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
The authors prove the uniqueness in the inverse acoustic scattering problem within convex polygonal domains by a single incident direction in the sound-soft case and the sound-hard case, and by two incident directions...The authors prove the uniqueness in the inverse acoustic scattering problem within convex polygonal domains by a single incident direction in the sound-soft case and the sound-hard case, and by two incident directions in the case of the impedance boundary condition. The proof is based on analytic continuation on a straight line.展开更多
The transverse injection flow field has an important impact on the flowpath design of scramjet engines. At present a combination of the transverse injection scheme and any other flame holder has been widely employed i...The transverse injection flow field has an important impact on the flowpath design of scramjet engines. At present a combination of the transverse injection scheme and any other flame holder has been widely employed in hypersonic propulsion systems to promote the mixing process between the fuel and the supersonic freestream; combustion efficiency has been improved thereby, as well as engine thrust. Research on mixing techniques for the transverse injection flow field is summarized from four aspects, namely the jet-to-crossflow pressure ratio, the geometric configuration of the injection port, the number of injection ports, and the injection angle. In conclusion, urgent investigations of mixing techniques of the transverse injection flow field are pro- posed, especiaUy data mining in the quantitative analytical results for transverse injection flow field, based on results from multi-objective design optimization theory.展开更多
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Project supported by the National Natural Science Foundation of China (No.10271032) the Nonlinear Mathematical Models and Methods Laboratory and the Grants 1534002715654015 from the Japan Society for the Promotion of Science and Sanwa Systems Development Co.Ltd. (Tokyo).
文摘The authors prove the uniqueness in the inverse acoustic scattering problem within convex polygonal domains by a single incident direction in the sound-soft case and the sound-hard case, and by two incident directions in the case of the impedance boundary condition. The proof is based on analytic continuation on a straight line.
基金supported by the Science Foundation of National University of Defense Technology (No. JC11-01-02)the Hunan Provincial Natural Science Foundation of China (No.12jj4047)
文摘The transverse injection flow field has an important impact on the flowpath design of scramjet engines. At present a combination of the transverse injection scheme and any other flame holder has been widely employed in hypersonic propulsion systems to promote the mixing process between the fuel and the supersonic freestream; combustion efficiency has been improved thereby, as well as engine thrust. Research on mixing techniques for the transverse injection flow field is summarized from four aspects, namely the jet-to-crossflow pressure ratio, the geometric configuration of the injection port, the number of injection ports, and the injection angle. In conclusion, urgent investigations of mixing techniques of the transverse injection flow field are pro- posed, especiaUy data mining in the quantitative analytical results for transverse injection flow field, based on results from multi-objective design optimization theory.
