金属气化热与气化熵的经验估算     

梅平  李爱国 《湘潭师范学院学报(社会科学版)》1990,(6)

在详细分析金属气化热实验数据的基础上,本文总结出如下经验公式为金属的气化熵(KI·k-~1·mol-~1),T_b为沸点(k)。  相似文献   

太阳能、空气源热泵系统、锅炉供暖联合供热方式的探讨     

张明昭 《河北能源职业技术学院学报》2008,8(4):61-63

本文针对唐山市某示范工程中应用的太阳能-空气源热泵-锅炉供热联合使用技术进行阐述,分析了三者联合运行的技术可行性,强调了可再生能源综合利用的必要性。  相似文献   

热处理对A356合金力学性能的影响     

刘栓江  李建新  刘忠侠 《安阳工学院学报》2008,(2):24-27

通过对比实验研究了在相同Ti含量和相同钛硼比Wti/WB时,热处理对以不同加Ti、B方式（电解加钛,熔配加钛,钛盐加钛,电解加钛＋Al-B,熔配＋Al-Ti-B,钛盐加钛＋硼盐）配制的A356合金的冲击韧度的影响。结果表明：T5、T6热处理工艺较大提高了A356合金的强度,明显改善了A356合金的冲击韧度;T5、T6工艺对A356合金的强度、冲击韧度的影响差别较小,T6略优;不同的加钛方式对A356合金冲击韧度有显著的影响,电解加钛合金表现出比其他加钛方式具有更好的韧度。  相似文献   

Numerical simulation and optimization design of the EGR cooler in vehicle     

Yu-qi Huang  Xiao-li Yu  Guo-dong Lu 《浙江大学学报(A卷英文版)》2008,9(9):1270-1276

The EGR （exhaust gas recirculation） technique can greatly reduce the NOx emission of diesel engines, especially when an EGR cooler is employed. Numerical simulations are applied to study the flow field and temperature distributions inside the EGR cooler. Three different models of EGR cooler are investigated, among which model A is a traditional one, and models B and C are improved by adding a helical baffle in the cooling area. In models B and C the entry directions of cooling water are different, which mostly influences the flow resistance. The results show that the improved structures not only lengthen the flow path of the cooling water, but also enhance the heat exchange rate between the cool and hot media. In conclusion we suggest that the improved structures are more powerful than the traditional one.  相似文献   

Theoretical and experimental research on heat transfer performance of the semi-open heat pipe     

Hua ZHU Bo ZHUAN Jin-jun TAN Rong-hua HONG 《浙江大学学报(A卷英文版)》2008,9(3):410-415

This paper focuses on the heat transfer performance of semi-open heat pipe which is a new type of heat pipe. After analyzing its condensation heat transfer mechanisms theoretically, several semi-open heat pipes in different length ratios and upper hole diameters are studied experimentally and compared with the same dimensions closed heat pipes. Experimental results show that the heat transfer performance of semi-open heat pipe becomes better by increasing heat transfer rate. At the first transitional point, the heat transfer performance of semi-open heat pipe approaches the level of the closed heat pipe. It is suitable to choose upper small hole about 1 mm in diameter and length ratio larger than 0.6 for the semi-open heat pipe.  相似文献   

计及两阶段需求侧响应荷源协调消纳弃风调度模型     

杨晓辉  芮松宏  陈再星  徐青山  黄鑫 《实验室研究与探索》2021,(2):1-7

提出一种针对弃风消纳的日前日内两阶段调度模型。与传统的热电联合模型相比,引入了基于消费者心理学模型的价格需求响应,其通过极具代表性的历史数据拟合得来且充分考虑用户对电价的响应规律,更符合实际用户情况,最大程度对负荷进行削峰填谷以应对风电的反调峰特性,为风电上网提供空间。日内引入激励性需求响应协调调度,调度模型是以系统总经济成本最小为目标函数的混合整数规划问题。以某地电网为算例表明:所提模型有效,系统总运行经济成本明显减少,弃风状况得到改善。  相似文献   

微型管带式冷凝器的性能实验研究     

汪洪伟  崔廷  俞坚  马重芳 《实验技术与管理》2008,25(2):36-39

建立了微型冷凝器测试实验台,在微型管带式冷凝器内进行了制冷剂(R134a)的冷凝实验,获得了空气侧和制冷剂侧流动阻力关系式,并与前人实验结果进行了比较,验证了设计换热量.  相似文献   

Implementation of service-learning in engineering and its impact on students’ attitudes and identity   总被引：1，自引：1，他引：0  

N. Dukhan  M.R. Schumack  J.J. Daniels 《European Journal of Engineering Education》2008,33(1):21-31

The current paper outlines a concise engineering service-learning model and describes its implementation and logistics in the context of a typical heat transfer course for undergraduate engineering students. The project was executed in collaboration with a not-for-profit organisation. Summative reflections were conducted by the students by answering a set of carefully-phrased questions after conducting the project. The students had to write about their feelings, attitudes, identity, and the physical, social, ethnic and economical environment they had experienced as they performed the service. A quantitative method for analysing reflections is presented. Analysis of the students’ responses clearly showed that they became more aware and sensitive to their roles as engineers in a societal context.  相似文献   

CD44v6mRNA和HSP70mRNA在胃癌中的表达及研究     

陈秀玲  杨燕君  张江兰  苏华  郜攀峰  薄爱华  张晓丽  邢立强 《河北北方学院学报(医学版)》2005,22(1):35-37

目的:检测CD44v6mRNA和HSP70mRNA在胃癌组织中的表达,探讨CD44v6mRNA和HSP70mRNA在胃癌发生发展中的作用.方法:利用核酸原位杂交技术对39例胃癌组织进行检测.结果:CD44v6mRNA和HSP70mRNA在胃癌组织表达的阳性率都为61.54%(24/39),CD44v6mRNA和HSP70mRNA在高分化管状腺癌与低分化管状腺癌中的表达都有显著性差异(P＜0.05),但HSP70mRNA在胃癌组织的表达与性别、年龄、浸润深度及淋巴结有无转移都无关(P＞0.05),而CD44v6mRNA与淋巴结有无转移有关(P＜0.05).结论:CD44v6mRNA和HSP70mRNA在胃癌组织都有较高的表达,两者均可作为评估胃癌预后的指标.  相似文献   

大温差空气源热泵热水器实验台的研制     

陈建中  金苏敏  王伟 《实验室研究与探索》2008,27(6):51-54

介绍了研制本实验台的背景,给出了实验台的工作原理图及各主要部件的技术参数。通过实验(在人工环境实验室内)分别对实验台在单级压缩模式及双级压缩模式下的运行特性进行分析比较,显示在低温工况下双级压缩模式的运行性能比单级压缩模式有很大提高。系统设计合理,运行可靠。为进一步研究大温差风冷热泵热水器创造了条件。  相似文献