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1.
利用三点弯曲法研究了掺杂和末掺杂碳纳米管薄膜应力诱导电阻的变化。该研究中所用的碳纳米管是用热灯丝化学汽相沉积法合成的。实验结果表明,碳纳米管有显著的应力诱导电阻变化的效应。当应力从0.2GPa增加到1GPa时,膜的电阻相对变化从7%增加到11%,而非掺杂的薄膜电阻变化小于掺杂膜的情况。电阻随应力变化的原因也许是带隙变化(掺杂)和管之间接触电阻变化(非掺杂)所致。  相似文献   

2.
利用三点弯曲法研究了掺杂和末掺杂碳纳米管薄膜应力诱导电阻的变化。该研究中所用的碳纳米管是用热灯丝化学汽相沉积法合成的。实验结果表明 ,碳纳米管有显著的应力诱导电阻变化的效应。当应力从 0 .2GPa增加到 1GPa时 ,膜的电阻相对变化从 7%增加到 11% ,而非掺杂的薄膜电阻变化小于掺杂膜的情况。电阻随应力变化的原因也许是带隙变化 (掺杂 )和管之间接触电阻变化 (非掺杂 )所致  相似文献   

3.
利用三点弯曲法研究了掺杂和末掺杂碳纳米管薄膜应力诱导电阻的变化.该研究中所用的碳纳米管是用热灯丝化学汽相沉积法合成的.实验结果表明,碳纳米管有显著的应力诱导电阻变化的效应.当应力从0.2GPa增加到1GPa时,膜的电阻相对变化从7%增加到11%,而非掺杂的薄膜电阻变化小于掺杂膜的情况.电阻随应力变化的原因也许是带隙变化(掺杂)和管之间接触电阻变化(非掺杂)所致.  相似文献   

4.
研究了多壁碳纳米管的湿敏效应。研究中所用碳纳米管是用热灯丝化学汽相沉积法生长的。实验结果表明,经由化学修饰后碳纳米管的湿敏效应有了极大的增强。化学修饰后碳纳米管在水蒸汽中电阻相对变化达到了300%,而未修饰只有3.25%。本文对其结果进行了分析和讨论。  相似文献   

5.
研究了多壁碳纳米管的湿敏效应。研究中所用碳纳米管是用热灯丝化学汽相沉积法生长的。实验结果表明 ,经由化学修饰后碳纳米管的湿敏效应有了极大的增强。化学修饰后碳纳米管在水蒸汽中电阻相对变化达到了 30 0 % ,而未修饰只有 3.2 5 %。本文对其结果进行了分析和讨论  相似文献   

6.
理论与实验研究发现碳纳米管在流体中存在一种电子拖曳现象,据此原理进行了多壁碳纳米管流体速度传感器的实验研究。实验中所用的碳纳米管是用热灯丝化学气相沉积法制备的。实验结果表明流动液体在多壁碳纳米管中诱导出的电流随流体速度的增加而增加,并与液体中离子浓度和温度密切相关。在室温下,当流体速度从0增加到10^-1m/s时,电流从0增加到51μA。碳纳米管中这种效应可作为一种新型的流体速度传感器。并对所得的结果进行了讨论。  相似文献   

7.
研究了多壁碳纳米管的湿敏效应.研究中所用碳纳米管是用热灯丝化学汽相沉积法生长的.实验结果表明,经由化学修饰后碳纳米管的湿敏效应有了极大的增强.化学修饰后碳纳米管在水蒸汽中电阻相对变化达到了300%,而未修饰只有3.25%.本文对其结果进行了分析和讨论.  相似文献   

8.
基于SU-8胶转子的非接触压电微马达   总被引:2,自引:0,他引:2  
研制了一种非接触压电微马达,通过阻抗分析仪对定子进行扫频测试,确定其共振频率,并且详细介绍了SU-8胶转子制作的工艺流程。利用转速仪比较不同形状和尺寸的转子在调频和调压下的转速,从而确立压电微马达的最优转子。转子半径为6mm,叶片宽度为6mm的三叶片转子转速最高为3569r/min。转子的启动电压和最高电压分别为8V和24V。  相似文献   

9.
转换垂直阵列式碳纳米管基底的研究   总被引:3,自引:1,他引:2  
描述了一种将阵列式排列的碳纳米管膜完整地从沉积基底上逐层分离组装到新基底的技术。用扫描电镜研究了被分离的碳纳米管膜的形貌、黏结层的特点,并且对被分离的膜和膜与新基底的导电特性分别做了测试。电镜形貌分析表明构成碳纳米管膜的碳纳米管在被分离后可以保持原来的形貌,也可以呈弯曲状,这取决于分离膜时作用于膜表面的压力。电阻测试表明膜的表面电阻为10Ω,而膜与基底的电阻在有黏结层条件下小于0.1Ω。  相似文献   

10.
GMR(giant magneto resistance,巨磁电阻)材料是指磁场微弱变化时,会导致某些物体电阻率突然改变的现象,具有极高的磁电阻效应。1988年,首次在纳米结构的Fe/Cr多层膜中发现它的磁电阻效应比铁磁性坡莫合金(磁电阻相对变化室温值约2—3%)大一个数量级.  相似文献   

11.
High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.  相似文献   

12.
In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.  相似文献   

13.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

16.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

17.
This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.  相似文献   

18.
An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.  相似文献   

19.
The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO>6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.  相似文献   

20.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

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