Some techniques such as die surface description, contact judgement algorithm and remeshing are proposed to improve the robustness of the numerical solution. Based on these techniques, a three-dimensional rigid-plastic...Some techniques such as die surface description, contact judgement algorithm and remeshing are proposed to improve the robustness of the numerical solution. Based on these techniques, a three-dimensional rigid-plastic FEM code has been developed. Isothermal forging process of a cylindrical housing has been simulated. The simulation results show that the given techniques and the FEM code are reasonable and feasible for three-dimensional bulk forming processes.展开更多
Multi-function,multiband,cost-effective,miniaturized reconfigurable radio frequency(RF)components are highly demanded in modern and future wireless communication systems.This paper discusses the needs and implementati...Multi-function,multiband,cost-effective,miniaturized reconfigurable radio frequency(RF)components are highly demanded in modern and future wireless communication systems.This paper discusses the needs and implementation of multiband reconfigurable RF components with microfabrication techniques and advanced materials.RF applications of fabrication methods such as surface and bulk micromachining techniques are reviewed,especially on the development of RF microelectromechanical systems(MEMS)and other tunable components.Works on the application of ferroelectric and ferromagnetic materials are investigated,which enables RF components with continuous tunability,reduced size,and enhanced performance.Methods and strategies with nano-patterning to improve high frequency characteristics of ferromagnetic thin film(e.g.,ferromagnetic resonance frequency and losses)and their applications on the development of fully electrically tunable RF components are fully demonstrated.展开更多
The new bulk purple yam variety Suyu 2,which had high quality,efficiency and was suitable for production in a highly mechanized cultivation,was bred by special and was suitable for whole-course mechanized cultivation....The new bulk purple yam variety Suyu 2,which had high quality,efficiency and was suitable for production in a highly mechanized cultivation,was bred by special and was suitable for whole-course mechanized cultivation.Integrated with agricultural machinery and agricultural trait,four kinds of machines produced by two factories from Jiangsu and Shandong could complete 10 kinds of main production processes,including rotary tillage,ridging,sowing,intertillage,topdressing,drug delivery,weeding,hilling,vine cutting and harvest.The work efficiency of single machine was 4-5 hm^2/d,and the production pattern got the cost saving and effectiveness increasing in the main yam producing area.The benefit reached over RMB 37500 yuan/hm^2 in special vegetable area.It was simple,feasible and easy to popularize the mechanization cultivation technique.展开更多
A method to generate the optical quadruple frequency millimeter-wave with high power efficiency is pro- posed and demonstrated based on the combination of the injection 2nd-order rational harmonic mode- locked fiber r...A method to generate the optical quadruple frequency millimeter-wave with high power efficiency is pro- posed and demonstrated based on the combination of the injection 2nd-order rational harmonic mode- locked fiber ring laser technique and the fiber grating notch filter. In this approach, the fiber Bragg grating notch filter is inserted into the laser cavity to prevent the undesired optical carrier, so that the pump power can be converted to 2nd-order harmonic wave more efficiently. In our experiment, the power efficiency of optical quadruple frequency millimeter-wave （40 GHz） generation is ten folds of that of our previous method based only on the rational harmonic mode-locked technique.展开更多
In recent times,solar energy has become one of the largest available sources of renewable energy at our disposal.However,the design of highly efficient solar cells is increasingly becoming crucial as there has been a ...In recent times,solar energy has become one of the largest available sources of renewable energy at our disposal.However,the design of highly efficient solar cells is increasingly becoming crucial as there has been a surge for economically viable alternative energy sources with the lowest cost.Significant advances have been made through different routes to make photovoltaic(PV)/solar technologies economically viable,eco-friendly and consequently scalable.As a result,cellulose nanomaterials have become one of the emerging technologies in this regard because of the advantages of high-value bio-based nanostructured materials,such as their abundance and sustainability.Nanocellulose-based photoactive nanocomposite materials can be made by integrating conducting photoactive and electroconductive materials with hydrophilic biocompatible cellulose.Inorganic nanoparticles,such as graphene/reduced graphene oxide cadmium sulphide quantum dots,amongst others,can be introduced into the nanocellulose matrix and can be applied either as charge transporters or photoactive materials in different types of solar cells.Thus,in this review,we highlight the optoelectronic properties of different photoactive materials,particularly nanocellulose-based graphene nanocomposites;their efficiencies and drawbacks were X-rayed.The effect of doping each PV material on the PV performance is also discussed.It is anticipated that the novel material would result in a reduction in the cost of solar cells,jointly enhancing their efficacy in generating environmentally friendly electricity.Since the fabrication techniques and equipment play a crucial role in the development of solar cells,the fabrication techniques of bulk-heterojunction(BHJ)cells containing a nanocellulose-based graphene composite and case studies of already fabricated BHJ PV cells with nanocellulose-based graphene composite are discussed.展开更多
基金This work was supported by the Brain Korea 2lProject and the Grallt of Post-Doc Program, KyungpookNational University (1999).
文摘Some techniques such as die surface description, contact judgement algorithm and remeshing are proposed to improve the robustness of the numerical solution. Based on these techniques, a three-dimensional rigid-plastic FEM code has been developed. Isothermal forging process of a cylindrical housing has been simulated. The simulation results show that the given techniques and the FEM code are reasonable and feasible for three-dimensional bulk forming processes.
基金Projects(1253929,1910853)supported by the National Natural Science Foundation of China。
文摘Multi-function,multiband,cost-effective,miniaturized reconfigurable radio frequency(RF)components are highly demanded in modern and future wireless communication systems.This paper discusses the needs and implementation of multiband reconfigurable RF components with microfabrication techniques and advanced materials.RF applications of fabrication methods such as surface and bulk micromachining techniques are reviewed,especially on the development of RF microelectromechanical systems(MEMS)and other tunable components.Works on the application of ferroelectric and ferromagnetic materials are investigated,which enables RF components with continuous tunability,reduced size,and enhanced performance.Methods and strategies with nano-patterning to improve high frequency characteristics of ferromagnetic thin film(e.g.,ferromagnetic resonance frequency and losses)and their applications on the development of fully electrically tunable RF components are fully demonstrated.
文摘The new bulk purple yam variety Suyu 2,which had high quality,efficiency and was suitable for production in a highly mechanized cultivation,was bred by special and was suitable for whole-course mechanized cultivation.Integrated with agricultural machinery and agricultural trait,four kinds of machines produced by two factories from Jiangsu and Shandong could complete 10 kinds of main production processes,including rotary tillage,ridging,sowing,intertillage,topdressing,drug delivery,weeding,hilling,vine cutting and harvest.The work efficiency of single machine was 4-5 hm^2/d,and the production pattern got the cost saving and effectiveness increasing in the main yam producing area.The benefit reached over RMB 37500 yuan/hm^2 in special vegetable area.It was simple,feasible and easy to popularize the mechanization cultivation technique.
基金supported by the National "973" Program of China under Grant No. 2006CB302806
文摘A method to generate the optical quadruple frequency millimeter-wave with high power efficiency is pro- posed and demonstrated based on the combination of the injection 2nd-order rational harmonic mode- locked fiber ring laser technique and the fiber grating notch filter. In this approach, the fiber Bragg grating notch filter is inserted into the laser cavity to prevent the undesired optical carrier, so that the pump power can be converted to 2nd-order harmonic wave more efficiently. In our experiment, the power efficiency of optical quadruple frequency millimeter-wave （40 GHz） generation is ten folds of that of our previous method based only on the rational harmonic mode-locked technique.
文摘In recent times,solar energy has become one of the largest available sources of renewable energy at our disposal.However,the design of highly efficient solar cells is increasingly becoming crucial as there has been a surge for economically viable alternative energy sources with the lowest cost.Significant advances have been made through different routes to make photovoltaic(PV)/solar technologies economically viable,eco-friendly and consequently scalable.As a result,cellulose nanomaterials have become one of the emerging technologies in this regard because of the advantages of high-value bio-based nanostructured materials,such as their abundance and sustainability.Nanocellulose-based photoactive nanocomposite materials can be made by integrating conducting photoactive and electroconductive materials with hydrophilic biocompatible cellulose.Inorganic nanoparticles,such as graphene/reduced graphene oxide cadmium sulphide quantum dots,amongst others,can be introduced into the nanocellulose matrix and can be applied either as charge transporters or photoactive materials in different types of solar cells.Thus,in this review,we highlight the optoelectronic properties of different photoactive materials,particularly nanocellulose-based graphene nanocomposites;their efficiencies and drawbacks were X-rayed.The effect of doping each PV material on the PV performance is also discussed.It is anticipated that the novel material would result in a reduction in the cost of solar cells,jointly enhancing their efficacy in generating environmentally friendly electricity.Since the fabrication techniques and equipment play a crucial role in the development of solar cells,the fabrication techniques of bulk-heterojunction(BHJ)cells containing a nanocellulose-based graphene composite and case studies of already fabricated BHJ PV cells with nanocellulose-based graphene composite are discussed.
