Diffusive transport with consecutive catalytic wall reactions

A new complete solution is obtained for the plug flow reactor with consecutive catalytic wall reactions at low Peclet number flow. The significant effects of the Peclet number and the wall reaction kinetics on the concentration field, the Sherwood number, the yield of the intermediate product and the optimal reactor length are established. A useful graph for the design purpose is presented for the determination of the optimal yield of the intermediate product B and the reactor length for Pe = 1.     

Potent 2''-amino-, and 2''-fluoro-2''-deoxyribonucleotide RNA inhibitors of keratinocyte growth factor

BACKGROUND: Results of in vitro studies have documented colonic absorption of lactose in the newborn. A stable isotope model was developed for assessing the entry rate of intact lactose into the portal circulation in newborn piglets. METHODS: In experiment 1, unlabeled and [D-1-(13C)]-lactose were infused into two separate mesenteric veins, and in experiment 2, labeled lactose was infused into a mesenteric vein and unlabeled lactose was infused into the colon. The 13C-enrichment of plasma lactose was assessed by high performance liquid chromatography gas chromatography combined with mass spectrometry. RESULTS: The isotopic estimate of the mesenteric venous infusion rate of lactose was 91% of the theoretical. In the second experiment 13% of the unlabeled lactose infused into the colon reached the portal circulation. CONCLUSIONS: The current study provides the first, direct, in vivo confirmation of colon absorption of intact lactose. The tracer model could be used to evaluate intestinal or colonic absorption of other organic compounds not endogenously synthesized, including vitamins or drugs.     

Delivering services by building and running virtual organisations

Customers in the future are likely to obtain their services from coalitions of service providers. These coalitions can be described as virtual organisations (VOs); they are groups of service providers that form relationships to service customers’ demands on an ad-hoc basis. For a VO to be effective, it must be reliable and scalable, and, realistically, it must be created and maintained in a dynamic, open and competitive environment. The CONOISE-G project has focused on resolving the technology challenges that emerged from these requirements. Specifically, CONOISE-G provides mechanisms to assure effective operation of VOs in the face of failure, unexpected events and changing requirements in a dynamic, open and competitive environment. In this paper, we describe the CONOISE-G system, motivated by a scenario based on mobile service provision, outline its use in the context of VO formation and perturbation, and review current efforts to progress the work to deal with unreliable information sources.     

应用高碱值硫化烷基酚钙研制40TBN船用气缸油

介绍了利用新疆中间基础油和兰炼生产的高碱值硫化烷基酚钙为主要清净剂研制４０ＴＢＮ船用气缸油情况。     

钻机顶部驱动电动机的现状与展望

简述了国外钻机顶部驱动系统由直流顶驱逐步演变到变频顶驱的发展历史。结合现有电动顶驱的技术特点,对直流电动机、鼠笼式转子感应电动机、永磁无剧同步电动机和开关磁阻电动机等目前常用和正在开发的几种电动机性能做了分析对比。建议国内研究单位尽快开展开关磁阻电动机驱动方面的资料收集,为新一代顶驱的开发做一些前期工作。     

Recrystallization of YBa2Cu3Ox superconductors in vacuum

YBa₂Cu₃O _x ceramics were recrystallized in vacuum at high temperatures. Recrystallized layers consisting of small grains were observed near the surfaces of the original large-grain 1 2 3 ceramics. The small grains consisted of transformation twins and were identified to orthorhombic 1 2 3 using X-ray diffraction. As vacuum annealing time increased, the thickness of the recrystallized layer increased. The relationship between the thickness and the annealing time showed a linear relationship and an effective diffusion coefficient of 6.25 × 10^–10cm²s^–1. The recrystallized layer showed a critical temperature of 90 K.     

一种用于低频测量的模数转换器

ＡＤ７７１０作为一种信号调节型模数转换器，在低频测量应用中十分理想，在某些应用场合具有不可替代的优势。本文着重对该器件的特性、基本电路以及与８０５１的接口作了介绍。     

Use of a fluorescent radiolabeled triacylglycerol as a substrate for lipoprotein lipase and hepatic triglyceride lipase

A fluorescent radiolabeled triacylglycerol has been synthesized by using a fluorescent fatty acid (pyrene decanoic acid) and a radiolabeled oleic acid. This analog of the natural substrate, 1(3)pyrene decanoic-2,3(1,2)-dioleoyl-sn-glycerol, has been tested as substrate for determining lipoprotein lipase and hepatic triacylglycerol lipase activities in post-heparin plasma. Optimal conditions for the determination of the two post-heparin plasma lipases were similar to those using radiolabeled triolein. Using this substrate, both post-heparin lipases exhibited their characteristic properties (pH optimum and effect of inhibitors) and attacked external ester bonds (1 or 3) containing pyrene decanoic and oleic acids at a similar rate     

用VB6.0实现测漏仪地面系统的软件设计

介绍用VB6．0实现串行通信编程的方法，对采用了RS-232接口的仪器串口读取数据，并将测量数据转存到磁盘上形成数据文件，根据编制的处理系统软件进行数据可视化(图形形式)处理。