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在由对甲基苯磺酸催化的1,3;2,4-二亚苄基山梨糖醇(DBS)合成的非均相缩醛化反应中,通过对反应规律的研究,以及运用Klymko等提出的一个分形介质上暂态反应的化学动力学模型,得到了适合该过程的山梨糖醇浓度与反应时间的关系,并验证了该过程模型的正确性,得到动力学方程ln1c=0.325 lnt 2.727。 相似文献
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Karin Hain Christoph Hugenschmidt Philip Pikart Peter B?ni 《Science and Technology of Advanced Materials》2010,11(2)
A friction stir welded (FSW) Al alloy sample was investigated by Doppler broadening spectroscopy (DBS) of the positron annihilation line. The spatially resolved defect distribution showed that the material in the joint zone becomes completely annealed during the welding process at the shoulder of the FSW tool, whereas at the tip, annealing is prevailed by the deterioration of the material due to the tool movement. This might be responsible for the increased probability of cracking in the heat affected zone of friction stir welds. Examination of a material pairing of steel S235 and the Al alloy Silafont36 by coincident Doppler broadening spectroscopy (CDBS) indicates the formation of annealed steel clusters in the Al alloy component of the sample. The clear visibility of Fe in the CDB spectra is explained by the very efficient trapping at the interface between steel cluster and bulk. 相似文献
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本文介绍一种建立在Autocad计算机环境下的洞室爆破CAD系统,既称为DBS系统,该系统关键技术是解决洞室爆破设计中药包空间布置及药包调节这一难题。并通过工程实时应用,阐述了DBS系统设计步骤和结果。实践表明,它优化了设计,取得了良好的技术经济效益。 相似文献
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The application of nano-fluids in refrigerating systems is considered to be a potential way to improve the energy efficiency and reliability of HVAC&R facilities and to make economic the use of environment-friendly refrigerants. In this paper, we report a method that uses nanoparticles to enhance the energy efficiency of retrofitted residential air conditioners (RAC) employing HFCs as alternative refrigerants. The reliability and performance of RAC with nanoparticles in the working fluid have been investigated experimentally. A new mineral-based nano-refrigeration oil (MNRO), formed by blending some nanoparticles (NiFe2O4) into naphthene based oil B32, was employed in the RAC using R410a as refrigerant. A method showing how to disperse the NiFe2O4 nanoparticles in the mineral oil refrigeration lubricants is presented together with an investigation of their stability. The solubilities of the new MNRO in R134a, R407C, R410a and R425a were measured. The performances of the RAC, such as the cooling/heating capacity, the power input and the energy efficiency ratio, were determined. The results indicate that the mixture of R410a/MNRO works normally in the RAC. The cooling/heating EER of the RAC increased about 6% by replacing the Polyol-Easter oil VG 32 lubricant with MNRO. 相似文献
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指出面对有线电视数字化 ,网络公司面临的几方面问题 ,提出目前应当着手进行的工作 ,同时对未来将会出现的问题进行简要分析并提出应对措施。 相似文献
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