Based on the helix rotating screen and the digital micro-mirror device （DMD）, the former proto of volumetric-swept display system is improved. The 3-D display system adopting a helix rotating screen to construct an ...Based on the helix rotating screen and the digital micro-mirror device （DMD）, the former proto of volumetric-swept display system is improved. The 3-D display system adopting a helix rotating screen to construct an imaging space meliorate the defects, such as the smaller image space, the fewer voxels and the severer voxel overlap dead zone caused by planar rotating screen. DMD with spatial light modular （SLM） technology increases the transmission bandwidth of 3-D data in the voxel activation subsystem and activate multi-voxel once time. The volumetric-swept system based on helix rotating screen and DMD is developed. The experimental results show that the image space, the vision dead zone, the voxels on slice, and the voxel activation capacity of the designed proto are superior to the plane rotating screen system.展开更多
The main problem in an efficient Zn（CH3COO）2/AC （AC-activated carbon） catalyst preparation is the achievement of uniform distribution of highly dispersed salt component on the activated carbon （AC） surface. The ...The main problem in an efficient Zn（CH3COO）2/AC （AC-activated carbon） catalyst preparation is the achievement of uniform distribution of highly dispersed salt component on the activated carbon （AC） surface. The solution of this problem is modification of the AC by hydrogen peroxide （H202） oxidation of the surface and treatment of AC with acetic acid as well as special methods of salt deposition and catalyst drying. The investigations of these ways of AC surface modification （treatment of AC with acetic acid and H2O2） have demonstrated the obtained AC to have both an increased adsorption capacity as to Zn（OAc）2 and optimum volumes of meso- and micro-pores as well as high catalyst activity in vinyl acetate （VA） synthesis. The characteristics of supports and catalysts were found out by benzene, water and acetic acid vapors adsorption. The distribution of the salt on the AC surface was studied by small-angle X-ray scattering （SAXS）, by scanning electron microscopy （SEM） and X-ray micro-analysis （XMA）. The catalysts were tested in vinyl acetate synthesis in flow-bed isothermal reactor by cyclic method at 175, 205 and 230℃.展开更多
For laser surface hardening of metal components with large superficies,a binary grating is proposed to generate single-row laser beam with proportional-intensity diffractive orders.To obtain a uniform hardened band di...For laser surface hardening of metal components with large superficies,a binary grating is proposed to generate single-row laser beam with proportional-intensity diffractive orders.To obtain a uniform hardened band distribution and improve the wear resistance of the sample surface,the binary grating is designed to produce single-row laser beam with energy strengthened at the two ends.The profile of the laser beam spot was designed to be strip with high length-width ratio to improve the machining efficiency of the hardening of large surfaces.A new advantage is suggested to obtain proportional intensity spots with evenness.The design results show that the diffractive efficiency of the binary grating is more than 70%,and the uniformity is less than 3%.The surface profile of the grating fabricated was measured,which shows that the fabrication error is less than 2%.The application of the binary grating in the laser surface hardening of metal components with large superficies is experimentally investigated,and the results show that the hardness distribution of the modified layer is more uniform than that hardened by Gaussian laser beam or array spots with equal intensity distribution.展开更多
基金Supported by the National High Technology Research and Development Program of China(″863″Program)(2007AA01Z338)the National Science Foundation for Post-doctoral Scientists of China(20080441051)the Jiangsu Province Science Foundation for Post-doctoral Scientists(0802014c)~~
文摘Based on the helix rotating screen and the digital micro-mirror device （DMD）, the former proto of volumetric-swept display system is improved. The 3-D display system adopting a helix rotating screen to construct an imaging space meliorate the defects, such as the smaller image space, the fewer voxels and the severer voxel overlap dead zone caused by planar rotating screen. DMD with spatial light modular （SLM） technology increases the transmission bandwidth of 3-D data in the voxel activation subsystem and activate multi-voxel once time. The volumetric-swept system based on helix rotating screen and DMD is developed. The experimental results show that the image space, the vision dead zone, the voxels on slice, and the voxel activation capacity of the designed proto are superior to the plane rotating screen system.
文摘The main problem in an efficient Zn（CH3COO）2/AC （AC-activated carbon） catalyst preparation is the achievement of uniform distribution of highly dispersed salt component on the activated carbon （AC） surface. The solution of this problem is modification of the AC by hydrogen peroxide （H202） oxidation of the surface and treatment of AC with acetic acid as well as special methods of salt deposition and catalyst drying. The investigations of these ways of AC surface modification （treatment of AC with acetic acid and H2O2） have demonstrated the obtained AC to have both an increased adsorption capacity as to Zn（OAc）2 and optimum volumes of meso- and micro-pores as well as high catalyst activity in vinyl acetate （VA） synthesis. The characteristics of supports and catalysts were found out by benzene, water and acetic acid vapors adsorption. The distribution of the salt on the AC surface was studied by small-angle X-ray scattering （SAXS）, by scanning electron microscopy （SEM） and X-ray micro-analysis （XMA）. The catalysts were tested in vinyl acetate synthesis in flow-bed isothermal reactor by cyclic method at 175, 205 and 230℃.
基金supported by the China Postdoctoral Science Foundation Funded Project (Grant No. 201104092)
文摘For laser surface hardening of metal components with large superficies,a binary grating is proposed to generate single-row laser beam with proportional-intensity diffractive orders.To obtain a uniform hardened band distribution and improve the wear resistance of the sample surface,the binary grating is designed to produce single-row laser beam with energy strengthened at the two ends.The profile of the laser beam spot was designed to be strip with high length-width ratio to improve the machining efficiency of the hardening of large surfaces.A new advantage is suggested to obtain proportional intensity spots with evenness.The design results show that the diffractive efficiency of the binary grating is more than 70%,and the uniformity is less than 3%.The surface profile of the grating fabricated was measured,which shows that the fabrication error is less than 2%.The application of the binary grating in the laser surface hardening of metal components with large superficies is experimentally investigated,and the results show that the hardness distribution of the modified layer is more uniform than that hardened by Gaussian laser beam or array spots with equal intensity distribution.
