防腐涂料及涂装技术(Ⅷ)

防腐涂料及涂装技术讲座系列介绍防腐蚀涂料的品种和各类应用及最新产品研究进展。本讲主要介绍涂装前的表面预处理方法及表面处理质量的评定等     

Modeling of current-voltage characteristics for strained andlattice matched HEMT's on InP substrate using a variational chargecontrol model

A model for the calculation of the current-voltage characteristics of strained In_0.52Al_0.48As/In_xGa_1-xAs on InP substrate High Electron Mobility Transistors (HEMT's), based on a variational charge control model, is presented. A polynomial fit of the two-dimensional electron gas (2DEG) density is used for the calculation of the current-voltage characteristics. The effect of strain is introduced into the 2DEG density versus gate voltage relation. Very good agreement between the calculated and measured I-V characteristics was obtained. In addition, our results show that, for an indium mole fraction of the In_xGa_1-xAs channel in the range 0.53-0.60, increasing the indium mole fraction lowers the threshold voltage and hence increases the drain current at the same gate bias     

开放、交流与凝聚--广州大学城广外学生活动中心设计

2003年夏天，广州大学城广州外语外贸大学一期项目的单体设计在相当短的设计周期中紧张地铺开。     

梯形断面水力计算的一种新方法

本文从梯形水力最优断面的基本思路出发，通过理论分析找到了梯形断面水力计算的一种新方法——即通过特征参数进行梯形断面的水力计算。     

A novel dynamic survivable routing in WDM optical networks with/without sparse wavelength conversion

In this paper, we study the dynamic survivable routing problem, both in optical networks without wavelength conversion and in optical networks with sparse wavelength conversion, and propose a novel hybrid algorithm for it based on the combination of mobile agents technique and genetic algorithms (GA). By keeping a suitable number of mobile agents in the network to cooperatively explore the network states and continuously report cycles (that are formed by two disjoint-link routes) into the routing tables, our new hybrid algorithm can promptly determine the first population of cycles for a new request based on the routing table of its source node, without the time consuming process associated with current GA-based lightpath protection schemes. We further improve the performance of our algorithm by introducing a more advanced fitness function that is suitable for both the above networks. Extensive simulation studies on the ns-2 network simulator show that our hybrid algorithm achieves a significantly lower blocking probability than the conventional survivable routing algorithms for all the cases we studied.     

官能团化MCM-41在分离低碳醇-水混合物中的应用

采用一步法水热合成了介孔材料氯丙基官能团化的MCM-41(Cl(CH2)3-MCM-41)、氨丙基官能团化MCM-41(NH2(CH2)3-MCM-41)、甲基官能团化MCM-41(CH3-MCM-41)和氯丙基官能团化硅胶,并考察了它们作为气相色谱固定相分离低碳醇-水混合物的情况。实验结果表明,Cl(CH2)3-MCM-41能够分离低碳醇-水混合物中的各组分,随水、甲醇、乙醇、异丙醇、正丁醇极性的减小,各分子与Cl(CH2)3-MCM-41的作用力增强,保留时间延长。氯丙基官能团化硅胶、NH2(CH2)3-MCM-41)和CH3-MCM-41均不能分离低碳醇-水混合物,表明介孔材料规则的孔道结构、表面嫁接基团等对低碳醇-水混合物的分离有重要影响。同时考察了Cl(CH2)3-MCM-41的氯丙基负载量对低碳醇-水混合物分离效果的影响,结果表明,当氯丙基的摩尔分数为15%时,分离效果最佳。     

Y-Ba-Cu-O超导涂层的研制

用等离子喷涂工艺制备了 Y-Ba-Cu-O 高临界温度超导涂层,涂层的初始转变温度为101K、零电阻温度为86K。电阻率与磁化率的测量结果表明这种超导涂层具有与烧结超导块体相类似的性能,X 光衍射谱显示出涂层主要由 YBa_2Cu_3O_(?)单相化合物组成。     

大变量逻辑函数最佳覆盖问题研究

逻辑函数的最佳覆盖，一直是逻辑综合领域的关键环节。尤其是大变量逻辑函数最佳覆盖，对复杂的逻辑综合更为重要，但也更加困难。本文在对逻辑覆盖算法研究的基础上，提出了适合大变量逻辑函数最佳覆盖的Beister改进算法。经过大量算题的测试表明，改进的列覆盖算法在时间复杂度和选择效果方面均优于Beister算法。     

A bibliometric study of China’s semiconductor literature compared with other major asian countries

In this paper we compare the scientific research in the semiconductor-related field in China with some other major nations in Asia. It is based on the bibliometric information from SCI-Expanded database during the time period of 1995–2004. We show that China has been developing fast in semiconductor research, and become the second productive country in Asia as reflected by the publication profile. The evidences indicate a significant increasing trend in the research efforts and readership among Asian countries. Similar to the scientists in Japan and South Korea, Chinese scientists were more inclined to work in larger groups, typically 4 or more authors. The assessment of research quality is further conducted based on citation-based measures. As benchmarks, two western countries, namely USA and Germany, have been compared in the citation analysis. It is revealed that the impacts of research outputs in the Asian countries, except for Japan, have been badly incommensurate with their devoted research efforts compared with USA and Germany. Like most of other Asian countries the research results of Chinese scientists in semiconductor have a low international visibility despite their strong research efforts and increasingly large domestic readership. The application of Leimkuhler curve illustrates vividly the inequality of citation times among the compared countries. Furthermore, the Gini Indices of each country and each pair of countries are calculated which illustrates again the inequality of informetric productivities.     

唐钢ER70S-6焊丝钢的生产工艺研究及质量分析

介绍了唐钢ER70S-6焊丝钢的特点，对盘条质量进行了分析。对该钢化学成分、冶炼和轧制工艺进行了优化研究，使其综合性能明显改善。