红外焦平面探测器杜瓦组件真空寿命分析

介绍了探测器杜瓦组件的加速寿命试验方法,对用于某机载红外热成像系统长波576×6 HgCdTe红外焦平面探测器组件的无维护真空寿命进行了分析,结果表明,产品真空寿命超过10年（可靠度为95%）,满足产品应用要求。     

时域反相对称与扩频技术的混合技术研究

根据噪声在时域上的相关性以及反相对称法的抗噪原理,将反相对称法与扩频通信相结合,提出了一种新的扩频通信方法。通过仿真和实验验证表明,时域反相对称扩频技术能使系统获得较高的输出信噪比,且在相同的传输条件下,反相对称扩频技术的性能优于一般的扩频技术。     

变压器绝缘纸的聚合度变化规律

针对目前变压器固体绝缘寿命判断方法存在的问题,通过实验室加速老化试验,发现变压器绝缘纸的老化过程分为快老化和慢老化2个阶段。利用不同温度下的初始老化速率,使用Arrhenius作图法,得出了绝缘纸初始快老化Arrhenius系数与温度的关系,确定出绝缘纸初始老化活化能为E-110．942kJ／mol,并得出了反映快老化...     

Modeling of an anode-supported Ni–YSZ|Ni–ScSZ|ScSZ|LSM–ScSZ multiple layers SOFC cell: Part I. Experiments,model development and validation

This paper is the first part of a two-part paper and presents the development, calibration and validation of a two-dimensional isothermal mechanistic model of a composite yttria/scandia-stabilized zirconia anode-supported multiple layers solid oxide fuel cell (Ni–YSZ|Ni–ScSZ|ScSZ|LSM–ScSZ). This model was developed to describe the intricate interdependency among the ionic conduction, electronic conduction, multi-component species transport, electrochemical reaction processes and electrode microstructure for intermediate temperatures operation between 750 and 850 °C. This model takes into account the fact that the electrochemical reactions take place throughout the electrodes and not only at the electrolyte/electrode boundaries. The model was calibrated using experimental polarization curves and then validated by comparing each cell component polarizations (anodic, cathodic and electrolyte) determined from the simulation and from specific experiments using a symmetric cell and EIS measurements.     

基于对称多项式的GSM-R身份认证协议

GSM-R(GSM for Railways)网络结构中的一个重要组成部分是身份认证,为了能够解决现有的GSM-R身份认证协议中存在的一些安全隐患,针对SIM卡不易丢失的车载设备,提出了一种基于对称多项式的身份认证协议.该协议在每个移动用户初始认证时分配一个共享多项式,在随后的认证请求中,用户与服务GPRS支持节点(S...     

Reliability test and failure analysis of high power LED packages

A new type application specific light emitting diode(LED) package(ASLP) with freeform polycarbonate lens for street lighting is developed,whose manufacturing processes are compatible with a typical LED packaging process.The reliability test methods and failure criterions from different vendors are reviewed and compared.It is found that test methods and failure criterions are quite different.The rapid reliability assessment standards are urgently needed for the LED industry.85℃/85 RH with 700 mA is used to test our LED modules with three other vendors for 1000 h,showing no visible degradation in optical performance for our modules,with two other vendors showing significant degradation.Some failure analysis methods such as C-SAM,Nano X-ray CT and optical microscope are used for LED packages.Some failure mechanisms such as delaminations and cracks are detected in the LED packages after the accelerated reliability testing.The finite element simulation method is helpful for the failure analysis and design of the reliability of the LED packaging.One example is used to show one currently used module in industry is vulnerable and may not easily pass the harsh thermal cycle testing.     

嵌入式EPROM数据保持能力评估方法优化

高温加速老化测试是半导体存储器产品可靠性评估必经的步骤.其中产品失效激活能的确定对数据保持能力研究有重要意义,它决定了老化可靠性评估的原则.文章首先介绍了可靠性评估原则的确定方法,然后在不同的温度下进行老化测试,利用数据规一划方法确定了相关重要数据,最后给出了在工艺稳定后的活化能和量产时的数据保持能力测试前烘烤的温度和...     

实时全息干涉法重建轴对称温度场

将激光加热技术与激光实时全息干涉法结合，发展了传统的实时全息干涉测量技术。运用实时全息干涉测量技术，得到轴对称颗粒周围的光学干涉图，通过Abel变换法由干涉条位移量计算出颗粒周围的折射率空间分布、温度场空间分布。将其运用到喷钙脱硫对煤粉着火的影响研究，证明激光加热技术及实时全息干涉法的结合技术是研究煤粉着火的有力工具。     

The De Casteljau Algorithm on Lie Groups and Spheres

We examine the De Casteljau algorithm in the context of Riemannian symmetric spaces. This algorithm, whose classical form is used to generate interpolating polynomials in , was also generalized to arbitrary Riemannian manifolds by others. However, the implementation of the generalized algorithm is difficult since detailed structure, such as boundary value expressions, has not been available. Lie groups are the most simple symmetric spaces, and for these spaces we develop expressions for the first and second order derivatives of curves of arbitrary order obtained from the algorithm. As an application of this theory we consider the problem of implementing the generalized De Casteljau algorithm on an m-dimensional sphere. We are able to fully develop the algorithm for cubic splines with Hermite boundary conditions and more general boundary conditions for arbitrary m.     

食管癌全程三维适形放疗后程加速超分割的疗效观察

Objective:The aim of the study was to evaluate the therapeutic effect and safety of whole-course three-dimen-sional conformal radiotherapy (3DCRT) combined with late-course accelerated hyperfractionated radiotherapy (LCAFR) on patients with esophageal carcinoma.Methods:one hundred and one patients with esophageal carcinoma were divided into two groups.Observing group (49 cases) were treated by whole-course 3DCRT.Patients in control group (52 cases) were treated by conventional radiotherapy.Clinical efficiencies and radiation toxicities were compared between two groups.Re-sults:The side effects including radiation esophagitis (63.2%) and tracheitis (49.0%) decreased in observing group,but there was no significant difference between two groups (69.2% and 55.7% in controls).The 1-,2- and 3-year tumor local control rates and overall survival rates in the observing group were significantly improved compared with the control group,being respectively 87.8%,75.5%,63.3% vs 71.2%,55.8%,42.3% and 85.7%,71.4%,46.7% vs 69.2%,51.9%,26.9% (all P < 0.05).Conclusion:The therapeutic effect of whole-course 3DCRT combined with LCAFR for esophageal carcinomas is superior to conventional radiotherapy.