中日铁路项目国民经济评价方法比较与分析

以日本《铁路费用效益分析手册 (99版 )》和中国《铁路建设项目经济评价办法 (第 2版 )》为参照 ,通过对比分析中日铁路项目国民经济评价方法的差异 ,提出日本铁路费用效益分析方法中的可借鉴之处 :借鉴日本评价方法分 3类界定受益群体的思路 ,解决我国现行方法存在的效益重复计算问题 ;以福利经济学和“有无对比法”作为项目评价的基本指导原则 ,解决我国由于评价原则模糊导致的同一项目不同评价结论的问题等     

Induced recovery of defective membrane expression of a CC chemokine receptor 5 mutant by phytohemagglutinin

CC chemokine receptor 5 (CCR5) is a member of the G-protein-coupled receptor superfamily. It plays an important role in macrophage tropic human immunodeficiency virus-1 entry and in some inflammatory reactions. CCR5-893(–) is a single-nucleotide deletion that results in complete truncation of the C tail of the gene product. We detected CCR5-893(–) in a sample of patients infected with non-tuberculosis mycobacteria and found that it was maintained heterozygously with a frequency of 2%. There is no association between this mutation and any immunodeficiency. Membrane expression of CCR5-893(–) was substantially reduced compared to the wild type, but this defective surface presentation recovered greatly recovered in the presence of 2 mg l-1 phytohemagglutinin (PHA). However, PHA inducement did not affect the total intracellular expression of CCR5-893(–) or wild-type CCR5. Thus we suggest there exist some PHA-induced factor(s) that could mediate the presentation of truncated CCR5.Received 23 July 2003; accepted 18 August 2003     

Research on data combination for Phased-array Ground Penetrating Radar

0　IntroductionGroundPenetratingRadar (GPR)isanewandefficientex ploringmeanstodetecttheobjectinshallowsubsurface.Comparedwithotherdetectingmethods,GPRhasmanyadvan tages,suchasquickness,highresolution ,convenientoperationetc.SoGPRisappliedtonationaldefenseandnationaleconomy .IndevelopmentofGPRtechnology ,therecomeforthcontinuous waveradar,FMcontinuous waveradar,andshockpulseradar.Amongoftheseradars,shockpulseradarsendsgreatamplitudeimpulsewithperiodinns,receivingequivalentsamplingtoreali…     

A CORBA-Based Multidatabase System——Panorama Project

0　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｎｅｅｄｆｏｒｉｎｔｅｇｒａｔｉｏｎｏｆｄｉｆｆｅｒｅｎｔｄａｔａｂａｓｅｍａｎａｇｅｍｅｎｔｓｙｓｔｅｍｓ (ＤＢＭＳｓ) ,ｍａｋｉｎｇｄｉｆｆｅｒｅｎｃｅｓｂｅｔｗｅｅｎｔｈｅｓｅｓｙｓｔｅｍｓｉｎｖｉｓｉｂｌｅａｎｄｐｒｏｖｉｄｉｎｇｕｓｅｒｓｗｉｔｈａｕｎｉｆｏｒｍａｃｃｅｓｓｔｏａｌｌｔｈｅｄａｔａｂａｓｅｓｈａｓｇｒｏｗｎｒａｐｉｄｌｙｄｕｒｉｎｇｔｈｅｌａｓｔｄｅｃａｄｅ .Ｈｏｗｅｖｅｒ,ｄａｔａｂａｓｅａｕｔｏｎｏｍｙａｎｄｈｅｔｅｒｏｇｅｎｅｉｔｙ…     

商业银行构建"金融超市"路径初探

文章阐述了商业银行构建“金融超市”的成因、必要性,提出通过商业银行经营实体的微观金融创新和金融监管部门的金融制度创新互动来构建“金融超市”。     

叩问“经典”：《雷雨》主题、人物及其它

曹禺的《雷雨》从问世以来,就一直处在不断的争论之中,但它仍然获得了“精品”、“经典”的美誉。然而,《雷雨》表现的主题,描写的主要人物以及运用的艺术技巧表明：《雷雨》是一部思想上极其幼稚、单纯,艺术上极其笨拙、不成熟的作品。有必要将其还原到曹禺当时的思想实际和创作实际中。     

冲激信号的产生技术研究

将冲激脉冲的产生技术分为两类利用储能电路和高速开关的传统产生技术和利用周期信号傅立叶级数的傅立叶合成技术.全面介绍了各种形式的产生方法及其目前所具备的技术水平.分析比较了各类方法的优缺点以及在应用中所要注意的问题.     

诗骚性情漂泊魂－－杨骚心解

现代学史研究中有一种“寻找－转变－定格”的评价模式,以此来评价诗人杨骚多有失当。作为一位浪漫诗人,诗骚性情是进入其艺术世界的关键入口,贫病、多情、精神漂泊是他诗骚性情的一体三面。他的创作活动主要活跃于20－30年代,而他最好的诗作就在前期而不是在“转变”之后。即便是“转变”后的创作、爱情生活和社会政治活动也能够从其诗骚性情作由内而外的解释。     

Dynamic instabilities and memory effects in vortex matter

The magnetic flux line lattice in type II superconductors serves as a useful system in which to study condensed matter flow, as its dynamic properties are tunable. Recent studies have shown a number of puzzling phenomena associated with vortex motion, including: low-frequency noise and slow voltage oscillations; a history-dependent dynamic response, and memory of the direction, amplitude duration and frequency of the previously applied current; high vortex mobility for alternating current, but no apparent vortex motion for direct currents; and strong suppression of an a.c. response by small d.c. bias. Taken together, these phenomena are incompatible with current understanding of vortex dynamics. Here we report a generic mechanism that accounts for these observations. Our model, which is derived from investigations of the current distribution across single crystals of NbSe2, is based on a competition between the injection of a disordered vortex phase at the sample edges, and the dynamic annealing of this metastable disorder by the transport current. For an alternating current, only narrow regions near the edges are in the disordered phase, while for d.c. bias, most of the sample is in the disordered phase--preventing vortex motion because of more efficient pinning. The resulting spatial dependence of the disordered vortex system serves as an active memory of the previous history.     

关于产权明晰问题的探讨

本文研究产权明晰问题,提出了产权明晰的三个层次,即国家与公民和法人企业、投资者之间及其企业、企业与员工三个层次的产权明晰问题,国有企业现在的产权明晰主要是指第一和第二层次的产权明晰;在第三层次上的要素价格市场化才是产权明晰的关键;引入多元投资主体仅有助于明晰第三层次的产权;产权明晰是经济人利益主体之间的一个动态博弈工程。