语音指导查询与数据自动传输方法

为了建立远程分布式测量系统,提出了一个新颖高效的传输方法。利用双音多频数据编码和自行定义的传输协议使数据传输与语音传输相结合,创建了语音指导查询、超限自动报警的电话自动数据传输方法。通过对系统的设计、分析和样机试验,对这种方法进行了深入研究。试验应用证明这种传输方法结构简单、保密性强、实时性和可靠性很高,可以扩展到其他远程测量、控制系统中,具有重要实际应用价值和推广价值。     

中原地区森林环境电波传播实验研究

本文给出在中原地区进行的森林环境电波衰减测试的结果分析，提出经验预测模式     

A method for calculating static transmission errors of plastic spur gears using FEM evaluation

There are many ways to calculate the static transmission errors of steel gears, but none is developed for plastic gears. Since the Young's modulus of the plastic material is lower than that of steel by two orders, the effects of large tooth deflection on the static transmission errors of plastic gears become significant. A multi-tooth contact analysis using finite element method for calculating the static transmission errors of plastic spur gears is established to compare with the existing method for steel spur gears. According to the comparison results, a modification of the existing method is proposed for plastic spur gears and verified by the same finite element contact analysis.     

Transmission boundary condition for mixed variable finite-difference method

All kinds of numerical methods based on the discretization of first-order velocity-stress hyperbolic system of elastic wave equations are named mixed variable finite-difference method in this paper, and the transmission boundary condition of artificial boundaries is studied here by the mixed variable finite-difference method. The transmission condition of complex geometrical boundaries of a transversely isotropic medium is presented based on the characteristic variables of wavefields propagating in the normal direction of the boundary. The boundary condition proposed in this paper is a local artificial boundary condition, with which the computation cost is very low. Elastic wave propagations in transversely isotropic medium are modelled by the staggered grid finite-difference method incorporated with the boundary condition presented. Numerical results and analysis of reflection coefficients show that the reflections of incoming waves by artificial boundaries are efficiently reduced.Supported by National Natural Science Foundation and Liaoning Province Science Foundation.     

激光表面硬化效果的计算与实验

本文从求解高能激光束加热工件产生的温度场入手，给出由于温度场引起的金属结构变化的计算模型，并求出处理后的表层硬度。利用这些计算公式对不同含碳量钢的热处理进行计算，得出了最终处理硬度与激光功率，钢含碳量等参数之间的关系，计算结果与实验数据吻合。     

SDH光纤传输系统的信道处理及接收定时特性

本文从ＳＤＨ信号流的帧结构和ＳＤＨ光传输系统采用的简单扰码的线路码型出发，分析了系统对信道的要求，提出了对通道带宽、定时恢复、对信号图案抖动抑制等有关系统设备设计参数的计算方法。     

Investigation of 9.6 kb/s data transmission via a pcm link at 64 kb/s with and without link errors

The problem of pulse code modulation (PCM) bit errors causing voice frequency (VF) modem errors has been studied in detail. The error mechanism consists of the addition of an impulse response type error signal added to the reconstructed VF data signal waveform at the digital-to-analogue (D/A) output of the PCM decoder. This error signal may cause a burst of errors registering in the VF modem receiver, depending on which PCM bit is in error. Numerous data have been collected in a laboratory experiment and analysed in various ways. The average bit error rate (BER) enhancement factor of VF data over PCM is between 10 and 20. For each PCM bit in error, an average of two VF data bits are in error. The analysis leads to suggestions for possible solutions to the problem.     

具有两次透射的无光焦度校正透镜组的准施密特系统

本文介绍一种新型的、具有两次透射的无光焦度校正透镜组的准施密特系统，并给出设计结果：焦距f'=2．7m，f／数为5.5最大视场角为3．42。，在全视场内成像质量达到衍射极限，同时介绍设计思想和方法．     

On the impact of an event

Given an information structure a function that measures how the inferences made by the agents spread among the states is defined; it specifies for each event its impact at each state, for each agent. Several properties are established. Received November 1994/Revised version September 1996