提高开启式2F48型活塞式制冷压缩机性能的研究

本文通过对2F4.8制冷压缩机热力过程的计算机模拟,获得气阀参数对压缩机热力性能影响的数据资料,以改进气阀结构。经过试验证明,可提高压缩机制冷量和性能系数10%以上。     

从关联理论看语篇连贯

语篇连贯是语篇与非语篇的最大区别 ,韩礼德和哈桑把语篇的显性衔接看作是连贯的必要前提条件 ,本文对此作了批评 ,并以斯佩尔和威尔逊的关联理论为基点 ,集中讨论用关联认知方法构建连贯的语篇。     

Bayesian Experimental Design for Long-Term Longitudinal HIV Dynamic Studies

The study of HIV dynamics is one of the most important developments in recent AIDS research for understanding the pathogenesis of HIV-1 infection and antiviral treatment strategies. Currently a large number of AIDS clinical trials on HIV dynamics are in development worldwide. However, many design issues that arise from AIDS clinical trials have not been addressed. In this paper, we use a simulation-based approach to deal with design problems in Bayesian hierarchical nonlinear (mixed-effects) models. The underlying model characterizes the long-term viral dynamics with antiretroviral treatment where we directly incorporate drug susceptibility and exposure into a function of treatment efficacy. The Bayesian design method is investigated under the framework of hierarchical Bayesian (mixed-effects) models. We compare a finite number of feasible candidate designs numerically, which are currently used in AIDS clinical trials from different perspectives, and provide guidance on how a design might be chosen in practice.     

民族艺术展演空间的审美想像——湘西德夯苗寨的个案分析

民族艺术展演空间的建构是与民族艺术展演文本的生成紧密相联的,两者同时并进,互补互动。不同样式的展演文本需要不同形式的展演空间,同样,不同特质的展演空间适合不同审美风格的展演文本。受制于展演文本内容的复杂性特点,展演空间的建构因而也显得复杂。它是在对既有文化符号和形式进行陌生化结构重组的基础上,将原本作为自然村落的物理空间转换为置于"他者"视野中的文化世界,使得展演空间呈现为一个开放的、动态的和充满现代性追求意念的审美消费文化空间。     

城市发展中土地供应调控机制初探

一、我国城市土地供应机制的基本特点 1.以需定供,总量不限 我国大多数城市土地供应基本上采用"以需定供,总量不限"的方式,由于城市土地利用规划的滞后,土地管理的力度尚待加强,加上地方政府片面强调"以地生财"、"筑巢引凤",城市土地的供应往往缺乏时段性和空间性,在土地供应总量上也基本没有严格的限制.     

经济责任审计风险的成因与防范

经济责任审计是一项非常严肃的工作。审计评价是否恰当 ,不仅影响对领导干部的业绩评估 ,而且直接关系到审计机关的信誉和形象。这就要求审计人员客观公正 ,尽量降低审计风险。     

政府投资与扶持:解决农村公共产品短缺的中坚力量——渠县农村公共产品供给的调查报告

农村公共产品对农村经济和社会发展起着基础性作用,它与农村经济社会发展和广大农民的幸福安康息息相关.以政府为主导的农村公共产品供给制度对我国农村经济社会的发展能起到非常重要的作用.作为农村经济发展基础的公共产品供给是实施城乡统筹发展战略,也是实现和谐社会和全面建设小康社会社会的重要途径,政府在农村公共产品的供给方面责无旁贷.面对农村与世界市场经济的接轨和重大的经济结构调整对农村公共产品的巨大需需求和现代农民日益增长的物质文化生活水平的需求,农村公共产品短缺的问题是当地政府应当高度重视的问题.     

鲁迅视野中的屈原

本文结合鲁迅评价屈原的文章和相关言论，指出鲁迅运用阶级的、历史的观点评说屈原，达到了同时代文学史家所难达到的高度。鲁迅评价屈原，不仅看其“全人”，而且看其“全文”，避免了评价的狭隘性、单一性和片面性。     

实现以人为本的的图书馆服务理念

"用户至上,服务第一"是图书馆的核心价值观,图书馆的服务质量直接影响着图书馆工作的发展。本文介绍了新时期图书馆读者服务工作的特征,探讨了图书馆的以人为本、个性化服务内容和服务方式。     

A partial score test for difference among heterogeneous populations

In event time data analysis, comparisons between distributions are made by the logrank test. When the data appear to contain crossing hazards phenomena, nonparametric weighted logrank statistics are usually suggested to accommodate different-weighted functions to increase the power. However, the gain in power by imposing different weights has its limits since differences before and after the crossing point may balance each other out. In contrast to the weighted logrank tests, we propose a score-type statistic based on the semiparametric-, heteroscedastic-hazards regression model of Hsieh [2001. On heteroscedastic hazards regression models: theory and application. J. Roy. Statist. Soc. Ser. B 63, 63–79.], by which the nonproportionality is explicitly modeled. Our score test is based on estimating functions derived from partial likelihood under the heteroscedastic model considered herein. Simulation results show the benefit of modeling the heteroscedasticity and power of the proposed test to two classes of weighted logrank tests (including Fleming–Harrington's test and Moreau's locally most powerful test), a Renyi-type test, and the Breslow's test for acceleration. We also demonstrate the application of this test by analyzing actual data in clinical trials.