蒸发式冷凝器管束中强制对流空气CFD模拟

运用FLUENT软件对圆管、椭圆管及交变曲面波纹管管束中强制对流空气热力过程进行了模拟,模拟数据经过Tecplot.10处理后直观地表征了3种管型管束中空气的速度场、压力场及温度场。结果表明,交变曲面波纹管在提高流体湍动程度及强化传热温差方面优于其它两种管型。     

乌江流域大型复杂水电站群联合优化调控关键技术及其应用研究

根据乌江流域总体规划、长江三峡以上防洪要求、南方电网运行特点、乌江流域水文特性等,贵州乌江水电开发有限责任公司组织开展了乌江梯级水库优化调度和发电优化控制的基本理论研究,并根据该研究建立了乌江流域水电站群联合优化调控系统,经过一系列优化调度规则、方法、措施在系统中的应用,实现了节水增发电的目的,取得了良好的社会经济效益。     

第二套常减压装置低温热回收技术的应用

常减压装置低温余热较多.利用较少,造成热量损失。利用初顶油气、稳定石脑油等低温余热加热除盐水建立热水站,在节汽、节电等方面取得了较好的效果。     

Extended-spectrum beta-lactamase-producing Klebsiella pneumoniae strains causing nosocomial outbreaks of infection in the United Kingdom

Representative isolates from 10 distinct extended-spectrum beta-lactamase-producing strains of Klebsiella pneumoniae that caused hospital outbreaks in the United Kingdom from 1991 to 1994 were examined for relationships between their enzymes and plasmids. The beta-lactamases were identified by a combination of isoelectric focusing and gene sequencing. SHV-2 beta-lactamase was produced by isolates from four outbreaks, SHV-5 was involved in three, and SHV-4, TEM-15, and TEM-26 were involved in one outbreak each. All of the extended-spectrum beta-lactamases were encoded by self-transmissible plasmids, with sizes ranging from about 70 to 160 kb. No similarities between the restriction digest patterns of the extended-spectrum beta-lactamase-encoding plasmids were detected, except to some extent between those that produced TEM-15 and TEM-26. Thus, outbreaks of hospital infection with these organisms in the United Kingdom from 1991 to 1994 involved distinct organisms and resistance plasmids and appeared to be unrelated.     

Synthesis and triplex forming properties of an acyclic N7-glycosylated guanine nucleoside

A chiral acyclic nucleoside, one in which the ribose carbohydrate has been replaced with a glycerol-based linker, is prepared by glycosylating guanine at the N7-nitrogen. The stereochemically pure derivative is converted to a DMT-protected phosphoramidite for incorporation into DNA sequences. Sequence containing the acyclic N7-dG nucleoside are capable of forming DNA triplexes in which it is likely that the N1-H and N2-amino groups of the N7-dG are involved in recognition of the guanine base in G-C base pairs.     

气体动压轴承动态参数测定原理

将气体动压轴压简化为转化气膜系统后，针对其动力特点，给出气膜在微幅振动下动压轴承的实用数学模型和测定动态参数的方法，并进行了测量误差的修正。     

基于多模型半参数非线性回归模型的外弹道节省参数估计

双星定位系统的应用是外弹道估计中的一种发展趋势。文章给出基于双星、光雷的联合测量模型,建立基于半参数回归的外弹道节省参数估计模型;给出基于半参数回归的外弹道节省参数估计算法及计算步骤,并从理论上分析了基于半参数回归的外弹道节省参数估计算法能有效地消除非线性因素对参数估计性能的影响,其估计精度优于经典的节省参数建模方法,并通过仿真得到：该算法确实有效。     

石化行业自动化控制仪表常见故障分析及其处理

介绍化工生产过程中仪表故障及其处理措施。