该正面地、积极地阐述你对加入该公司的热切期盼。首先你可以提及该公司在业界的良好业绩和口碑，另外说明该公司的待遇、福利预计培训等发展机会对于你来说很有吸引力，同时加盟该公司完全契合自己的职业发展规划。总之，你在回答这一问题时表现出对公司的了解越清晰、深入，对方对你的印象就越深刻，评分也就越高。 错误回答： "公司的福利待遇很好啊。" --只想得到，人家会认为你不想付出。 "其实我也不是特别了解贵公司，是和同学一起来试试运气的。" --如果这样回答，面试官就会告诉你：很遗憾，你的运气不是太好。 3．你做得最成功的一件事是什么？ 这是外企面试中问得很多的问题之一。这个问题主要是想引导你描述自己在个人学业或者社会实践中的成功经历，从而考察你的领导才能以及分析、解决问题的能力；同时也可以考察你的价值观。 面试前，你应该充分准备几个自己经过拼搏取得成功的例子，在表述时要尽量贴近该公司的价值观。比如应聘销售类职位，可以陈述"经过千辛万苦推销出某些产品"的经历和心得；应聘管理培训职位，可以陈述作为学生会主席是如何策划、组织、协调某一大型学生活动的经历。 错误回答： "我成功的例子有很多，例如……例如……" --一大堆成功案例的堆积，会让人觉得你在炫耀成绩；陈述不分主次，也说明你对"成功"没有一个成熟的看法和明确的标准。 "我大学最成功的事情是追到了现在的女朋友。" --这可能是句大实话，但你的成功案例会让面试官觉得你胸无大志。 4．能谈谈你自己的缺点吗？ "你性格上有什么弱点？""你的缺点是什么？"这类问题在面试中屡见不鲜，相当多的求职者就是栽在了