Characterization of large format lithium ion battery exposed to extremely high temperature

Characterization of large format lithium ion battery exposed to extremely high temperature
Characterization of large format lithium ion battery exposed to extremely high temperature

Characterization of large format lithium ion battery exposed to extremely high temperature

Xuning Feng a,b,Jing Sun b,Minggao Ouyang a,*,Xiangming He a,c,Languang Lu a, Xuebing Han a,Mou Fang c,Huei Peng d

a State Key Laboratory of Automotive Safety and Energy,Tsinghua University,Beijing100084,China

b Department of Naval Architecture and Marine Engineering,University of Michigan,Ann Arbor,MI48109,USA

c Institute of Nuclear an

d New Energy Technology,Tsinghua University,Beijing100084,China

d Department of Mechanical Engineering,University of Michigan,Ann Arbor,MI48109,USA

h i g h l i g h t s

Fading mechanisms for large Li-ion battery during a thermal runaway were studied.

EV-ARC test was terminated before thermal runaway to study the fading mechanism.

The separator melting point dictates the reusability of the battery after heating.

Cycled after heating,the lost capacity of the battery may be recovered partially.

Capacity loss was analyzed using ICA and discussed using a mechanistic model.

a r t i c l e i n f o

Article history:

Received24May2014

Received in revised form

2August2014

Accepted22August2014 Available online2September2014

Keywords:

Lithium ion battery

Thermal runaway

High temperature capacity fading Incremental capacity analysis Battery safety a b s t r a c t

This paper provides a study on the characterizations of large format lithium ion battery cells exposed to extreme high temperature but without thermal runaway.A unique test is set up:an extended volume-accelerating rate calorimetry(EV-ARC)test is terminated at a speci?c temperature before thermal runaway happens in the battery.The battery was cooled down after an EV-ARC test with early termi-nation.The performances of the battery before and after the EV-ARC test are investigated in detail.The results show that(a)the melting point of the separator dictates the reusability of the25Ah NCM battery after a near-runaway event.The battery cannot be reused after being heated to140 C or higher because of the exponential rise in ohmic resistance;(b)a battery can lose up to20%of its capacity after being heated to120 C just one time;(c)if a battery is cycled after a thermal event,its lost capacity may be recovered partially.Furthermore,the fading and recovery mechanisms are analyzed by incremental capacity analysis(ICA)and a prognostic/mechanistic model.Model analysis con?rms that the capacity loss at extremely high temperature is caused by the increase of the resistance,the loss of lithium ion(LLI) at the anode and the loss of active material(LAM)at the cathode.

?2014Elsevier B.V.All rights reserved.

1.Introduction

Lithium ion batteries are the prevailing choices to power today's electric vehicles(EV),because of its high energy/power density and long cycle life compared with other choices.However,incidents such as battery?res after crashes have attracted much attention [1e3]and given rise to public concerns about the safety of the lithium ion batteries.Thermal runaway behavior is an important research topic which has been at the center of safety events.

Large format battery is of particular interest because of their increasing popularity in production of electric https://www.360docs.net/doc/d914142715.html,rge format batteries have the advantages of reduced cell number and pack complexity[4],which lead to the improved reliability of a battery pack[5].However,a large format battery is more vulnerable to thermal runaway because it contains more stored energy.Cool-ing is less effective because of its lower surface/volume ratio,which leads to higher non-uniformity of temperature distribution within the cell[5].

Batteries with LiNi x Co y Mn z O2(NCM)cathode are promising for EV applications.NCM cathode material demonstrates higher

*Corresponding author.Tel.:t861062773437;fax:t861062785708.

E-mail addresses:fxn07@https://www.360docs.net/doc/d914142715.html,(X.Feng),ouymg@https://www.360docs.net/doc/d914142715.html, (M.

Ouyang).

Contents lists available at ScienceDirect

Journal of Power Sources

journal h omepage:www.elsevier.co m/lo cate/jp owsou

r

https://www.360docs.net/doc/d914142715.html,/10.1016/j.jpowsour.2014.08.094

0378-7753/?2014Elsevier B.V.All rights reserved.

Journal of Power Sources272(2014)457e467

capacity,lower cost and less toxicity within the family of Li-ion batteries[6,7].In thermal runaway tests,batteries with NCM cathode perform better than those with LiCoO2(LCO)and LiNi0.8-Co0.15Al0.05O2(NCA)do,but worse than those with LiMn2O4(LMO) and LiFePO4(LFP)[8].Nevertheless,the NCM cathode shows better high temperature durability and higher speci?c capacity than LMO and higher energy density than LFP[8].

We have reported the thermal runaway features of large format prismatic lithium ion battery with NCM cathode using extended volume accelerating rate calorimetry(EV-ARC)in Ref.[9].The thermal runaway process for the speci?c NCM large format battery has been divided into6stages based on the general knowledge from those reviews[10e14]of Li-ion battery safety.In Stage I,the capacity fades at high temperature(>50 C).In Stage II,the solid electrolyte interface(SEI)decomposition starts and releases detectable heat if the reaction continues[15e21].And it should be noted that the SEI decomposition will continue to a temperature as high as250 C(ends at Stage IV)[20,21].Losing its protection layer, the lithium intercalated in anode starts to react with the electrolyte [15,17,20e22].In Stage III,the separator melting causes a decrease in temperature rise rate as the temperature goes higher (120 C e140 C).In Stage IV(140 C e240 C),some cathode ma-terials start to react with the electrolyte and release heat[5,23e25], while the NCM cathode seems to be strong enough not to react until the temperature reaches240 C or higher[26e31].

Besides thermal runaway,batteries may experience“near”thermal runaway conditions where they are exposed to extreme temperature beyond the limit set by a battery management system. To understand the safety features of the battery and to characterize the impact of the high temperature exposure on the battery per-formance,we investigate the status of the battery at different speci?c high temperature near thermal runaway point.We try to “freeze”the battery during a thermal runaway test like P.Roeder et al.did in Ref.[32]using an interrupted ARC test to see what the behavior of a large format battery is after being exposed to extreme high temperature before thermal runaway.It is indicated that high temperature capacity fading will happen as reported in Refs.[33e37].Therefore,we can exploit previous mechanistic/ prognostic methods to analyze and quantify the capacity degra-dation of a battery exposed to extremely high temperature.

Capacity degradation for lithium ion battery is mainly caused by the loss of cyclable lithium inventory(LLI)and the loss of active material(LAM)[38e44].As shown in Refs.[42],the LLI at anode happens?rst,followed by the LAM at cathode as temperature rises. The LLI is mainly caused by the SEI decomposition and the anode reaction with electrolyte,while the LAM is mainly caused by the cathode decomposition.To analyze LLI and LAM,a parameterized prognostic and mechanistic model presented in Refs.[38,39,43e50] can be used,whose parameters are linked directly to certain ca-pacity fading mechanisms.In such a prognostic and mechanistic model,the capacity loss can be quanti?ed in simulation by selecting proper stoichiometric coef?cient x and y in Li x C6and Li y Ni a-Co b Mn c O2,respectively[39,43].Moreover,incremental capacity analysis(ICA)has been used to analyze battery aging data and interpret the capacity fading mechanisms in many publications [51e59].

In this paper,we have investigated the characterization of large format lithium ion battery after suffering a short period of high temperature exposure.The battery was heated to an extremely high temperature using EV-ARC then cooled down before it runs into thermal runaway.The voltage drop and internal resistance rise during heating were quanti?ed.The reusability of the25Ah NCM battery was evaluated by its discharge capacity.Scanning electron microscope(SEM)was employed to?nd the in?uence of the melting point of the separator on the reusability of the25Ah NCM battery.The capacity fading mechanisms were analyzed using ICA, and discussed using a prognostic/mechanistic model.

2.Experiment

2.1.An EV-ARC test with early termination

This work is a follow-up work of[9].The battery was heated by an EV-ARC(Fig.1),manufactured by Thermal Hazard Technology?. The functions of the EV-ARC are essentially the same as those pervasively used ARC.A common EV-ARC test also follows the heat-wait-seek method.The difference is that the calorimeter of the EV-ARC is much larger than that of the standard ARC.The selected EV-ARC can hold a large format battery with a capacity of25Ah investigated in this paper.

The25Ah battery employed for the EV-ARC test is a recharge-able LiNi x Co y Mn z O2polymer battery manufactured by AE Energy Co.Ltd.It has LiNi x Co y Mn z O2as its cathode and graphite as its anode.The separator is polyethylene(PE)based with ceramic coating.We have reported differential scanning calorimetry test result on the separator in our previous research in Ref.[9].The detailed material composition of the battery is shown in Fig.2.

Fig.3shows the locations of the thermal couples as reported in Ref.[9].Table1summarizes the setup of all the EV-ARC tests. Battery No.1and No.2were installed with a thermal-couple TC1 inserted inside the battery,as in Ref.[9].Note that our previous research has established that for the EV-ARC test following the heat-wait-seek approach,the maximum temperature difference within the battery does not exceed1 C for97%of the time during a thermal runaway test[9].Therefore,no thermal couple is used for internal temperature measurement in most of our tests.Tempera-ture data measured by thermal couple No.2(TC2),which is representative of the internal temperature of the battery under the uniform temperature distribution condition,is used for thermal analysis in the following sections.

A unique test,which is called EV-ARC test with early termina-tion,is set up to study the fading mechanisms for lithium ion battery exposed to extreme high temperature and“near”runaway conditions.In the EV-ARC test with early termination,the heating process was stopped once the temperature reaches a pre-de?ned value.The battery was pulled out of the chamber and a fan

was Fig.1.Picture of the EV-ARC used for this research.

X.Feng et al./Journal of Power Sources272(2014)457e467 458

used for forced cooling,as shown in Fig.4(a).In such a forced cooling process,the battery was expected to be cooled down to ambient temperature within 90min,and the cooling process has found to be reproducible.

The fading mechanism of the battery heated to different stages in a thermal runaway test can be studied through such a forced cooling.T cool is the terminal temperature of the heating process,and is selected to be within Stage I ~IV of the thermal runaway process as de ?ned in Ref.[9]and shown in Fig.4(b).Here T cool was selected to satisfy T 1 T cool T 3(where T 1and T 3are shown in Fig.4(b))and the selected values are {80 C,90 C,100 C,110 C,120 C,130 C,140 C,160 C}.T 1is the temperature when the temperature rising rate of the battery exceed 0.01 C min à1,which is the detected sensitivity of EV-ARC.In other words,T 1is the temperature when the heat generation of the battery caused by side reactions is detectable.T 3is the onset temperature of thermal runaway,after which the temperature rises exponentially.We choose T 1 T cool T 3in order to investigate the characterization of the battery after being exposed to extremely high temperature but not reached thermal runaway.

Table 1summarizes the setup of the EV-ARC tests with early termination,the tests were repeated for eight batteries with different values of T cool .Note that the voltage was also monitored throughout the EV-ARC test with early termination as in Fig.3(b).A pulse charge/discharge pro ?le (as shown in Fig.4(c))was applied to study the variation of the internal resistance during the entire process,like T.Yoshida et al.did in Ref.[37].Fig.4(c)shows the temperature and voltage curve for one of the EV-ARC tests with early termination.The temperature keeps rising until the cooling starts at 120 C.Meanwhile the voltage drops continuously with symmetric pulse charge/discharge.

Table 1also shows that pulse charge/discharge pro ?le was not conducted on the ?rst two batteries.Battery No.3was tested by different pulse currents.All of the batteries have been charged to full SOC with an initial voltage of 4.17e 4.18V before heating.2.2.The performance test

Performance tests were conducted before and after the ARC tests,with a constant current of 5A (C/5),see Fig.5and Table 2.In Section 3.5,further ICA is performed on those C/5discharge data sets.

3.Results and discussions

3.1.The voltage drop after being heated

Fig.6shows the initial voltage and the terminal voltage for EV-ARC tests that were terminated at different temperatures T cool .

The

Fig.3.Thermal couple placement for the EV-ARC test with early

termination.

Fig.2.The components of the 25Ah NCM battery.

Table 1

Experiment settings for an EV-ARC test with early termination.No.T cool / C With thermal

couple TC 1inside?With pulse

charge/discharge?Pulse

current/A Initial voltage/V 180Y N / 4.1753290Y N / 4.17223100N Y 0.5 4.17474110N Y 0.25 4.17385120N Y 0.25 4.17536130N Y 0.25 4.17607140N Y 0.25 4.17948

160

N

Y

0.25

4.1800

X.Feng et al./Journal of Power Sources 272(2014)457e 467459

terminal voltage drops as heating process is extended and T cool rises.A linear curve ?tting was performed for the terminal voltage in Fig.6.A constant slope d V /d T cool ?à0.002877V K à1can be observed.

3.2.The variation of the internal resistance

As the battery went through the heating process,internal resistance and capacity were both affected.The variation of the

internal resistance was investigated using pulse current charge/discharge pro ?le as shown in Fig.4(c)).The internal resistance R in is de ?ned as the quotient of the average pulse voltage and the pulse current,Eq.(1).D V 1(D V 2)is the pulse voltage rise (drop)shown in Fig.4(c).

R in ?eD V 1tD V 2T=e2D I T(1)

Fig.7shows the variations of battery internal resistance during the heating/cooling process for Experiment No.6in Table 1,where T cool ?130 C.R in rises from 82.7m U to 95.0m U during the heating process.However,R in increases sharply to 214.2m U after the battery was cooled down to ambient.Table 3collects R in before heating,after heating but before cooling,and after cooling.It is interesting

to

Fig.4.A typical EV-ARC test with early

termination.

Fig.5.The performance test pro ?le.

Table 2

Pro ?le for the performance test.Step no.Step name Duration Condition

Cycle no.

1Rest 10min 2Discharge 5A (C/5)until 2.75V 3Rest 90min 4Constant current charge 5A (C/5)until 4.2V 5Constant voltage charge 4.2V until I <0.05A

6Rest 90min 7Cycle,step 2e 6N 8

End

X.Feng et al./Journal of Power Sources 272(2014)457e 467

460

note that no signi ?cant rises were observed towards the end of heating and before the cooling started,while R in displays a sharp rise after the cooling started for T cool !120 C.The PE-based separator inside the battery melts in a range of 120e 140 C as reported in Ref.[9].For T cool ?130 C (140 C),R in after cooling down is shown an increase of 159.0%(210%)of the initial value before heating.How-ever,R in only increases by 14.9%(14.8%)before cooling down.In addition,for T cool ?160 C,R in shows a prominent increase of 1343.8%.Given that the rise of internal resistance only happened after cooling started,it seems that the separator shutdown did not happen at high temperature but was activated by the cool down process.

R in determines how much energy the battery can be re-?lled with a ?xed charging current of I ?5A in this case and how much power the battery can output.Note that the battery should operate within a voltage range of 2.75V e 4.2V (i.e,a maximum voltage difference of 4.2e 2.75?1.45V)de ?ned in the manual of the 25Ah battery provided by the manufacturer,the maximum internal resistance permitted for charge/discharge cycle should be less than 1.45V/5A ?0.290U ?290m U ,considering the current I ?5A in Table 2.Therefore the battery was not reusable after being cooled down from 160 C,as will be further discussed in Section 3.4.

Despite separator melting,the thickness growth of SEI,the battery in ?ation and the electrolyte leakage may all contribute to the increase of R in .First,the lithium intercalated in graphite anode may react with the electrolyte at high temperature [20,21].Such a reaction contributes to SEI reforming that adds up the SEI thickness,

which leads to the internal resistance rise as explained in Ref.[37].Second,note that the solvent used in the 25Ah NCM battery gas-i ?es at around 100e 110 C,which lead to a swell or even a leakage above 110 C.The battery swell can cause a contact loose between the electrodes,leading to an increase of R in .Third,the leaked electrolyte and solvent carried out some of the lithium within the battery,causing a nominal LLI in the analysis.In addition,the leakage may lead to insuf ?cient electrolyte and solvent at some area on the electrode,causing a nominal LAM in the analysis and an increase of R in .

3.3.SEM results for the separator

Further physical characteristics for the ceramic coated PE-based separator are reported here.The separator has two different sides:one looks smooth (Fig.8(a)),the other looks coarse (Fig.8(b)).The two sides can be distinguished by naked eyes.The ceramic is coated on the coarse side.

Scanning electron microscope (SEM)images for the separator were collected and the results reported in Fig.9.The magni ?cation time for the smooth side is 20,000,while for the coarse side is 1000.The endothermic reaction happens within a range of 120e 140 C [9].Therefore,holes can both be seen on the smooth side for the sample before and after heated to 120 C.However,no regular holes can be found on the smooth side after the sample was heated to 140 C,indicating that the internal resistance rose signi ?cantly.3.4.The capacity retention rate

Charge/discharge cycles,as in Table 2,were conducted on the battery after an EV-ARC test with early termination.At ?rst,the charge/discharge cycle number de ?ned for Step 7of Table 2is set to N ?3.The battery could recover part of its lost capacity after a few charge/discharge cycles,as the V-type curve shown in Fig.10.The values of capacity have all been normalized to 100%according to their original values of capacity,as shown in Fig.10.When T cool rises to 110 C or higher,the battery capacity needs more cycles to recover.Consequently,the cycle number was changed to N ?5or more.The battery recovery behaviors (Fig.10)and mechanisms are studied in detail using ICA in the following section.

Fig.11illustrates the recovery behavior of the battery after being heated.The battery preserves at least 60%of its initial capacity after being heated to T cool 120 C.Furthermore,after a recovery pro-cess,the battery retains at least 80%of its original capacity following the heat-up process for T cool 120 C.The capacity loss increases signi ?cantly above 120 C.The increased loss of capacity was due to signi ?cant increase in internal resistance.3.5.The incremental capacity analysis (ICA)

To understand the impact of the heating process on the capacity fading,ICA is employed to analyze the fading mechanisms for an EV-ARC test with early termination,using the method developed in Refs.[51e 59]

.

Fig.6.The voltage before and after an EV-ARC test with early

termination.

Fig.7.The variation of the internal resistance during a typical EV-ARC test with early termination.

Table 3

The internal resistance before and after cooling.Exp.No.T cool / C

R in before heating/m U R in before cooling R in after cooling/m U m U %Rise m U %Rise 4110102.8115.812.6%121.918.6%512034.136.57.0%70.9107.9%613082.795.014.9%214.2159.0%714082.694.814.8%256210.0%8

160

45.2

95.5

111.3%

652.6

1343.8%

X.Feng et al./Journal of Power Sources 272(2014)457e 467

461

Fig.12shows the IC curves for the discharge process of Exper-iment No.1~No.6,representing T cool ?80 C,90 C,100 C,110 C,120 C and 130 C,respectively.Fig.12(a)e (c)compare the IC curves before and after heating,the change is minor for those batteries heated to 80 C e 100 C.Remember that the capacity retention rates for them in Fig.10are 96.9%,94.1%and 89.1%,respectively.Fig.12(d)e (f)show the IC curves for the battery heated to 110 C e 130 C.The shift of the IC curves (marked with black arrow)indicates both the capacity loss and the capacity recovery for the batteries after being heated.The convergence of the IC curves for the last few cycles indicates that after recovery the battery returned to an equilibrium state.Fig.12(g)illustrates the trend of the IC curve for the ?rst discharge cycle after the heat-up and cooling down

process,while Fig.12(h)shows the data of the same batteries but for the last discharge cycles.

Here we exploited a prognostic and mechanistic model to further explain the behavior of the battery after being exposed to “near ”runaway conditions.Similar model-based ICA was done by Dubarry et al.in Ref.[43]with reference made to [38,39,44e 50].The model for the discharge curve is built by Eq.(2),referring to [44].The discharge voltage,V simu (t ),is the difference of the cathode potential V ca (y (t ))and the anode potential V an (x (t ))with an ohmic potential loss of I $R .I ?5A is the discharge current used in the experiment,while R is the average ohmic resistance of the battery throughout the discharge process.

V simu et T?V ca ey et TTàV an ex et TTàI $R

(2)

Fig.8.Two sides of the separator,photos taken from a battery without going through the EV-ARC

test.

Fig.9.SEM images for the

separator.

Fig.10.The capacity recovery behavior after cooling

down.Fig.11.The capacity recovery map.

X.Feng et al./Journal of Power Sources 272(2014)457e 467

462

Fig.12.ICA ?gures.

X.Feng et al./Journal of Power Sources 272(2014)457e 467463

V ca (y (t ))and V an (x (t ))are determined by the cathode and anode materials.V ca (y (t ))varies with y (t ),while V an (x (t ))varies with x (t ).Fig.13(b)and (d)shows the cathode voltage V ca (y )varying with y and the anode voltage V an (x )varying with x used in the model,respectively.A coin cell with NCM/Li electrode was built using a piece of cathode cut from one of the 25Ah NCM batteries to get the cathode voltage V ca (y ).The anode OCV shown in Fig.13(d)is consistent with that in Refs.[44,60].

Let y (t )and x (t )represent the state of charge (SOC)of the cathode and the anode,respectively.At the beginning of discharge,the cathode is at its low SOC (y /0)and the anode in its high SOC (x /1).As the discharge process goes on,y (t )and x (t )will change proportionally to the current I according to Eqs.(3)and (4),where Q ca and Q an are the capacity for the cathode and anode,respectively.y 0and x 0denote the initial value for y (t ?0)and x (t ?0)in the discharge process.

y et T?y 0t

I Q ca $t (3)

x et T?x 0àI Q an

$t (4)

By setting proper values of {Q ca ?27.55Ah,Q an ?32.93Ah,y 0?0.0037,x 0?0.8805,R ?12.3m U },we can get a good ?t of the mechanistic model with the experimental data,as shown in Fig.14(a).The IC curve derived by the model can also ?t well with that derived from the experimental data,Fig.14(b).

The peaks seen in the IC curve re ?ect different phases in cath-ode/anode during discharging [53,54].The cathode has three peaks marked as ①,②,③in Fig.13(a),while the anode has three peaks marked as I,II,III in Fig.13(c).The peaks are also re ?ected in the IC curve derived by the model,as shown in Fig.14(b).

Fig.15shows the in ?uences of the model parameters on the shapes of IC curves.The characteristics of the IC curve change caused by speci ?c parameter change have been de ?ned as abbre-viations in Table 4.Fig.15(a)and (b)show that the IC curve will maintain its shape and shift to lower voltage as R increases (marked as R [).The IC curve shift to the lower (higher)voltage is marked as SL (SH)in Table 4.Fig.15(c)and (d)show that when Q ca decreases (marked as Q ca Y ),the height of peak ①,②and ③drop and the location of the peak ①move to higher voltage.The peak value drop of ①,②or ③is marked as P1Y ,P2Y and P3Y ,respectively,as in Table 4.The location move to the higher voltage of peak ①is marked as P1/in Table 4.Fig.15(e)and (f)show that when Q an decreases (marked as Q an Y ),peak ①,②drop then disappear.The peaks ③tII and ③tI form an M-type in the IC curve when Q an decreases to 40%or less of its original value.The drop and disappear behavior of the peak ①and ②is marked as P1Y -D and P2Y -D,respectively,as in Table 4.The appearance (disappearance)of the M-type in IC curve is marked as MA (MD)in Table 4.Fig.15(g)and (h)show that when y 0increases (marked as y 0[),peak ③and III disappear.The peak locations tend to converge to 3.6V.The disappearance of peak ③is marked as P3Y -D as in Table 4.The convergence for the peak locations is marked as SC as in Table 4.Fig.15(i)and (j)show that when x 0decreases (marked as x 0Y ),peak ①,②and I drop then disappear.And peak ③tIII and ③tII form an M-type in the IC curve when x 0is less than 0.4.A plateau can be seen <3.5V,which is a unique characteristic caused by the decrease of x 0.The plateau rising at voltage lower than 3.5V is de ?ned as PL [marked in Table 4.

Table 5concludes the characteristics of the IC curves for different degradation (recovery)mechanisms shown in Fig.15

.

Fig.13.The OCV and IC curve for the cathode and anode used in the model (a)IC for cathode,(b)OCV for cathode,(c)IC for anode,(d)OCV for

anode.

Fig.14.Validation of the model,(a)validation of the voltage,(b)validation of the IC.

X.Feng et al./Journal of Power Sources 272(2014)457e 467

464

Characteristics of the IC curve changes from the before-heating cycle to the ?rst discharge cycle after cooling for T cool ?120 C (Fig.12(e))and T cool ?130 C (Fig.12(f))have been collected in Table 6.The degradation mechanism can be inferred comparing with the characteristics of the IC curves listed in Tables 5and 6.During high temperature exposure,the R [and the x 0Y can be con ?rmed,because only the R [can cause SL,and only the x 0Y can cause PL [,see Table 5.The x 0Y indicates the LLI at the anode,as discussed in Refs.[38-44].An M-type IC curve can be seen for the ?rst discharge cycle of the battery with T cool ?130 C (MA).The MA can be caused by both the Q an Y and

the x 0Y ,see Table 5.However,the Q an Y is less likely to happen,because the anode active material does not decompose at T <160 C.

LAM at cathode as reported in Refs.[7,61]can be inferred using the information on IC in Tables 5and 6.The Q ca Y and the y 0[,which both represent LAM at cathode,can both lead to P3Y while other parameters cannot.Therefore P3Y shown in Table 6can be caused by either Q ca Y or y 0[.However,a big y 0[is less likely to happen,because a big y 0[will cause P3Y -D according to Table 5,while peak ③can still be seen in the IC derived from experiment

results.

Fig.15.The in ?uence of the parameters used in the mechanistic model on the IC curves.

X.Feng et al./Journal of Power Sources 272(2014)457e 467465

The recovery characteristics of the IC variation from the ?rst cycle after cooling to the last cycle after cooling for T cool ?120 C (Fig.12(e))and T cool ?130 C (Fig.12(f))can also be inferred from Tables 5and 6.SH during recovery indicates the R Y ,while the disappearance of M-type (MD)indicates x 0[during the capacity recovery process.Meanwhile,P2[and P3[indicate a recovery of the active material loss at the

cathode.

Fig.15.(continued ).

Table 4

Descriptions for the abbreviations used in Tables 5and 6.Abbreviations of characteristics Descriptions

Curve shift

SL (SH)The peak locations in the IC

curve shift to lower (higher)voltage.SC

The peak locations in the IC curve converge to center.

For peak ①

P1Y (P1[)The height of peak ①drops (rises).P1Y -D The height of peak ①drops,then peak ①disappears.

P1/(P1))

The location of peak ①moves to higher (lower)voltage.

For peak ②

P2Y (P2[)The height of peak ②drops (rises).P2Y -D The height of peak ②drops,then peak ②disappears.

For peak ③

P3Y (P3[)The height of peak ③drops (rises).P3Y -D The height of peak ③drops,then peak ③disappears.

M-type

MA (MD)The M-type appears (disappears).

Plateau <3.5V

PL [(PL Y )

A plateau lower than 3.5V rises (drops).

Table 5

Characteristics of the IC curve changes under different degradation mechanisms.Case Characteristics of the IC curve changes Degradation

R [SL

Q ca Y P1Y ,P2Y ,P3Y ,P1/Q an Y P1Y -D,P2Y -D,MA y 0[P3Y -D,SC,P1/

x 0Y P1Y -D,P2Y -D,MA,PL [Recovery

R Y SH

Q ca [P1[,P2[,P3[,P1)Q an [P1[,P2[,MD y 0Y P3[,P1)

x 0[

P1[,P2[,MD,PL Y

Table 6

Characteristics of the IC curve changes for T cool ?120 C and 130 C.Case

Characteristics Degradation T cool ?120 C,change from “before heating ”

to “after 1st cycle ”,Fig.12(e)

SL,PL [,P1Y -D,P2Y ,P3Y

T cool ?130 C,change from “before heating ”to “after 1st cycle ”,Fig.12(f)

SL,PL [,MA,P1Y -D,P2Y ,P3Y Recovery T cool ?120 C,change from “after 1st cycle ”

to “after last cycle ”,Fig.12(e)

SH,P2[,P3[T cool ?130 C,change from “after 1st cycle ”to “after last cycle ”,Fig.12(f)

SH,MD,P2[,P3[

X.Feng et al./Journal of Power Sources 272(2014)457e 467

466

4.Conclusion

A follow-up study of[9]is provided in this paper to analyze the fading mechanisms of a25Ah NCM battery exposed to extreme temperature but without thermal runaway during an EV-ARC test. Series of EV-ARC tests with early termination were conducted by heating the sample battery to several temperature levels below thermal runaway.

Reusability of the batteries after exposed to extreme tempera-tures or near runaway condition is investigated.The range for the terminal temperature that the battery can be exposed to and still remains useful is determined.The experimental data reveal that the melting point of the separator dictates the reusability of the 25Ah NCM battery.The battery capacity may partly recover through several discharge/charge cycles,but some of the capacity loss is permanent.

The capacity fading mechanisms are studied using incremental capacity analysis(ICA).In addition,the fading mechanism and the capacity recovery behavior are analyzed using a mechanistic model. The increase of the resistance,loss of lithium inventory(LLI)in anode and the loss of active material(LAM)in cathode can be con?rmed by comparing the IC curves derived from the experi-mental data with the IC curves derived from the mechanistic model.

Future work will focus on quantifying the capacity loss at the cathode and anode to provide quantitative data to calibrate a thermal-electrochemical model that can predict both the voltage and the temperature simultaneously.

Acknowledgment

This work is funded by US-China Clean Energy Research Center-Clean Vehicle Consortium(CERC-CVC),and the MOST(Ministry of Science and Technology)of China under the contract of No. 2014DFG71590.The?rst author is funded by China Scholarship Council.

The?rst author appreciates the substantial discussions and suggestions by Mr.Caihao Weng and other co-workmates in the RACE Lab.The author would like to thank Mr.Maogang Li(from Thermal Hazard Technology),Mr.Hengwei Liu and Ms.Xiaoyi Xie for the experiment support.Gratitude should be also given to Mr. Jinguo Cheng in Advanced Energy for providing physical data of the battery.

References

[1]Q.S.Wang,P.Ping,X.Zhao,G.Chu,J.Sun,C.Chen,J.Power Sources208(2012)

210e224.

[2]Garrett P.Beauregard,Report of Investigation:Hybrids Plus Plug in Hybrid

Electric Vehicle,eTec,Phoenix AZ,2008.

[3] B.Smith,Chevrolet Volt Battery Incident Overview Report,U.S.Department of

Transportation,National Highway Traf?c Safety Administration,2012,p.1.

[4]K.J.Lee,K.Smith,A.Pesaran,G.H.Kim,J.Power Sources241(2013)20e32.

[5]G.H.Kim,A.Pesaran,R.Spotnitz,J.Power Sources170(2007)476e489.

[6]H.Zheng,Q.Sun,G.Liu,X.Song,V.S.Battaglia,J.Power Sources207(2012)

134e140.

[7]W.Liu,M.Wang,J.Chen,X.Zhang,H.Zhou,J.Electrochem.18(2)(2012)

118e124(in Chinese).

[8] D.H.Doughty,Vehicle Battery Safety Roadmap Guidance,Oct.2012,pp.

65e66.

[9]X.Feng,M.Fang,X.He,M.Ouyang,L.Lu,H.Wang,M.Zhang,J.Power Sources

255(2014)294e301.

[10]R.Spotnitz,J.Franklin,J.Power Sources113(2003)81e100.

[11]T.M.Bandhauer,S.Garimella,T.F.Fuller,J.Electrochem.Soc.158(3)(2011)

1e25.[12] D.Lisbona,T.Snee,Process Saf.Environ.Prot.89(2011)434e442.

[13]J.Wen,Y.Yu,C.Chen,Mater.Express2(3)(2012)197e212.

[14]L.Lu,X.Han,J.Li,J.Hua,M.Ouyang,J.Power Sources226(2013)272e288.

[15]M.N.Richard,J.R.Dahn,J.Electrochem.Soc.146(6)(1999)2068e2077.

[16] D.D.Macneil, https://www.360docs.net/doc/d914142715.html,rcher,J.R.Dahn,J.Elecrochem.Soc.146(10)(1999)

3596e3602.

[17]H.Maleki,G.Deng,A.Anani,J.Howard,J.Electrochem.Soc.146(9)(1999)

3224e3229.

[18]M.H.Ryou,J.N.Lee,D.J.Lee,W.Kim,Y.K.Jeong,J.W.Choi,J.Park,Y.M.Lee,

Electrochim.Acta83(2012)259e263.

[19]Q.S.Wang,J.Sun,X.Yan,C.Chen,Thermochim.Acta487(2005)12e16.

[20]M.Zhou,L.Zhao,S.Okada,J.Yamaki,J.Electrochem.Soc.159(1)(2012)

A44e A48.

[21]J.Yamaki,H.Takatsuji,T.Kawamura,M.Egashira,Solid State Ionics148(2002)

241e245.

[22]P.Biensan,B.Simon,J.P.Peres,A.Guibert,M.Broussely,J.M.Bodet,F.Perton,

J.Power Sources81e82(1999)906e912.

[23]Z.Zhang,D.Fouchard,J.R.Rea,J.Power Sources70(1998)16e20.

[24] D.D.Macneil,J.R.Dahn,J.Phys.Chem.A105(2001)4430e4439.

[25]H.Arai,M.Tsuda,K.Saito,M.Hayashi,Y.Sakurai,J.Electrochem.Soc.149(4)

(2002)401e406.

[26]H.Y.Wang,A.D.Tang,K.L.Huang,Chin.J.Chem.29(2011)1583e1588.

[27]H.Kim,M.Kong,K.Kim,I.Kim,H.Gu,J.Power Sources171(2007)917e921.

[28]H.Kim,K.Kim,S.I.Moon,I.Kim,H.Gu,J.Solid State Electrochem.12(2008)

867e872.

[29]I.Belharouak,Y.K.Sun,J.Lin,K.Amine,J.Power Sources123(2003)247e252.

[30]J.Jiang,K.W.Eberman,L.J.Krause,J.R.Dahn,J.Electrochem.Soc.152(3)(2005)

566e569.

[31]Y.H.Chen,Investigation on LiCo1/3Ni1/3Mn1/3O2Cathode Material and Safety

of Lithium-ion Battery,Ph.D Thesis,Tianjin:College of Chemical Engineering, Tianjin University,China,2006,12,pp50,(in Chinese).

[32]P.Roeder,N.Baba,H.D.WiemHoefer,J.Power Sources248(2014)978e987.

[33]K.Takei,K.Kumai,Y.Kobayashi,H.Miyashir,N.Terada,T.Iwahori,T.Tanaka,

J.Power Sources97-98(2001)697e701.

[34]R.D.Ramasamy,R.E.White,B.N.Popov,J.Power Sources141(2005)298e306.

[35]K.Amine,J.Liu,S.Kang,I.Belharouak,Y.Hyung,D.Vissers,G.Henriksen,

J.Power Sources129(2004)14e19.

[36]K.Amine,J.Liu,I.Belharouak,https://www.360docs.net/doc/d914142715.html,mun.7(2005)669e673.

[37]T.Yoshida,M.Takahashi,S.Morikawa,C.Ihara,H.Hatsukawa,T.Shiratsuchi,

J.Yamaki,J.Electrochem.Soc.153(3)(2006)A576e A582.

[38]J.Christensen,J.Newman,J.Electrochem.Soc.105(11)(2003)A1416e A1420.

[39]J.Christensen,J.Newman,J.Electrochem.Soc.152(4)(2005)A818e A829.

[40]Q.Zhang,R.E.White,J.Power Sources173(2007)990e997.

[41]Q.Zhang,R.E.White,J.Power Sources179(2008)785e792.

[42]Q.Zhang,R.E.White,J.Power Sources179(2008)793e798.

[43]M.Dubarry,C.Truchot,B.Y.Liaw,J.Power Sources219(2012)204e216.

[44]X.Han,M.Ouyang,L.Lu,J.Li,Y.Zheng,Z.Li,J.Power Sources251(2014)

38e54.

[45]J.H.Kim,N.Pieczonka,Z.Li,Y.Wu,S.Harris,B.R.Powell,Electrochem.Acta90

(2013)556e562.

[46]K.Honkura,K.Takahashi,T.Horiba,J.Power Sources196(2011)

10141e10147.

[47]H.M.Dahn,A.J.Smith,J.C.Burns,D.A.Stevens,J.R.Dahn,J.Electrochem.Soc.

159(9)(2012)A1405e A1409.

[48]I.Bloom, A.N.Jansen, D.P.Abraham,J.Knuth,S.A.Jones,V.S.Battaglia,

G.L.Herriksen,J.Power Sources139(2005)295e303.

[49]I.Bloom,J.P.Christophersen,K.Gering,J.Power Sources139(2005)304e313.

[50]I.Bloom,L.K.Walker,J.K.Basco,D.P.Abraham,J.P.Christophersen,C.D.Ho,

J.Power Sources195(2010)877e882.

[51]M.Dubarry,V.Svoboda,R.Hwu, B.Y.Liaw,J.Power Sources165(2007)

566e572.

[52]M.Dubarry,V.Svoboda,R.Hwu, B.Y.Liaw,J.Power Sources174(2007)

1121e1125.

[53]M.Dubarry,C.Truchot,M.Cugnet,B.Y.Liaw,K.Gering,S.Sazhin,D.Jamison,

C.Michel bacher,J.Power Sources196(2011)10328e10335.

[54]M.Dubarry, C.Truchot, B.Y.Liaw,K.Gering,S.Sazhin, D.Jamison,

C.Michelbacher,J.Power Sources196(2011)103336e110343.

[55]M.Dubarry,B.Y.Liaw,J.Power Sources194(2009)541e549.

[56]M.Dubarry,B.Y.Liaw,M.S.Chen,S.Chyan,K.Han,W.Sie,S.Wu,J.Power

Sources196(2011)3420e3425.

[57] C.Weng,Y.Cui,J.Sun,H.Peng,J.Power Sources235(2013)36e44.

[58] C.Weng,J.Sun,H.Peng,J.Power Sources258(2014)228e237.

[59]X.Feng,J.Li,M.Ouyang,L.Lu,J.Li,X.He,J.Power Sources232(2013)

209e218.

[60]T.Ohzuku,Y.Iwakoshi,K.Sawai,J.Electrochem.Soc.140(9)(1993)

2490e2498.

[61]Y.K.Sun,S.T.Myung,C.S.Yoon,D.W.Kim,Electrochem.Solid State Lett.12(8)

(2009)A163e A166.

X.Feng et al./Journal of Power Sources272(2014)457e467467

Proe中的常用函数关系

Proe中的部分函数关系 一、函数关系 sin 正弦Cos 余弦tan 正切asin 反正弦acos 反余弦atan 反正切sinh 双曲线余弦cosh 双曲线正弦tanh 双曲线正切spar 平方根exp e的幂方根abs 绝对值log 以10为底的对数ln 自然对数 ceil 不小于其值的最小整数floor 不超过其值的最大整数 二、齿轮公式 alpha=20 m=2 z=30 c=0.25 ha=1 db=m*z*cos(alpha) r=(db/2)/cos(t*50) theta=(180/pi)*tan(t*50)-t*50 z=0 三、蜗杆的公式da=8为蜗杆外径m=0.8 为模数angle=20压力角 L=30长度q直径系数d分度圆直径f齿根圆直径n实数

其中之间的关系 q=da/m-2 d=q*m df=(q-2.4)*m n=ceil(2*l/(pi*m)) 在可变剖面扫描的时候运用公式sd4=trajpar*360*n 在扫描切口的时候绘制此图形,其中红色的高的计算公式是sd5=pi*m/2 五、方向盘的公式sd4=sd6*(1-(sin(trajpar*360*36)+1)/8) 其中sd4是sd6的(3/4或者7/8),sin(trajpar*360*36的意思是转过360度且有36个振幅似的 六、凸轮的公式sd5=evalgraph("cam2",trajpar*360) r=150 theta=t*360 z=9*sin(10*t*360) 在方向按sin(10*t*360)的函数关系,9为高的9倍10为10个振幅似的 七、锥齿轮公式 m=4模数z =50齿轮齿数z-am=40与之啮合的齿轮齿数angle=20压力角b=30齿厚long分度圆锥角 d分度圆直径da齿顶圆直径df齿根圆直径db基圆直径关系:long=atan(z/z-am) d=m*z da=d+2*m*cos(long)

衣服尺码尺寸对应表

说明:裤子上的尺码,如160/68A,160是指身高,68表示腰围,A代表体型;体型分类:A正常体B偏胖体C肥胖体Y偏瘦体 说明:34号到38号是属于超大尺寸的超大号牛仔裤 尺寸、裤长测量方法: 1、腰围 裤子腰围:两边腰围接缝处围量一周;净腰围:在单裤外沿腰间最细处围量一周,按需要加放尺寸; 2、臀围 裤子臀围:由腰口往下,裤子最宽处横向围量一周;净臀围:沿臀部最丰满处平衡围量一周,按需要加放松度;

3、裤长 由腰口往下到裤子最底边的距离;休闲裤、牛仔裤裤长不含脚口贴边,脚口贴边另预留3-4CM长供自行缭边使用; 4、净裤长 由腰口到您裤子的实际缭边处的距离;男士净裤长标准测量长度在:皮鞋鞋帮 身高裤长对照表 身高(CM) 裤长(市尺) 裤长(CM) 160~165 2尺9寸97 165~170 3尺100 170~175 3尺1寸103 175~180 3尺2寸107 180~185 3尺3寸110 男式衬衫尺码对照表单位(厘米) 身高/胸围尺码身高腰围肩宽胸围衣长袖长165/84Y 37165 94 44 104 78 58 165/88Y 38165 98 45 108 78 59.5

170/92Y 39170 102 46 112 79 59.5 175/96Y 40175 106 47 115 79 60.5 175/100Y 41175 110 48 118 80 60.5 180/104Y 42180 113 49 121 81 61.5 180/108Y 43180 116 50 124 81 61.5 185/112Y 44185 119 51 126 82 62.5 185/116Y 45185 122 51 128 82 62.5 185/120Y 46185 124 52 130 83 64 注:(身高/胸围)为净尺寸。一般实际紧腰围和成衣相差12~22厘米。 女式衬衫尺码对照表单位(厘米) 规格尺码肩宽胸围腰围下摆围后衣长短袖长短袖口长袖长长袖口155/80 3537 86 71 89 56 19.5 30 54 21 155/83 3638 89 74 92 57 19.5 31 55 22 160/86 3739 92 77 95 58 20 32 56 22 160/89 3840 95 80 98 59 20 33 56 23 165/92 3941 98 83 101 60 20.5 34 57 23 165/95 4042 101 86 104 61 20.5 35 57 24 170/98 4143 104 89 107 62 21 36 58 24 170/101 4244 107 92 110 63 21 37 58 25 173/104 4345 110 95 113 64 21.5 38 59 25 注:尺寸表中的规格表示为(身高/胸围净尺寸)的参考尺寸。 男士西服尺码对照表单位(厘米)

毕业设计外文翻译附原文

外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华

外文资料名称: Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处:Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件: 1.外文资料翻译译文 2.外文原文

应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金,洪城铱昌,宰瑾李, 刘链柱译 摘要:旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率,压降,并切成尺寸被粒度对应于分级收集的50%的效率进行了研究。颗粒切成大小降低入口面积,体直径,减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法,用于收集在家庭中产生的粉尘。 摘要及关键词:吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子,工作场所,或其他建筑,因此,室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物,毒物,食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤,预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中,吸入压力下降说唱空转成比例地清洗的时间,以及纸过滤器也应定期更换,由于压力下降,气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形,在粗颗粒(>2.0微米)模式为主要的外部来源,如风吹尘,海盐喷雾,火山,从工厂直接排放和车辆废气排放,以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式,典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克,可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。

男装、女装衣服尺码对照表

男装、女装衣服尺码对照表
1、男装尺码对照表
身高 (cm)
衬衣尺码 (领围 cm)
西服尺码夹克尺码西裤尺码
(肩宽 (胸围 (腰围
cm)
cm)
cm)
西(腰裤围尺寸码) T
恤尺码
毛衣尺码 内裤尺码 统计比例
160 37(S) 44(S) 80(S) 72
28
S
S
S
0
165 38(M) 46(M) 84(M) 74,76 29
M
M
M
1
170 39(L) 48(L) 88(S) 78
30
L
L
L
2
175 40(XL) 50(XL) 92(M) 80
31
XL
XL
XL
3
180 41(2XL) 52(2XL) 96(L) 82
32
2XL
2XL
2XL
3
185 42(3XL) 54(3XL) 100(XL) 84,86 33
3XL
3XL
3XL
2
190 43(4XL) 56(4XL) 104(4XL) 88
34
4XL
4XL
4XL
1
195 44(5XL)
90
35
5XL
5XL
5XL
0
2、衬衫尺寸(除个别款尺寸,买前询问)
平铺尺寸 M
XL
胸围 97cm 99cm 101cm
肩宽 43cm 44cm 45cm
衣长 67cm 68cm 69cm
袖长 62cm 64cm 65cm
3、裤装尺码为: 26 代表腰围为:“尺” 28 代表腰围为:“尺” 30 代表腰围为:“尺” 32 代表腰围为:“尺” 34 代表腰围为:“尺” 38 代表腰围为:“尺” 42 代表腰围为:“尺” 50 代表腰围为:“尺” 54 代表腰围为:“尺”
27 代表腰围为:“尺” 29 代表腰围为:“尺” 31 代表腰围为:“尺” 33 代表腰围为:“尺” 36 代表腰围为:“尺” 40 代表腰围为:“尺” 44 代表腰围为:“尺” 52 代表腰围为:“尺”
4.女装尺码对照表
上装尺码
“女上装”尺码对照表(cm)
S
M
L
155/80A
160/84A
165/88A
XL 170/92A

衣服尺码尺寸对应表

裤子尺寸对照表1 裤子尺寸对照表2 说明:裤子上的尺码,如160/68A,160是指身高,68表示腰围,A代表体型;体型分类:A正常体B偏胖体C肥胖体Y偏瘦体 牛仔裤尺码对照表:(以下测量误差在+-2cm) 说明:34号到38号是属于超大尺寸的超大号牛仔裤

尺寸、裤长测量方法: 1、腰围 裤子腰围:两边腰围接缝处围量一周;净腰围:在单裤外沿腰间最细处围量一周,按需要加放尺寸; 2、臀围 裤子臀围:由腰口往下,裤子最宽处横向围量一周;净臀围:沿臀部最丰满处平衡围量一周,按需要加放松度; 3、裤长 由腰口往下到裤子最底边的距离;休闲裤、牛仔裤裤长不含脚口贴边,脚口贴边另预留3-4CM长供自行缭边使用; 4、净裤长 由腰口到您裤子的实际缭边处的距离;男士净裤长标准测量长度在:皮鞋鞋帮和鞋底交接处;

男式衬衫尺码对照表 单位(厘米) 身高/胸围 尺码 身高 腰围 肩宽 胸围 衣长 袖长 165/84Y 37 165 94 44 104 78 58 165/88Y 38 165 98 45 108 78 59.5 170/92Y 39 170 102 46 112 79 59.5 175/96Y 40 175 106 47 115 79 60.5 175/100Y 41 175 110 48 118 80 60.5 180/104Y 42 180 113 49 121 81 61.5 180/108Y 43 180 116 50 124 81 61.5 185/112Y 44 185 119 51 126 82 62.5 185/116Y 45 185 122 51 128 82 62.5 185/120Y 46 185 124 52 130 83 64 注:(身高/胸围)为净尺寸。一般实际紧腰围和成衣相差12~22厘米。

毕业设计(论文)外文资料翻译〔含原文〕

南京理工大学 毕业设计(论文)外文资料翻译 教学点:南京信息职业技术学院 专业:电子信息工程 姓名:陈洁 学号: 014910253034 外文出处:《 Pci System Architecture 》 (用外文写) 附件: 1.外文资料翻译译文;2.外文原文。 指导教师评语: 该生外文翻译没有基本的语法错误,用词准确,没 有重要误译,忠实原文;译文通顺,条理清楚,数量与 质量上达到了本科水平。 签名: 年月日 注:请将该封面与附件装订成册。

附件1:外文资料翻译译文 64位PCI扩展 1.64位数据传送和64位寻址:独立的能力 PCI规范给出了允许64位总线主设备与64位目标实现64位数据传送的机理。在传送的开始,如果回应目标是一个64位或32位设备,64位总线设备会自动识别。如果它是64位设备,达到8个字节(一个4字)可以在每个数据段中传送。假定是一串0等待状态数据段。在33MHz总线速率上可以每秒264兆字节获取(8字节/传送*33百万传送字/秒),在66MHz总线上可以528M字节/秒获取。如果回应目标是32位设备,总线主设备会自动识别并且在下部4位数据通道上(AD[31::00])引导,所以数据指向或来自目标。 规范也定义了64位存储器寻址功能。此功能只用于寻址驻留在4GB地址边界以上的存储器目标。32位和64位总线主设备都可以实现64位寻址。此外,对64位寻址反映的存储器目标(驻留在4GB地址边界上)可以看作32位或64位目标来实现。 注意64位寻址和64位数据传送功能是两种特性,各自独立并且严格区分开来是非常重要的。一个设备可以支持一种、另一种、都支持或都不支持。 2.64位扩展信号 为了支持64位数据传送功能,PCI总线另有39个引脚。 ●REQ64#被64位总线主设备有效表明它想执行64位数据传送操作。REQ64#与FRAME#信号具有相同的时序和间隔。REQ64#信号必须由系统主板上的上拉电阻来支持。当32位总线主设备进行传送时,REQ64#不能又漂移。 ●ACK64#被目标有效以回应被主设备有效的REQ64#(如果目标支持64位数据传送),ACK64#与DEVSEL#具有相同的时序和间隔(但是直到REQ64#被主设备有效,ACK64#才可被有效)。像REQ64#一样,ACK64#信号线也必须由系统主板上的上拉电阻来支持。当32位设备是传送目标时,ACK64#不能漂移。 ●AD[64::32]包含上部4位地址/数据通道。 ●C/BE#[7::4]包含高4位命令/字节使能信号。 ●PAR64是为上部4个AD通道和上部4位C/BE信号线提供偶校验的奇偶校验位。 以下是几小结详细讨论64位数据传送和寻址功能。 3.在32位插入式连接器上的64位卡

男装女装衣服尺码对照表

男装、女装衣服尺码对照表1、男装尺码对照表 2、衬衫尺寸(除个别款尺寸,买前询问)

3、裤装尺码为: 26代表腰围为:“尺” 27代表腰围为:“尺” 28代表腰围为:“尺” 29代表腰围为:“尺” 30代表腰围为:“尺” 31代表腰围为:“尺” 32代表腰围为:“尺” 33代表腰围为:“尺” 34代表腰围为:“尺” 36代表腰围为:“尺” 38代表腰围为:“尺” 40代表腰围为:“尺” 42代表腰围为:“尺” 44代表腰围为:“尺” 50代表腰围为:“尺” 52代表腰围为:“尺” 54代表腰围为:“尺” 4.女装尺码对照表 “女上装”尺码对照表(cm)

“女下装”尺码详细对照表(cm) 其他算法

裤子尺码对照表 26号------1尺9寸臀围2尺632号------2尺6寸臀围3尺2 27号------2尺0寸臀围2尺734号------2尺7寸臀围3尺4 28号------2尺1寸臀围2尺836号------2尺8寸臀围3尺5-6 29号------2尺2寸臀围2尺938号------2尺9寸臀围3尺7-8 30号------2尺3寸臀围3尺040号------3尺0寸臀围3尺9-4尺 31号------2尺4寸臀围3尺142号------3尺1-2寸臀围4尺1-2 牛仔裤尺码对照表 5.尺码换算参照表 女装(外衣、裙装、恤衫、上装、套装) 标准尺码明细 中国 (cm) 160-165 / 84-86 165-170 / 88-90 167-172 / 92-96 168-173 / 98-102 170-176 / 106-110 国际 XS S M L XL

衣服尺寸对照表

衣服尺寸对照表 女款上装 女裤 尺码XL 3XL

女式内裤 女式泳装 女鞋 2尺4 2尺6 2尺7 2尺8 2尺9 3尺 3尺1 (市尺) 尺码 S M L XL 3XL 光脚长度 女裙对应臀围 尺码 XS/32 S/34 M/36 L/38 XL/40 腰围 63-70 70-76 80-86 86-93 93-100

文胸 80,83,85,88,9 85,88,90,93,95,9 90,93,95,98100,1 95,98,100,103,105,1 103,105,108,110,1 胸 女袜胸 68-72(cm) 73-77(cm) 78-82(cm) 83-87(cm) 88-92(cm) 03 08 13 A,B,C,D,DD A,B,C,D,DD,E 型 A,B,C,D,DD,E A,B,C,D,DD,E B,C,D,DD,E 尺 70A,70B,70C 75A,75B,75C, 80A,80B,80C 85A,85B,85C 90B,90C,90D 码 70D,70DD 75D,75DD,75E 80D,80DD,80E 85D,85DD,85E 90DD,90E 英 32A,32B,32C 34A,34B,34C 36A,36B,36C 38A,38B,38C 40B,40C,40D

女式衬衫 数目为12.5公分者为B 罩杯。以此类推计算,即下胸围尺寸为 75公分者,可容许+/-2.5公分的误差,凡 介于72.5?77.5公分者皆可穿75。假设您的下胸围尺寸为 72.5公分,则建议选购75的胸罩而非70,因 为在 穿着时会比较舒适,二来也比较耐穿。 臀围 型号 80-88cm (约 34 85-93cm (约 36 90-98cm (约 38 100-108cm (约 罩杯 【罩杯的尺寸】上胸围尺寸减去下胸围尺寸之数目为 10.0公分者为A 罩杯。上胸围尺寸减去下胸围尺寸之 式 32D,32DD 34D,34DD,34E 36D,36DD,36E 38D,38DD,38E 40DD,40E XL 范围

工程造价外文翻译(有出处)

预测高速公路建设项目最终的预算和时间 摘要 目的——本文的目的是开发模型来预测公路建设项目施工阶段最后的预算和持续的时间。 设计——测算收集告诉公路建设项目,在发展预测模型之前找出影响项目最终的预算和时间,研究内容是基于人工神经网络(ANN)的原理。与预测结果提出的方法进行比较,其精度从当前方法基于挣值。 结果——根据影响因素最后提出了预算和时间,基于人工神经网络的应用原理方法获得的预测结果比当前基于挣值法得到的结果更准确和稳定。 研究局限性/意义——因素影响最终的预算和时间可能不同,如果应用于其他国家,由于该项目数据收集的都是泰国的预测模型,因此,必须重新考虑更好的结果。 实际意义——这项研究为用于高速公路建设项目经理来预测项目最终的预算和时间提供了一个有用的工具,可为结果提供早期预算和进度延误的警告。 创意/价值——用ANN模型来预测最后的预算和时间的高速公路建设项目,开发利用项目数据反映出持续的和季节性周期数据, 在施工阶段可以提供更好的预测结果。 关键词:神经网、建筑业、预测、道路、泰国 文章类型:案例研究 前言 一个建设工程项普遍的目的是为了在时间和在预算内满足既定的质量要求和其他规格。为了实现这个目标,大量的工作在施工过程的管理必须提供且不能没有计划地做成本控制系统。一个控制系统定期收集实际成本和进度数据,然后对比与计划的时间表来衡量工作进展是否提前或落后时间表和强调潜在的问题(泰克兹,1993)。成本和时间是两个关键参数,在建设项目管理和相关参数的研究中扮演着重要的角色,不断提供适当的方法和

工具,使施工经理有效处理一个项目,以实现其在前期建设和在施工阶段的目标。在施工阶段,一个常见的问题要求各方参与一个项目,尤其是一个所有者,最终项目的预算到底是多少?或什么时候该项目能被完成? 在跟踪和控制一个建设项目时,预测项目的性能是非常必要的。目前已经提出了几种方法,如基于挣值技术、模糊逻辑、社会判断理论和神经网络。将挣值法视为一个确定的方法,其一般假设,无论是性能效率可达至报告日期保持不变,或整个项目其余部分将计划超出申报日期(克里斯坦森,1992;弗莱明和坎普曼,2000 ;阿萨班尼,1999;维卡尔等人,2000)。然而,挣值法的基本概念在研究确定潜在的进度延误、成本和进度的差异成本超支的地区。吉布利(1985)利用平均每个成本帐户执行工作的实际成本,也称作单位收入的成本,其标准差来预测项目完工成本。各成本帐户每月的进度是一个平均平稳过程标准偏差,显示预测模型的可靠性,然而,接受的单位成本收益在每个报告期在变化。埃尔丁和休斯(1992)和阿萨班尼(1999)利用分解组成成本的结构来提高预测精度。迪克曼和Al-Tabtabai(1992)基于社会判断理论提出了一个方法,该方法在预测未来的基础上的一组线索,源于人的判断而不是从纯粹的数学算法。有经验的项目经理要求基于社会判断理论方法的使用得到满意的结果。Moselhi等人(2006)应用“模糊逻辑”来预测潜在的成本超支和对建设工程项目的进度延迟。该方法的结果在评估特定时间状态的项目和评价该项目的利润效率有作用。这有助于工程人员所完成的项目时间限制和监控项目预算。Kaastra和博伊德(1996)开发的“人工神经网络”,此网络作为一种有效的预测工具,可以利用过去“模式识别”工作和显示各种影响因素的关系,然后预测未来的发展趋势。罗威等人(2006)开发的成本回归模型能在项目的早期阶段估计建筑成本。总共有41个潜在的独立变量被确定,但只有四个变量:总建筑面积,持续时间,机械设备,和打桩,是线性成本的关键驱动因素,因为它们出现在所有的模型中。模型提出了进一步的洞察了施工成本和预测变量的各种关系。从模型得到的估计结果可以提供早期阶段的造价咨询(威廉姆斯(2003))——最终竞标利用回归模型预测的建设项目成本。 人工神经网络已被广泛用在不同的施工功能中,如估价、计划和产能预测。神经网络建设是Moselhi等人(1991)指出,由Hegazy(1998)开发了一个模型,该模型考虑了项目的外在特征,估计加拿大的公路建设成本: ·项目类型 ·项目范围

衣服尺码对照(最全的一份)

男装、女装衣服尺码对照表 1、男装尺码对照表 身高(cm)衬衣尺码 (领围cm) 西服尺码 (肩宽cm) 夹克尺码 (胸围cm) 西裤尺码 (腰围cm) 西裤尺码 (腰围寸) T恤尺码毛衣尺码内裤尺码统计比例 16037(S)44(S)80(S)7228S S S0 16538(M)46(M)84(M)74,7629M M M1 17039(L)48(L)88(S)7830L L L2 17540(XL)50(XL)92(M)8031XL XL XL3 18041(2XL)52(2XL)96(L)82322XL2XL2XL3 18542(3XL)54(3XL)100(XL)84,86333XL3XL3XL2 19043(4XL)56(4XL)104(4XL)88344XL4XL4XL1 19544(5XL)90355XL5XL5XL0

2、衬衫尺寸(除个别款尺寸,买前询问) 3、裤装尺码为: 26代表腰围为:“尺”27代表腰围为:“尺”28代表腰围为:“尺”29代表腰围为:“尺”30代表腰围为:“尺”31代表腰围为:“尺”32代表腰围为:“尺”33代表腰围为:“尺”34代表腰围为:“尺”36代表腰围为:“尺”38代表腰围为:“尺”40代表腰围为:“尺”42代表腰围为:“尺”44代表腰围为:“尺”50代表腰围为:“尺”52代表腰围为:“尺”54代表腰围为:“尺” 4.女装尺码对照表

“女下装”尺码详细对照表(cm) 其他算法

裤子尺码对照表 26号------1尺9寸臀围2尺6 32号------2尺6寸臀围3尺2 27号------2尺0寸臀围2尺734号------2尺7寸臀围3尺4 28号------2尺1寸臀围2尺836号------2尺8寸臀围3尺5-6 29号------2尺2寸臀围2尺938号------2尺9寸臀围3尺7-8 30号------2尺3寸臀围3尺040号------3尺0寸臀围3尺9-4尺 31号------2尺4寸臀围3尺142号------3尺1-2寸臀围4尺1-2 牛仔裤尺码对照表 5.尺码换算参照表 女装(外衣、裙装、恤衫、上装、套装) 标准尺码明细 中国(cm) 160-165 / 84-86 165-170 / 88-90 167-172 / 92-96 168-173 / 98-102 170-176 / 106-110

高中常用函数性质及图像汇总

高中常用函数性质及图像 一次函数 (一)函数 1、确定函数定义域的方法: (1)关系式为整式时,函数定义域为全体实数; (2)关系式含有分式时,分式的分母不等于零; (3)关系式含有二次根式时,被开放方数大于等于零; (4)关系式中含有指数为零的式子时,底数不等于零; (5)实际问题中,函数定义域还要和实际情况相符合,使之有意义。 (二)一次函数 1、一次函数的定义 一般地,形如y kx b =+(k ,b 是常数,且0k ≠)的函数,叫做一次函数,其中x 是自变量。当0b =时,一次函数y kx =,又叫做正比例函数。 ⑴一次函数的解析式的形式是y kx b =+,要判断一个函数是否是一次函数,就是判断是否能化成以上形式. ⑵当0b =,0k ≠时,y kx =仍是一次函数. ⑶当0b =,0k =时,它不是一次函数. ⑷正比例函数是一次函数的特例,一次函数包括正比例函数. 2、正比例函数及性质 一般地,形如y=kx(k 是常数,k≠0)的函数叫做正比例函数,其中k 叫做比例系数. 注:正比例函数一般形式 y=kx (k 不为零) ① k 不为零 ② x 指数为1 ③ b 取零 当k>0时,直线y=kx 经过三、一象限,从左向右上升,即随x 的增大y 也增大;当k<0时,?直线y=kx 经过二、四象限,从左向右下降,即随x 增大y 反而减小. (1) 解析式:y=kx (k 是常数,k ≠0) (2) 必过点:(0,0)、(1,k ) (3) 走向:k>0时,图像经过一、三象限;k<0时,?图像经过二、四象限 (4) 增减性:k>0,y 随x 的增大而增大;k<0,y 随x 增大而减小 (5) 倾斜度:|k|越大,越接近y 轴;|k|越小,越接近x 轴 3、一次函数及性质 一般地,形如y=kx +b(k,b 是常数,k≠0),那么y 叫做x 的一次函数.当b=0时,y=kx +b 即y=kx ,所以说正比例函数是一种特殊的一次函数. 注:一次函数一般形式 y=kx+b (k 不为零) ① k 不为零 ②x 指数为1 ③ b 取任意实数 一次函数y=kx+b 的图象是经过(0,b )和(- k b ,0)两点的一条直线,我们称它为直线y=kx+b,它可以看作由直线y=kx 平移|b|个单位长度得到.(当b>0时,向上平移;当b<0时,向下平移)

衣服尺寸对照表

衣服尺寸对照表 女款上装 上衣S M L XL XXL XXXL 服装384042444648胸围(cm)78-8182-8586-8990-9394-9798-102腰围(cm)62-6667-7071-7475-7980-8485-89 肩宽(cm)363840424446适合身高(cm)153/157158/162163/167168/172173/177177/180, 女裤 尺码24 26 27 28 29 30 31 对应臀围(市 2尺4 2尺6 2尺7 2尺8 2尺9 3尺3尺1 尺) 对应臀围 80 87 90 93 97 100 103 (cm) 对应腰围(市 1尺8 1尺9 2尺2尺1 2尺2 2尺3 2尺4 尺) 对应腰围 59 63 67 70 74 78 82 (cm) 女式背心 尺码S M L XL 3XL

胸围72-80 79-87 86-94 94-97 98-102 腰围58-64 64-70 69-77 77-85 85-93 臀围82-90 87-95 92-100 97-105 102-110 女式内裤 尺码S M L XL 3XL 型号150-155 155-160 160-165 165-170 170-175 腰围55-61 61-67 67-73 73-79 79-85 臀围80-86 85-93 90-98 95-103 100-108 女式泳装 尺码XS/32 S/34 M/36 L/38 XL/40 腰围63-70 70-76 80-86 86-93 93-100 女鞋 光脚长度 22.0 22.5 23.0 23.5 24.0 24.5 25.0 (cm) 鞋码(中国) 34码35码36码37码38码39码40码 鞋码(美国) 4.5 5 5.5 6 6.5 7 7.5 鞋码(英国) 3.5 4 4.5 5 5.5 6 6.5 女裙 尺码24 26 27 28 29 30 31 对应臀围 2尺4 2尺6 2尺7 2尺8 2尺9 3尺3尺1 (市尺)

外国历史文学外文翻译 (节选)

2100单词,11500英文字符,4300汉字 出处:Do?an E. New Historicism and Renaissance Culture*J+. Ankara üniversitesiDilveTarih-Co?rafyaFakültesiDergisi, 2005, 45(1): 77-95. 原文 NEW HISTORICISM AND RENAISSANCE CULTURE EvrimDogan Although this new form of historicism centers history as the subject of research, it differs from the "old" in its understanding of history. While traditional historicism regards history as "universal," new historicism considers it to be "cultural." According to Jeffrey N. Cox and Larry J.Reynolds, "new" historicism can be differentiated from "old" historicism "by its lack of faith in 'objectivity' and 'permanence' and its stress not upon the direct recreation of the past, but rather the process by which the past is constructed or invented" (1993: 4). This new outlook on history also brings about a new outlook on literature and literary criticism. Traditional literary historicism holds that the proper aim of literary criticism is to attempt to reconstruct the past objectively, whereas new historicism suggests that history is only knowable in the same sense literature is—through subjective interpretation: our understanding of the past is always conducted by our present consciousness’s. Louis Montrose, in his "Professing the Renaissance," lays out that as critics we are historically bound and we may only reconstruct the histories through the filter of our consciousness: Our analyses and our understandings necessarily proceed from our own historically, socially and institutionally shaped vantage points; that the histories we reconstruct are the textual constructs of critics who are, ourselves, historical subjects (1989: 23). For Montrose, contemporary historicism must recognize that "not only the poet but also the critic exists in history" and that the texts are "inscriptions of history" and furthermore that "our comprehension, representation, interpretation of the texts of the past always proceeds by a mixture of estrangement and appropriation.". Montrose suggests that this kind of critical practice constitutes a continuous dialogue between a "poetics" and a "politics" of culture. In Montrose's opinion, the complete recovery of meanings in a diverse historical outlook is considered necessary since older historical criticism is "illusory," in that it attempts to "recover meanings that are in any final or absolute sense authentic, correct, and complete," because scholarship constantly "constructs and delimits" the objects of study and the scholar is "historically positioned vis-a-vis that object:" The practice of a new historical criticism invites rhetorical strategies by which to foreground the constitutive acts of textuality that traditional modes of literary history efface or misrecognize. It also necessitates efforts to historicize the present as well as the past, and to historicize the dialectic between them—those reciprocal historical pressures by which the past has shaped the present and the present reshapes the past. The new historicist outlook on literary criticism is primarily against literary formalism that excludes all considerations external to the "text," and evaluates it in isolation.The preliminary concern of new historicism is to refigure the relationship between texts and the cultural system in which they were produced. In terms of new historicism, a literary text can only be evaluated in its social, historical, and political contexts. Therefore, new historicism renounces the formalist conception of literature as an autonomous aesthetic order that transcends the needs and interests of

Matlab之print,fprint,fscanf,disp函数的用法

print: print函数可以把函数图形保存成图片: minbnd = -4*pi; maxbnd = 4*pi; t = minbnd:0.1*pi:maxbnd; plot(t, sin(t), 'g', 'Linewidth', 2); line([minbnd, maxbnd], [0, 0]); %绘制x轴 axis([-10, 10, -2, 2]) %定义显示的坐标区间:x在(-10,10)之间,y在(-2,2)之间 grid on; title('sin(x)'); xlabel('x'); ylabel('sin(x)'); print('-dpng','sin.png'); %保存为png图片,在Matlab当前的工作目录下 如下: 打开Matlab当前的工作目录下可以看到有sin.png图片了 print('-dpng', 'sin.png')表示保存为png图片,文件名为sin.png,其中第一个参数可以是: -dbmp:保存为bmp格式 -djpeg:保存为jpeg格式 -dpng:保存为png格式 -dpcx:保存为pcx格式 -dpdf:保存为pdf格式 -dtiff:保存为tiff格式

fprintf: fprintf函数可以将数据按指定格式写入到文本文件中: data = [5, 1, 2; 3, 7, 4]; [row, col] = size(data); for i=1:row for j=1:col fprintf('data(%d, %d) = %d\n', i, j, data(i, j)); %直接输出到屏幕;类似于C语言的输出格式end end fprintf(fid, format, data)中的fid表示由fopen函数打开的文件句柄,如果fid 省略,则直接输出在屏幕上,format是字符串形式的输出格式,data是要输出的数据。其中format可以为: %c 单个字符 %d 有符号十进制数(%i也可以) %u 无符号十进制数 %f 浮点数(%8.4f表示对浮点数取8位宽度,同时4位小数) %o 无符号八进制数 %s 字符串 %x 小写a-f的十六进制数 %X 大小a-f的十六进制数 输出到文件: data = [5, 1, 2; 3, 7, 4]; [row, col] = size(data); %求出矩阵data的行数和列数 %加t表示按Windows格式输出换行,即0xOD 0x0A,没有t表示按Linux格式输出换行,即0x0A fid=fopen('test.txt', 'wt'); %打开文件 for i=1:row

【最新推荐】应急法律外文文献翻译原文+译文

文献出处:Thronson P. Toward Comprehensive Reform of America’s Emergency Law Regime [J]. University of Michigan Journal of Law Reform, 2013, 46(2). 原文 TOWARD COMPREHENSIVE REFORM OF AMERICA’S EMERGENCY LAW REGIME Patrick A. Thronson Unbenownst to most Americans, the United States is presently under thirty presidentially declared states of emergency. They confer vast powers on the Executive Branch, including the ability to financially incapacitate any person or organization in the United States, seize control of the nation’s communications infrastructure, mobilize military forces, expand the permissible size of the military without congressional authorization, and extend tours of duty without consent from service personnel. Declared states of emergency may also activate Presidential Emergency Action Documents and other continuity-of-government procedures, which confer powers on the President—such as the unilateral suspension of habeas corpus—that appear fundamentally opposed to the American constitutional order.

相关文档
最新文档