一种用于测试坡莫合金薄膜机械性能的拉伸模型

坡莫合金(Ni80Fe20)薄膜是微机电系统常用的磁性材料之一.介绍了一种用于测试其机械性能的单轴拉伸试验模型.此模型的特点是微小试件两端固定、且与加载机构集成在基片上,从而可减少操作工作量、提高对准精度.整个机构以微细加工方法制成:坡莫合金拉伸试件以光刻和电镀技术成型,其余的加载机构以湿法蚀刻制成.实验表明:使用此机构可以简单且高精度地对薄膜试件进行拉伸试验,获得多项力学性能参数,从而为MEMS器件设计和分析提供可靠的理论基础.     

Moving‐picture response time (MPRT) of LCDs for the oblique viewing direction

Abstract— The dynamic performance of displays is an important characteristic for multimedia applications. Motion‐picture response time (MPRT) has been used as an indicator of the dynamic performance of LCDs. This paper describes a comprehensive method of MPRT evaluation for the oblique viewing direction. By using a tilted camera configuration, the angular dependency of MPRT is investigated for the condition that the horizontally scrolling patterns are observed from the vertical direction. For each gray‐to‐gray transition, distinct changes in MPRT and the luminance profile of blur are observed.     

一种MEMS薄膜材料的力学性能测试方法

介绍了一种用于MEMS薄膜材料力学特性测试的单轴拉伸试验方法。其特点是微小试件两端固定,且与加载机构集成在基片上,从而可减少操作工作量,提高对准精度。整个机构以微细加工方法制成,硅类试件以干法蚀刻成型,金属类试件以电镀方法成型,其余加载机构以湿法刻蚀制成。试验表明:使用此机构可以简单且高精度地对薄膜试件进行拉伸试验,获得多项力学性能参数,从而为MEMS器件设计和分析提供可靠的理论基础。     

基于鼓膜法的薄膜力学性能测试研究

采用自行研制的鼓膜实验装置,结合迈克尔逊激光干涉位移测量技术,获取薄膜的变形值与压力值之间的关系曲线,以实现薄膜试样力学性能的测试.对鼓膜法测试薄膜力学性能的现状做了评述;对实验原理以及装置设计进行论述;进行实验测量,并对实验结果进行有限元分析与仿真.对纯铝薄膜(纯度99.9％,厚为210 μm)进行鼓膜实验,测得其弹性模量E为68.3 GPa,与资料结果基本一致,说明研制的鼓膜实验装置测量薄膜力学性能方法切实可行.实验装置对于在微/纳机电系统(MEMS/NEMS)中广泛应用的薄膜材料的力学性能表征具有十分重要的意义.     

Design and implementation of a wavelet‐based addressing technique (WAT)

Abstract— The design and implementation of a wavelet‐based addressing technique capable of displaying gray shades is presented. The hardware complexity of the display drivers has been reduced by adding a few analog multiplexers that are common to the drivers. The controller was implemented by using a low‐cost complex programmable logic device (CPLD) and it was demonstrated by displaying 16 gray shades in a liquid‐crystal display.     

First principle study of electronic,mechanical, optical and thermoelectric properties of CsMO3 (M = Ta,Nb) compounds for optoelectronic devices

The electronic, mechanical, optical and thermoelectric properties of Cesium based perovskites CsMO₃ (M = Nb, Ta) in the cubic phase has been performed through PBEsol-mBJ scheme in the framework of DFT. The electronic band structures and density of states show the studied materials having a direct band gap in the visible range. The mechanical stability and ductile behavior have been analyzed from elastic constants. Moreover, the optical behavior of the studied materials has been analyzed in terms of dielectric functions, refractive index, extinction coefficient, absorption coefficient, optical conductivity, reflectivity and energy loss factor. Finally, the material response with temperature has been elaborated by electrical conductivity, thermal conductivity, Seebeck coefficient, power factor, heat capacity, Hall coefficient, susceptibility and electron density by using BoltzTraP code. This first principle calculation of optical and thermoelectric properties of the novel compounds provides a new route to the experimentalist for the potential application in energy renewable devices.     

Effects of temperature and pressure on the structural and optical properties of ZnO films grown by pulsed laser deposition

ZnO thin films were deposited on fused silica via pulsed laser deposition (PLD) at substrate temperatures from 300°C to 800°C and ambient oxygen pressures ranging from 10-2 mTorr to 240 mTorr. X-ray diffraction (XRD) and Raman spectra indicated that wurtzite ZnO was obtained in all cases. The highly c-oriented ZnO films were obtained for oxygen pressures above 11 mTorr. The room-temperature photoluminescence (PL) spectra demonstrated that all the films exhibited strong near-band-edge (NBE) emission, while d...     

Structural, optical and electrical properties of CdO/Cd(OH)2 thin films grown by the SILAR method

Successive Ionic Layer Adsorption and Reaction (SILAR) was used to form Cd(OH)₂ thin films from aqueous cadmium–ammonia complex on glass substrates at room temperature and the thermal annealing effect on thin films was studied. The as-deposited films were annealed at 200, 300 and 400 °C for 1 h in an oxygen atmosphere for conversion from Cd(OH)₂ to CdO and change in the structural, optical and electrical properties of the films and the effect of the light on the electrical properties of the films were investigated. The structural and surface morphological properties of the films were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that Cd(OH)₂ phase is converted into the cubic CdO films by annealing. The band gap energy values of films decreased from 3.59 to 2.13 eV through increasing annealing temperature. It was found that the current increased with increasing light intensity and CdO films were more conductive than the as-deposited films.     

Development of a new fluorescent sensor based on a triazolo-thiadiazin derivative immobilized in polyvinyl chloride membrane for sensitive detection of lead(II) ions

A new sensor membrane based on a novel triazolo-thiadiazin derivative immobilized in polyvinyl chloride has been developed for the determination of Pb(II) ions that displays excellent performance. The parameters involved in the preparation of the optode and determination of Pb(II) were optimized. Under the optimal conditions, the proposed sensor displays a calibration response for Pb(II) over a wide concentration range of 5.0 × 10⁻⁸ to 3.8 × 10⁻⁴ M with the detection limit of 2.2 × 10⁻⁸ M. In addition to high reproducibility and reversibility of the fluorescence signal, the sensor also exhibits good selectivity over common metal ions. The optode membrane developed is easily prepared, stable, rapid, and simple for the determination of Pb(II). The accuracy of the proposed sensor was confirmed by analyzing standard reference materials of natural water and surface water. The sensor was successfully used for the determination of Pb(II) ions in water samples with satisfactory results.     

温控型非易失性数字电位器DS1847(8)智能接口的设计与其在测量中的应用

本文设计了温控电位器DSl847(8)智能接口,采用80c552单片机及C51编程技术,使该接口可方便的作为计算机系统的外设使用,上级计算机系统可以通过并行接口或RS-232接口方便对电位器进行操作。文中还介绍了该电位器在温差测量系统的应用。最后给出了使用该电位器的一些建议。     

Fluorescence quenching of benzo[k]fluoranthene in poly(vinyl alcohol) film: a possible optical sensor for nitro aromatic compounds

Benzo[k]fluoranthene (BkF) is a condensed multi-ring compounds with high fluorescence quantum yield and Stokes’ shift. Nitro aromatic compounds (NACs) are known to be good electron acceptors and quenchers. The fluorescence quenching of benzo[k]fluoranthene in poly(vinyl alcohol) film by different NACs, e.g. nitrobenzene, m-dinitrobenzene, o-nitrotoluene, m-nitrotoluene, p-nitrobromobenzene, o-nitroaniline, p-nitrophenol, etc. has been studied. The BkF film shows a strong quenching in the NACs concentration range from 1×10⁻⁴ to 1×10⁻³ M. The Stern–Volmer plots for NACs are found to be non-linear, but regular in this concentration range, which can be used for estimation of these compounds. The typical response time of the sensing film is found to be 2–10 s. The sensor film also shows minimal interference from different organic molecules and has good reversibility and reproducibility. The sensor gives a sensitivity of 1×10⁻⁵ M for p-nitrophenol.     

The influence of the surface morphologies of Langmuir Blodgett (LB) thin films of porphyrins on their gas sensing properties

In this work, 2,3,7,8,12,13,17,18-Octaethyl-21H,23H-porphine (OEP) in its free base form and metalated with iron (III) chloride (FeOEP), magnesium(II) (MgOEP) and cobalt(II) (CoOEP) have been used to fabricate Langmuir-Blodgett (LB) thin films. Using the surface pressure-surface area (Π-A) isotherm graphs optimum conditions for thin film deposition have been determined and by changing the deposition parameters various thin films have been deposited. Quartz Crystal Microbalance (QCM) system was used to investigate their gas sensing performances during exposure to Volatile Organic Compounds (VOCs) including chloroform, benzene and toluene. The surface properties have been investigated using Atomic Force Microscopy (AFM) and analyzed together with the QCM results to understand the effect of the surface properties on gas sensing mechanism. It is observed that larger surface area leads to higher response in gas sensing applications in terms of resonance frequency change.     

Measurement of minimum angle of resolution (MAR) for the spatial grating consisting of lines of two colors

Minimum angle of resolution (MAR) was measured for the grating which consisted of lines of two colors selected from Red, Green, Blue, White and Black. Method of two alternative forced choice (2AFC) was used where the participants were asked to answer the direction of the color grating of the horizontal or vertical directions. From the measured psychometric function of the ratio of the correct answers, MAR which corresponded to the threshold of 75% correct answer ratio was determined. MAR of the grating patches with more than one primary color was measured to be affected by the combination of colors and to be 10–30% larger than that of the grating patch of White–Black. While the resolving power for Blue pattern had been known to be worse than those for Green and Red patterns, MAR of the grating including Blue was not always the worst.     

Function identification for the intrinsic strength and elastic properties of granitic rocks via genetic programming (GP)

Symbolic Regression (SR) analysis, employing a genetic programming (GP) approach, was used to analyse laboratory strength and elasticity modulus data for some granitic rocks from selected regions in Turkey. Total porosity (n), sonic velocity (vp), point load index (Is) and Schmidt Hammer values (SH) for test specimens were used to develop relations between these index tests and uniaxial compressive strength (σ_c), tensile strength (σ_t) and elasticity modulus (E). Three GP models were developed. Each GP model was run more than 50 times to optimise the GP functions. Results from the GP functions were compared with the measured data set and it was found that simple functions may not be adequate in explaining strength relations with index properties. The results also indicated that GP is a potential tool for identifying the key and optimal variables (terminals) for building functions for predicting the elasticity modulus and the strength of granitic rocks.