labview畢業(yè)設(shè)計(jì)外文翻譯

1、<p>　　羅蒂莁裊袁蒁蒃蚇艿蒀蚆袃膅葿螈螆肁蒈蒈羈羇肅薀螄袃肄螞羀膂肅莂螂肈膂蒄羈羄膁薇螁袀膀蝿薃羋膀葿衿膄腿薁螞肀膈蚃袇羆膇莃蝕袂芆蒅裊膁芅薇蚈肇芄蝕襖羃芄葿蚇罿芃薂羂裊節(jié)蚄螅膄芁莄羀肀芀蒆螃羆荿薈罿袂莈蟻螁膀莈莀薄膆莇薃螀肂莆蚅蚃羈蒞蒞袈襖莄蕆蟻膃莃蕿袆聿蒃蟻蠆羅蒂莁裊袁蒁蒃蚇艿蒀蚆袃膅葿螈螆肁蒈蒈羈羇肅薀螄袃肄螞羀膂肅莂螂肈膂蒄羈羄膁薇螁袀膀蝿薃羋膀葿衿膄腿薁螞肀膈蚃袇羆膇莃蝕袂芆蒅裊膁芅薇蚈肇芄蝕襖羃芄葿蚇罿芃薂羂裊

2、節(jié)蚄螅膄芁莄羀肀芀蒆螃羆荿薈罿袂莈蟻螁膀莈莀薄膆莇薃螀肂莆蚅蚃羈蒞蒞袈襖莄蕆蟻膃莃蕿袆聿蒃蟻蠆羅蒂莁裊袁蒁蒃蚇艿蒀蚆袃膅葿螈螆肁蒈蒈羈羇肅薀螄袃肄螞羀膂肅莂螂肈膂蒄羈羄膁薇螁袀膀蝿薃羋膀葿衿膄腿薁螞肀膈蚃袇羆膇莃蝕袂芆蒅裊膁芅薇蚈肇芄蝕襖羃芄葿蚇罿芃薂羂裊節(jié)蚄螅膄芁莄羀肀芀蒆螃羆荿薈罿袂莈蟻螁膀莈莀薄膆莇薃螀肂莆蚅蚃羈蒞蒞袈襖莄蕆蟻膃莃蕿袆聿蒃蟻蠆羅蒂莁裊袁蒁蒃蚇艿蒀蚆袃膅葿螈螆肁蒈蒈羈羇肅薀螄袃肄螞羀膂肅莂螂肈膂蒄羈羄膁薇螁袀膀蝿薃羋

3、膀葿衿膄腿薁螞肀膈蚃袇羆膇莃蝕袂芆蒅裊膁芅薇蚈肇芄蝕襖羃芄葿蚇罿芃薂羂裊節(jié)蚄螅膄芁莄羀肀芀蒆螃羆荿薈罿袂莈蟻螁膀莈莀薄膆莇薃螀肂莆蚅蚃羈蒞蒞袈</p><p><b>　　蘭州理工大學(xué)</b></p><p>　　畢 業(yè) 設(shè) 計(jì)（論 文）外 文 參 考 資 料 及 譯 文</p><p>　　譯文題目：基于LabVIEW的壓力開關(guān)測(cè)試系統(tǒng)設(shè)計(jì)

4、 </p><p>　　學(xué)生姓名： 凌施亮 學(xué) 號(hào)： 07260429 </p><p>　　專 業(yè)： 電子信息科學(xué)與技術(shù) </p><p>　　所在學(xué)院： 電氣工程與信息工

5、程學(xué)院 </p><p>　　指導(dǎo)教師： 李建海 </p><p>　　2011年 3月 27 日</p><p>　　外文資料（一）：Labview programming</p><p>　　T

6、he pressure switch test system, involving an important concept: the virtual instrument. Virtual instrument is the United States National Instruments Corporation (NI) out of the concept of modern computer technology and i

7、nstrumentation technology in-depth integration of the product. Virtual Instrument "virtual" There are two levels of meaning: 1. A virtual control panel, two virtual test and measurement and analysis. Virtual in

8、strument is characterized by high-performance, scalability strong lit</p><p>　　LabVIEW, short for Laboratory Virtual Instrument Engineering Workbench, is a programming environment in which you create program

9、s using a graphical notation (connecting functional nodes via wires through which data flows); in this regard, it differs from traditional programming languages like C, C++, or Java, in which you program with text. Howev

10、er, LabVIEW is much more than a programming language. It is an interactive program development and execution system designed for people, like scientists</p><p>　　Using the very powerful graphical programming

11、 language that many LabVIEW users affectionately call "G" (for graphical), LabVIEW can increase your productivity by orders of magnitude. Programs that take weeks or months to write using conventional programmi

12、ng languages can be completed in hours using LabVIEW because it is specifically designed to take measurements, analyze data, and present results to the user. And because LabVIEW has such a versatile graphical user interf

13、ace and is so easy to pro</p><p>　　Labiew feature continuously enriched and powerful, Labiew used for data acquisition and control, data analysis and data representation, so that engineers and scientists to

14、take full advantage of PC functions, quickly and easily complete their own power to make. Labview main features can be summarized as follows: a graphical environment for two instruments into a built-in program compiler,

15、so that run faster three flexible means of four supports multiple debugging platform 5 supports DDE function</p><p>　　Labiew years of development from 1986 to now, has launched a number of different versions

16、 that can support multiple popular operating systems, Labview main course of development are as follows:</p><p>　　1.1983 years in April, Labview Development System in the United States Austin, Texas, the suc

17、cessful development of</p><p>　　2.1985-year in May, NI introduced the Labview Beta test version</p><p>　　3.1986-year in October, NI company officially released the Labview1.0 for Macintosh versi

18、on of the</p><p>　　4.1990-year in January, Labview2.0 came</p><p>　　5.1992-year in August in support of SUN Solaris workstation and PC-Labview version available</p><p>　　6.1993-year

19、 in January, Labview3.0 version is developed</p><p>　　7.1998-year in February, Labview5.0 version available, this version is a milestone in the history of Labview</p><p>　　8.2003 years, Labview7

20、Express and Labview 7 Series start into the market, in the Labview 7 series, introduced a new data type - Dynamic Data Types</p><p>　　9.2005 years, Labview 8 version of the interview, the version of the spec

21、ific distributed, intelligent outstanding features</p><p>　　10.2006, the 20th anniversary edition of Labview 8.20 an interview. 8.21 is the Chinese version of</p><p>　　11.2007-year in August, La

22、bview8.5 available</p><p>　　12.2008-year in August, Labview8.6 version available</p><p>　　After 20 years of continuous innovation, development, Labview to rely on the concept of a new and unique

23、 advantages, and has maintained an efficient and powerful, and open the three basic characteristics, and gradually become the industry standard.</p><p>　　The above describes the characteristics of Labview an

24、d development, described below how the kind of virtual instrument design</p><p>　　Typically, a virtual instrument design steps are as follows:</p><p>　　(1). In the design window, place the front

25、 panel controls, front panel using the tool template development window, the corresponding tools, from the control template and place a good access control is needed to carry out parameter setting control properties, sti

26、ckers text description tag.</p><p>　　(2). In the flow chart editing window, place the nodes, frame, in the flow chart editing window, use the tool template corresponding tools, from a functional template and

27、 put a good access to the required icon, they are the flow chart in the "nodes" , "frame."</p><p>　　(3). The data flow programming, data flow using the connection tool according to the di

28、rection of the port, node, frame in turn connected to data from the source sent to the prescribed purpose terminal operating mode.</p><p>　　(4). Run test, when the completion of step (a), (2), (3), the front

29、 panel procedure and flow chart graphic design program is completed, a virtual instrument has been basically established, whether to achieve the desired functionality, need to run the test. There are two kinds of test me

30、thods.</p><p>　　a. Simulation Test: do not use I / O interface hardware. I needed to run tests on the signal data is from "array" or "signal-generating function," resulting "emulatio

31、n signal."</p><p>　　b. Measured test: it is through the I / O interface to hardware devices, gathering input standard signal, to test the virtual instrument capabilities. Simulation test in experimental

32、 tests carried out prior to the virtual instrument unique advantage because of its repeated testing, debugging, and constantly improve the improvement of virtual instrument is extremely convenient, is a traditional instr

33、ument can not be used in test methods.</p><p>　　(5).debugging techniques, use the toolbar shortcut "Run", "highlight the implementation of", "Step", "Breakpoint set" t

34、o the following steps to program debugging.</p><p>　　a. to identify grammatical errors, if there is a syntax error, then when start the Shortcut Bar "Run" button, the button becomes a broken arrow,

35、 the program can not perform. Mouse click on the button, a list will pop up an error window, the window listed in the wrong item, and then click any one of the listed errors, click the "Find" function button, t

36、hen the error object, or the port will be changed bright.</p><p>　　b. slow tracking program running, use the shortcut in the toolbar's "highlight the implementation of" button, click the button

37、, the button icon becomes highlighted form, and then click "Run" button, the program on a slower speed. The implementation of the code was not grayed out after the implementation of the code highlighting, and d

38、isplay data on the value of the data stream. This allows the data flow, and track the implementation of the procedures.</p><p>　　c. breakpoints and single-step, in order to check the program logic error, you

39、 may want to program a block diagram node in a node implementation. Breakpoint tool to use a certain location in the program to suspend program execution, using probes or single-step ways to view the data.</p><

40、;p>　　d. set the probe, you can view the block diagram by setting the probe to open a connection procedure by a data value.</p><p>　　(6). data observed, when the inspection observations were found to have

41、an error, the mouse click "Highlight Execution" button, and observe the various nodes in the data stream values.</p><p>　　(7). named Save, save the designed I.</p><p>　　翻譯（一）：Labiew的程序

42、設(shè)計(jì)</p><p>　　壓力開關(guān)測(cè)試系統(tǒng)，涉及到一個(gè)重要的概念：虛擬儀器。虛擬儀器是美國(guó)國(guó)家儀器公司（簡(jiǎn)稱NI）退出的概念，是現(xiàn)代計(jì)算機(jī)技術(shù)和儀器技術(shù)深層次結(jié)合的產(chǎn)物。虛擬儀器的“虛擬”有兩個(gè)層面的意思:1.虛擬的控制面板，2虛擬的測(cè)量測(cè)試與分析。虛擬儀器特點(diǎn)是性能高，擴(kuò)展性強(qiáng)，開發(fā)時(shí)間少，無縫集成。NI公司退出一個(gè)專業(yè)圖形化編程軟件來設(shè)計(jì)開發(fā)虛擬儀器，就是Labiew.</p><p>

43、;　　Labview是Laboratory Virtual Instrument Engineering Workbench的英文縮寫，它是一種圖形化的編程環(huán)境，使用圖形化的符號(hào)來創(chuàng)建程序（通過連線把函數(shù)節(jié)點(diǎn)連接起來，數(shù)據(jù)就是在這些連線上流動(dòng)的）；在 這點(diǎn)上，它不同于傳統(tǒng)的文本編程語言像C, C++, 或者Java。然而，LabVIEW不僅僅是一種編程語言，它是專門為那些工作中需要大量編程的工程師和科學(xué)家們?cè)O(shè)計(jì)的一種交互式的程序程開發(fā)和

44、執(zhí)行的系 統(tǒng)。LabVIEW開發(fā)環(huán)境可以工作在裝有Windows, Mac OS X, 或Linu任何一種操作系統(tǒng)的計(jì)算機(jī)上。LabVIEW創(chuàng)建的程序可以在上述平臺(tái)上運(yùn)行，同時(shí)也可以運(yùn)行于Microsoft Pocket PC, Microsoft Windows CE, Palm OS和大量的嵌入式平臺(tái)，包括現(xiàn)場(chǎng)可編程門陣列(FPGAs)，數(shù)字信號(hào)處理器（DSPs）和微處理器。</p><p>　　許多使用功能

45、強(qiáng)大的圖形化編程語言LabVIEW的用戶親切的稱之為“G”語言（取自graphical），LabVIEW能夠讓你的開發(fā)效率提高 幾個(gè)數(shù)量級(jí)。使用傳統(tǒng)語言可能需要幾周或者幾個(gè)月才能完成的程序，如果用LabVIEW編寫，幾個(gè)小時(shí)就能完成，其中一個(gè)原因是LabVIEW是專為用戶 設(shè)計(jì)的，用來進(jìn)行測(cè)量，分析數(shù)據(jù)和顯示結(jié)果。另一個(gè)原因是LabVIEW有豐富的圖形化用戶接口（GUI）,使用這些接口使編程變得很容易。它也非常適合 用來進(jìn)行仿真，表述思

46、想，編寫一般程序，或者講述基本編程概念。</p><p>　　Labiew的功能不斷豐富和強(qiáng)大，Labiew用來進(jìn)行數(shù)據(jù)采集與控制，數(shù)據(jù)分析和數(shù)據(jù)表達(dá)，使工程師和科學(xué)家能充分利用PC的功能，快速簡(jiǎn)便的完成自己的功作。Labview主要特點(diǎn)可以概括如下：1圖形化的儀器變成環(huán)境2內(nèi)置的程序編譯器，使運(yùn)行速度加快3靈活的程序調(diào)試手段4支持多種系統(tǒng)平臺(tái)5支持DDE等功能。</p><p>　　La

47、biew從1986年發(fā)展至今，已經(jīng)推出數(shù)個(gè)不同版本，可以支持多個(gè)目前流行的操作系統(tǒng)，Labview主要發(fā)展歷程如下：</p><p>　　1.1983年4月，Labview開發(fā)系統(tǒng)在美國(guó)德克薩斯州奧斯汀研制成功</p><p>　　2.1985年5月，NI公司推出了Labview Beta測(cè)試版</p><p>　　3.1986年10月，NI公司正式發(fā)布了Labvi

48、ew1.0 for Macintosh版本</p><p>　　4.1990年1月，Labview2.0問世</p><p>　　5.1992年8月，支持SUN Solaris工作站和PC的Labview版本面世</p><p>　　6.1993年1月，Labview3.0版本開發(fā)完成</p><p>　　7.1998年2月，Labview5

49、.0版本面世，該版本是Labview歷史上有一個(gè)里程碑</p><p>　　8.2003年，Labview7Express和Labview 7系列開始推向市場(chǎng)，在Labview 7系列中，引入了新的數(shù)據(jù)類型—?jiǎng)討B(tài)數(shù)據(jù)類型</p><p>　　9.2005年，Labview 8版本面試，該版本具體分布式，智能化的優(yōu)異特性</p><p>　　10.2006年，20周年

50、紀(jì)念版Labview 8.20面試。8.21是中文版本</p><p>　　11.2007年8月，Labview8.5面世</p><p>　　12.2008年8月，Labview8.6版本面世</p><p>　　經(jīng)過20年的持續(xù)創(chuàng)新，發(fā)展，Labview依靠全新的概念和獨(dú)特的優(yōu)勢(shì)，并一直保持著高效和強(qiáng)大和開放這3個(gè)最基本的特征，逐步成為業(yè)界標(biāo)準(zhǔn)。</p&g

51、t;<p>　　上面介紹了Labview的特點(diǎn)與發(fā)展，下面介紹虛擬儀器是怎么樣設(shè)計(jì)的 通常，一個(gè)虛擬儀器的設(shè)計(jì)步驟如下： （1).在前面板上設(shè)計(jì)窗口放置控件，在前面板開發(fā)窗口使用工具模板中的相應(yīng)工具，從控制模板中取用和放置好所需控件，進(jìn)行控件屬性參數(shù)設(shè)置，標(biāo)貼文字說明標(biāo)簽。 （2).在流程圖編輯窗口，放置節(jié)點(diǎn)、圖框，在流程圖編輯窗口，使用工具模板中相應(yīng)工具，從功能模板中取用并放置好所需圖標(biāo)，它們是流程圖中的“

52、節(jié)點(diǎn)”、“圖框”。 （3).數(shù)據(jù)流程編程，使用連線工具按數(shù)據(jù)流的方向?qū)⒍丝?、?jié)點(diǎn)、圖框依次相連，實(shí)現(xiàn)數(shù)據(jù)從源頭按規(guī)定的運(yùn)行方式送到目的終點(diǎn)。 （4).運(yùn)行檢驗(yàn)，當(dāng)完成步驟（1）、（2）、（3）后，前面板程序與流程圖圖形化程序的設(shè)計(jì)完畢，一個(gè)虛擬儀器已經(jīng)基本建立，是否達(dá)到預(yù)期功能，還需運(yùn)行檢驗(yàn)。有如下兩種檢驗(yàn)方式。a.仿真檢驗(yàn)：不使用I/O接口硬件設(shè)備。對(duì)I檢驗(yàn)運(yùn)行所需的信號(hào)數(shù)據(jù)采用由“數(shù)組”或“信號(hào)生成函數(shù)”產(chǎn)生的“仿真信

53、號(hào)”。b.實(shí)測(cè)檢驗(yàn)：它通過I/O接口硬件設(shè)備，采集輸入標(biāo)準(zhǔn)信號(hào)，來檢驗(yàn)虛擬儀器功能。仿真檢驗(yàn)在實(shí)測(cè)檢驗(yàn)之前進(jìn)行，是虛擬儀器所特有的優(yōu)勢(shì)，因?yàn)樗鼘?duì)反復(fù)</p><p>　　外文資料（二）：A Nano-Tuneable Pressure Switch System Design Based On Single Wall Carbon Nanotubes</p><p>　　S.S.Hoss

54、eini Yazdi and M.Mousavi Mashadi Faculty of Mechanical Engineering,University of Tehran, Iran</p><p>　　Abstract:Under hydrostatic pressure, the cross section of a Single Wall Carbon Nanotube(SWNT) reduces un

55、iformly and proportionally to the applied pressure until it reaches to SWNT's first transition pressure.In addition, SWNT kinks,becomes unstable and collapses on a ground plane due to bending loads.This phenomenon is

56、 a function of SWNT diameter. Bending loads can be generated by inducing a voltage between SWNT and a conductive ground plane. Therefore ,by inducing a certain Pull-in voltage rela</p><p>　　Key words:Single

57、wall carbon nanotube, pull-in voltages, electrostatic bending forces, kink, phase transition, transient pressure</p><p>　　INTRODUCTION</p><p>　　Single Wall Carbon Nanotubes(SWNTs) has novel mech

58、anical properties and behaviors which have attracted many considerations and studies recently. Under hydrostatic Pressure, SWNT's cross section is reduced uniformly and proportionally to applied pressure, until it re

59、aches SWNT's first transient pressure. In this case the SWNT physical properties change and its cross section becomes elliptical. This characteristics has been used in previous presented nano pressure sensors by Wu e

60、t al.(2004), When </p><p>　　To overcome the pressure sensing range restriction of the previous introduced switch, in this study, a tuneable pressure switch system has been introduced which can switches with

61、higher resolution using much simpler system. It consists of a fixed ends SWNT and a graphite ground plane which are conductive. When various Pull-in voltage are induced, SWNT collapses on the ground plane only if the rel

62、ative hydrostatic pressures are applied. The upper bound of pressure sensing range of this switch is </p><p>　　TRANSITION PRESSURE</p><p>　　Zang et al.(2004), Sun et al.(2004) and Sood (2004) sh

63、owed that SWNTs under applied hydrostatic pressure encounter phase transition. This phase transition is due to difference between energy which is needed to alter Carbon-Carbon bond length and Carbon-Carbon-Carbon angle.

64、At first stage, the SWNT cross section reduces uniformly and proportionally under pressure, which is the result of Carbon-Carbon bond uniform length reduction. At a certain point, the cross section shape collapses from c

65、ircula</p><p>　　The reason is:</p><p>　　Carbon-Carbon-Carbon angle variation needs much less energy in comparison to Carbon-Carbon bond length variation. Thus, SWNT undergoes a greater deformati

66、on after facing pressure higher than its first transition pressure. As a result, the isotropic SWNT turns into an anisotropic SWNT which is semi-conductive substance. The first SWNT transition pressure is obtained by (Fi

67、g.3):</p><p>　　Where R0 is SWNT initial radius and D is SWNT elastic constant. For SWNTs, D=0.76eV which is obtained by Molecular Dynamics. In consequence, the dimension of Pt1 is:</p><p>　　PULL

68、-IN PHENOMENON</p><p>　　Dequensnes ey al.(2004) has demonstrated when a voltage is include between a SWNT and a conductive ground plane, the SWNT deflects. When the deflection reaches to a certain amount, SW

69、NT becomes unstable and collapses. This phenomenon is called Pull-in and the relative voltage, Pull-in voltage. The applied electrostatic force per length is found by classic capacitance model as:</p><p>　　W

70、here ε0 is vacuum permittivity, V is include voltage, Rnt is SWNT radius and r is SWNT and ground plane distance.</p><p>　　Wang and Varadan(2005) prove that this instability is because of SWNT kink under ben

71、ding conditions, which has been observed by high resolution transmission electron, when the strain energy at the inner wall of the compressive side reaches the critical value. Since stress and strain follow a linear dist

72、ribution in radial direction, it is reasonable to assume that kink instability happens when in-plane strain under uniformly distributed compression. The kink slope being a function of dnt can be f</p><p>　　T

73、hat L is SWNT length, dNT, is its diameter and h is SWNT effective thickness.</p><p>　　DEFINITION OF TUNEABLE PRESSURE SWITCH</p><p>　　By combining the above mentioned concepts about Pull-in phe

74、nomenon and transition pressure of SWNTs, the tuneable pressure switch mechanism can be defined. As it can be seen, from Eq.3, the θer is a function of SWNT diameter. While a hydrostatic pressure is applied on SWNT, its

75、diameter reduces uniformly and proportionally to the applied pressure:</p><p>　　WheredNT0 is SWNT's initial diameter (at zero pressure) and E is its effective young Modulus (Fig.5)</p><p>　　

76、To calculate the Pull-in voltage, elastic and electrostatic domains should be considered. Van der Waals forces are quite small in comparison to electrostatic force; therefore, they are neglected in this study.</p>

77、<p>　　The system obeys the classical beam equation</p><p>　　Which is highly none-linear. Therefore, it has no analytical solution. Without losing the generality, it is possible to use lump model derive

78、d by Dequensenes et al.(2002) which assumes bending electrostatic force distribution is uniform before Pull-in phenomenon happens. The pull-in voltage for a lump model is calcuated by:</p><p>　　That rinit is

79、 the initial distance between SWNT and ground plane and rpl=2rinit/3 is the distance which Pull-in happens.</p><p>　　By considering RNT as a function of applied pressure, the relation between Pull-in voltage

80、 and applied pressure is obtained(Fig.6).</p><p>　　In consequence, the mechanism of suggested pressure switch consists of a both end fixed SWNT, a conductive ground plane and a tuneable voltage source to ind

81、uce voltage between the SWNT and the ground plane(Fig.7).</p><p>　　CONCLUSIONS</p><p>　　In summary, a tuneable pressure switch has been obtained which uses only one SWNT and its mechanism run as

82、 following:</p><p>　　When a Pull-in voltage related to a certain pressure is induced to the system, the SWNT does not kink and does not on the ground plane, until the applied pressure reaches to that certain

83、 amount.When due to the application of pressure and voltage, SWNT collapses on the ground plane, because both of them are conductive, an electric circuit is closed and the switch is considered ON.As a result, its sensing

84、 and switching mechanism is much simpler in comparison to previous presented pressure sensor b</p><p>　　Here for such a typical system, the kink and deflection graphs for two pressure conditions are brought.

85、 The SWNT effective physical properties are as followings, which was calculated by authors based on inter-atomic force field constants for Carbon lattice presented by Leamy(2005);L=27.14nm,dNT0=1.88nm,rinit=6nm,h=0.34nm

86、and Eeffective=1.03nm(Fig.8 and 9).</p><p>　　翻譯（二）：一種基于單壁碳納米管的納米可調(diào)諧壓力開關(guān)系統(tǒng)的設(shè)計(jì)</p><p>　　SSHosseini亞茲迪和M.穆薩維Mashadi機(jī)械工程學(xué)院，德黑蘭大學(xué)，伊朗</p><p>　　摘要：在靜水壓力下，單壁碳納米管（SWNT）的截面按比例均勻減少所施加的壓力，直到它達(dá)到

87、單壁碳納米管的第一個(gè)過渡壓力。此外，單壁碳納米管的扭曲，由于彎曲的通道在水平面上變得不穩(wěn)定和塌陷。這種現(xiàn)象顯示的是單壁碳納米管直徑的函數(shù)。彎曲的載荷可以通過誘導(dǎo)產(chǎn)生在單壁碳納米管和傳導(dǎo)的地平面之間的電壓。因此，通過相對(duì)于一定直徑（壓力）施感一定的吸合電壓，直到所施加的壓力達(dá)到一個(gè)可以引起單壁碳納米管直徑減少的確定的數(shù)值，單壁碳納米管才會(huì)倒塌。I在這種情況下，由于單壁碳納米管在水平面的塌陷，在它們之間的就會(huì)有連接使電路斷開。在這項(xiàng)研究中，

88、這些功能是由于采用一個(gè)可調(diào)諧的壓力開關(guān)。這種壓力開關(guān)與前面提出的一個(gè)相比，只是用一種單壁碳納米管的開關(guān)，是能夠在較高的分辨率下感覺壓力并且有一個(gè)簡(jiǎn)單得多的系統(tǒng)。</p><p>　　關(guān)鍵詞：?jiǎn)伪谔技{米管，吸合電壓，靜電彎曲力，扭結(jié)，相變，瞬態(tài)壓力</p><p><b>　　簡(jiǎn)介 </b></p><p>　　單壁碳納米管（SWNTs）最近以其

89、新穎的機(jī)械性能和面板吸引了眾多的使用者和研究者。在靜水壓力作用下，單壁碳納米管的截面按比例均勻減少所施加的壓力，直到它達(dá)到單壁碳納米管的第一個(gè)短暫的壓力。在這種情況下，單壁碳納米管的物理性質(zhì)的改變并且其截面變成橢圓形。這一特點(diǎn)在以前由吳等人在2004年提出的納米壓力傳感器中已經(jīng)使用過。當(dāng)施加的壓力達(dá)到了單壁碳納米管的過渡壓力，其橫截面形狀將會(huì)變化，使單壁碳納米管變成一個(gè)半導(dǎo)電材料。它的壓力傳感系統(tǒng)有能力感知單壁碳納米管開關(guān)從導(dǎo)電材料的變

90、化到半導(dǎo)電物質(zhì)。因此，以這種方式，壓力傳感器需要許多單壁碳納米管。然而，單壁碳納米管數(shù)量的使用由高等人在1998年提出，當(dāng)單壁碳納米管直徑超過一定限制，其天然的形狀是倒塌的形式。因此，在系統(tǒng)中它們是不可能被使用的。結(jié)論，壓力傳感器只能夠感應(yīng)一定數(shù)值的壓力（單壁碳納米管的過渡壓力）（圖1和2）。 </p><p>　　為了克服以前推出的開關(guān)的壓力感應(yīng)范圍的限制，在這項(xiàng)研究中，一個(gè)可調(diào)諧的可以使用非常簡(jiǎn)單的系統(tǒng)切換較

91、高的分辨率壓力開關(guān)系統(tǒng)已經(jīng)推出。它由一端固定的壁碳納米管和可導(dǎo)電的石墨平面組成。當(dāng)各種吸合電壓的誘導(dǎo)，單壁碳納米管倒塌在地平面上只有相對(duì)靜水壓力得到應(yīng)用。此開關(guān)的傳感壓力范圍的上限是第一個(gè)單壁碳納米管的限制壓力。要了解關(guān)于開關(guān)基本的機(jī)械設(shè)計(jì)，單壁碳納米管過渡壓力和上拉的現(xiàn)象都在后續(xù)部分進(jìn)行闡釋。</p><p><b>　　過渡壓力 </b></p><p>　　臧，

92、孫，蘇德等人在2004年研究表明，單壁碳納米管在靜水壓力下相位發(fā)生變化。這種相變現(xiàn)象是由于需要改變碳碳鍵長(zhǎng)和碳碳碳角度的能量不同。在第一階段，單壁碳納米管在壓力下其橫截面部分統(tǒng)一地均勻地減少，這是碳碳鍵統(tǒng)一長(zhǎng)度減少所致。在某一個(gè)點(diǎn)，橫截面形狀由圓形塌陷成橢圓形。在這種情況下，單壁碳納米管的變形也遠(yuǎn)遠(yuǎn)大于先前的。 </p><p><b>　　理由是： </b></p><

93、p>　　碳碳碳角度的變化與碳碳鍵的長(zhǎng)度變化相比需要少得多的能量的。因此，單壁碳納米管在面對(duì)的壓力高于它的過渡壓力時(shí)經(jīng)歷了一次較大的變形。因此，各向同性的單壁碳納米管變成一個(gè)各向異性的半導(dǎo)電物質(zhì)的單壁碳納米管。第一單壁碳納米管的過渡壓力如（圖3）所示： </p><p>　　R0是單壁碳納米管的初始半徑，D為單壁碳納米管彈性常數(shù)。對(duì)于單壁碳納米管，D= 0.76eV這是由分子動(dòng)力學(xué)獲得。結(jié)論，對(duì)Pt1尺寸是：

94、</p><p><b>　　吸合現(xiàn)象 </b></p><p>　　Dequensnes在2004年已經(jīng)證明當(dāng)單壁碳納米管和導(dǎo)電地平面之間有電壓時(shí)，單壁碳納米管偏轉(zhuǎn)。當(dāng)變形達(dá)到一定量時(shí)，單壁碳納米管變得不穩(wěn)定和塌陷。這種現(xiàn)象被稱為吸合和相對(duì)電壓，稱為吸合電壓。適用于發(fā)現(xiàn)的單位長(zhǎng)度的靜電力經(jīng)典電容模型為： </p><p>　　當(dāng)ε0為真空介電

95、常數(shù)，V為包括電壓，Rnt是單壁碳納米管的半徑，R是單壁碳納米管和地平面的距離。 王和Varadan在2005年證明，這種不穩(wěn)定性是因?yàn)閱伪谔技{米管彎曲扭結(jié)條件下，當(dāng)在壓力側(cè)內(nèi)壁應(yīng)變能量達(dá)到臨界值時(shí)，已經(jīng)被高分辨透射電子器觀察到。當(dāng)壓力和應(yīng)變力在徑向方向呈線性分布，當(dāng)發(fā)生在平面內(nèi)均勻分布下的壓縮應(yīng)變時(shí)，扭結(jié)不穩(wěn)定的假設(shè)是合理的?？梢园l(fā)現(xiàn)扭結(jié)形狀變?yōu)镈NT的函數(shù)： </p><p>　　當(dāng)L是單壁碳納米管的長(zhǎng)度，d

96、NT是其直徑，H是單壁碳納米管和有效厚度。 </p><p>　　可調(diào)諧的定義壓力開關(guān) </p><p>　　通過結(jié)合上述關(guān)于吸合現(xiàn)象和單壁碳納米管的躍遷壓力的概念，可調(diào)諧壓力開關(guān)的結(jié)構(gòu)可以被定義。從圖3可以看出θer是單壁碳納米管直徑的函數(shù)。當(dāng)靜水壓力應(yīng)用到單壁碳納米管，它的直徑按比例均勻減少所施加的壓力： </p><p>　　dNT0是單壁碳納米管的初始直徑（

97、在零壓力）和E是其有效楊氏模量（圖5） </p><p>　　為了計(jì)算上拉電壓，彈性和靜電領(lǐng)域應(yīng)予以考慮。范德華力相比于靜電引力要小的多，因此，他們?cè)谶@項(xiàng)研究中被忽略。 該系統(tǒng)遵循的經(jīng)典線性方程 沒有哪一個(gè)是高度非線性的。因此，它沒有解析解。又不失一般性，可以使用Dequensenes在2002年提出的一次性模型得到，即假設(shè)彎曲靜電力分布均勻，然后吸合現(xiàn)象發(fā)生。上拉電壓一次性模型計(jì)算公式： </p>

98、<p>　　這rinit是單壁碳納米管和地平面之間和RPL = 2rinit / 3的初始距離是吸合發(fā)生的距離。 </p><p>　　通過考慮RNT作為一種施加壓力的函數(shù)，上拉電壓和施加壓力的關(guān)系就能得到（圖6）。 </p><p>　　結(jié)果，建議的壓力開關(guān)的結(jié)構(gòu)由一個(gè)兩端固定的單壁碳納米管組成，一個(gè)導(dǎo)電地平面和可調(diào)諧電壓源包含單壁碳納米管和地平面的電壓（圖7）。 </

99、p><p><b>　　結(jié)論 </b></p><p>　　綜上所述，一個(gè)只使用一個(gè)單壁碳納米管的可調(diào)諧壓力開關(guān)已經(jīng)生產(chǎn)出來，其運(yùn)行機(jī)制如下： </p><p>　　當(dāng)關(guān)于一定的壓力的吸合電壓誘導(dǎo)系統(tǒng)，直到施加的壓力達(dá)到一定數(shù)值，單壁碳納米管才不會(huì)扭結(jié)并且不會(huì)在地平面上。由于壓力和電壓的應(yīng)用，單壁碳納米管在地平面上塌陷，因?yàn)樗麄兌紝?dǎo)電，電路閉合但開

100、關(guān)被認(rèn)為是打開的。結(jié)果，它的感應(yīng)和轉(zhuǎn)換結(jié)構(gòu)與以前的壓力傳感器相比要簡(jiǎn)單得多，因?yàn)橐粋€(gè)復(fù)雜的系統(tǒng)，可以感受到兩種不同導(dǎo)電和半導(dǎo)電材料的差異被消除。最近的系統(tǒng)，也可以在任何愿望的壓力開關(guān)，它是通過決議索取檢測(cè)范圍內(nèi)是（它的壓力感應(yīng)范圍從零和使用單壁碳納米管的壓力是第一次轉(zhuǎn)換）。因此，它不局限于單壁碳納米管的數(shù)量有限的幾個(gè)轉(zhuǎn)變壓力的壓力。決議的電壓誘因，決定了壓力開關(guān)的決議，其中PtV 。</p><p>　　這是一

101、個(gè)典型的系統(tǒng)，兩個(gè)壓力條件下的扭結(jié)和撓度圖被帶到。單壁碳納米管有效的物理性能如下，這是由原子間力的利米提出碳晶格常數(shù)場(chǎng)的作者在2005年計(jì)算的L = 27.14nm，dNT0 = 1.88nm，rinit = 6nm，高= 0.34nm和Eeffective = 1.03nm（圖8和9）。 莃袆袂蒃蒅蠆膁蒂薇裊肇蒁蝕蚇羃蒀葿袃罿肆薂螆裊肆蚄羈膄肅莄螄肀肄蒆羀羆肅薈螂袂膂蟻薅膀膁莀螁肆膀薃薃肂膀蚅衿羈腿蒞螞襖膈蕆袇膃膇蕿蝕聿膆

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