Microchannel reactors are commonly used in micro-chemical technology. The performance of microreactors is greatly affected by the velocity field in the microchannel. The flow field is disturbed by the cylindrical etch...Microchannel reactors are commonly used in micro-chemical technology. The performance of microreactors is greatly affected by the velocity field in the microchannel. The flow field is disturbed by the cylindrical etch holes caused by air dust on the microchannel surface during its processing procedure. In this approach, a two-dimensional computational fluid dynamics （CFD） model is put forward to study the effect of etch holes on flow field. The influenced area of single or two concave etch holes is studied for the case of laminar flow. The hole diameter, the Reynolds number and the distance between the center of holes are found to have influences on the flow field. Numerical results indicate that the effects of etch hole on the flow field should be evaluated and the way of choosing the economic class of cleanroom for microreactor manufacture is presented.展开更多
Flow field in multilayer gob area, which formed in small hiden-depth, multi-coal layer groups, close distance, hard coal layer, and hard roof, possesses characteristics such as complex, changeable and unstable. Dynami...Flow field in multilayer gob area, which formed in small hiden-depth, multi-coal layer groups, close distance, hard coal layer, and hard roof, possesses characteristics such as complex, changeable and unstable. Dynamic balance theory of local flow field in multilayer gob area was built based on the realistic requirement that the serious threat on current mining coal layer by large-scale spontaneous combustion fire on close spontaneous combustion coal layer group of Datong Coal mining area at the ＇di-hard＇ conditions was caused by small coal pit mining. The kernel was in dynamic balance between flow field pressures of working face and local flow field in multilayer gob area was kept by transformation. Corresponding technology and set of devices were developed.展开更多
After joining in WTO,Chinese enterprises face more intense competitive environments. The problems, such as many foreign capital enterprises swarming into China, increasing market competitive ability, keeping on nation...After joining in WTO,Chinese enterprises face more intense competitive environments. The problems, such as many foreign capital enterprises swarming into China, increasing market competitive ability, keeping on national and international market, have become more serious to enterprise’s decision maker. At the same time, the information technology is developing quickly, then business process re engineering will become valid path for enterprise increasing market competitive ability. As a case study, this paper applies Business Process Re engineering(BPR) approach to analyze a Chinese company.展开更多
基金Supported by the National Natural Science Foundation of China （20676093）.
文摘Microchannel reactors are commonly used in micro-chemical technology. The performance of microreactors is greatly affected by the velocity field in the microchannel. The flow field is disturbed by the cylindrical etch holes caused by air dust on the microchannel surface during its processing procedure. In this approach, a two-dimensional computational fluid dynamics （CFD） model is put forward to study the effect of etch holes on flow field. The influenced area of single or two concave etch holes is studied for the case of laminar flow. The hole diameter, the Reynolds number and the distance between the center of holes are found to have influences on the flow field. Numerical results indicate that the effects of etch hole on the flow field should be evaluated and the way of choosing the economic class of cleanroom for microreactor manufacture is presented.
基金Supported by the Key Projects of the National Natural Science Foundation of China （50834002）
文摘Flow field in multilayer gob area, which formed in small hiden-depth, multi-coal layer groups, close distance, hard coal layer, and hard roof, possesses characteristics such as complex, changeable and unstable. Dynamic balance theory of local flow field in multilayer gob area was built based on the realistic requirement that the serious threat on current mining coal layer by large-scale spontaneous combustion fire on close spontaneous combustion coal layer group of Datong Coal mining area at the ＇di-hard＇ conditions was caused by small coal pit mining. The kernel was in dynamic balance between flow field pressures of working face and local flow field in multilayer gob area was kept by transformation. Corresponding technology and set of devices were developed.
文摘After joining in WTO,Chinese enterprises face more intense competitive environments. The problems, such as many foreign capital enterprises swarming into China, increasing market competitive ability, keeping on national and international market, have become more serious to enterprise’s decision maker. At the same time, the information technology is developing quickly, then business process re engineering will become valid path for enterprise increasing market competitive ability. As a case study, this paper applies Business Process Re engineering(BPR) approach to analyze a Chinese company.
