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采用惰性膜反应器(IMR)和固定床反应器(FBR)研究了V-Mg-O催化剂上丁烷氧化脱氢制丁二烯和丁烯的反应,采用在陶瓷膜上部分涂釉方法得到的惰性膜的渗透率符合实验要求,用多级全混流模型描述IMR中丁烷氧化脱氢反应,数学模型的计算结果与实验结果相差较小,分析了IMR和FBR中轴向气体分压,反应速率及瞬时选择性的分布,结果表明,用惰性陶瓷膜管作为空气分布器的膜反应器,可以降低丁烷氧化脱氢反应中催化剂床层的氧气分压,提高C4烯烃(丁二烯和丁烯)的选择性。 相似文献
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王立秋 《山东大学学报(工学版)》1991,(3)
引入外功的概念,导出构成(火用)分析理论基础的三个基本定理,给出一个明确的物质系统(火用)的定义和常用物质系统(火用)的表达式。 相似文献
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档案信息化建设是新时期档案部门的一项基础性业务工作,是档案工作向现代化迈进的必由之路,是档案工作实现历史与未来有机链接的战略之举,是全面提升档案工作为社会服务能力的不可或缺的手段. 相似文献
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采用C语言搭建了碳化硅(SiC)晶体生长炉三维温度场数值模拟平台,基于柱坐标系构建生长炉物理模型,采用有限体积法离散数学模型,利用S2S(Surface to Surface)辐射模型考察了生长室内的辐射换热特性,提出判断辐射面可视性的最短距离法. 模拟了电流强度1250 A、电流频率16 kHz条件下的生长炉温度场,定量揭示了生长室内的辐射换热强度;采用标准偏差法研究了线圈结构对晶体内部温度及温度梯度均匀性的影响. 结果表明,螺旋电磁加热线圈容易导致生长炉内部温度场呈非轴对称特性分布;辐射热流较导热热流大102~103倍,辐射换热促使生长室内温度分布均匀;螺旋线圈的布置方式使晶体截面温度呈非轴对称分布,造成温度梯度的均匀性变差,晶体生长过程中容易产生热应力,影响晶体质量. 相似文献
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The main cause to the deactivation of ZSM-5 catalyst, used for oxidation of benzene to phenol (BTOP) by nitrous oxide, is that the carbon deposition on the catalyst surface blocks the mouth of pores of the catalyst.In the experiments, ZSM-5 catalyst was modified by chemical surface deposition of silicon, and then the effect of modification condition on the catalyst activation was studied. The catalyst samples were characterized by XRF,EPS, XRD, TEM, N2 adsorption at low temperature, pyridine adsorption-infrared technique and etc. All the above results show that the uniform SiO2 membrane can be formed on ZSM-5 crystal surface. The SiO2 membrane covers the acid centers on ZSM-5 surface to inhibit surface coking, to avoid or decrease the possibility of ZSM-5 pore blockage so that the catalyst activity and stability can be improved efficiently. The optimum siliconiting conditions determined by the experiments are as follows: 4% load of silanizing agent, volume (ml)/mass (g) ratio of hexane/ZSM-5=15/1, and 16 h of modification time. Compared with the samples without siliconiting treatment,the samples treated under the above optimum condition can increase the productivity of phenol by 14% for 3 h reaction time and by 41% for 6 h reaction time respectively. 相似文献