非接触式主动阻尼电磁作动器的稳定性分析

介绍了非接触式精密电磁作动器在高精度主动阻尼控制系统中的应用前景,并探讨该精密电磁作动器的动力学特性及其局部稳定性问题,给出该作动器工作的稳定条件、工程参数及设计实例。主要讨论了非接触式精密电磁作动器平衡气隙的稳定性,这项技术在光学工业、精密测量和晶体材料制造等行业有着广泛的应用。     

压电作动器在微力微位移装置中的应用

在微力微位移装置中采用闭环控制压电作动器实现微位移进给和微力加载，设计了加载机构，建立加载机构的压电作动器输入电压、加载装置输位移和输出力之间的关系。通过电容测位移仪检测输出位移，实验得到加载系统刚度，根据压电作动器输入电压、加载装置刚度，计算出加载力大小。该方法为微机械力学性能测试仪打下了基础。     

推动科技进步的动力之一——表面微机械技术

表面微机械加工是一种使机械部件微型化的工艺。传感器和致动器都是利用改进的集成电路制造技术来完成的。第一个表面微机械器件是谐振栅晶体管，大约在３０年以前就发表了。该晶体管的栅极采用了自由活动的金属悬梁，多晶硅表面微机械加工在十几年前就有报道，此后出现了许多传感器件的原型，并在最近制造出第一只商品化的传感器。     

压电作动器位移输出特性分析

通过对一种用于微隔振平台的压电作动器进行实验研究,得出了位移迟滞非线性输出曲线,综合整理并分析了压电作动器输出位移曲线特点,从微观上系统分析了作动器位移输出特性的机理.结果表明,蠕变导致作动器驱动电压回零时,作动器输出存在残留位移;迟滞大小不仅与预压力有关,还与加压次数和加压频率等有关;作动器位移输出曲线具有一定的漂移特性,对作动器的精确建模造成一定困难.为进一步修正和减少建模误差的影响、提高系统的控制精度,提供了科学的依据.     

微动平台压电作动器低频模型

针对六自由度平台的低频扰动,设计出一种用于低频隔振的压电作动器.通过作动器动态实验系统实验分析输入电压-输出力关系,结果表明,在低于25 Hz的动态电压驱动下,输入-输出不符合压电效应.因此,建立适用于平台低频控制的作动器低频双折线模型,并通过实验表明,所建低频模型能很好的吻合作动器的实际特性.     

磁致伸缩作动器结构优化设计

根据电磁学原理,在对磁致伸缩作动器内部磁路分析的基础上,推导出了作动器输出位移与Terfenol-D棒及上下端盖的尺寸之间的关系,并以此为根据对作动器结构进行优化设计,以使其在充分发挥Terfenol-D棒性能的前提下结构更加紧凑.由于Terfenol-D棒和上下端盖、作动器内壁组成了闭合磁路,使螺线管端部的磁场分布情况得到了明显改善,同时考虑到温升对作动器输出位移的影响,采用热膨胀抵消补偿法降低了温度对作动器输出位移的影响,从而最大限度地消除了作动器输出非线性.另外,为了消除作动器中磁场对周围器件的干扰,对作动器采取了磁屏蔽措施,通过有限元软件ansys仿真表明,该作动器内部磁场较均匀,而外部漏磁几乎为零,实现了预期效果.     

微机电系统在电子信息领域的应用

借助于当代先进的大规模集成电路制造工艺,MEMS（微机电系统）技术将多种光、机、电功能器件集成于一体,真正实现了传统意义上的光机电一体化、微型化、数字化和智能化,在汽车工业、航空航天、消费电子等领域得到了越来越广泛的应用,实现了电子信息技术的新飞越。文中主要阐述MEMS在基础电子元器件、通信、汽车电子、消费电子等电子信息领域的发展应用。     

大型空间桁架面天线的结构 —电磁耦合优化设计

 由于载荷变化及各种随机干扰,大型空间桁架面天线必须保持非常精确的形状.基于提高空间天线电磁性能以及降低作动器能耗的目的,结合大型空间桁架天线结构的特点,建立了以天线轴向增益和作动器能耗为目标函数,以结构强度、作动器变形和轴力为约束条件的多目标优化模型.数值试验结果表明,结构—电磁耦合优化设计模型只需较低的作动器能耗,就能明显提高天线电性能,很好地满足了天线结构与电磁设计要求.     

磁性LIGA微致动器

在许多微系统工程的研究工作中,预测微致动器有着巨大的应用潜力。因为在不断增多的微型化中有了适当的标度,又因为有可能在一块基板上相当简单地并行加工,所以,静电驱动原理得到多方的重视。与之不同磁性致动器的制造要求三维结构:一个碱性材料制作的铁磁心,它被线圈所环绕。随着微技术加工方法的进步,这一问题最近得到解决。     

压电致动器双向电源研究

提出并研究了一种压电致动器电源，它可以实现对压电致动器的从负电压到正电压的双向电压作用，且作用电压可以很高并可不间断连续作用。该电源具有易于实现压电致动器输出自动控制和输出范围大的特点，适宜逆压电效应为基本原理的压电器件在以静态位移输出为主要目的的场合应用。文中论述和分析了这种电源的工作原理和电路实现方法，推导出理论计算公式，并给出了实验结论与应用情况。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

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.