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Cyclic loading test of T-shaped mid-rise shear wall

Cyclic loading test of T-shaped mid-rise shear wall
Cyclic loading test of T-shaped mid-rise shear wall

Cyclic loading test of T-shaped mid-rise shear wall

Zhang Pin-Le *,?and Li Qing-ning

Department of Civil Engineering,Kunming University of Science and Technology,Kunming,China

SUMMARY

Shear wall systems are the most commonly used lateral load resisting systems in high-rise buildings.Six 1:2scale mid-rise T-shaped reinforced concrete shear wall specimens with aspect ratio of 1.75,2.15and 2.80were respectively tested under reversed cyclic loading.The seismic behavior and displacement ductility were investigated.The effects of aspect ratio,axial load level and transverse steel ratio on the seismic behavior and displacement ductility were also analyzed.Test results were discussed and compared with T-shaped steel –concrete composite shear wall.Results mainly showed that the T-shaped shear wall speci-mens mainly presented bending –shear failure mode and were all destroyed because of the concrete crushing at the web (negative direction)and the longitudinal reinforcement of the web reaching the limited deforma-tion (positive direction),showing that the web was the weakest part of T-shape shear wall.The ductility of the specimens was decreased,and the ultimate load-bearing capacity was increased by increasing the axial load.To specimens with smaller aspect ratio and higher axial load ratio,the special transverse steel ratio of the web should be increased to improve the crushing strain of the con ?ned concrete of the web in order to satisfy the ductility of the walls.The seismic performance was obviously improved in the T-shaped steel –concrete shear wall compared with that of the T-shaped reinforced concrete shear wall.Copyright ?2011John Wiley &Sons,Ltd.

Received 11October 2010;Revised 28July 2011;Accepted 1August 2011

KEY WORDS :

mid-rise shear wall;steel shear wall;seismic behavior;test research;load-bearing capacity;ductility

1.INTRODUCTION

Shear walls have been widely used as lateral resisting structures to resist seismic load in high-rise buildings because of its good lateral resistance.A mid-rise shear wall is a shear wall that has a height-to-width ratio of more than 1.0,and its seismic behavior is different from a low-rise shear wall.Many works have been investigated on low-rise shear wall in the past 20years.The bearing capacity,ductility characteristic,stiffness characteristic,shear strength,energy dissipation and aspects of shear walls under earthquake excitation have been studied (Eberhard and Sozen,1993;Colotti,1993;Lopes,2001;Mo and Lee,2000).Test results show that low-rise shear walls have less ductility and low energy dissipation in the hysteretic response of shear walls,and the failure of low-rise shear wall is mainly governed by shear.

Much research works have been carried on the shear wall system now (Lu and Chen,2005;Lee and Haldar,2003;Subedi,1991;Wang et al .,2005).Seismic performance of L-shaped and rectangular shear wall has been investigated in many research works too.Zhang and Li (2010)investigated six L-shaped mid-rise shear wall specimens and test results showed that the L-shaped mid-rise shear wall mainly presented bending –shear failure mode and the bottom of web was the weakest part of the speci-mens.Zhang and Lu (2001)investigated a 1/20scale model of a shear wall structure.Research showed that seismic performance of an L-shaped shear wall was better than that of a conventional rectangular shear wall for the force participation of ?ange.Rectangular shear walls under cyclic loading test

*Correspondence to:Zhang Pin-le,68#Wen Chang Road,Kunming University of Science and Technology,Kunming,650093,China.?

E-mail:zhangpinle@https://www.sodocs.net/doc/1714681038.html,

THE STRUCTURAL DESIGN OF TALL AND SPECIAL BUILDINGS Struct.Design Tall Spec.Build.22,759–769(2013)

Published online 7September 2011in Wiley Online Library (https://www.sodocs.net/doc/1714681038.html,).DOI:10.1002/tal.723

generally showed relatively poor energy dissipation characteristics,showing pinched hysteresis loops and experiencing signi?cant stiffness degradation and possible sudden loss in lateral capacity (Pilakoutas and Elnashai,1995;Tansnimi,2000).

Few documents have investigated the seismic performance of T-shaped shear walls.The destruction that occurred during the earthquake in Wen Chuan demonstrates the importance of seismic perform-ance.Ductility is one of the most important seismic performance indexes.More time is left for people to escape from the damaged buildings when it is subjected to severe earthquake attack if ductility is good.To avoid catastrophic collapse during extreme earthquakes,the lateral load resisting members in buildings must be ductile and strong enough to absorb and dissipate strain energy by inelastic be-havior(Aristizabal-Ochoa,1987).Tests results showed that a T-shaped shear wall may be seriously damaged in the web when subjected to severe earthquake even if excessive energy could be partly dis-sipated in other structural components(Wallace and Moehle,1992;Thomsen and Wallace,2004).The deformability of a T-shaped shear wall was investigated by Wallace(1994)and Taylor et al.(1998). Wu and Yang(2010)investigated the effects of parameters on the mechanical properties of a T-shaped shear wall by using?nite element analysis,and the results showed that axial load and longitudinal steel ratio had remarkable effects on the shear wall.

T-shaped shear walls are widely used in the crossed parts of shear walls.Seismic behavior of a T-shaped shear wall was better than a conventional rectangular shear wall and an L-shaped shear wall for the ef?cient force participation of?ange(Li et al.,2011;Zhang and Lu,2001).Reversed horizontal cyclic loading tests of six T-shaped mid-rise shear wall specimens were conducted to thoroughly ex-plore seismic behavior in this paper.The load-bearing capacity,deformability,ductility characteristic, hysteretic characteristic,energy dissipation and failure patterns were investigated.The effects of aspect ratio,axial load capacity and transverse steel ratio on the seismic behavior and displacement ductility of a T-shaped shear wall were also critically https://www.sodocs.net/doc/1714681038.html,stly,test results were compared with a T-shaped steel–concrete shear wall.x

2.TEST PROGRAM

2.1.Descriptions of shear wall specimens

Six mid-rise T-shaped reinforcement concrete shear wall specimens with height-to-width aspect ratios of1.75,2.15and2.80were fabricated and tested under reversed cyclic loading in this test.One T-shaped steel–concrete shear wall specimen was fabricated just by adding section steel to the web edge

as shown in Figure1,which was tested in the project of Yang(2010).The vertical height of walls

was

Figure1.Internal structure of steel–concrete shear wall. 760Z.PIN-LE AND L.QING-NING

1.4m,and their cross-section thickness was100mm.The cross-section height-to-width ratio of walls was5.0,6.5and8,respectively.Six walls were divided into three groups according to the cross-section height-to-width ratio and axial load level.The design parameters of the shear wall specimens and the steel–concrete shear wall specimen are listed in Table1.Section parameters and reinforcements of shear wall specimens and steel–concrete shear wall specimen are shown in Figure

2.The average con-crete compressive strength of the shear wall and steel–concrete shear wall specimens was respectively Table1.Design parameters of shear walls and steel–concrete shear wall.

Specimens Cross-section height-to-

width ratio

Axial load

(kN)

Transverse steel

ratio(%)

Longitudinal reinforcement

ratio(%)

Aspect

ratio

T500-1 5.0554.40.59 1.95 2.80 T500-2 5.0831.60.59 1.95 2.80 T650-1 6.51108.80.59 1.71 2.15 T650-2 6.5739.20.59 1.71 2.15 T800-18.0924.00.42 1.74 1.75 T800-28.0462.00.84 1.74 1.75 SRC-T5 5.0831.6 1.18 2.86 2.80

100 100 100 100 100

100

100

100

100

100

(a) T500-1 and T500-2(b) SRC-T5

100450

100

(c)T650-1 and T650-2(d) T800-2 (T800-1)

Figure2.Section parameters and reinforcements of shear walls and steel–concrete shear wall.

CYCLIC LOADING TEST OF T-SHAPED MID-RISE SHEAR WALL761

47.2MPa and55.2MPa.Steel properties of the shear wall and steel–concrete shear wall are respectively listed in Table2(the strength of#4rebar was bigger than the others because it was made of cold-drawn steel wire)and Table3.

2.2.Test setup and procedure

The specimens were mounted with steel beams.Axial load were?rst applied on the center of the shear wall and remained constant;then,reversed cyclic horizontal loadings were applied on the top of the shear wall and steel shear wall as shown in Figure3.Both load and displacement controls were adopted at different loading stages.The load-control method was used at the early loading stage, and a displacement control program was applied after the longitudinal reinforcement in the edge of ten-sion area reached yield strain.Loading program of the steel–concrete shear wall was the same as that of the shear wall and was tested with the same equipments.The scheme of the loading program is shown in Figure4;herein,F r is the cracking load corresponding to the lateral load when the?rst crack appears in the tension area,F y is the yield load corresponding to the lateral load when the longitudinal Table2.Yield and ultimate stresses of reinforcement of shear wall.

Yield stress(MPa)Ultimate stress(MPa) #4rebar730985

#8rebar295510

#12rebar345600

Table3.Yield and ultimate stresses of reinforcement and section steel of steel–concrete shear wall.

Yield stress(MPa)Ultimate stress(MPa) #4rebar530620

#6.5rebar400505

#10rebar350520

#12rebar345600

Section steel400

470

Figure3.Test setup. 762Z.PIN-LE AND L.QING-NING

reinforcement in the edge of tension area reached yield strain and D is the yield displacement corre-sponding to the horizontal displacement when the longitudinal reinforcement in the edge of tension area reached yield strain.

3..TEST RESULTS ANALYSIS

3.1.General behavior and failure mode

Figure 5shows the cracking patterns and failure mode of shear wall specimens and the steel shear wall specimen.During the test,?exural cracks were ?rst observed at the bottom of the web when the speci-mens were loaded to approximately half the maximum applied lateral load.Extensive ?exural cracks were commonly developed,and diagonal shear cracks appeared,running at approximately 45 when the specimens were loaded to approximately 0.8times of the maximum applied lateral load.Diagonal shear crack was increased with the increment of axial load and the decrement of aspect ratio as shown in Figure 5,indicating that the walls with a lower aspect ratio and higher axial load may be more vul-nerable to shear failure than those with a higher aspect ratio and lower axial load.All shear wall speci-mens presented bending –shear failure,and specimens were destroyed mainly because of longitudinal reinforcement yielding (positive direction)and web concrete crushing (negative direction)as shown in Figure 6.Most of stirrups and longitudinal reinforcements can be yielded when the specimens were destroyed.The T-shaped steel –concrete shear wall also presented bending –shear failure,but the failure position was different from that of the shear wall.Failure position mainly occurred at the bottom of the web in T-shaped shear wall specimens,and failure position mainly occurred at larger areas from the bottom of the web to the concealed column of the section steel in the T-shaped steel –concrete shear wall specimen.

3.2.Loading capacity and ductility

Table 4shows the yield load,yield displacement,ultimate load and ultimate displacement of the shear wall and the steel –concrete shear wall.In this table,the ultimate load or displacement represented load or displacement when the test was ended.Each test continued until the specimen experienced a signi ?-cant loss of capacity,where it was assumed that the failure occurred when the restoring force dropped to 85%of the maximum applied lateral load (Kuang and Ho,2009).Forward loading (positive direc-tion)was de ?ned as when the web was subjected to tension,and backward loading (negative direction)was de ?ned as when the web was subjected to compression during the test process.The horizontal loading direction diagram is shown in Figure 7.

-0.5-0.5-1.0Figure 4.Loading program.

CYCLIC LOADING TEST OF T-SHAPED MID-RISE SHEAR WALL 763

764Z.PIN-LE AND L.QING-NING

(a)T500-1 at failure stage(b)T500-2 at failure stage(c)SRC-T5 at failure stage

(d)T650-1 at failure stage(e)T650-2 at failure stage

(f)T800-1 at failure stage(g) T800-2 at failure stage

Figure5.Crack patterns and failure mode of specimens.

Shear wall specimens were all destroyed because of the concrete crushing at the bottom of the web (negative direction)and the longitudinal reinforcement of the web edge reaching the limited deform-ation(positive direction);the web was the weakest part of shear wall.The mechanical behavior of

the shear wall specimens was not symmetric in two directions.The load-bearing capacity was bigger,and the ductility was worse in the negative direction.The ultimate load was obviously increased with the increment of the cross-section height-to-width ratio when the width is kept constant.Ductility was decreased,and the ultimate load in the positive direction was obviously increased and increased a little even decreased in specimens with smaller aspect ratio in the negative direction with the increment of axial load.The higher the axial load and the smaller the aspect ratio used,the bigger the transverse steel ratio should be taken,such as specimen T800-1and T800-2.The ductility in the negative position of T800-1was only 2.6,meaning the transverse steel ratio (0.42%)was not enough and the transverse steel ratio (0.84%)was just enough to achieve the displacement ductility factor of 3in

T800-2.

Figure 6.Web crushing.

Table 4.Loading capacity and ductility.

Specimens

Loading direction

F y (kN)

Δy (mm)

F u (kN)

Δu (mm)

u

T500-1Positive 93.58.4111.233.1 3.9Negative 133.5 4.7163.918.3 3.9T500-2Positive 137.67.5146.037.9 5.1Negative 178.77.3186.318.8 2.6T650-1Positive 150.9 6.1196.639.2 6.4Negative 210.8 3.8298.818.1 4.8T650-2Positive 120.0 5.1153.434.9 6.8Negative 140.0 3.5239.322.5 6.4T800-1Positive 280.97.5312.027.0 3.6Negative 322.4 5.8312.312.8 2.2T800-2Positive 161.37.3227.643.8 3.7Negative 250.9 6.1336.918.7 3.1SRC-T5

Positive 192.67.6228.438.0 5.0Negative

195.8

7.7

230.4

38.5

4.9

Note:F y =yield load,corresponding to the lateral load when the longitudinal reinforcement in the edge of tension area reached yield strain.

Δy =yield displacement,corresponding to the horizontal displacement when the longitudinal reinforcement in the edge of tension area reached yield strain.

F u =ultimate load,corresponding to the lateral load of the ending test.

Δu =ultimate displacement,corresponding to the horizontal displacement of the ending test.u =ductility (Δu /Δy ).

CYCLIC LOADING TEST OF T-SHAPED MID-RISE SHEAR WALL 765

Displacement ductility factor of 3could be easily achieved for the T-shaped mid-rise walls in the posi-tive position with the transverse steel ratio (0.84%).The ductility was very good in specimens with sectional height-to-width ratio of 6.5.

The mechanical behavior of steel –concrete shear wall was symmetric compared with that of shear wall specimens,and ductility was almost equal in two directions and even good in the negative direc-tion.Adding section steel to the web of the shear wall increased (a)the longitudinal reinforcement ratio because of the maximum tensile and bucking capacity that the section steel provided and (b)the trans-verse steel ratio because of the effective con ?nement effect on the concrete of the web that the section steel exerted.

3.3.Hysteretic behavior and capacity of energy dissipation

Figures 8and 9show the hysteretic loops of test specimens.The hysteretic curves of the shear wall specimens were not symmetric,and the hysteretic curves were plump when the specimens were under forward loading.Pinching effect was all found from the hysteretic loops of specimens in the negative direction for the effect of shear deformation.Hysteretic loops of specimens in the positive direction showed a much wider and thicker shape,where the larger enclosed area of the loops indicated much higher energy dissipation capacity as compared with that in the negative direction.Hysteretic curves of shear wall specimens with cross-section height-to-width ratio of 6.5were very plump,and their en-ergy dissipation was very good.Pinching effect was very obvious in hysteretic curves of shear wall specimens with smaller aspect ratio and higher axial load,e.g.T800-1.Stiffness degradation character-istic of T800-1was very obvious,and the restoring force was suddenly dropped to 80%of the max-imum applied lateral load.Ductility was worse,serious shear damage occurred at the middle part of the web and energy dissipation was also worse,meaning the transverse steel ratio (0.42%)of the web was not enough.

Compared with those of the shear wall specimens,the hysteretic curves of the steel shear wall speci-mens were plump and symmetric in two directions,and ductility was good,which justi ?ed the signi ?-cant improvement in seismic performance.

4..CONCLUSIONS

Test results showed that T-shaped mid-rise reinforced concrete shear wall and steel –concrete compos-ite shear wall specimens mainly presented bending –shear failure.Shear wall specimens were destroyed because of the concrete crushed at the bottom of the web in the negative position and then deformation capacity,ductility and energy dissipation were worse,and pinching effect was found from the hystere-tic loops for the effect of shear deformation.The higher the axial load level and the smaller the aspect ratio used,the bigger the shear deformation occurred in the specimens.Shear wall specimens were destroyed in the positive direction when the longitudinal reinforcement reached the limited deform-ation and then the deformation capacity,ductility and energy dissipation were good,but the load-bearing capacity was little.So the web was the weakest part of a T-shaped shear wall.Some ef ?cient

(a) Forward loading (positive direction) (b) Backward loading (negative direction)

Figure 7.Horizontal loading direction diagram.

766Z.PIN-LE AND L.QING-NING

measures must be taken to improve the seismic performance of it.The most ef ?cient way to improve the load-bearing capacity of a T-shaped mid-rise shear wall in the positive direction is increasing the longitu-dinal reinforcement ratio of the web edge.

(a) Force-displacement of T500-1

(b) Force-displacement of T500-2

(c) Force-displacement of T650-1

(d)

Force-displacement of T650-2

(e) Force-displacement of T800-1(f) Force-displacement of T800-2

Figure 8.Force-displacement T-shaped shear wall.

-300

-200

-1000

100

200

300-30

-20

-100

10

20

30

Displacement (mm)

F o r c e (K N )

Figure 9.Force-displacement of SRC-T

CYCLIC LOADING TEST OF T-SHAPED MID-RISE SHEAR WALL 767

768Z.PIN-LE AND L.QING-NING

The transverse steel ratio of the web edge must be big enough to satisfy the required deformation

capacity and ductility of a T-shaped mid-rise shear wall in the negative direction.The transverse con-?nement serves to increase(a)the crushing strain of the con?ned concrete of web,(b)the buckling capacity of the main?exural bars and(c)the ductility of the walls.The higher the axial load level

and the smaller the aspect ratio used,the bigger the transverse steel ratio must be taken,such as speci-

mens T800-1and T800-2.The transverse steel ratio(0.42%)of T800-1was far from enough,but the

transverse steel ratio(0.84%)was just enough to achieve the displacement ductility factor of3in

T800-2.Displacement ductility factor of3could be easily achieved for the T-shaped mid-rise shear

walls in the positive position with the transverse steel ratio(0.84%).The?exural ductility was the best

for sectional height-to-width ratio of6.5,so it is suggested to adopt this ratio in designing this type of

T-shaped shear wall.Adding section steel to the web is a good and easy way to improve the compre-

hensive seismic performance of a mid-rise T-shaped reinforced concrete shear wall if the economy is

acceptable.

ACKNOWLEDGEMENTS

The writers would like to express their deep appreciation to the laboratory teachers and workers at the

Xi’An University of Architecture&Technology,and the research work supported by the National Nat-

ural Science Foundation of China(grant no:10572107)is also highly acknowledged.

REFERENCES

Aristizabal-Ochoa JD.1987.Seismic behavior of slender coupled wall systems.Journal of Structural Engineering113(10): 2221–2234.

Colotti V.1993.Shear behavior of RC structural walls.Journal of Structural Engineering119(3):728–746.

Eberhard MO,Sozen MA.1993.Behavior-based method to determine design shear in earthquake-resistant walls.Journal of Structural Engineering119(2):619–640.

Kuang JS,Ho YB.2009.Seismic behavior and ductility of squat reinforced concrete shear walls with non-seismic detailing.ACI Structural Journal105(2):225–232.

Lee SY,Haldar A.2003.Reliability of frame and shear wall structural systems.I:static loading..Journal of Structural Engineering129(2):224–232.

Li QN,Li XL.2011.Experimental research on seismic performance of reinforced concrete short-leg shear wall.Journal of Building Structures32(4):53–63.

Lopes MS.2001.Experimental shear-dominated response of RC walls.Part I:Objectives,methodology and results.Engineering Structures23(3):229–239.

Lu,XL,and Chen,YT.2005.Modeling of coupled shear walls and its experimental veri?cation.Journal of Structural En-gineering131(1):75–84.

Mo,YL,and Lee,YC.2000.Shake table tests on small-scale low-rise structural walls with various sections.Magazine of Con-crete Research52(3):177–184.

Pilakoutas K,Elnashai AS.1995.Cyclic behavior of reinforced concrete cantilever walls,Part II:discussions and theoretical comparisons.ACI Structural Journal92(4):425–434.

Subedi NK.1991.RC coupled shear wall structures.II:Ultimate Strength Calculations.Journal of Structural Engineering 117(3):681–698.

Tansnimi AA.2000.Strength and deformation of mid-rise shear walls under load reversal.Engineering Structures22(4): 311–322.

Taylor CP,Cote PA,Wallace JW.1998.Design of slender reinforced walls with openings.Struct.J95(4):420–433. Thomsen JH,Wallace JW2004.Displacement-based design of Slender reinforced concrete structural walls-experimental veri?-cation.Journal of Structural Engineering130(4):618–630.

Wallace JW.1994.New methodology for seismic design of reinforced concrete shears walls.Journal of Structural Engineering 120(3):863–884.

Wallace JW,Moehle JP1992.Ductility and detailing requirements of bearing wall buildings.Journal of Structural Engineering 118(6):1625–1644.

Wang QF,Wang LY.2005.Estimating periods of vibration of buildings with coupled shear walls.Journal of Structural Engin-eering131(12):1931–1935.

Wu MZ,Yang YD.2010.Nonlinear analysis of the T-shaped short-limbed shear wall.Industrial Construction40(4):60–64. Yang YD.2010.Experimental study and nonlinear analysis on the T-shaped steel reinforced short-limb shear wall.Ph.D thesis.

Xi’An University of Architecture&Technology.

Zhang PL,Li QN.2010.Experimental research on seismic performance of short pier shear wall with L-shaped section.Journal of Earthquake Engineering and Engineering Vibration30(4):51–56.

Zhang J,Lu ZT.2001.Earthquake simulation test of short-leg shear wall-tube model.Journal of Southeast University31(6):4–8.

CYCLIC LOADING TEST OF T-SHAPED MID-RISE SHEAR WALL769

AUTHORS’BIOGRAPHIES

Zhang Pin-Le received his Bachelor’s degree in Civil Engineering from Nanchang University, Nanchang,China,from September1997to June2001.Subsequently,he carried out research in shear wall structures in Xi’an University of Architecture and Technology and?nished his PhD in2011.He is now a Lecturer in the Department of Civil Engineering in Kunming University of Science and Technology.His research interests focus on seismic design and analysis of high-rise building.

Li Qing-ning received his Bachelor’s degree in Civil Engineering from Xi’an University of Architec-ture and Technology,Xian,China,from September1970to June1974.He is now a professor in the Department of Civil Engineering in Xi’an University of Architecture and Technology.He is interested in the area of numerical analysis of bridge structures as well as designs of high-rise building.

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新速马ZoomPad 平板电脑刷机软件包及教程 本文部分内容源于百度ZoomPad吧ZoomPad刷机软件包下载(115网盘):SUTLR1.70.rar ViewPad7_Android_v2.2.2.rar FM6-316R-0-0015-A01_VSI.rar(备选2.2.0刷机包) [indent]SUT LR 1.7.0刷机详解 一软件和安装 1) 软件SUT LR 1.7.0软件以压缩形式传播:SUT LR_1.7.0.rar,文件大小为64MB。解压后,有一个主安装程序setup.exe和两个文件夹:x64和x86。这两个文件夹是安装SUT LR 1.7.0需要的驱动程序,x86对应于32位计算机,x64对应于64位计算机。 2) 安装把SUT LR_1.7.0.rar解压到计算机。双击setup.exe,软件就会自动安装。注意:(1) 安装会用几分钟,耐心等待把每一个步骤都走完,直到安装结束,(2) 安装过程中,根据计算机的CPU类型(32位或64位)选正确的驱动。 二用SUT LR 1.7.0刷机过程 请严格遵守下列步骤刷机: 1) 开始双击SUT LR 1.7.0软件图标,程序开始执行,进入下列画面。按“Next”后,进入下一个画面。 2) 选择刷机ROM 按图示位置的按钮,找到你的ROM的文件,并导入,见下图。 3) 选项下一步要选择“Update Option”。有4个选项如下:可以选“None”或“Erase user data”。通常选后者。 4) 连线用USB电缆将手机与计算机连接。这时,最下一行的“Next”按钮会由灰色变成激活状态。见下图。 5) 开始刷机按“Next”开始刷机。你会看到绿色进度条显示刷机进程。整个刷机过程需要3到4分钟。 6) 结束刷机结束后,窗口显示过程结束,刷机成功。按“Finish”结束。断开USB 电缆,等待手机自动启动。第一次启动需要时间较长,大约几分钟。请耐心等待。用SUT LR 1.7.0刷机就是这么简单! 三常见问题 1) 建议先到Recovery模式下去用Wipe清除以前的数据,然后把手机放在Reboot system now处刷机。 2) 你可以在导入刷机ROM文件后再连机。当然,你也可以在打开SUT程序之前就把手机与计算机连好。这只是操作程序问题,两者的刷机结果相同。 3) 刷机开始时,有可能出现提醒信息“The model of software image file doesn’t match with your phone software. Click OK button to continue update process only if you confirm the warning could be skipped.”或者“The phone model can not be correctly identified. Click OK button to continue update process only if you confirm the warning could be skipped.” 或者“The image model can not be correctly identified. Click OK button to continue update process only if you confirm the

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return i; } void aaa(inty,int n)//判断某年的第N天是是当年的几月几日{ int i=0; int a1[]={0,31,28,31,30,31,30,31,31,30,31,30,31}; i=lea(y); a1[2]=i?29:28; i=1; while(n>a1[2]) n-=a1[i++]; printf("这是%d年的第%d月的第%d天\n",y,i,n); } intbbb(inty,intm,int n)//计算某年某月某日是当年的第几天{ int i=0; int a1[]={0,31,28,31,30,31,30,31,31,30,31,30,31}; i=lea(y); a1[2]=i?29:28; for(i=1;i

Excel中常用函数及其使用方法简介

目录 一、IF函数——————————————————————————————————2 二、ASC函数—————————————————————————————————4 三、SEARCH函数——————————————————————————————4 四、CONCATENATE函数———————————————————————————4 五、EXACT函数———————————————————————————————5 六、find函数—————————————————————————————————5 七、PROPER函数——————————————————————————————7 八、LEFT函数————————————————————————————————7 九、LOWER函数———————————————————————————————7 十、MID函数————————————————————————————————8 十一、REPT函数———————————————————————————————8 十二、Replace函数——————————————————————————————9 十三、Right函数———————————————————————————————10 十四、UPPER函数——————————————————————————————10 十五、SUBSTITUTE函数———————————————————————————10 十六、VALUE函数——————————————————————————————12 十七、WIDECHAR函数———————————————————————————12 十八、AND函数———————————————————————————————12 十九、NOT函数———————————————————————————————13 二十、OR函数————————————————————————————————13 二十一、COUNT函数—————————————————————————————14 二十二、MAX函数——————————————————————————————15 二十三、MIN函数——————————————————————————————15 二十四、SUMIF函数—————————————————————————————16 二十五、OFFSET函数————————————————————————————17 二十六、ROW函数——————————————————————————————20 二十七、INDEX 函数————————————————————————————21 二十八、LARGE函数—————————————————————————————22 二十九、ADDRESS函数————————————————————————————23 三十、Choose函数——————————————————————————————24 三十一、HLOOKUP函数———————————————————————————24 三十二、VLOOKUP函数———————————————————————————26 三十三、LOOKUP函数————————————————————————————29 三十四、MATCH函数————————————————————————————29 三十五、HYPERLINK函数——————————————————————————30 三十六、ROUND函数————————————————————————————31 三十七、TREND函数—————————————————————————————32

Excel表格中的一些基本函数使用方法

Excel表格中的一些基本函数使用方法 一、输入三个“=”,回车,得到一条双直线; 二、输入三个“~”,回车,得到一条波浪线; 三、输入三个“*”或“-”或“#”,回车,惊喜多多; 在单元格内输入=now()显示日期 在单元格内输入=CHOOSE(WEEKDAY(I3,2),"星期一","星期二","星期三","星期四","星期五","星期六","星期日") 显示星期几 Excel常用函数大全 1、ABS函数 函数名称:ABS 主要功能:求出相应数字的绝对值。 使用格式:ABS(number) 参数说明:number代表需要求绝对值的数值或引用的单元格。 应用举例:如果在B2单元格中输入公式:=ABS(A2),则在A2单元格中无论输入正数(如100)还是负数(如-100),B2中均显示出正数(如100)。 特别提醒:如果number参数不是数值,而是一些字符(如A等),则B2中返回错误值“#VALUE!”。 2、AND函数 函数名称:AND 主要功能:返回逻辑值:如果所有参数值均为逻辑“真(TRUE)”,则返回逻辑“真(TRUE)”,反之返回逻辑“假(FALSE)”。

使用格式:AND(logical1,logical2, ...) 参数说明:Logical1,Logical2,Logical3……:表示待测试的条件值或表达式,最多这30个。 应用举例:在C5单元格输入公式:=AND(A5>=60,B5>=60),确认。如果C5中返回TRUE,说明A5和B5中的数值均大于等于60,如果返回FALSE,说明A5和B5中的数值至少有一个小于60。 特别提醒:如果指定的逻辑条件参数中包含非逻辑值时,则函数返回错误值“#VALUE!”或“#NAME”。 3、AVERAGE函数 函数名称:AVERAGE 主要功能:求出所有参数的算术平均值。 使用格式:AVERAGE(number1,number2,……) 参数说明:number1,number2,……:需要求平均值的数值或引用单元格(区域),参数不超过30个。 应用举例:在B8单元格中输入公式: =AVERAGE(B7:D7,F7:H7,7,8),确认后,即可求出B7至D7区域、F7至H7区域中的数值和7、8的平均值。 特别提醒:如果引用区域中包含“0”值单元格,则计算在内;如果引用区域中包含空白或字符单元格,则不计算在内。 4、COLUMN 函数 函数名称:COLUMN 主要功能:显示所引用单元格的列标号值。

C#中的日期时间函数

DateTime dt = DateTime.Now; Label1.Text = dt.ToString();//2005-11-5 13:21:25 Label2.Text = dt.ToFileTime().ToString();//127756416859912816 Label3.Text = dt.ToFileTimeUtc().ToString();//127756704859912816 Label4.Text = dt.ToLocalTime().ToString();//2005-11-5 21:21:25 Label5.Text = dt.ToLongDateString().ToString();//2005年11月5日Label6.Text = dt.ToLongTimeString().ToString();//13:21:25 Label7.Text = dt.ToOADate().ToString();//38661.5565508218 Label8.Text = dt.ToShortDateString().ToString();//2005-11-5 Label9.Text = dt.ToShortTimeString().ToString();//13:21 Label10.Text = dt.ToUniversalTime().ToString();//2005-11-5 5:21:25 ?2005-11-5 13:30:28.4412864 Label1.Text = dt.Year.ToString();//2005 Label2.Text = dt.Date.ToString();//2005-11-5 0:00:00 Label3.Text = dt.DayOfWeek.ToString();//Saturday Label4.Text = dt.DayOfYear.ToString();//309 Label5.Text = dt.Hour.ToString();//13 Label6.Text = https://www.sodocs.net/doc/1714681038.html,lisecond.ToString();//441 Label7.Text = dt.Minute.ToString();//30 Label8.Text = dt.Month.ToString();//11 Label9.Text = dt.Second.ToString();//28 Label10.Text = dt.Ticks.ToString();//632667942284412864 Label11.Text = dt.TimeOfDay.ToString();//13:30:28.4412864 Label1.Text = dt.ToString();//2005-11-5 13:47:04 Label2.Text = dt.AddYears(1).ToString();//2006-11-5 13:47:04 Label3.Text = dt.AddDays(1.1).ToString();//2005-11-6 16:11:04 Label4.Text = dt.AddHours(1.1).ToString();//2005-11-5 14:53:04 Label5.Text = dt.AddMilliseconds(1.1).ToString();//2005-11-5 13:47:04 Label6.Text = dt.AddMonths(1).ToString();//2005-12-5 13:47:04 Label7.Text = dt.AddSeconds(1.1).ToString();//2005-11-5 13:47:05

Excel常用函数及使用方法

excel常用函数及使用方法 一、数字处理 (一)取绝对值:=ABS(数字) (二)数字取整:=INT(数字) (三)数字四舍五入:=ROUND(数字,小数位数) 二、判断公式 (一)把公式返回的错误值显示为空: 1、公式:C2=IFERROR(A2/B2,"") 2、说明:如果是错误值则显示为空,否则正常显示。 (二)IF的多条件判断 1、公式:C2=IF(AND(A2<500,B2="未到期"),"补款","") 2、说明:两个条件同时成立用AND,任一个成立用OR函数。 三、统计公式 (一)统计两表重复 1、公式:B2=COUNTIF(Sheet15!A:A,A2) 2、说明:如果返回值大于0说明在另一个表中存在,0则不存在。 (二)统计年龄在30~40之间的员工个数 公式=FREQUENCY(D2:D8,{40,29} (三)统计不重复的总人数 1、公式:C2=SUMPRODUCT(1/COUNTIF(A2:A8,A2:A8)) 2、说明:用COUNTIF统计出每人的出现次数,用1除的方式把出现次数变成分母,然后相加。

(四)按多条件统计平均值 =AVERAGEIFS(D:D,B:B,"财务",C:C,"大专") (五)中国式排名公式 =SUMPRODUCT(($D$4:$D$9>=D4)*(1/COUNTIF(D$4:D$9,D$4:D$9))) 四、求和公式 (一)隔列求和 1、公式:H3=SUMIF($A$2:$G$2,H$2,A3:G3) 或=SUMPRODUCT((MOD(COLUMN(B3:G3),2)=0)*B3:G3) 2、说明:如果标题行没有规则用第2个公式 (二)单条件求和 1、公式:F2=SUMIF(A:A,E2,C:C) 2、说明:SUMIF函数的基本用法 (三)单条件模糊求和 说明:如果需要进行模糊求和,就需要掌握通配符的使用,其中星号是表示任意多个字符,如"*A*"就表示a前和后有任意多个字符,即包含A。 (四)多条求模糊求和 1、公式:=SUMIFS(C2:C7,A2:A7,A11&"*",B2:B7,B11) 2、说明:在sumifs中可以使用通配符* (五)多表相同位置求和 1、公式:=SUM(Sheet1:Sheet19!B2) 2、说明:在表中间删除或添加表后,公式结果会自动更新。

Excel常用函数的使用方法

1、ABS函数 函数名称:ABS 主要功能:求出相应数字的绝对值。 使用格式:ABS(number) 参数说明:number代表需要求绝对值的数值或引用的单元格。 应用举例:如果在B2单元格中输入公式:=ABS(A2),则在A2单元格中无论输入正数(如100)还是负数(如-100),B2中均显示出正数(如100)。 特别提醒:如果number参数不是数值,而是一些字符(如A等),则B2中返回错误值“#VALUE!”。 2、AND函数 函数名称:AND 主要功能:返回逻辑值:如果所有参数值均为逻辑“真(TRUE)”,则返回逻辑“真(TRUE)”,反之返回逻辑“假(FALSE)”。 使用格式:AND(logical1,logical2, ...) 参数说明:Logical1,Logical2,Logical3……:表示待测试的条件值或表达式,最多这30个。 应用举例:在C5单元格输入公式:=AND(A5>=60,B5>=60),确认。如果C5中返回TRUE,说明A5和B5中的数值均大于等于60,如果返回FALSE,说明A5和B5中的数值至少有一个小于60。 特别提醒:如果指定的逻辑条件参数中包含非逻辑值时,则函数返回错误值“#VALUE!”或“#NAME”。 3、AVERAGE函数 函数名称:AVERAGE 主要功能:求出所有参数的算术平均值。 使用格式:AVERAGE(number1,number2,……) 参数说明:number1,number2,……:需要求平均值的数值或引用单元格(区域),参数不超过30个。

应用举例:在B8单元格中输入公式:=AVERAGE(B7:D7,F7:H7,7,8),确认后,即可求出B7至D7区域、F7至H7区域中的数值和7、8的平均值。 特别提醒:如果引用区域中包含“0”值单元格,则计算在内;如果引用区域中包含空白或字符单元格,则不计算在内。 4、COLUMN 函数 函数名称:COLUMN 主要功能:显示所引用单元格的列标号值。 使用格式:COLUMN(reference) 参数说明:reference为引用的单元格。 应用举例:在C11单元格中输入公式:=COLUMN(B11),确认后显示为2(即B列)。 特别提醒:如果在B11单元格中输入公式:=COLUMN(),也显示出2;与之相对应的还有一个返回行标号值的函数——ROW(reference)。 5、CONCATENATE函数 函数名称:CONCATENATE 主要功能:将多个字符文本或单元格中的数据连接在一起,显示在一个单元格中。 使用格式:CONCATENATE(Text1,Text……) 参数说明:Text1、Text2……为需要连接的字符文本或引用的单元格。 应用举例:在C14单元格中输入公式:=CONCATENATE(A14,"@",B14,".com"),确认后,即可将A14单元格中字符、@、B14单元格中的字符和.com连接成一个整体,显示在C14单元格中。 特别提醒:如果参数不是引用的单元格,且为文本格式的,请给参数加上英文状态下的双引号,如果将上述公式改为:=A14&"@"&B14&".com",也能达到相同的目的。 6、COUNTIF函数 函数名称:COUNTIF 主要功能:统计某个单元格区域中符合指定条件的单元格数目。 使用格式:COUNTIF(Range,Criteria) 参数说明:Range代表要统计的单元格区域;Criteria表示指定的条件表达式。

五元素平板电脑刷机升级教程

1、下载五元素平板电脑刷机升级工具 PS:养成良好的习惯,刷机前请先备份 2、安装升级工具 3、驱动(Driver)在此路径中,十分重要请务必牢记 4、Next即可,直至最后完成 安装完升级工具之后, 1.关闭平板电脑:长按关机键,点击确认平板关机为止。 2.①Ifive2S/X2的机子,按住音量+键不放,然后连接MICROUSB数据线。 ②Ifivemini3机子在开机状况下长按开关机键10秒后别松手,等2秒后连接MICROUSB 数据线。 连接好电脑后,Win7/Vista电脑会提示未能成功安装驱动程序,关闭此消息即可,此时可以松开按键。 在桌面或者开始菜单对着计算机/我的电脑点鼠标右键,然后选择管理。 提示:WindowsVista/7系统是计算机,Windows2000/XP系统是我的电脑。 打开管理后,选择设备管理器,这时候可以看到一个未知设备。 对着未知设备点击鼠标右键,然后选择更新驱动程序软件。 点击选择浏览计算机以查找驱动程序软件。注意:不能点击自动搜索。 点击浏览,然后选择驱动程序的位置 位置地址是 在升级工具的文件夹下有一个Driver文件夹,Driver文件夹包含了个版本升级驱动 如果您的电脑系统是64位的,请选择X64,然后再根据操作系统进行选择。 如果您使用的系统是WindowsXP/2000,那么只能选择X86目录下的XP。不区分CPU型号。

如果您的电脑的CPU是X86架构的,请选择X86文件夹,然后再根据您的电脑现在使用的操作系统进行选择: 2000表示Windows2000 Vista表示WindowsVista Win7表示Windows7 Win8表示Windows8 XP表示WindowsXP (PS:如果您也不知道您的电脑是什么X86或者X64,首选X86,若果不成功再换成X64即可) 弹出是否安装这个设备软件,选择安装。 安装完成之后,在设备管理器可以看到RockusbDevice这个驱动。 提示:这时候可以打开升级工具进行升级了。 打开升级工具显示发现一个LOADER设备,点击按钮,选择你之前下载解压出来的img 格式的刷机固件,点击打开。 根据你的电脑系统及所安装的程序不同,显示也会不同。 选择好固件之后就点击修复,如下图: 之后会弹出这个界面,点击是即可 修复正在进行中。 自动修复直至提示修复成功,点确定即可。 修复完成之后点击退出,然后拔下数据线,等待机器自动升级完成。第一次升级结束,等待本机自动开启,时间会有点长因此,请耐心等待。 注:更多精彩教程请关注三联电脑教程栏目,三联电脑办公群:189034526欢迎你的加入

用c++编写计算日期的函数

14.1 分解与抽象 人类解决复杂问题采用的主要策略是“分而治之”,也就是对问题进行分解,然后分别解决各个子问题。著名的计算机科学家Parnas认为,巧妙的分解系统可以有效地系统的状态空间,降低软件系统的复杂性所带来的影响。对于复杂的软件系统,可以逐个将它分解为越来越小的组成部分,直至不能分解为止。这样在小的分解层次上,人就很容易理解并实现了。当所有小的问题解决完毕,整个大的系统也就解决完毕了。 在分解过程中会分解出很多类似的小问题,他们的解决方式是一样的,因而可以把这些小问题,抽象出来,只需要给出一个实现即可,凡是需要用到该问题时直接使用即可。 案例日期运算 给定日期由年、月、日(三个整数,年的取值在1970-2050之间)组成,完成以下功能: (1)判断给定日期的合法性; (2)计算两个日期相差的天数; (3)计算一个日期加上一个整数后对应的日期; (4)计算一个日期减去一个整数后对应的日期; (5)计算一个日期是星期几。 针对这个问题,很自然想到本例分解为5个模块,如图14.1所示。 图14.1日期计算功能分解图 仔细分析每一个模块的功能的具体流程: 1. 判断给定日期的合法性: 首先判断给定年份是否位于1970到2050之间。然后判断给定月份是否在1到12之间。最后判定日的合法性。判定日的合法性与月份有关,还涉及到闰年问题。当月份为1、3、5、7、8、10、12时,日的有效范围为1到31;当月份为4、6、9、11时,日的有效范围为1到30;当月份为2时,若年为闰年,日的有效范围为1到29;当月份为2时,若年不为闰年,日的有效范围为1到28。

图14.2日期合法性判定盒图 判断日期合法性要要用到判断年份是否为闰年,在图14.2中并未给出实现方法,在图14.3中给出。 图14.3闰年判定盒图 2. 计算两个日期相差的天数 计算日期A (yearA 、monthA 、dayA )和日期B (yearB 、monthB 、dayB )相差天数,假定A 小于B 并且A 和B 不在同一年份,很自然想到把天数分成3段: 2.1 A 日期到A 所在年份12月31日的天数; 2.2 A 之后到B 之前的整年的天数(A 、B 相邻年份这部分没有); 2.3 B 日期所在年份1月1日到B 日期的天数。 A 日期 A 日期12月31日 B 日期 B 日期1月1日 整年部分 整年部分 图14.4日期差分段计算图 若A 小于B 并且A 和B 在同一年份,直接在年内计算。 2.1和2.3都是计算年内的一段时间,并且涉及到闰年问题。2.2计算整年比较容易,但

excel中的vlookup函数的使用方法及注意事项

excel博大精深,其使用中有许多细节的地方需要注意。 vlookup函数的使用,其语法我就不解释了,百度很多,其实我自己也没看懂语法的解释,下面就按照我自己的理解来说说怎么用的。首先,这个函数是将一个表中的数据导入另一个表中,其中这两个表有一列数据是相同项,但是排列顺序不同。举例说明; 表1 表2 将表1中的face量一列导入表2中,但两表中的名称一列的排列顺序是不同的。此时需要使用vlookup函数。 下面介绍vlookup的使用方法。

将鼠标放到表2中的D2单元格上,点击fx,会出现一个对话框,里面有vlookup函数。若在常用函数里面没有,下拉找“查找与引用”,里面有此函数。点确定。表示此函数是在表2中的D2单元格中应用。 此时出现对话框: 在第个格里输入B2,直接用鼠标在表2中点击B2单元格即可。表示需要在查找的对象是表2中的B2单元格中的内容。

然后是第二个格,点表1,用鼠标选择整个表的所有数据。表示要在表1中的B1—C14区域查找表2中的B2单元格中的内容。

第三个格里输入在表2中要导入的列数在表1中的列数的数字。在此例中为C列,其列数数字为2.表示将表1中(B1—C14)区域中查找到的单元格里的内容相对应的列(第2列)中的单元格中的内容(face量列中的数据)导入表2中相应的单元格(D2)。 最后一个格中输入“0”。表示查找不到就出现#N/A。点确定,即出现相应数据,然后下拉复制格式。

当下拉出现这种情况的时候: 其实是其查找区域在下拉过程中随着行的改变而改变了。需要对查找区域做一下固定。其方法为,在选择区域后,在区域前面加“$”号($B$1:$C$14)。

昂达VI30豪华版平板电脑刷机操作说明

升级操作说明 本升级工具在WindowsXP、Vista及Win7系统上可正常运行。 操作步骤: 1.把下载的固件包解压,生成相应文件夹,如下图演示: 2.打开解压后的文件夹,双击文件,生成升级所必需的文件,这一步会自动安装驱动程序,如下图是XP系统下弹出的对话框,请点击“仍然继续” 完成驱动程序的自动安装。 3.找到升级工具文件双击打开,如下图所示: 4.点击上图的“否”关闭用户向导升级,并点击“选择固件”按钮选择本目录下后缀名为.img 文件,如下图:

5.平板电脑先关机,然后长按平板上的M键(屏幕下方三个按键的中间那个键)不放,再通过USB数据线连上电脑,再短按开机键3次,待出现下图界面时,松开M键开始升 级。(注:如果此时弹出安装驱动程序的对话框,请把路径指向本目录下的UsbDriver 文件夹,并按下一步提示完成驱动程序的安装)。 6.点击“是”,再次弹出确认对话框,请选择“是”,如下图所示: 7.大约半分钟左右,显示升级进度条走动界面,如下图所示: 8.当进度条走完以后,出现如下界面时,表示升级成功:

9.此时平板会自动开机(如果平板没有自动开机,可长按开机键重新开机),并进入本机更新界面,完成更新以后进入主界面,升级结束! 注: 1.升级前请备份播放器内存放的有用数据,如果本机插有TF卡,请先拔出TF卡; 2.升级前请仔细阅读此说明,刷机存在风险,操作不当造成播放器无法使用,需联系购机 处返厂作维修处理; 3.驱动程序装完以后,在电脑的设置管理器里显示的文件名为: ,这种是正常现象,表示驱动已安装。 另: 附驱动安装教程: 1、当电脑发现新的设备,并弹出如下图所示窗口时,请选择:从列表或指定位置安装(高 级)这一项: 2、点击下一步按钮,进入驱动程序路径选择界面。勾选“在搜索中包括这个位置”,并点 击右边的“浏览”按钮,如下图:

日期函数使用大全

//今天 DateTime.Now.Date.ToString(); //昨天 DateTime.Now.AddDays(-1).ToString(); //明天 DateTime.Now.AddDays(1).ToString(); //本周第1天及最后1天 (要注意的是这里的每一周是从周日始至周六止) DateTime.Today.AddDays (-(int)DateTime.Today.DayOfWeek).ToString(); DateTime.Today.AddDays (6 -(int)DateTime.Today.DayOfWeek).ToString(); //上周, 一周是7天,上周就是本周再减去7天 DateTime.Today.AddDays (-(int)DateTime.Today.DayOfWeek - 7).ToString(); DateTime.Today.AddDays (6 -(int)DateTime.Today.DayOfWeek - 7).ToString(); //下周 DateTime.Today.AddDays (-(int)DateTime.Today.DayOfWeek + 7).ToString(); DateTime.Today.AddDays (6 -(int)DateTime.Today.DayOfWeek + 7).ToString(); 巧用C#裡ToString的字符格式化 //本月第1天及最后1天 DateTime.Now.ToString("yyyy-MM-01"); DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(1).AddDays(-1).To String(); //上个月第1天及最后1天 DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(-1).ToString(); DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddDays(-1).ToString(); //下个月第1天及最后1天 DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(1).ToString(); DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(2).AddDays(-1).To String(); //今年第1天 DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).ToString(); //今年最后1天 DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(1).AddDays(-1).ToS tring(); //去年第1天及最后1天 DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(-1).ToString(); DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddDays(-1).ToString();

EXCEL中常用函数及使用方法

EXCEL中常用函数及使用方法 Excel函数一共有11类:数据库函数、日期与时间函数、工程函数、财务函数、信息函数、逻辑函数、查询和引用函数、数学和三角函数、统计函数、文本函数以及用户自定义函数。 1.数据库函数 当需要分析数据清单中的数值是否符合特定条件时,可以使用数据库工作表函数。例如,在一个包含销售信息的数据清单中,可以计算出所有销售数值大于1,000 且小于2,500 的行或记录的总数。Microsoft Excel 共有12 个工作表函数用于对存储在数据清单或数据库中的数据进行分析,这些函数的统一名称为Dfunctions,也称为D 函数,每个函数均有三个相同的参数:database、field 和criteria。这些参数指向数据库函数所使用的工作表区域。其中参数database 为工作表上包含数据清单的区域。参数field 为需要汇总的列的标志。参数criteria 为工作表上包含指定条件的区域。 2.日期与时间函数 通过日期与时间函数,可以在公式中分析和处理日期值和时间值。 3.工程函数 工程工作表函数用于工程分析。这类函数中的大多数可分为三种类型:对复数进行处理的函数、在不同的数字系统(如十进制系统、十六进制系统、八进制系统和二进制系统)间进行数值转换的函数、在不同的度量系统中进行数值转换的函数。 4.财务函数 财务函数可以进行一般的财务计算,如确定贷款的支付额、投资的未来值或净现值,以及债券或息票的价值。财务函数中常见的参数: 未来值(fv)--在所有付款发生后的投资或贷款的价值。 期间数(nper)--投资的总支付期间数。 付款(pmt)--对于一项投资或贷款的定期支付数额。 现值(pv)--在投资期初的投资或贷款的价值。例如,贷款的现值为所借入的本金数额。 利率(rate)--投资或贷款的利率或贴现率。 类型(type)--付款期间内进行支付的间隔,如在月初或月末。 5.信息函数 可以使用信息工作表函数确定存储在单元格中的数据的类型。信息函数包含一组称为IS 的工作表函数,在单元格满足条件时返回TRUE。例如,如果单元格包含一个偶数值,ISEVEN 工作表函数返回TRUE。如果需要确定某个单元格区域中是否存在空白单元格,可以使用COUNTBLANK 工作表函数对单元格区域中的空白单元格进行计数,或者使用ISBLANK 工作表函数确定区域中的某个单元格是否为空。 6.逻辑函数 使用逻辑函数可以进行真假值判断,或者进行复合检验。例如,可以使用IF 函数确定条件为真还是假,并由此返回不同的数值。

原道平板电脑升级刷机通用教程

原道平板电脑升级刷机通用教程 准备工作: 电脑一台(笔记本更好,可防止断电) 原道平板电脑一台 USB数据线一条 RK2918驱动文件 RK2918量产工具 固件文件,比如:原道固件.img 原道平板电脑升级刷机通用教程 准备工作: 电脑一台(笔记本更好,可防止断电) 原道平板电脑一台 USB数据线一条 RK2918驱动文件 RK2918量产工具 固件文件,比如:原道固件.img 一、安装驱动 1、关闭原道平板电脑电源。 2、一直按住原道平板电脑(N10 M键N11音量加键,再接电源;N12 M键;N12豪华版按 音量加,N50音量加键;N80音量加键;N90音量减键)。 3、按住原道平板电脑功能键不放手,把USB数据线连接电脑和原道平板电脑两端。 4、电脑上出现安装驱动界面,如下图:

一、安装驱动 1、关闭原道平板电脑电源。 2、一直按住原道平板电脑(N10 M键N11音量加键,再接电源;N12 M键;N50音量加键; N80音量加键;N90音量减键)。 3、按住原道平板电脑功能键不放手,把USB数据线连接电脑和原道平板电脑两端。 4、电脑上出现安装驱动界面,如下图: 选择“从列表或指定位置安装(高级)”,再点击下一步。

选择驱动文件存放目录,笔者这里是D:\RK2918驱动\xp目录,如您的电脑是VISTA或WIN7,就需要选择vista目录或win7目录。驱动文件选择好后,再一次点击下一步。 正在安装驱动文件。

驱动安装完毕,点击完成即可。 二、打开刷机升级工具 找到RK29量产工具压缩包。 解压后得到“RK29量产工具”文件夹。 打开文件夹,双击“29RKBatchTool”应用程序。

日期处理函数

select @bq=cast(year(getdate()) as varchar(4))+'年'+right('0'+cast(month(getdate()) as varchar(2)),2)+'月' select round(convert(money,111325,20)/6,2) select CONVERT(char(100),getdate(),120) convert(char(10),租赁_认租合同.合同起始日期,121) 通常,你需要获得当前日期和计算一些其他的日期,例如,你的程序可能需要判断一个月的第一天或者最后一天。你们大部分人大概都知道怎样把日期进行分割(年、月、日等),然后仅仅用分割出来的年、月、日等放在几个函数中计算出自己所需要的日期!在这篇文章里,我将告诉你如何使用DATEADD和DA TEDIFF函数来计算出在你的程序中可能你要用到的一些不同日期。 在使用本文中的例子之前,你必须注意以下的问题。大部分可能不是所有例子在不同的机器上执行的结果可能不一样,这完全由哪一天是一个星期的第一天这个设置决定。第一天(DA TEFIRST)设定决定了你的系统使用哪一天作为一周的第一天。所有以下的例子都是以星期天作为一周的第一天来建立,也就是第一天设置为7。假如你的第一天设置不一样,你可能需要调整这些例子,使它和不同的第一天设置相符合。你可以通过@@DATEFIRST 函数来检查第一天设置。 为了理解这些例子,我们先复习一下DATEDIFF和DA TEADD函数。DA TEDIFF函数计算两个日期之间的小时、天、周、月、年等时间间隔总数。DA TEADD函数计算一个日期通过给时间间隔加减来获得一个新的日期。要了解更多的DATEDIFF和DATEADD函数以及时间间隔可以阅读微软联机帮助。 使用DATEDIFF和DATEADD函数来计算日期,和本来从当前日期转换到你需要的日期的考虑方法有点不同。你必须从时间间隔这个方面来考虑。比如,从当前日期到你要得到的日期之间有多少时间间隔,或者,从今天到某一天(比如1900-1-1)之间有多少时间间隔,等等。理解怎样着眼于时间间隔有助于你轻松的理解我的不同的日期计算例子。 一个月的第一天 第一个例子,我将告诉你如何从当前日期去这个月的最后一天。请注意:这个例子以及这篇文章中的其他例子都将只使用DA TEDIFF和DATEADD函数来计算我们想要的日期。每一个例子都将通过计算但前的时间间隔,然后进行加减来得到想要计算的日期。 这是计算一个月第一天的SQL 脚本: SELECT DATEADD(mm, DA TEDIFF(mm,0,getdate()), 0) 我们把这个语句分开来看看它是如何工作的。最核心的函数是getdate(),大部分人都知道这

爱魅A76刷机教程

爱魅平板电脑升级/刷机指南(适用于所有爱魅平板电脑)升级前的准备工作: 1、在爱魅官网下载相对应机器的固件并解压 2、升级前请您先将本机里面的重要文件备份好,以免刷机/升级时系统格式化造成数据掉失给您带来不必要的损失和麻烦。升级步骤: 1、打开已下载被解压的升级工具文件夹,选择“LiveSuit 工具”文件夹,双击打开“LiveSuitPack100_ex.exe” 2、双击“LiveSuit.exe ”工具,点击工具上的“选择工具”选项。 3、选择固件文件夹内与本机型相匹配的后缀名为.img固件文件(如您的机型是A90,选择“A90固件”文件夹里的后缀名为.img固件文件) 4、将平板电脑完全关机,然后按住除电源键外任一按键不放,同时用USB线连接电脑和平板,连续按三下电源键后松开按键,这时电脑右下方会出现如下图标: 5、接下来会提示安装驱动程序(第一次升级时电脑可能会出现此提示。)

注:以下升级步骤6-7为安装驱动程序,第一次升级时须先安装驱动程序,以后若在同一电脑的不同USB端口升级时,只需点击“下一步”即可。 6、在弹出如下这一步时请选择“从列表或指定位位置安装”,再点击“下一步”。 7、按如下图中所示选好驱动文件,点“下一步”。当电脑提示“完成安装向导”表示驱动已经装上。如果电脑出现二次安装提示时点“下一步”即可。

8、当您的驱动装好完成后,此时机器进入升级前的状态。请选择“是”。

9、出现如下提示时,请选择“是”。 10、当出现升级进度条时,表示机器正在升级。请耐心等待一下。 11、当出现如下提示表示机器升级完成。点击“确定”机器会自己重新启动。(注:部分机型升级完后要进行屏幕校准后才可进入主界面。)

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