第三代移动通信系统的一种多址访问协议——分组预约多址协议

论文介绍未来第三代移动通信系统可能采用的多址访问协议——分组预约多址协议(PRMA),包括PRMA协议的适用范围、内容及研究状况。     

A note on optimum checkpointing policies

In this paper, we treat checkpointing policies. We derive the total expected loss time and obtain the optimum checkpointing policy which minimizes that expected loss time. We further present the numerical examples using the exponential and the Weibull distributions. First, we discuss the model in which the intervals between checkpointing completion times may vary, and secondly the model with constant intervals.     

Quality assessment models for initial production process control based on stochastic differential equations

It is of great importance to assess an initial production process prior to the regular mass-production. For this purpose, many statistical methods have been proposed for practical use. In this paper, we propose two stochastic models for an assessment method of the initial production process control: a Markov process model and a Markov approximation model. These models are continuous state space models and formulated by applying mathematical techniques of stochastic differential equations. Based on each model, we derive several quantitative assessment measures for initial production process control.     

EMC测试系统中混合接头的研制

本文就ＴＥＭ ｃｅｌｌ辐射发射测试系统中一个关键部件进行了研制。采用高性能的魔Ｔ混合网络，从而实现了２路信号的“和”与“差”输出。最后，给出了其测试结果。     

Electron spin resonance study of defects in CVD-grown 3C-SiC irradiated with 2MeV protons

Electron spin resonance (ESR) was used to study defects induced by 2MeV-proton irradiation in cubic silicon carbide (3C-SiC) epitaxially grown on Si substrates by chemical vapor deposition. A new ESR signal labeled T5 was observed at temperatures lower than ≈100 K in Al doped, p-type 3C-SiC epilayers irradiated. The T5 signal has anisotropic g-values of g₁ = 2.0020 ± 0.0001, g₂ = 2.0007 ± 0.0001,and g₃ = 1.9951 ± 0.0001. The principal axes of the g-tensor were found to be along the 〈100〉 directions, indicating that the T5 center has D₂ symmetry. Isochronal annealing of the irradiated epilayers showed that the T5 center was annealed at temperatures around 150° C. A tentative model is discussed for the T5 center.     

星载合成孔径雷达成像处理快速相关算法研究

本文给出了星载合成孔径雷达成像处理的典型算法，并在此基础上提出了基于Hartley变换的快速相关算法。文中对该算法的优越性进行了理论论证，通过对Seasat实数据成像处理表明，该算法运算时间节约32％左右。     

本科毕业生就业情况影响因素分析

大学扩招给企业就业体制带来了很大的变革,越来越多的大学生面临着毕业即失业的局面,而本科毕业是从学生时代走向工作岗。本文针对本科毕业生的就业情况进行调研和分析,归纳影响本科毕业生的影响因素,这些因素包括城市生活水平、家庭地位、行业发展前景等,针对这些因素进行分析之后,可以为本科毕业生就业创造一个积极的参考平台,使本科毕业生能够清楚地认识到自己的定位,积极的改变毕业生的就业技巧,进一步提升就业率。     

Flexibility of epoxy coatings part 1: Determination of molecular weight of network chains

The chemistry of network formation for an epoxy/phenolic coating determines structure of baked film. The theory of partitioning of components between sol and gel proposed by Flory was applied to determine the crosslink density and the molecular weight of the network chains, M_c. This procedure appears useful to eliminate the problems in the determination procedure of M_c by equilibrium swelling.