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近几年来,我局大力推广红外诊断技术。在大量的实践工作和红外诊断实例中,我们不断对设备热缺陷的特征研究探讨,并积累了一定的经验方法,望电力同行给予指导和建议,共建经验交流平台,携手推进电力设备状态检修工作的快速发展。 相似文献
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Sutthisak Phongthanapanich Suthee Traivivatana Parinya Boonmaruth Pramote Dechaumphai 《Acta Mechanica Sinica》2006,22(2):138-147
Based on flux-based formulation, a nodeless variable element method is developed to analyze two-dimensional steady-state and
transient heat transfer problems. The nodeless variable element employs quadratic interpolation functions to provide higher
solution accuracy without necessity to actually generate additional nodes. The flux-based formulation is applied to reduce
the complexity in deriving the finite element equations as compared to the conventional finite element method. The solution
accuracy is further improved by implementing an adaptive meshing technique to generate finite element mesh that can adapt
and move along corresponding to the solution behavior. The technique generates small elements in the regions of steep solution
gradients to provide accurate solution, and meanwhile it generates larger elements in the other regions where the solution
gradients are slight to reduce the computational time and the computer memory. The effectiveness of the combined procedure
is demonstrated by heat transfer problems that have exact solutions. These problems are: (a) a steady-state heat conduction
analysis in a square plate subjected to a highly localized surface heating, and (b) a transient heat conduction analysis in
a long plate subjected to a moving heat source.
The English text was polished by Yunming Chen. 相似文献
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The gas quenching is a modern, effective processing technology. On the basis of nonlinear surface heat-transfer coefficient obtained by Cheng during the gas quenching, the coupled problem between temperature and phase transformation during gas quenching in high pressure was simulated by means of finite element method. In the numerical calculation, the thermal physical properties were treated as the functions of temperature and the volume fraction of phase constituents. In order to avoid effectual "oscillation" of the numerical solutions under smaller time step, the Norsette rational approximate method was used. 相似文献
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美国IBM研究开发部门IBM Research当地时间2009年3月1日宣布.成功开发出通过电流测量碳纳米管(CNT)发热和热传递的技术。将CNT作为电路元件使用时,该技术有助于收集基本数据和改善性能。详细内容将刊登在英国科学杂志“《自然-纳米技术》(Nature Nanotechnology)”上。 相似文献
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In the framework of Green's function theory out of equilibrium, a Landauer-Buttiker (LB) formula for thermal conductance is derived. A simplified model for describing extremely cold dielectric chains is proposed for the first time. Further we apply the present LB formula for studying thermal conductance at low-lying modes, emerging in dielectric atom chains. We find that quantum thermal conductance undergoes an anomalous transition due to new quasiparticle excitations, resulting from nonlinear atom-atom interactions. This theoretical prediction is in excellent agreement with a high-accuracy measurement to thermal conductance quantum. 相似文献
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《现代表面贴装资讯》2011,(4):6-7
强制控制对流技术:采用ERSA独特的多点回流技术,对传统的强制对流技术进行改革,形成了”强制控制对流”技术。采用该技术增加了热传递系数,降低了温差。多点回流系统形成了一个持续、连贯、均匀的气流区,由于气体垂直经过旁边的各个喷嘴回流,低压区现象、气体的横向及扰乱流动被最大程度的降低了。 相似文献
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Numerical analysis of thermal distortion of the mirror in space-to-ground laser communication links 总被引:1,自引:0,他引:1
LI Xiao-feng ZHANG Bai-lei LIN Mi QI Li-mei 《光电子快报》2005,1(3):209-212
Thereis cold-heat exchange under the large tempera-ture gradient in the space environment ,andin space-to-ground laser communication links the optical reflectorson a satellite in orbit someti mes need to be placed out-side the capsule.Therefore,tremendous thermal distor-tions will occur onthe optical mirror surface,which maybring shift andspreading ofits reflectedfocus andthere-by influences the performance of space-to-ground lasercommunicationlinks . Although there are many reports on thermal… 相似文献