The flow field in a cold model of 2500 t/d five-stage cyclone preheater and precalciner system was numerically simulated. Renault stress model (RSM) turbulent model was adopted to simulate the flow field, and a hybrid...The flow field in a cold model of 2500 t/d five-stage cyclone preheater and precalciner system was numerically simulated. Renault stress model (RSM) turbulent model was adopted to simulate the flow field, and a hybrid mesh scheme was selected to generate calculation mesh. With the first order upwind difference, finite-volume method was used to convert turbulent equations into difference equations pressure-velocity coupling which were solved by the classic simple algorithm, and during the course of numerical solution, mesh self-adapting technology was applied. The main flow field structures of the whole system and each part of the cold model were studied by analyzing the simulation results.展开更多
Abstract: The great majority of the Palaeozoic orogenic belts of Central Asia are of the intercontinental type, whose evolution always follows a five-stage model, i.e. the basal continental crust-extensional transitio...Abstract: The great majority of the Palaeozoic orogenic belts of Central Asia are of the intercontinental type, whose evolution always follows a five-stage model, i.e. the basal continental crust-extensional transitional crust-oceanic crust-convergent transitional crust-new continental crust model. The stage for the extensional transitional crust is a pretty long, independent and inevitable phase. The dismembering mechanism of the basal continental crust becoming an extensional continental crust is delineated by the simple shear model put forward by Wernike (1981). The continental margins on the sides of a gently dipping detachment zone and moving along it are asymmetric: one side is of the nonmagmatic type and the other of the magmatic type with a typical bimodal volcanic formation. In the latter case, however, they were often confused with island arcs. This paper discusses the five-stage process of the crustal evolution of some typical orogenic belts in Xinjiang.展开更多
阐明世界科学中心的形成与迁移机理,是理解全球创新格局与大国科技竞争的核心议题。本文基于Web of Science、Scopus与中国知网收录的多语种核心文献,运用Citespace进行可视化分析,提炼出制度生态、经济动员、教育科研体系、人才流动、...阐明世界科学中心的形成与迁移机理,是理解全球创新格局与大国科技竞争的核心议题。本文基于Web of Science、Scopus与中国知网收录的多语种核心文献,运用Citespace进行可视化分析,提炼出制度生态、经济动员、教育科研体系、人才流动、思想范式、产学研协同及外部冲击七大维度,并据此构建了三层五阶段模型,为解释历史上多次科学中心转移现象提供整合性的理论框架。研究结论表明:(1)制度开放性、资本动员效率与教育科研协同是科技中心迈入孕育期的源头动因;(2)人才网络与思想范式的耦合效应在扩张—鼎盛跃迁中起促进作用;(3)产学研协同机制是成果规模化扩散的关键接口;(4)外部冲击具有“双刃剑”效应,适度压力可促进范式突破,过度封闭则加剧路径依赖,影响科技中心由鼎盛迈向衰退或再平衡的转折方向。展开更多
文摘The flow field in a cold model of 2500 t/d five-stage cyclone preheater and precalciner system was numerically simulated. Renault stress model (RSM) turbulent model was adopted to simulate the flow field, and a hybrid mesh scheme was selected to generate calculation mesh. With the first order upwind difference, finite-volume method was used to convert turbulent equations into difference equations pressure-velocity coupling which were solved by the classic simple algorithm, and during the course of numerical solution, mesh self-adapting technology was applied. The main flow field structures of the whole system and each part of the cold model were studied by analyzing the simulation results.
文摘Abstract: The great majority of the Palaeozoic orogenic belts of Central Asia are of the intercontinental type, whose evolution always follows a five-stage model, i.e. the basal continental crust-extensional transitional crust-oceanic crust-convergent transitional crust-new continental crust model. The stage for the extensional transitional crust is a pretty long, independent and inevitable phase. The dismembering mechanism of the basal continental crust becoming an extensional continental crust is delineated by the simple shear model put forward by Wernike (1981). The continental margins on the sides of a gently dipping detachment zone and moving along it are asymmetric: one side is of the nonmagmatic type and the other of the magmatic type with a typical bimodal volcanic formation. In the latter case, however, they were often confused with island arcs. This paper discusses the five-stage process of the crustal evolution of some typical orogenic belts in Xinjiang.
文摘阐明世界科学中心的形成与迁移机理,是理解全球创新格局与大国科技竞争的核心议题。本文基于Web of Science、Scopus与中国知网收录的多语种核心文献,运用Citespace进行可视化分析,提炼出制度生态、经济动员、教育科研体系、人才流动、思想范式、产学研协同及外部冲击七大维度,并据此构建了三层五阶段模型,为解释历史上多次科学中心转移现象提供整合性的理论框架。研究结论表明:(1)制度开放性、资本动员效率与教育科研协同是科技中心迈入孕育期的源头动因;(2)人才网络与思想范式的耦合效应在扩张—鼎盛跃迁中起促进作用;(3)产学研协同机制是成果规模化扩散的关键接口;(4)外部冲击具有“双刃剑”效应,适度压力可促进范式突破,过度封闭则加剧路径依赖,影响科技中心由鼎盛迈向衰退或再平衡的转折方向。
