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1.
强化单相对流换热的基本机制   总被引:4,自引:2,他引:2  
对强化对流换热的强化机制研究的进展做了回顾与综述,包括:①将场协同原理从抛物形流动推广到椭圆形流动.②通过数值模拟与试验的手段,对场协同原理进行了多方面的验证,特别是设计了专门的试验台,验证了当流速与流体的温度梯度方向垂直时流体流动对该方向的热量传递没有贡献.③用数值分析实例论证了场协同原理能将现有文献中三种关于强化传热的解释统一起来,从而是一种最基本的强化传热的机制.④应用场协同原理开发了两种高效强化传热结构,它们与基本结构相比,具有传热强化的倍率高于阻力增加的比的特点.最后提出了场协同原理需要进一步研究的内容.  相似文献
2.
Several kinds of alkylenebis(dialkyldithiocarbamates) were synthesized and the tribological properties as additives in base oil (100N) and Li-soap greases were evaluated using 4-ball tester and SRV tester (Schwingreibverschleissprüfung für Schmierstoffe). The results show that all additives reduce wear. Especially, when Mo(Zn)-donor additives such as Mo-DTC, Zn-DTP, and a vegetable oil modified organomolybdenum complex were blended in base oil containing methylenebisdibutyldithiocarbamate as sulfur donor, synergism was seen both in terms of oxidation stability through thermo gravimetric analysis (TGA) and wear properties using a 4-ball tester. TGA showed that oils containing sulfur-donor and Mo(Zn)-donor additive mixtures possess improved oxidation stabilities. Also, these oils have good antiwear properties under mild pressure conditions. The elemental composition of the antiwear films generated on steel counterfaces were investigated with scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). It was found that sulfur-donor and Mo-donor additives reacted with the counterface metal and generated a surface protective film consisting of FeS and MoS2.  相似文献
3.
制造业信息技术应用之间的协同效应分析方法   总被引:1,自引:0,他引:1  
应用信息技术是企业提高其竞争能力的重要手段之一。企业实施的各种信息技术应用通过信息集成组成企业的信息技术应用组合系统,各子系统互配合而产生协同效应,使得系统总体功能可以大于各子系统功能之和。协同效应分析对于信息应用的可行性分析和企业信息技术应用水平的正确评价具有重要意义。本文给出的协同效应分析方法以及计算机排样为例,首先通过信息技术应用的功能原理分析绘制考察的应用与其它各种信息技术应用之间的数据流表,然后根据信息流表对协同系数进行估计,根据协同系数计算信息技术的权数。最后说明了协同效应分析方法的应用价值。  相似文献
4.
协同及其在制造业信息化中的典型应用   总被引:1,自引:0,他引:1  
分析了对于协同概念理解的差异性,并对制造业信息化领域中的几种典型的协同应用模式和发展趋势进行了探讨。  相似文献
5.
供需链协同的定量评价   总被引:1,自引:0,他引:1  
供需链协同是供需链系统在某种契约或合作机制下,在各成员企业个体利益满意的前提下达到整体利益最大化的状态.供需链系统并不是在任意合作机制下都可以达到协同状态.为评价供需链系统的协同程度,引入供需链协同度的概念及其计算方法,并通过理论分析和数值仿真结果,验证了其有效性.供需链协同度指标不仅反映供需链系统运作的资源利用率,也为改进契约设计、提高供需链系统的协同性能提供了数量依据.  相似文献
6.
Robert J.K. Wood 《Wear》2006,261(9):1012-1023
Increasingly the demands of modern fluid handling systems are for low costs with increased reliability and longevity along with no loss of fluid containment. These cannot be achieved without minimising the material damage caused by the combined surface degradation mechanisms of erosion and corrosion when systems are handling solids or are cavitating. This paper reviews the rationale behind the selection of erosion resistance surfaces for fluid handling equipment and highlights the complexities encountered when these surfaces are exposed to environments which contain sand particles or cavitation in a corrosive medium. The erosion and erosion-corrosion performance of a variety of coatings and bulk surfaces are discussed using volume loss rate versus sand impact energy maps. Synergistic terms are identified using standard deviation ratios of electrochemical current noise. Recent researches on the erosion-corrosion of coatings of aluminium, cermets and nickel aluminium bronze are reviewed as candidates for erosion-corrosion resistant surfaces. Electrochemical techniques designed to monitor the erosion-corrosion mechanisms and coating integrity are used to quantify the synergistic terms present when both erosion and corrosion act simultaneously.  相似文献
7.
浅谈制造物联与集成协同技术应用中注意的问题及对策   总被引:1,自引:0,他引:1  
姚燕茹 《机械管理开发》2012,(4):131-132,134
选取经纬股份公司实施应用物联与集成协同技术为研究对象,详细论述了企业实施该技术的必要性。在进行深入探讨的同时,提出了企业实施和应用过程中应注意的技术及管理问题。  相似文献
8.
Erosion by solid particles in oil/water slurries is a technologically important area. In such conditions, it is necessary to distinguish between the effects of the sand, aqueous environment, and the oil. Erosion-corrosion maps provide a means of identification between erosion-corrosion regimes as a function of erosion and corrosion parameters. However, there has been no work carried out to map the effects of parameters in oil/water slurries. This paper investigates the effect of erosion-corrosion on carbon steel in oil field production and maps the results. Distinctions between “synergistic” and “additive” erosion-corrosion behaviour are superimposed on the maps in the various environments.  相似文献
9.
透视丰田第二代普锐斯混合动力汽车技术   总被引:1,自引:0,他引:1  
介绍丰田第二代普锐斯混合动力汽车整车性能参数,采用的新一代油电混合动力系统(THS—Ⅱ)以及其他大量的新技术。  相似文献
10.
A rubber wheel type test apparatus has been constructed which allows abrasion testing to be conducted in slurry or dry environments in otherwise identical conditions. Abrasion tests of a steel, a sintered tungsten carbide–cobalt hardmetal and an HVOF sprayed nickel chrome–chromium carbide cermet coating have been performed in dry and aqueous slurry conditions, the latter with both neutral and acidic carriers. It has been shown that the aqueous carrier acts as an effective lubricant and thus significantly reduces the abrasion rate over that observed in dry conditions. However, enhancement of corrosion by use of an acid slurry lead to an increase in the rate of material removal over that of the neutral aqueous conditions in all cases. Increases were small for the corrosion resistant cermet coating and moderate for the steel. Significant enhancement of wear was observed for the sintered WC–Co hardmetal where rapid removal of the cobalt binder by the acid resulted in a change in dominant mechanism of carbide removal from attritive wear to pullout.  相似文献
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