English education in China has its problems due to its history and teaching environment,such as deficiency of communication purpose,insufficiency of teaching on oral expression and so on.Consequently,to solve the prob...English education in China has its problems due to its history and teaching environment,such as deficiency of communication purpose,insufficiency of teaching on oral expression and so on.Consequently,to solve the problems of English teaching in China seems necessary.Therefore,the solutions as the changes of policy,updated teaching methods,improvement of teacher’s skills on teaching and diverse ways of teaching should be pointed out.展开更多
Repetitious simulation after modifying parameters of multi-domain physical system based on Modelica often appears in model experiment and optimization design. At present, the solvers based on Modelica need calculate a...Repetitious simulation after modifying parameters of multi-domain physical system based on Modelica often appears in model experiment and optimization design. At present, the solvers based on Modelica need calculate all the coupled blocks during every simulation run after updating parameters. Based on discussing scale decomposition methods of simulation model, subdivision solving strategy and minimum solving strategy are put forward to improve the efficiency of repetitious simulation, by which the numerical solution of the simulation model can be achieved by only calculating the solving sequence influenced by altered parameters. A simplified model of aircraft is used to demonstrate the efficiency of the strategies presented.展开更多
The equation used to model the unidirectional flow of methane gas in coal seams is usually formulated as a nonlinear partial differential equation, which needs to be solved numerically with a computer program.Neverthe...The equation used to model the unidirectional flow of methane gas in coal seams is usually formulated as a nonlinear partial differential equation, which needs to be solved numerically with a computer program.Nevertheless, for people without access to the computer program, the conventional numerical method may be inconvenient. Thus, the objective here is to seek some method simpler than the conventional one for solving the flow problem. A commonly used model of the unidirectional methane gas flow is considered, where the methane adsorption is described by the Langmuir isotherm and the free gas is treated as real gas. By introducing the similarity solution, a simple method for solving the flow model is proposed, which can be done on a hand calculator. It is shown by two examples that the gas pressure profile obtained by the proposed method agrees well with the direct numerical solution of the flow model.展开更多
Aiming at the problem of structure design in reverse-design of mechanism,a structure mapping method based on reverse solving of locus and motion(RSLM)is presented.The mechanism scheme meeting the requirements of geome...Aiming at the problem of structure design in reverse-design of mechanism,a structure mapping method based on reverse solving of locus and motion(RSLM)is presented.The mechanism scheme meeting the requirements of geometric and structural features is obtained through RSLM.The element instance subsets related to component are established based on the element type mapping,pair structure type mapping and design knowledge mapping between components and elements layer by layer.The assembly position mapping of elements is established based on the topological structure information of mechanism scheme,and the product modeling of structure mapping is realized.The algorithm program and prototype system of product structure mapping based on RSLM are developed.Application samples show that the method implements the integration of scheme design,assembly design and structure design,and modeling for product structure mapping based on RSLM.The feasibility of assembly is analyzed in scheme design that contributes to reducing the design error,and raising the design efficiency and quality.展开更多
Adva nces in orga nic photovoltaic tech no logies have been geared toward industrial high-throughput printing manufacturing,which requires in sensitivity of photovoltaic performance reg a rd i ng to the light-harvesti...Adva nces in orga nic photovoltaic tech no logies have been geared toward industrial high-throughput printing manufacturing,which requires in sensitivity of photovoltaic performance reg a rd i ng to the light-harvesting layer thickness.However,the thickness of light-harvesti ng layer for all polymer solar cells(all-PSCs)is often limited to about 100 nm due to the dramatically decreased fill factor upon increasing film thickness,which hampers the light harvesting capability to in crease the power con versio n efficie ncy,and is un favorable for fabricating large-area devices.Here we dem on strate that by tuning the bulk heterojuncti on morphology using a non-halogenated solvent,cyclopentyl methyl ether,in the presence of a gree n solve nt additive of dibenzyl ether,the power con versio n efficie ncy of all-PSCs with photoactive layer thick nesses of over 500 nm reached an impressively high value of 9%.The gen eric applicability of this gree n solvent additive to boost the power conversion efficiency of thick-film devices is also validated in various bulk heterojunction active layer systems,thus representing a promising approach for the fabrication of all-PSCs toward industrial production,as well as further commercialization.展开更多
This paper applies genetic simulated annealing algorithm (SAGA) to solving geometric constraint problems. This method makes full use of the advantages of SAGA and can handle under-/over- constraint problems naturally....This paper applies genetic simulated annealing algorithm (SAGA) to solving geometric constraint problems. This method makes full use of the advantages of SAGA and can handle under-/over- constraint problems naturally. It has advantages (due to its not being sensitive to the initial values) over the Newton-Raphson method, and its yielding of multiple solutions, is an advantage over other optimal methods for multi-solution constraint system. Our experiments have proved the robustness and efficiency of this method.展开更多
文摘English education in China has its problems due to its history and teaching environment,such as deficiency of communication purpose,insufficiency of teaching on oral expression and so on.Consequently,to solve the problems of English teaching in China seems necessary.Therefore,the solutions as the changes of policy,updated teaching methods,improvement of teacher’s skills on teaching and diverse ways of teaching should be pointed out.
基金Supported by the National High Technology Research and Development Program (863 Program) of China (2006AA04Z121)the National Natural Science Foundation of China (50775084)
文摘Repetitious simulation after modifying parameters of multi-domain physical system based on Modelica often appears in model experiment and optimization design. At present, the solvers based on Modelica need calculate all the coupled blocks during every simulation run after updating parameters. Based on discussing scale decomposition methods of simulation model, subdivision solving strategy and minimum solving strategy are put forward to improve the efficiency of repetitious simulation, by which the numerical solution of the simulation model can be achieved by only calculating the solving sequence influenced by altered parameters. A simplified model of aircraft is used to demonstrate the efficiency of the strategies presented.
基金provided by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘The equation used to model the unidirectional flow of methane gas in coal seams is usually formulated as a nonlinear partial differential equation, which needs to be solved numerically with a computer program.Nevertheless, for people without access to the computer program, the conventional numerical method may be inconvenient. Thus, the objective here is to seek some method simpler than the conventional one for solving the flow problem. A commonly used model of the unidirectional methane gas flow is considered, where the methane adsorption is described by the Langmuir isotherm and the free gas is treated as real gas. By introducing the similarity solution, a simple method for solving the flow model is proposed, which can be done on a hand calculator. It is shown by two examples that the gas pressure profile obtained by the proposed method agrees well with the direct numerical solution of the flow model.
基金supported by National Hi-tech Research Development Program of China(863 Program,No.2006AA04ZlI4)Research Fund for the Doctoral Program of Higher Education,China(No.20040335060)Zhejiang Provincial Scientific Personnel Educational Foundation,China(No.R603240).
文摘Aiming at the problem of structure design in reverse-design of mechanism,a structure mapping method based on reverse solving of locus and motion(RSLM)is presented.The mechanism scheme meeting the requirements of geometric and structural features is obtained through RSLM.The element instance subsets related to component are established based on the element type mapping,pair structure type mapping and design knowledge mapping between components and elements layer by layer.The assembly position mapping of elements is established based on the topological structure information of mechanism scheme,and the product modeling of structure mapping is realized.The algorithm program and prototype system of product structure mapping based on RSLM are developed.Application samples show that the method implements the integration of scheme design,assembly design and structure design,and modeling for product structure mapping based on RSLM.The feasibility of assembly is analyzed in scheme design that contributes to reducing the design error,and raising the design efficiency and quality.
基金supported by the National Natural Science Foundation of China(Nos.21822505,91633301,51673069,and 21520102006)Program for Science and Technology Development of Dongguan(No.2019622163009)+1 种基金the Dongguan Innovative Research Team Program(No.2018607201002)Portions of this research used the resources of beamline 7.3.3 and 11.0.1.2 at Advanced Light Source,Materials Science Division,The Molecular Foundry,Lawrenee Berkeley National Laboratory,which was supported by the Office of Scienee,Office of Basic Energy Sciences,of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231.
文摘Adva nces in orga nic photovoltaic tech no logies have been geared toward industrial high-throughput printing manufacturing,which requires in sensitivity of photovoltaic performance reg a rd i ng to the light-harvesting layer thickness.However,the thickness of light-harvesti ng layer for all polymer solar cells(all-PSCs)is often limited to about 100 nm due to the dramatically decreased fill factor upon increasing film thickness,which hampers the light harvesting capability to in crease the power con versio n efficie ncy,and is un favorable for fabricating large-area devices.Here we dem on strate that by tuning the bulk heterojuncti on morphology using a non-halogenated solvent,cyclopentyl methyl ether,in the presence of a gree n solve nt additive of dibenzyl ether,the power con versio n efficie ncy of all-PSCs with photoactive layer thick nesses of over 500 nm reached an impressively high value of 9%.The gen eric applicability of this gree n solvent additive to boost the power conversion efficiency of thick-film devices is also validated in various bulk heterojunction active layer systems,thus representing a promising approach for the fabrication of all-PSCs toward industrial production,as well as further commercialization.
文摘This paper applies genetic simulated annealing algorithm (SAGA) to solving geometric constraint problems. This method makes full use of the advantages of SAGA and can handle under-/over- constraint problems naturally. It has advantages (due to its not being sensitive to the initial values) over the Newton-Raphson method, and its yielding of multiple solutions, is an advantage over other optimal methods for multi-solution constraint system. Our experiments have proved the robustness and efficiency of this method.
