入射光的偏振和强度对分光镜透／反比的影响

采用能量流分析法推导了一束线偏振光经分光镜分光形成透射／反射光的能量表达式。分别讨论了入射光强度不变而偏振方向变化以及二者同时变化对分光镜透／反比的影响。通过旋转主光路中的偏振片来模拟入射光的偏振方向和强度变化，实验验证了分光比的变化规律。     

高速光通信系统中的色散问题及其补偿研究

当光纤通信系统单信道速度升级到40Gbit/s及以上时，色度色散（CD）和偏振模色散（PMD）已经成为严重影响系统性能的主要因素。本文主要从补偿的必要性、关键技术、主要方法和解决方案等方面分别对CD和PMD及其补偿进行了较详细的研究。     

黄河龙青段主要环境工程地质问题分析思路

介绍了黄河上游龙青段主要环境工程地质问题的分析思路，以达到抛砖引玉，交流和提高电工程地质勘测水平的目的。     

Study of impurity induced modifications in amorphous N-type (GeSe3·5)100−x Bi x using high pressure technique

The technique of high pressure is utilized to study the carrier transport behaviour in doped and undoped bulk amorphous (GeSe_3·5)_100−x Bi _x (x=0, 2, 4, 10) down to liquid nitrogen temperature to observe impurity induced modifications in amorphous semiconductors. It is observed that pressure induced effects in lightly doped (2 at % Bi) and heavily doped (x=4, 10) semiconductors are markedly different. Results are discussed in view of the incorporation behaviour of the bismuth impurity.     

Alpha induced reactions on Sn: An experimental study of excitation functions and possible production pathways

In the frame of a systematic study of light ion induced threshold reactions on natural tin (Sn) excitation functions for alpha particles induced reactions are presented in a 12–38 MeV energy domain. Using a stacked foil activation method the following radioisotopes were identified: ¹¹⁶Te, ¹¹⁷Te, ¹¹⁸Te, ¹¹⁹Te, ¹²¹Te, ¹²³Te, ¹¹⁷Sb, ¹¹⁸Sb, ¹²⁰Sb, ¹²²Sb, ¹²⁴Sb, ¹²⁶Sb, ¹¹⁷Sn, ¹¹¹In. The experimental cross sections for these isotopes are presented for the first time in this energy range and a direct comparison with values calculated with the ALICE-IPPE code is discussed. Possible use of these data for production of some isotopes relevant in nuclear medicine is suggested.     

Stability of hydrogenated nanodiamonds under extreme ultraviolet irradiation

It is generally accepted that diamond is resistant to a wide spectrum of electromagnetic radiation from the ultraviolet through to the soft X-ray range, which makes it very attractive for the fabrication of diamond-based photodetectors. However the effect of photon radiation on the diamond structure has not yet been examined. In the work presented here, photoelectron spectroscopy has been used to study the graphitization of nanodiamond crystallites exposed to extreme ultraviolet radiation. Under such irradiation, the surface hydrogen groups and graphite species are found to prevent graphitization. The mechanism of radiation-induced nanodiamond graphitization is discussed.     

激电法找油的原理及应用

激电法是非地震物探手段中的一种，由于油气在向上渗透的过程中会与地层发生一系列的生物。化学反应而形成次生黄铁矿，激电法正是通过发现油气藏上方形成的次生黄铁矿晕来寻找油气的一种间接找油方法。通过详细介绍激电法寻找油气的基本原理。仪器设备等，从实践角度论述了激电法在油田勘探开发中的应用范围及其特点，最后通过兴例说明了其良好的应用效果。     

Preparation of clean coal by flotation following ultra fine liberation

This paper reports the results of current fundamental research at the Department of Process Engineering, University of Miskolc on the processing of clean coal from Mecsek bituminous coal, Southern Hungary. The theoretical possibility of the separation of different petrographic components was proven experimentally and their liberation degree was determined based on the petrographic composition, flotation kinetic study of isolated components (groups of components), scanning electron microscopy and microprobe analyses. The mill with stirred ball media was chosen for the ultra-fine liberation of the coal components. It was revealed that along with the liberation of coal components, their surface oxidation and spontaneous agglomeration, entrapping the mineral impurities take place in ultra-fine grinding. This paper discusses the interfacial phenomena occurring in the ultra-fine grinding process and their influence on the flotation. The concept for the advanced preparation of clean coal was developed, tested and proved. The main steps of this concept are the ultra-fine liberation in the stirred-media mill, the de-agglomeration of flocs spontaneously formed during the ultra-fine grinding and the induced (hydrophobic) flocculation with the following two-step flotation in a flotation column.     

InP基应变补偿结构偏振不灵敏半导体光放大器制作的研究

为了制备偏振不灵敏的半导体光放大器(SOA)，将有源区设计为由4个压应变、3个张应变阱层及晶格匹配的垒层InGaAsP交替组合而成的应变补偿结构。器件做成带有倾角的扇形脊形波导结构，避免了常规制作SOA的复杂工艺。对样品3在80～125mA电流范围内，获得了偏振灵敏度≤0．6dB．最小可达0．1dB；较大的电流范围内FWHM值为40nm。     

A three‐dimensional model describing stress‐temperature induced solid phase transformations: solution algorithm and boundary value problems

An always increasing knowledge on material properties as well as a progressively more sophisticated production technology make shape memory alloys (SMA) extremely interesting for the industrial world. At the same time, SMA devices are typically characterized by complex multi‐axial stress states as well as non‐homogeneous and non‐isothermal conditions both in space and time. This aspect suggests the finite element method as a useful tool to help and improve application design and realization. With this aim, we focus on a three‐dimensional macroscopic thermo‐mechanical model able to reproduce the most significant SMA features (Int. J. Numer. Methods Eng. 2002; 55 : 1255–1264), proposing a simple modification of such a model. However, the suggested modification allows the development of a time‐discrete solution algorithm, which is more effective and robust than the one previously discussed in the literature. We verify the computational tool ability to simulate realistic mechanical boundary value problems with prescribed temperature dependence, studying three SMA applications: a spring actuator, a self‐expanding stent, a coupling device for vacuum tightness. The effectiveness of the model to solve thermo‐mechanical coupled problems will be discussed in a forthcoming work. Copyright © 2004 John Wiley & Sons, Ltd.