四乙酰乙二胺溶解度的测定与关联

测定了较宽温度范围内四乙酰乙二胺 (TAED)在乙醇、水、DMF、等八种常见溶剂中的溶解度 ,实验数据利用溶解度简化方程关联 ,总平均相对误差为 5 4 1% ,结果较好     

直流辉光和磁控增强放电等离子体的空间分辨发射光谱技术

光学发射光谱(OES)方法是等离子体诊断的有力工具之一,可以定量地给出等离子体的多种重要参数,如等离子体中的物种成分、粒子能态分布、激发温度、粒子相对密度等.本文介绍了一种用于电子回旋共振(ECR)微波等离子体磁控溅射靶附近的增强放电和直流辉光放电等离子体空间分辨诊断的发射光谱装置.其特点是光学收集系统的位置可以水平精细移动,因而可以对放电区域进行空间分辨发射光谱测量.作者利用这套装置对氩气的ECR微波等离子体和直流辉光放电等离子体进行诊断.在ECR微波等离子体的下游区内氩离子谱线的发射强度很弱,主要是高激发态原子的辐射.在磁共振增强放电区,离子谱线强度有所增加但仍比原子谱线弱,类似于直流辉光放电正柱区的光发射特性.     

同步辐射与分析测试

本文介绍一种大科学装置——同步辐射装置。这是一种数百人可同时在其上进行不同的科学技术实验的设备，其可达到的水平比实验室的极限水平高许多，从某些角度代表了国家的科学和技术水平。本文扼要介绍了同步辐射的特性，同步辐射装置的构造及一些主要的分析测试技术，如：X射线吸收精细结构光谱，X射线散射，高分辨X射线衍射，能量色散与时间分辨技术，聚集与微分析，成像与显微放大，综合测试原位测试及作铯对标定等。     

国内模具钢的市场前景及生产现状

本文简要介绍了我国模具工业及模具钢的市场概况，分析了我国近几年的模具钢的生产现状及市场前景，探讨了发展我国模具钢的发展思路及策略。     

355MPa级船用钢板试制

本文介绍了首钢355MPa级船板进行CCS工厂认可的试制情况．分析了各工艺要素对钢质量的影响，讨论了355MPa级船板试制中存在的问题，提出了改进质量的建议。     

Applying grey forecasting to predicting the operating energy performance of air cooled water chillers

Grey forecasting has found applications in finance, social science, economics, etc. However, its applications in air conditioning and refrigeration have not been reported. This paper reports on a study where grey forecasting method is applied to predicting the operating energy performance for an air cooled water chiller (ACWC) units, so as to demonstrate this forecasting approach can be applied to building Heating Ventilation and Air Conditioning (HVAC) installations. In this paper, a brief introduction of the background and fundamentals of grey forecasting is firstly presented. This is followed by reporting the application of grey forecasting to an ACWC unit installed in Northern China for predicting its operating energy performance using the variation ratio of coefficient of performance (ΔCOP). The predicted values of ΔCOP agreed well with the measured ΔCOP, demonstrating that grey forecasting may be used for predicting the operating energy performance of an ACWC unit with a high accuracy. Finally, the potential use of grey forecasting in fault detection and diagnostics (FDD) or energy management systems (EMSs) for air conditioning and refrigeration systems is assessed, and the comparison with the prediction method based on artificial neural network (ANN) discussed.     

提高第三方物流企业服务水平的对策

要促进第三方物流企业的发展,提高第三方物流企业的竞争力,使其具有参与国内外竞争能力,就必须提高其服务水平,使其与国际水平接轨。笔者分析了目前我国第三方物流企业的服务现状,并提出改进第三方物流企业服务水平的建议。     

A neural network for predicting the stability of RNA/DNA hybrid duplexes

A back propagation (BP) neural network (NN) method has been developed to predict the stability of RNA/DNA duplex. Calculated T_m of hybrid formation with the present parameters fits the experimental values within reasonable errors (AD=1.2887 K, SEP=1.782, R²=0.9673 for NN1; AD=2.1388 K, SEP=3.506, R²=0.8889 for NN2). And it has the advantage that the determinations of thermodynamic parameters (TP) are not needed.     

A comparative study of research performance in computer science

The paper compares the research performance in computer science of four major Western countries, India and China, based on the data abstracted from INSPEC database during the period 1993–2002. A total of 9,632 computer science papers recorded in INSPEC database were used for the comparison. The findings indicate that, on the one hand, the number of papers produced in China has considerably increased in the past few years. Particularly, in recent years, China occupies a remarkable high position in terms of counts of papers indexed by the INSPEC database. On the other hand, Chinese scientists preferred to publish in domestic journals and proceedings and shares of SCI-papers to the total journal papers for China have still remained the lowest. This indicates that the research activities of Chinese scientists in computer science are still rather “local” and suffer from a low international visibility. Various scientometric indicators, such as Normalized Impact Factor, ratio of papers in high quality journals are further adopted to analyze research performance and diverse finding are obtained. Nevertheless, for these surrogate indicators, China has optimistically achieved great progress, characterized with “low level of beginning and high speed of developing”. The policy implication of the findings lies in that China, as well as other less developed countries in science, can earn relative competitive advantages in some new emerging or younger disciplines such as computer science by properly using catch-up strategy. This revised version was published online in June 2006 with corrections to the Cover Date.