单光纤传输光推动便携式压力测量仪的研究

介绍了用单根光纤传输测量信号和功率信号的光功率推动液体压力测量仪及其工作原理。该仪器以电容式压力传感器的δ元件作为压力检测元件，采用低功耗前置器电路和简单直杆结构，实现了便携式测量。测量范围为O～100kPa，精度为O．01kPa。     

V波段小型化低相噪频率综合器

本文研究了一种V波段超小型低相噪频率综合器,研制了L段捷变频频综、Ku波段取样锁相源、上变频组件、倍频器等四个小型化组件.为了得到较低的相位噪声和捷变频速度,本捷变频频综采用上变频-倍频方案,其中DRO PLS保证低相位噪声性能,L波段捷变频频综保证捷变频功能.该频综尺寸为100×80×30mm³,相位噪声低于-86dBc/Hz(1kHz),捷变频时间小于40μs,杂波抑制优于-60dBc.     

Phase separation in blends of two homopolymers and a diblock copolymer during film casting

Demixing during film casting of blends of polystyrene, polymethylmethacrylate, and a symmetric diblock copolymer of styrene and methylmethacrylate is discussed. The concentration fluctuations in the homogeneous solutions were calculated in mean field approximation. The structures in the homogeneous and demixed solutions and in the dry films were measured by small-angle x-ray scattering, and the morphologies of the dry films were characterized by transmission electron microscopy. The structure of the dry blends is evidently already pre-formed in solution.     

光束发散度对紫外写入光纤光栅的影响

用傅里叶衍射光学分析了准分子激光束发散度对于光纤光栅制备的影响，发现光束发散角使光纤光栅的布拉格波长发生改变，相位版后干涉场沿光纤轴向和径向不均匀，对制备30dB高反射率光纤光栅造成困难。实验结果与理论分析基本一致，相对于理想平行光束情况，会聚光束使得光纤光栅布拉格波长出现在短波一边，发射光束使得光纤光栅布拉格波长出现在长波一边。     

中低速率语音波形编码

提出了一种波形编码的新方法，阐述了其编码原理。该编码算法简单，恢复的语音质量较好。由于利用了矢量量化技术，所以该编码速率较低。     

Σ-ΔA/D转换技术及仿真

Σ－ΔＡ／Ｄ转换技术近年来颇受重视，因为基于该技术的Ａ／Ｄ转换器能达到很高的分辨率（１６ｂｉｔ以上），并另具一系列优点。本文对Σ－ΔＡ／Ｄ转换器的基本原理，包括过采样（Ｏｖｅｒｓａｍｐｌｉｎｇ），噪声成形（ＮｏｉｓｅＳｈａｐｉｎｇ），以及数字抽取滤波（ＤｉｇｉｔａｌＤｅｃｉｍａｔｉｏｎＦｉｌｔｅｒｉｎｇ）等内容，均作了叙述。作者还对一个２０ｂｉｔΣ－Δ转换器的算法进行了计算机仿真。该转换器采用了高阶ＭＡＳＨ噪声成形技术，而其数字抽取滤波部分则由梳状滤波器与级联的半带滤波器构成。文章中给出了仿真结果。     

Selectivity changes towards steroids in packed column supercritical fluid chromatography (SFC) induced by temperature and pressure variation

Summary Pressure/temperature variation in SFC was shown to influence selectivity towards steroids. Major changes were observed for polar column packings compared to non-polar packings and variation of the amount of modifier showed that this is valid over the whole investigated range. The effect is underlined by a fall in resolution in the low density range (low pressure/high temperature) for polar stationary phases and appears to be significantly larger than for non-polar phases. Major selectivity shifts induced by variation of the physical properties of the mobile phase are considered to be due to the greater effect of polar modifiers on the nature of polar stationary phases than on non-polar phases.     

压力淬火过程中锗的相结构研究

 应用高压原位差热方法，直接测量了压力下锗的固化参数─—固化温度与过冷度。高压差热信号表明，当压力大于3 GPa时，锗在凝固过程中可能发生结构相变。X射线结构分析表明，在最终的样品中除GeⅠ相外，还形成GeⅢ相和GeⅣ相。     

Phasenbeziehungen und Natriumionenleitung im quasi-binären System Na2SiF6/Na3AlF6

Phase Relations and Sodium Ion Conductivity within the Quasi-binary System Na₂SiF₆/Na₂AIF₆ . The phase diagram of the Na₂SiF₆/Na₃AlF₆ system has been determined by means of x-ray powder diffraction, thermal analysis and conductivity measurements in the sub-solidus region. Na₃AlF₆ accomodates up to 73 mol.-% Na₂SiF₆ maintaining the crystal structure type. The sodium ion conductivity increases by about five orders of magnitude upon doping Na₃AlF₆ with Na₂SiF₆.     

On the Moments of Overflow and Freed Carried Traffic for the GI/M/C/0 System

In circuit-switched networks call streams are characterized by their mean and peakedness (two-moment method). The GI/M/C/0 system is used to model a single link, where the GI-stream is determined by fitting moments appropriately. For the moments of the overflow traffic of a GI/M/C/0 system there are efficient numerical algorithms available. However, for the moments of the freed carried traffic, defined as the moments of a virtual link of infinite capacity to which the process of calls accepted by the link (carried arrival process) is virtually directed and where the virtual calls get fresh exponential i.i.d. holding times, only complex numerical algorithms are available. This is the reason why the concept of the freed carried traffic is not used. The main result of this paper is a numerically stable and efficient algorithm for computing the moments of freed carried traffic, in particular an explicit formula for its peakedness. This result offers a unified handling of both overflow and carried traffics in networks. Furthermore, some refined characteristics for the overflow and freed carried streams are derived.