重庆市的杜鹃花科植物资源研究

杜鹃花科(Ericaceae)植物是一类较为重要的观赏植物，是我国西南四大名花之一．重庆市是我国杜鹃花科植物资源比较丰富的地区之一，经野外调查和查找文献知道，重庆市有杜鹃花科植物7属73种(含栽培种)，约占我国该科植物属、种总数的41．18％、10．43％．杜鹃属(Rhododendron)植物50种，生长在海拔1000m以下的18种可作为园林花卉引种培育．     

Protein Subcellular Localization Prediction and Genomic Polymorphism Analysis of the SARS Coronavirus

Introduction In March 2003, a novel coronavirus (CoV) was dis-covered in association with the outbreak of severe acute respiratory syndrome (SARS)[1-3]. The complete genome sequence of several SARS-CoV isolates was soon determined and characterized[4,5]. Comparison of variant SARS-CoV genome sequences has identified certain genetic signatures that can be used to trace sources of infection[6]. Vaccines are now being devel-oped and molecular modeling has suggested that modi-fied rhinovir…     

锡表面Mo(W)-S-Sn彩色簇合物膜的组成与结构研究

通过(NH4)2Mo(W)S4溶液浸渍,在金属Sn表面获得了不溶性且具有金属光泽的Mo(W)-S-Sn彩色簇合物膜。FT-IR、F-IR、FT-Raman、XPS和AES研究表明,簇合物膜中存在Mo(W)-S-Sn、端基Mo(W)-S和端基Mo(W)-O键,膜层由Mo(W)、S、Sn和O元素组成,膜为多分子层结构,从AES深度分布曲线的组成恒定区求得了元素的相对原子百分数和膜层厚度。     

酵母菌最适生长条件和自溶条件研究

采用正交实验设计,研究了酿酒酵母和扣囊拟内孢霉混合培养的最适条件和菌体的自溶作 用,得到了最佳的条件组合.实验结果表明,酿酒酵母和扣囊拟内孢霉混合培养的最适条件为: 1.5％豆饼,2％玉米粉,28℃,pH 5.0,0.2％酵母膏;酿酒酵母和扣囊拟内孢霉混合菌体的自溶条 件为:pH 5.0醋酸-醋酸钠缓冲液,55℃,0.5％NaCl.     

基于信息熵识别油气层和水层的聚类方法

简要地介绍了不确定性、信息熵、联合熵、条件熵、互信息的基本概念。将地层含有某种流体属性(如油层)的特征参数的概率分布应用于联合熵中,提出其概率分布是特征参数X与流体的特征参数Y的距离函数,再用熵与条件熵之差计算得到的互信息去识别地层的流体属性,即提出了基于信息熵识别油气层和水层的聚类方法。利用实际测井资料提取了油气层和水层的特征参数,并利用聚类方法识别出油气层和水层。识别结果与试油结论相符。该聚类方法不仅可用于识别油气层和水层,还可推广应用于划分地层岩性等领域。     

Testing and Evaluation for Web Usability Based on Extended Markov Chain Model

As the increasing popularity and complexity of Web applications and the emergence of their new characteristics. the testing and maintenance of large, complex Web applications are becoming more complex and difficult. Web applications generally contain lots of pages and are used by enormous users. Statistical testing is an effective way of ensuring their quality. Web usage can be accurately described by Markov chain which has been proved to be an ideal model for software statistical testing. The results of unit testing can b eutilized in the latter stages, wbich is an important strategy for bottom-to-top integration testing, and the other improvement of extended Markov chain model (FMM) is to present the error type vector which is treated as a part of page node. This paper also proposes the algorithm for generating test cases of usage paths. Finally, optional usage reliability evaluation methods and an incremental usability regression testing model for testing and evaluation are presented.     

Ionospheric eclipse factor method (IEFM) for determining the ionospheric delay using GPS data

By establishing the ionospheric eclipse factor (IEF) λ of the ionospheric pierce point (IPP) and its ionospheric influence factor (IFF) λ, and combining λ, λ with t of IPP, a new method of modeling high-precision ionospheric delay using GPS data-ionospheric eclipse factor method (IEFM)-is presented in this paper. The IEFM can effectively select the proper ionospheric models to model the total electron content (TEC) with different changes corresponding to annual, seasonal and diurnal variations. Initial experimental results show that the correction precision of ionospheric delay modeled by the IEFM seems to be close to that of using L3 GPS observations to directly correct the corresponding ionospheric delay.     

钢管混凝土拱极限承载力计算及相关参数分析

采用考虑材料非线性的钢管混凝土拱极限承载力计算方法,对两个模型拱进行了极限承载力计算及相关参数分析.在该方法中,对钢管混凝土拱结构采用纤维单元模型,该模型假定钢管与混凝土完全粘接,钢管对核心混凝土的套箍作用体现在以一维形式表达的核心混凝土的应力-应变关系曲线之中.针对材料非线性分析中单元内各点刚度参差不齐的特点,采用单元内设小元的方法(相当于子结构),编制了非线性有限元程序.在该程序中,计算模型完全是基于小元层次进行的,比如:单元刚度矩阵由小元刚度矩阵凝聚而成,单元节点的残余力由小元节点的残余力构成,故只需改变单元内小元个数这一个参数,就可实现对结构的重新划分,极大地降低了非线性方程组的阶数,且方便实用.在程序计算结果得到模型试验结果验证的基础上,还分析了套箍系数、截面含筋率及混凝土强度对结构极限承载力的影响.     

The Intelligent Decision Support System Model of SARS

Based on the intelligent decision support system, a new method was presented to defense the catastrophic infectious disease such as SARS, Bird Flu, etc.. By using All Set theory, the decision support system (DSS) model can be built to analyze the noise information and forecast the trend of the catastrophe then to give the method or policy to defend the disease. The model system is composed of four subsystems: the noise analysis subsystem, forecast and simulation subsystem, diagnosis subsystem and second recovery subsystem. They are discussed briefly in this paper. This model can be used not only for SARS but also for other paroxysmal accidences.     

Research ＆ Development of Grade X70 LSAW Steel Pipes for West-East Gas Pipeline

In this article the research and development of X70 large diameter longitudinal seam submerged arc welded (LSAW) steel pipes for West-East Gas Transportation Pipeline project (WEGTP) in China are introduced, including the key technique, fabrication of pipe production line, mass production and the latest progress of LSAW steel pipe technique.