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渣油中沥青质的缔合状况与热生焦趋势研究 被引量:14
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作者 王宗贤 张宏玉 +1 位作者 郭爱军 阙国和 《石油学报(石油加工)》 EI CAS CSCD 北大核心 2000年第4期60-64,共5页
分别以苯、氯代苯和硝基苯为溶剂用 VPO法研究了辽河、孤岛、胜利和大庆减压渣油中沥青质在不同溶剂和不同温度下的分子缔合状况及渣油热转化过程中沥青质平均相对分子质量、缔合度的变化规律及其与生焦行为的内在关系。结果表明 ,在苯... 分别以苯、氯代苯和硝基苯为溶剂用 VPO法研究了辽河、孤岛、胜利和大庆减压渣油中沥青质在不同溶剂和不同温度下的分子缔合状况及渣油热转化过程中沥青质平均相对分子质量、缔合度的变化规律及其与生焦行为的内在关系。结果表明 ,在苯溶液中原生沥青质以 2~ 3个分子缔合 ,渣油热处理后的残渣油中的沥青质以3~ 6个分子缔合 ;沥青质缔合指数与渣油的热生焦趋势有一定的相关性 ;以硝基苯为溶剂所测得的沥青质平均相对分子质量更能反映沥青质化学结构的实质。 展开更多
关键词 沥青质 缔合度 趋势 渣油 热生焦
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Radiative squeezing flow of unsteady magneto-hydrodynamic Casson fluid between two parallel plates 被引量:2
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作者 N. B. NADUVINAMANI Usha SHANKAR 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第5期1184-1204,共21页
Present numerical study examines the heat and mass transfer characteristics of magneto-hydrodynamic Casson fluid flow between two parallel plates under the influence of thermal radiation,internal heat generation or ab... Present numerical study examines the heat and mass transfer characteristics of magneto-hydrodynamic Casson fluid flow between two parallel plates under the influence of thermal radiation,internal heat generation or absorption and Joule dissipation effects with homogeneous first order chemical reaction.The non-Newtonian behaviour of Casson fluid is distinguished from those of Newtonian fluids by considering the well-established rheological Casson fluid flow model.The governing partial differential equations for the unsteady two-dimensional squeezing flow with heat and mass transfer of a Casson fluid are highly nonlinear and coupled in nature.The nonlinear ordinary differential equations governing the squeezing flow are obtained by imposing the similarity transformations on the conservation laws.The resulting equations have been solved by using two numerical techniques,namely Runge-Kutta fourth order integration scheme with shooting technique and bvp4c Matlab solver.The comparison between both the techniques is provided.Further,for the different set physical parameters,the numerical results are obtained and presented in the form of graphs and tables.However,in view of industrial use,the power required to generate the movement of the parallel plates is considerably reduced for the negative values of squeezing number.From the present investigation it is noticed that,due to the presence of stronger Lorentz forces,the temperature and velocity fields eventually suppressed for the enhancing values of Hartmann number.Also,higher values of squeezing number diminish the squeezing force on the fluid flow which in turn reduces the thermal field.Further,the destructive nature of the chemical reaction magnifies the concentration field;whereas constructive chemical reaction decreases the concentration field.The present numerical solutions are compared with previously published results and show the good agreement. 展开更多
关键词 squeezing flow thermal radiation heat generation or absorption Casson fluid Joule dissipation magnetic field
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