O463.1 96021393 电磁聚焦成象系统中曲轴宽电子束聚焦的象差理论=Aberration theory for wide electron beamfocusing having curvilineal optial axis in electro—staticand magnetic imaging systems[刊,中]/金伟其,周立伟,倪国强(...O463.1 96021393 电磁聚焦成象系统中曲轴宽电子束聚焦的象差理论=Aberration theory for wide electron beamfocusing having curvilineal optial axis in electro—staticand magnetic imaging systems[刊,中]/金伟其,周立伟,倪国强(北京理工大学工程光学系。北京(100081))∥北京理工大学学报。—1995。展开更多
In order to maintain the structural consistency during the welding of precipitation hardened copperchromium-zirconium(PH-CuCrZr)alloy components,electron beam welding(EBW)process was employed.Experimental study and nu...In order to maintain the structural consistency during the welding of precipitation hardened copperchromium-zirconium(PH-CuCrZr)alloy components,electron beam welding(EBW)process was employed.Experimental study and numerical modeling of EBW process during welding of PH-CuCrZr alloy components were carried out.A 3D finite element model was developed to predict the output responses(bead penetration and bead width)as a function of EBW input parameters(beam current,acceleration voltage and weld speed).A combined circular and conical source with Gaussian heat distribution was used to model the deep penetration characteristic of the EBW process.Numerical modeling was carried out by developing user defined function in Ansys software.Numerical predictions were compared with the experimental results which had a good agreement with each other.The developed model can be used for parametric study in wide range of problems involving complex geometries which are to be welded using EBW process.The present work illustrates that the input current with a contribution of 44.56%and 81.13%is the most significant input parameter for the bead penetration and bead width,respectively.展开更多
A design of coating on the entrance surface of the beam splitters with a transparent thin film of certain refractive index and thickness was presented.For this kind of beam splitters,it was possible to realize polariz...A design of coating on the entrance surface of the beam splitters with a transparent thin film of certain refractive index and thickness was presented.For this kind of beam splitters,it was possible to realize polarization-independent beam-splitting for chosen wavelength λ with incident angle .In addition,the simulation results using the coating designable software(Auto film) were consistent with the theoretical results,and the beam splitters are not sensitive to the small errors of film-thickness and film refractive-index over a broad spectra.展开更多
文摘O463.1 96021393 电磁聚焦成象系统中曲轴宽电子束聚焦的象差理论=Aberration theory for wide electron beamfocusing having curvilineal optial axis in electro—staticand magnetic imaging systems[刊,中]/金伟其,周立伟,倪国强(北京理工大学工程光学系。北京(100081))∥北京理工大学学报。—1995。
文摘In order to maintain the structural consistency during the welding of precipitation hardened copperchromium-zirconium(PH-CuCrZr)alloy components,electron beam welding(EBW)process was employed.Experimental study and numerical modeling of EBW process during welding of PH-CuCrZr alloy components were carried out.A 3D finite element model was developed to predict the output responses(bead penetration and bead width)as a function of EBW input parameters(beam current,acceleration voltage and weld speed).A combined circular and conical source with Gaussian heat distribution was used to model the deep penetration characteristic of the EBW process.Numerical modeling was carried out by developing user defined function in Ansys software.Numerical predictions were compared with the experimental results which had a good agreement with each other.The developed model can be used for parametric study in wide range of problems involving complex geometries which are to be welded using EBW process.The present work illustrates that the input current with a contribution of 44.56%and 81.13%is the most significant input parameter for the bead penetration and bead width,respectively.
文摘A design of coating on the entrance surface of the beam splitters with a transparent thin film of certain refractive index and thickness was presented.For this kind of beam splitters,it was possible to realize polarization-independent beam-splitting for chosen wavelength λ with incident angle .In addition,the simulation results using the coating designable software(Auto film) were consistent with the theoretical results,and the beam splitters are not sensitive to the small errors of film-thickness and film refractive-index over a broad spectra.
