冷中子源逆布雷顿循环氦制冷机性能分析和优化

运用能量守恒和(火用)分析方法,对冷中子源氦制冷逆布雷顿循环过程进行热力分析和(火用)分析.找出了系统(火用)效率和各部件(火用)损失随着压缩机压比、膨胀机等熵效率、跑冷量、换热器冷热流体平均温差变化的规律,并提出减小循环跑冷量、换热器内冷热流体温差,以及提高压缩机压比、膨胀机等熵效率、物料分配均匀度以提高循环性能和系统(火用)效率的措施.基于换热器内部冷热流体温差分布对循环性能影响的分析,设计了膨胀机预冷循环方案,该方案的(火用)效率相对于基本循环提高了24 %.     

冶金企业工业污染源的普查和评价

冶金企业中往往具有众多的工业污染源和排放种类多、数量大的污染物,这样就产生了如何确定企业污染防治重心的问题.本文对工业污染源的普查及评价方法进行了阐述,从而能使每个企业把握自身的污染防治重心,对企业环境污染状况的治理工作具有一定的借鉴意义.     

A comprehensive review concerning the problem of marine crudes sources in Tarim Basin

The issue of source of oil/gas in the platform basin area in Tarim Basin has been debated for a long time, and the debate is focused on whether the marine oil/gas resources that have been discovered in the basin were originated from hydrocarbon source rocks in the Cambrian-Lower Ordovician or in the Mid-Upper Ordovician. In this paper a summary was made in regard to the major points and supporting data by the predecessors, and a discussion was conducted toward the core issues related to the study on the oil source in the Tarim Basin area, such as choice of correlation parameters, influence of maturation and physical differentiation on oil source correlation parameters, and geological and geochemical significance of these relevant correlation indices. It is quite probable that different interpretation results could arise from the oil source correlation due to choice of parameters severely affected by the thermal maturation and physical differentiation effect, and insisted that only those parameters that come with clearly defined geochemical significance and are less affected by thermal maturation and variations occurring during secondary evolution process are valid ones. The marine crude in Tarim Basin covers contributions that were originated from two sets of hydrocarbon source rocks as mentioned above but dominated by the one from the Mid-Upper Ordovician hydrocarbon source rocks. Here oil of mixed sources occurs extensively, and crude from Cambrian sources was also discovered. It is suggested that for further study on the origin of marine crudes in Tarim Basin, the parameters used for correlation of oil sources shall be optimized, and a comprehensive set of geological and geochemical methods shall be adopted for this purpose.     

甲醇与葡萄糖为碳源在反硝化过程中的比较

在颗粒滤床反应器内 ,以葡萄糖或甲醇为碳源 ,碳源充足时 ,均可以比较完全地去除硝酸盐 ,但以葡萄糖为碳源的最佳碳氮比较甲醇为碳源高得多 ,为 6∶1～ 7∶1 (C6H1 2 O6∶NO-3 N)。当碳源不足时 ,反硝化过程存在亚硝酸盐积累现象 ,且葡萄糖为碳源时积累更严重。以CH3OH为碳源进行的反硝化速率较以C6H1 2 O6 为碳源的快得多 ,在相同条件下快 3倍。在本实验条件下 ,反硝化过程表现出 0级反应特征 ,k (CH3OH) =1 60mg/L·h ,k(C6H1 2 O6) =42mg/L·h。     

略论现代网络图书馆

随着信息网络化的飞速发展，信息高速公路的高速建设，传统图书馆面临着机遇和挑战。本文探讨传统图书馆向网络图书馆过渡所必须具备的条件；论述网络图书馆的基本特征、优越性、应用前景及意义；提出了相应的对策。     

数据集成系统中数据源描述的框架方法

查询重组是数据集成系统中必不可少的模块之一 ,关于数据源的内容以及它们之间联系的描述 ,是其首要任务 .在基于IA(InformationAgent)的数据集成系统中 ,可以利用多Agent系统中的匹配 (Matchmaking)机制来实现查询重组 ,本文首先给出在这种环境下查询重组模块的工作流程 ,然后提出一种知识表示中的框架来描述数据源和用户查询 ,以便系统高效地进行框架匹配和查询改写     

富营养化原水几种净水工艺处理效果的比较研究

对以某湖水为原水的几种净水工艺进行了对比试验研究，结果表明：与水厂现有工艺相比，生物陶粒预处理及预臭氧化＋生物陶粒预处理有较好的净水功效；预臭氧、生物陶粒、混凝沉淀、砂滤、活性炭等单元工艺有机地组合起来，对氨氮、叶绿素a、色度、浊度的去除率都比水厂工艺高，但出水氯化物Ames试验的致突变性增强，生物预处理对水中致突变前体物的去除能力有限，实践中净水工艺的组合应将健康风险与技术经济结合起来选择使用。     

弧焊逆变电源变结构控制规律的仿真研究

建立了CO2电弧焊的仿真模型，利用MATLAB软件对控制系统的动态过程进行了仿真试验。分析了输出回路中不同的直流电感（线性直流电感、可饱和电感、可变电感）对电源输出电流波形的影响，并获取得CO2短路过渡焊最佳的电流波形。仿真试验表明，只有采用可饱和电感和可变电感才能满足短路过渡过程中各阶段动态性能的要求，以达到减少飞溅的目的。     

Production of Poly(3-Hydroxybutyrate-co-3-Hydroxyhexanoate) Using Aeromonas hydrophila 4AK4 Grown in Mixed Carbon Source

IntroductionPolyhydroxyalkanoates (PHAs) are intracellularenergy storage materials and/or reduction agentsthat are synthesized by many microorganisms[1 ] .Because these bacterial PHAs are trulybiodegradable thermoplastics or elastomers,theyhave attracted much attention in industry[2 ,3 ] .Poly(3 -hydroxybutyrate) (PHB) wasthefirst PHA to beproduced on a large scale and poly (3 -hydroxybutyrate-co-3 -hydroxyvalerate) (PHBV)was laterused in commercial applications.Recently,novel PHA copo…     

面向对象多媒体素材管理系统设计

多媒体素材的制作与管理已成为软件开发的一道难关。本探讨了面向对象的领域知识的素材分类和面向对象的素材属性抽取法以及为提高多媒体素材的管理效率，进一步研究了面向对象的素材管理系统的模型和面向对象的多媒体素材库结构设计。