On distributing JASMIN's optimistic multiversioning page manager

JASMIN is a functionally distributed database system running on multiple microcomputers that communicate with each other by message passing. The software modules in JASMIN can be cloned and distributed across computer boundaries. One important module is the intelligent store, a page manager that includes transaction-management facilities. It provides an optimistic, multiversioning concurrency control scheme. This scheme allows read-only transactions to run almost without conflict checking; this is important in some real-time database applications like telephone switching and routing services. The initial implementation of the intelligent store deals with centralized database only. Experiences in modifying the JASMIN intelligent store module to handle distributed databases are described. Design principles and system implementation techniques in the following areas are explored; process structure, data structures and synchronization on data structures. The process structure is aimed to provide high throughput and the data structures are designed to facilitate fast response time     

Haemolysis complicating acute viral hepatitis in patients with normal or deficient glucose-6-phosphate dehydrogenase activity

Haemolytic anaemia as a complication of acute hepatitis has been reported in up to 23% of patients. However, the incidence may rise up to 70-87% in patients who have glucose-6-phosphate dehydrogenase (G6PD) deficiency. Massive intravascular haemolysis with renal failure, hepatic encephalopathy and even death have been reported. In our retrospective study of patients with acute viral hepatitis, the overall incidence of acute haemolysis was 4% (17/434). Only 53% (9/17) of them had G6PD deficiency. Patients with acute haemolysis had a significantly higher peak bilirubin level and required more prolonged hospitalization. Since hepatitis A virus vaccination, unlike hepatitis B virus vaccination, is not yet recommended for routine immunization, we suggest subjects who are G6PD-deficient should be vaccinated against hepatitis A. In endemic areas of hepatitis A virus infection, universal immunization remains the definitive answer.     

DC60T电炉上氧燃烧嘴的设计及实践

本文主要论述了用自主开发的油氧烧嘴－拉瓦尔烧嘴技术解决ALD520－60T直流炉的EBT冷区及东西炉壁挂料问题，并结合BSE碳氧枪加强二次燃烧应用，使60吨直流炉各项计经指标全面改善。     

方柱和双方柱绕流的数值模拟

通过采用时间分裂步势函数有限元法,求解非定常二维不可压Navier-Stokes方程。对绕单个方柱和串列双方柱的绕流问题进行了数值模拟。给出了随时间变化柱体周围的流速分布,柱体的受力情况。本文计算结果与文献[1]的计算结果及[2]的部分实验结果趋势相符。     

结合射频导纳与差压液位变送器测水中油

通过射频导纳和差压液位变送器测量水中含油性介质的原理，监测冷却水罐内是否有大量油性介质，从而判断苯乙烯冷却器内热交换管有无泄漏，根据水和苯乙烯的介电常数与密度解决这一问题。     

Performance of a proton exchange membrane fuel cell stack using conductive amorphous carbon-coated 304 stainless steel bipolar plates

In this study, 304 stainless steel (SS) bipolar plates are fabricated by flexible forming process and an amorphous carbon (a-C) film is coated by closed field unbalanced magnetron sputter ion plating (CFUBMSIP). The interfacial contact resistance (ICR), in-plane conductivity and surface energy of the a-C coated 304SS samples are investigated. The initial performance of the single cell with a-C coated bipolar plates is 923.9 mW cm⁻² at a cell voltage of 0.6 V, and the peak power density is 1150.6 mW cm⁻² at a current density of 2573.2 mA cm⁻². Performance comparison experiments between a-C coated and bare 304SS bipolar plates show that the single cell performance is greatly improved by the a-C coating. Lifetime test of the single cell over 200 h and contamination analysis of the tested membrane electrode assemble (MEA) indicate that the a-C coating has excellent chemical stability. A 100 W-class proton exchange membrane fuel cell (PEMFC) short stack with a-C coated bipolar plates is assembled and shows exciting initial performance. The stack also exhibits uniform voltage distribution, good short-term lifetime performance, and high volumetric power density and specific power. Therefore, a-C coated 304SS bipolar plates may be practically applied for commercialization of PEMFC technology.     

Visualization of the surface tension and gravitational effects on flow injection in center-gated disks

Flow injection in center-gated disks is numerically studied in this paper for possible applications in the manufacturing of composite materials in microgravity environment. The numerical method, which combines the finite element method with a predictor/corrector scheme, is used to determine the transient flow field. The effects of gravitation and surface tension on the development of flow front profile and velocity field are examined for a wide range of the governing parameters (namely, the capillary and Bonds numbers). It has been found that surface tension tends to hold the flow front in symmetric shape while gravitation is to distort it. The balance of these two forces has significant effects on the front shape, front tip traveling speed and required injection pressure. Good agreement is found between the numerical prediction and the experimental results concerning the advancement of the flow front and the front shape. The present results provide useful information in the design of resin transfer molding process in space.     

综合利用多种测井曲线进行地层划分与对比

地层划分与对比是地质工作的基础,也是油藏描述最基础的工作之一.一定地质历史时期内,相邻区域的沉积环境和沉积物是相似的,其测井曲线组合特征也应该具有一定的相似性.在缺乏标志层时,这种相似性可作为邻井地层(时间单元)对比的依据.只有根据地质规律划分地层并建立正确的等时对比,才能建立合理的地层格架,揭示储集层非均质性,指导油气田的合理开发.     

Discussion on refrigeration cycle for regenerative cryocoolers

Based on review and analysis of thermodynamic efficiency ε of the Carnot cycle and the cycle with two isothermal and two polytropic processes, another thermodynamic cycle with two isentropic and two polytropic processes, which can achieve the Carnot value of thermodynamic efficiency, is testified theoretically. Thermodynamic efficiency expressions of a number of ideal regenerative refrigeration cycles are derived, including the ideal pulse tube refrigeration cycle. A classified branch chart and a plot of ideal thermodynamic efficiency of regenerative refrigeration cycles are given for the purpose of comparison.