排序方式: 共有53条查询结果,搜索用时 973 毫秒
11.
压电晶体位移特性曲线干涉自动测量方法 总被引:6,自引:3,他引:3
本文提出了压电晶体(PZT)位移物曲线自动干涉测量方法,该方法利用干涉仪把PZT的微位移量转化成干涉条纹相位变化量,通过快速傅里叶变换(FFT)方法自动复原干涉条纹中包含的相位的变化量,从而高精度地检测出PZT的位移特性曲线.根据该方法,利用CCD摄象机、图象板和干涉仪组合成一套光、机、电一体化的微位移自动测试系统,实际测量了我们研制的PZT随电压变化的位移特性曲线.实验表明,该方法原理实现简单,且能实现高精度、自动、实时和动态测量. 相似文献
12.
QIAO LiPing CHAI ChangChun JIN Zhao YANG YinTang MA ZhenYang 《中国科学:物理学 力学 天文学(英文版)》2013,(9):1684-1688
Based on the k.p theory of Luttinger-Kohn and Bir-Pikus,analytical E-k solutions for the valence band of strained wurtzite ZnO materials are obtained.Strain effects on valence band edges and hole effective masses in strained wurtzite ZnO materials are also discussed.In comparison with unstrained ZnO materials,apparent movement of valence band edges such as "light hole band","heavy hole band" and "crystal splitting band" at Γ point is found in strained wurtzite ZnO materials.Moreover,effective masses of "light hole band","heavy hole band" and "crystal splitting band" for strained wurtzite ZnO materials as the function of stress are given.The analytical results can provide a theoretical foundation for the understanding of physics of strained ZnO materials and its applications with the framework for an effective mass theory. 相似文献
13.
<正>We propose a new type of wavelength division demultiplexer composed of a photonic crystal waveguide with asymmetric corrugated exit surface.The focus displacement for different symmetric corrugated surfaces is relative to the intensity of the excited surface mode.By systematically investigating the effects of the parameters of the corrugated surface on the focus shift,we demonstrate an on-axis focus by a photonic crystal waveguide with an asymmetric corrugated exit surface at a specific wavelength.The precise equivalences of surface modes at each side of the exit surface are broken.Thus,for the light source with other wavelengths,the emerging beams are off-axis focused at different directions,similar to the function of a wavelength division demultiplexer. 相似文献
14.
本文介绍了变磁阻式高精度角位移传感器的基本原理及设计特点;着重讨论了用电子计算机进行该类传感器绕组、磁场的联合设计计算以及输出特性和精度的仿真方法;并对影响变磁阻传感器精度的因素以及减小误差的方法进行分析讨论。变磁阻传感器精度的理论计算和设计数据与实验结果相符合。 相似文献
15.
PENG MingZeng ZHENG YingKui WEI Ke CHEN XiaoJuan & LIU XinYu Key Laboratory of Microelectronics Devices & Integrated Technology 《中国科学:物理学 力学 天文学(英文版)》2011,(3)
An X-band AlGaN/GaN high-electron-mobility transistor (HEMT) on SiC substrate with high microwave power performances has been achieved. Its small-signal characteristics with a gate-length of 0.4 μm showed a unity current gain cut-off frequency (fT) of 22 GHz and a maximum oscillation frequency (fmax) of 65 GHz. The GaN HEMT device with a gate width of 1 mm exhibited a continuous-wave saturated output power of 10.2 W and a linear gain of 14.8 dB at 8 GHz, and successfully achieved the power-added efficiency ... 相似文献
16.
17.
18.
Yu Zhang Shang Wen Yan Gong Lu Jin Shuang Man Li Zhong Ping Chen Ming Ma Ning Gu 《中国化学快报》2009,20(8):969-972
This paper describes the formation of magnetic and fluorescent nanocomposite particles which consist of superparamagnetic Fe_3O_4 core,SiO_2 shell and organic dye(FITC) coating layer on their surface.The obtained nanocomposites possess typical superparamagnetism and exhibit clear green fluorescence image.And their fluorescence emission is pH-dependent,which would be applied to pH sensing. 相似文献
19.
Kang Xu Zhi Rui Guo Ning Gu a State Key Laboratory of Bioelectronics Southeast University Nanjing China b Jiangsu Laboratory for Biomaterials Devices China c School of Chemistry Chemical engineering China 《中国化学快报》2009,(2)
We herein report a one-step,wet-chemical approach to synthesizing gold nanoplates in large quantities via the AuCl_4~-thermal reduction process by aniline,without introducing additional capping agent or suffactant.It is found that the reduction kinetics of AuCl_4~-is greatly altered by varying the initial molar ratio of aniline to AuCl_4~-.Moreover,further investigation reveals that the in- situ formed polyaniline could serve effectively as a capping agent to preferably adsorb the{111}facets of gold crys... 相似文献
20.
Zhulin Liu Jiangman Sun Yongxiang Zhu Peng Liu Lianjie Zhang Junwu Chen Fei Huang Yong Cao 《中国科学:化学(英文版)》2015,(2):267-275
Two new conjugated copolymers,PBDT-T6-TTF and PBDT-T12-TTF,were derived from a novel 4-fluorobenzoyl thienothiophene(TTF).In addition,two types of benzodithiophene(BDT)units with 2,3-dihexylthienyl(T6)and 2,3-didodecylthienyl(T12)substituents,respectively,were successfully synthesized.The effect of the dual two-dimensional(2D)substitutions of the building blocks upon the optoelectronic properties of the polymers was investigated.Generally,the two polymers exhibited good solubility and broad absorption,showing similar optical band gaps of~1.53 e V.However,PBDT-T6-TTF with its shorter alkyl chain length possessed a larger extinction coefficient in thin solid film.The highest occupied molecular orbital(HOMO)level of PBDT-T6-TTF was located at–5.38 e V while that of PBDT-T12-TTF was at–5.51 e V.In space charge-limitedcurrent(SCLC)measurement,PBDT-T6-TTF and PBDT-T12-TTF displayed respective hole mobilities of 3.0×10–4 and1.6×10–5 cm2 V1 s1.In polymer solar cells,PBDT-T6-TTF and PBDT-T12-TTF showed respective power conversion efficiencies(PCEs)of 2.86%and 1.67%.When 1,8-diiodooctane(DIO)was used as the solvent additive,the PCE of PBDT-T6-TTF was remarkably elevated to 4.85%,but the use of DIO for the PBDT-T12-TTF-blend film resulted in a lower PCE of 0.91%.Atomic force microscopy(AFM)indicated that the superior efficiency of PBDT-T6-TTF with 3%DIO(v/v)should be related to the better continuous phase separation of the blend film.Nevertheless,the morphology of the PBDT-T12-TTF deteriorated when the 3%DIO(v/v)was added.Our results suggest that the alkyl-chain length on the 2D BDT units play an important role in determining the optoelectronic properties of dual 2D BDT-TT-based polymers. 相似文献