室内热舒适性指标PMV影响因素分析与研究

服装热阻、空气温度及气流速度是影响人体热舒适性的三个主要因素。本文针对上送上回气流分布方式，采用K-ε湍流模型及热舒适性指标PMV数学分析式，对室内三维湍流流动和传热及PMV指标进行了数值模拟，研究不同送风速度下的室内流场、温度场及PMV值分布变化规律，并分析比较了不同送风速度、送风温度及服装热阻对室内PMV值的影响。研究结果表明：送风速度是影响室内流场、温度场及PMV值分布模式的主要因素，送风温度的改变对PMV值有一定的影响，而室内人员的服装热阻对PMV值的影响较大。本文的研究对如何合理确定空调送风参数，达到满足热舒适性的目的奠定了理论基础，同时促进了以人居舒适为核心的空调技术发展。     

基于热舒适性的SARS病房内空调参数探讨

SARS病房内医护人员的服装热阻偏大,传统的空调参数不能满足医护人员的热舒适性要求。采用数值模拟的方法,针对不同的室内设定温度、空调送风温度及送风速度,计算得到室内热舒适性指标PMV值的分布情况,最终确定合理的空调参数,达到改善SARS病房内医护人员工作热环境的目的。     

置换通风室内热舒适性影响研究

利用商业软件FLUENT。对置换通风室内热环境进行了数值模拟,根据计算出的流场、温度场,计算了PMV,采用正交实验方法考察了各因素的影响结果;根据PMV分布分析了送风口类型、送风速度和温度等因素对室内热舒适性的影响,并对实验设计的水平组合进行优化。结果表明：正交实验中,送风主要影响送风口附近区域的PMV,各工况PMV总体变化趋势趋于一致：送风速度是影响室内热舒适性最为显著的因素;送风速度为0．25m／s或送风温度为18℃的几种工况下所得到的室内热环境相对较好。     

环境因素对PMV指标的影响分析

热舒适指标PMV受环境因素和人的因素的影响。本文以大于舒适性空调房间室内环境参数的设计规范要求范围为例，着重分析了环境因素，即空气温度、平均辐射温度、空气中水蒸汽的分压力(或相对湿度)、空气流速对PMV指标的影响。提出了基于PMV指标的控制方法比基于恒定温度的传统控制方法更具有合理性。从而为改善室内热环境的舒适性提供了途径、方法和依据。     

医院空调节能运行方案及其舒适性研究

采用K-ε湍流模型对病房内三维紊流流动和传热进行了数值模拟，计算得到单元式集中空调系统与全热换热器在三种不同运行模式下室内热舒适性指标PMV及PPD的分布情况。通过比较不同运行模式下人体活动区域内的热舒适性指标分布情况，确定空调系统与全热换热器的节能运行方案。     

影响空调列车车厢内热舒适性的因素分析

分析了空气温、湿度变化对PMV值的影响,为采用基于PMV指标的热舒适性控制以改善车厢内热环境的舒适性提供了参考。     

室内环境热舒适指标PMV的神经网络预测及应用

智能化空调机以环境热舒适为控制目标,而PMV指标是环境热舒适评价的国际标准。本文采用人工神经网络的方法实现了对环境热舒适指标PMV的预测。试验证明这种新颖的方法是有效可行的。文中也给出了PMV指标在空调机控制中的应用。     

服装热阻在PMV计算中的影响

热舒适指标PMV的计算包含6个因素,使用Matlab编制计算程序,使复杂计算变得简单.对服装热阻对于PMV计算的影响进行了计算分析,主要计算了在制冷和采暖时,当服装热阻不同情况下室内温度和室内风速对PMV指标计算的影响,并绘制成图.为PMV计算时根据热环境采用不同服装热阻提供了借鉴和依据.     

教室中央空调联合风扇运行人体热舒适模拟分析

以南方某高校教室为研究对象,选取PMV、PPD指数为热舒适评价指标,结合实际状况采用CFD模拟,研究空调吊柜与风扇组合条件不同工况下对室内气流温度场、速度场和PMV、PPD指数的影响,分析室内热舒适状况。结果显示,适当提高室内设计温度与风速,可以满足热舒适要求。     

不同换气次数下室内热环境的模拟

供暖方式不同时，房间换气次数的高低将对室内热环境产生明显的影响。本文用数值模拟的方法对三种典型供暖方式在不同换气次数下的室内热状况分别进行了模拟和分析。结果表明，在换气量较大时，三种供暖方式对应的室内气温和热舒适指标PMV分布将具有不同的特征。因此，对于大换气量房间，供暖方式的选择应综合考虑热环境特点。     

Flow-Induced Instabilities in Pump-Turbines in China

The stability of pump-turbines is of great importance to the operation of pumped storage power (PSP) stations. Both hydraulic instabilities and operational instabilities have been reported in PSP stations in China. In order to provide a reference to the engineers and scientists working on pump-turbines, this paper summarizes the hydraulic instabilities and performance characteristics that promote the operational instabilities encountered in pump-turbine operations in China. Definitions, analytical methods, numerical and experimental studies, and main results are clarified. Precautions and countermeasures are also provided based on a literature review. The gaps between present studies and the need for engineering practice are pointed out.     

Differences in coagulation in clotting of vascular access in hemodialysis patients

Arteriovenous graft (AVG) thrombosis is a frequent cause of graft failure. We evaluated coagulation protein concentrations, platelet function, and viscoelasticity factors in 20 hemodialysis (HD) patients with AVGs. The goal was to determine whether significant differences in protein concentrations, platelet function, and viscoelasticity factors exist among dialysis patients requiring frequent AVG declot procedures vs. those who do not. Twenty HD patients were enrolled: 10 frequent clotters (>3 declots in the previous year) and 10 were nonclotters. Patients on antiplatelets or chronic anticoagulation were excluded. Laboratories were drawn pretreatment and heparinase was added to counteract any potential heparin effect. Coagulation protein concentrations including tissue factor (TF), thrombin/antithrombin III complex (TAT), and prothrombin fragment 1 + 2 (F₁₊₂) were assayed. The time to clot onset was measured by force onset time (FOT). Platelet contractile force (PCF) measured the force produced by platelets during clot retraction, whereas clot rigidity was measured as clot elastic modulus (CEM). FOT, CEM, and PCF were measured by Hemodyne. Both groups had upregulation of the TF pathway, as TF, TAT, and F₁₊₂ levels were similarly increased over baseline levels. Hemodialysis patients with frequent AVG clotting had higher levels of both PCF and CEM compared with nonclotters. Additionally, the frequent clotters had a lower FOT relative to nonclotters, although both were considered in the normal range. Our study suggests that HD patients with recurrent AVG thrombotic events form clots with higher tensile strength compared with HD patients without recurrent graft thrombosis.     

Trends in alcohol-impaired driving in Canada

While a general decreasing trend in the number of persons killed in a traffic crash involving a drinking driver has occurred in Canada since the 1980s, it is evident that much of this decrease occurred in the 1990s. Since 2002, less progress has been made as the number of persons killed in crashes involving drinking drivers remains high. To better understand the current situation, this paper describes trends in drinking and driving in Canada from 1998 to 2011 using multiple indicators based on data collected for the Traffic Injury Research Foundation's (TIRF) Road Safety Monitor (RSM), the National Opinion Poll on Drinking and Driving, and trends in alcohol-related crashes based on data collected for TIRF's national Fatality Database in Canada. There has been a continued and consistent decrease in the number of fatalities involving a drinking driver in Canada. This remains true when looking at the number of fatalities involving a drinking driver per 100,000 population and per 100,000 licensed drivers. This decreasing trend is also still apparent when considering the percentage of persons killed in a traffic crash in Canada involving a drinking driver although less pronounced. Data from the RSM further show that the percentage of those who reported driving after they thought they were over the legal limit has also declined. However, regardless of the apparent decreasing trend in drinking driving fatalities and behaviour, reductions have been relatively modest, and fatalities in crashes involving drivers who have consumed alcohol remain high at unacceptable levels.     

Gender differences in publication productivity in psychology in India

An analysis of gender differences in psychology in India provides quantitative and qualitative assessment of R&D output contributed by psychologists with the indication of the trend of growth, skewness, relatedness, co-authorship pattern of productivity.     

离子液体中电沉积的研究进展

离子液体作为绿色溶剂和可设计性溶剂越来越受到重视.对电沉积来说,离子液体融合了高温熔盐和水溶液的优点.分别综述了AlCl3型离子液体、非AlCl3型离子液体和其他新型离子液体3类离子液体中电沉积的研究现状,在此基础上指出了目前尚存在的问题及今后的研究方向.采用离子液体进行电沉积能克服传统水溶液电沉积时存在的缺点,为电沉积领域找到了新的突破点,是一种很有应用前景的方法.     

高聚物银纹化的研究进展

结合最新的研究进展,对银纹引发、生长与断裂,银纹细观结构以及裂纹在银纹中的扩展等问题作了较全面的介绍和分析,对这一领域未来的研究方向和重点进行了展望。     

铁电陶瓷中电畴翻转研究进展

电畴为铁电陶瓷固有的独特微观组织特征之一,铁电陶瓷的许多性能均与其密切有关.综述了铁电陶瓷中的电畴结构,系统介绍了电场、机械作用引起的电畴翻转,概述了电畴翻转对铁电陶瓷断裂韧性的影响及其研究进展.     

Standardization in the Cultural Heritage in China

China has begun its standardization process in the cultural heritage since 1960.The standards contributed a lot to the development of the heritage conservation practices. In this paper, the author summaries the existing condition of standardization in the cultural heritages and museums field in China, and presents Standards for the Classification of Collected Cultural Heritages. Also this paper points out the problems which exist in the standardization in the cultural heritage, and gives the advice to solve these problems.