平面研磨中影响工件起动力矩的因素

本文针对平面研磨过程中工件运动的随机性，从理论上求出了在机床起动瞬间磨具作用于工件上的合力矩；探讨了影响这个力矩的主要因素，偏心距和工件几何尺寸的作用规律；为选择研磨参数提供一理论依据。     

超快光电测量技术

本文综述了近年来趔快光电测量技术的新进展，其中包括扭快光电材料的特性、高速光电器件的基本原理，着重介绍了若干主要的用快光电测量技术．     

Evolution Characters of Thermodynamic Quantities in Thin Disk-Accretion of Black Holes

Evolution characters of thermodynamic quantities of the central black hole (BH) of an accretion disk. such as temperature, entropy and specific heat, are investigated in prograde accretion and retrograde accretion, respectively. Compared with prograde accretion, a BH has some unusual characters in retrograde accretion: (i) There exists a maximum BH temperature; (ii) There exists an infinite discontinuity of BH specific heat; (iii) The rates of change of BH temperature and entropy are much bigger for fast-spinning BH than those for slowly-spinning BH.     

Optosensing of hydrochloric acid based on the fluorescence quenching of a flavone copolymer

An optical fiber sensor for the continuous determination of hydrochloric acid is presented. It is based on the fluorescence quenching of a flavone containing copolymer membrane by hydrochloric acid. The quenching efficiency is greatly enhanced in the presence of Fe(III). This enhancement is attributed to the primary inner filter effect, as well as the formation of a complex between the 4′-N,N-dimethylaminoflavone group in the copolymer and the Fe(III) species extracted from hydrochloric acid solution. The optical response is linear and reversible for 0.10–6.00 mol L^–1 HCl with a response time of the order of a second. The standard deviations for repeated alternative measurements of 0.20 and 2.00 mol L^–1 hydrochloric acid are 0.32% and 0.46% (n = 10), respectively, indicating a good reproducibility. Because of the covalently bonding of the dye to polymer, the sensor exhibits also a good stability. Selectivity has also been evaluated for some potential interferents. The sensor in conjunction with a flow-injection system can be used for on-line determination of hydrochloric acid.     

NFZ-10工业辐照电子直线加速器

研制的电子直线加速器ＮＦＺ－１０的辐照加工能力相当于３０ＰＢｑ的６０Ｃｏ源，电子束能量为４～１２ＭｅＶ，平均束功率为３ｋＷ，扫描宽度为１ｍ，能量不稳定度≤±０．５％，束流不稳定度≤±０．６％，扫描不均匀度≤±２．５％。ＮＦＺ－１０加速器已被用于辐照各种电力半导体器件，一年多来运行稳定可靠并获得较好的经济效益。     

The practice for eight-year operation of the cobalt-60 irradiation facility at Beijing Radiation Application Research Center

The radiation facility was made by Sulzer Company in Switzerland. The designed capacity is 3.7 × 10¹⁶Bq( 1MCi) and 12.21 × 10¹⁵Bq(330kCi)of Cobalt -60 source was loaded at the first phase. Current cobalt -60 source-loading is 2.4 × 10¹⁶Bq(650kCi). The equipment assembling and installation regulating and testing were completed at the end of 1988. The facility was put into commissioning in 1989. It operates 7000–8000 hours per year. The facility has been utilized to carry out many research work and irradiate many kinds of items. Lots of economical benefits have been gained since then. Now it is becoming a radiation processing model base in China. This paper summarized the strong and weak points of the design of the facility through in eight years' practice and analysed the economical benefits.     

Gas transport through homogeneous and asymmetric polyethersulfone membranes

Both homogeneous and asymmetric polyethersulfone (PES) membranes were prepared by solvent casting. The sorption and permeation behavior of CO₂, O₂, and N₂ using these two kinds of cast PES membranes and commercially available homogeneous PES film was investigated to extract the pressure dependence of gas permeability and the permselectivity for CO₂ relative to N₂, and to confirm the validity of the working assumption that a skin layer in an asymmetric membrane can be essentially replaced by a thick homogeneous dense membrane. The pressure dependence of the mean permeability coefficient to CO₂ in homogeneous membranes obeys the dual-mode mobility model. The ideal separation factor for CO₂ relative to N₂ at an upstream pressure of 0.5 MPa attains ca. 40, while the permeability to CO₂ is about 2.7 Barrer at the same upstream pressure. The same separation factor in asymmetric membranes amounts to 35. The diffusion behavior for the skin layer in an asymmetric membrane with a thin skin layer can be simulated approximately by that in a homogeneous dense membrane. © 1993 John Wiley & Sons, Inc.     

激光二极管泵浦的高重复频率Nd：YAG激光器

报道两个１．５Ｗ连续激光二极管端面泵浦的声光调ＱＮｄ：ＹＡＧ激光器，输出激光脉冲的最高重复频率为３０ｋＨｚ重复频率１ｋＨｚ时，最窄脉宽为１２ｎｓ，最高峰值功率为１２．１ｋＷ。