Multielement trace determination in high purity advanced ceramics and high purity metals

In the field of advanced ceramics two CRMs were developed in the last few years by the Federal Institute for Materials Research and Testing, one for silicon nitride and one for silicon carbide. Besides their application by industry they are appropriate to be used for the validation of special methods used for trace determination in accordance with high purity materials. This is demonstrated, for example, on ultrapure silicon carbide which was analysed by solid sampling electrothermal atomic absorption spectrometry (SS ET AAS). BAM is also certifying primary pure reference materials used as the National Standards for inorganic analysis in Germany. The crucial point of this project is the certification of the total purity of high purity materials, each representing one element of the periodic table. A variety of different analytical methods was necessary to determine the trace contents of metallic and non-metallic impurities from almost the whole periodic table in the high purity materials. The primary CRMs of copper, iron and molybdenum are used as examples to demonstrate the modus operandi, analytical effects observed by using high resolution ICP mass spectrometry (HR ICP-MS) and the results.     

Virtual reality for the psychophysiological assessment of phobic fear: Responses during virtual tunnel driving.

An overall assessment of phobic fear requires not only a verbal self-report of fear but also an assessment of behavioral and physiological responses. Virtual reality can be used to simulate realistic (phobic) situations and therefore should be useful for inducing emotions in a controlled, standardized way. Verbal and physiological fear reactions were examined in 15 highly tunnel-fearful and 15 matched control participants in 3 virtual driving scenarios: an open environment, a partially open tunnel (gallery), and a closed tunnel. Highly tunnel-fearful participants were characterized by elevated fear responses specifically during tunnel drives as reflected in verbal fear ratings, heart rate reactions, and startle responses. Heart rate and fear ratings differentiated highly tunnel-fearful from control participants with an accuracy of 88% and 93%, respectively. Results indicate that virtual environments are valuable tools for the assessment of fear reactions and should be used in future experimental research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

IGBT的驱动模块HR065

介绍了HR0 6 5的工作原理、电气特性及外围电路的配置     

无线局域网(WLAN)中高速直接序列扩频(HR/DSSS)的实现

该文着重介绍了802.11b中提出的在WLAN中实现高速直接序列扩频(High Rate DirectSequence Spread Spectrum,HR/DSSS)的方法—补码键控(Complement Code Keying,CCK)调制,并以Intersil公司802.11解决方案中的基带信号处理芯片HFA3861b为例,说明了CCK调制在实际系统中的实现方法,最后对CCK调制的改进形式—格形编码(Trellis-Coded)CCK调制进行了概述。     

高性能193nm反射膜的制备与误差分析

分析了膜厚控制误差对反射膜设计曲线的影响,发现高低折射率材料厚度反方向变化时(高折射率膜层厚度增加,低折射率膜层厚度减小),反射膜的反射率变化不明显,设计的膜系结构对这种膜厚变化方式的制造误差宽容.在此基础上制备了193nm反射膜,结果表明退火前光学损耗相对较大,实验结果与理论计算结果存在一定差距,并且散射损耗在总的光学损耗中所占比例很小,而吸收损耗占光学损耗的主要部分,起主导作用.退火后光学损耗明显下降,实验结果与理论计算结果更为接近,193nm反射膜的反射率达98%以上.散射损耗增加至接近吸收损耗的水平,不过在总的光学损耗中仍然占比较小的比例.说明当吸收损耗下降到一定程度时,散射损耗所起的作用也是不可忽视的.     

高功率CO2激光器高反膜红外耦合窗热形变的半解析方法的研究

为了有效地解决高功率CO2 激光器高反膜红外耦合窗吸收谐振腔内激光能量产生热效应问题 ,通过对红外耦合窗镀膜参数和工作特性分析 ,建立了红外耦合窗热模型。基于热传导方程和边界条件 ,利用半解析热分析方法得出当CO2 激光器具有理想的TEMoo模式输出时红外耦合窗的温度场和热形变的计算表达式 ,同时对影响红外耦合窗温度场分布的各种因素进行了讨论。研究结果与以往将谐振腔内振荡激光做均匀光强处理作了对比 ,不仅热模型更符合激光器系统 ,而且计算出温度场分布也更加准确。研究方法和结论还可以应用到其它具有轴对称性激光束模式产生的温度场、热形变分析工作中     

人力资源管理信息化系统的研发与设计

作为现代企业管理的一个重要组成,人力资源管理对优化企业资源配置、降低企业管理成本、提高企业管理效率等方面具有关键作用。伴随着信息化技术的不断发展,人力资源管理信息化技术和水平也日益完善。人力资源管理信息化对于改变企业传统人力资源管理观念和方法,有效的将企业人力、财力、物力以及信息的结合,实现企业管理信息化具有积极意义。本文就是在介绍人力资源信息化管理现状基础上,对人力资源管理信息化系统含义和作用进行分析,着重探讨了人力资源管理信息化系统设计方案。     

高阻硅基铝硅合金弹性膜MEMS相移器

级联式MEMS相移器可通过悬浮于共平面波导之上的微机械可调电容的变化,来改变传输线的特性阻抗和相速,达到相移的目的.文中讨论了MEMS相移器特性对微机械电容和下拉电压的要求,并通过轻质量的铝硅合金弹性膜,获得了较低的下拉电压.测试结果表明,相移器的下拉电压不大于40V,且当控制电压大于10V时,即有明显的相移.该MEMS相移器制备于电阻率大于4000Ω*cm的高阻硅衬底上,获得了较好的传输特性,在整个测试频段1～40GHz,S21均小于3dB,并在25V时获得了大于25°的相移量.     

局部有源忆阻器电路及其在HR耦合神经元网络中的应用

该文提出一种新型局部有源忆阻器,使用标准非线性理论分析方法分析其特性,并通过直流伏安特性曲线来证明其局部有源性。此外,将局部有源忆阻器用于模拟生物突触,构建了一个局部有源忆阻突触耦合HR神经元网络。理论分析和数值仿真表明,在局部有源忆阻突触的影响下它能够产生多种放电模式和复杂的混沌行为。最后,实现了该局部有源忆阻突触耦合神经网络的模拟等效电路,并由功率模拟(PSIM)电路仿真验证了数值仿真的正确性。