惠普新年新实惠 至2003年3月28日,用户以正常渠道价格购买任意一款Compaq Presario,Compaq EvoN1000v或Compaq Evo N800v惠普笔记本产品,即可免费获得价值499元的HP Deskjet 3323喷墨打印机一台。同时,至3月28日,用户以正常渠道价格购...惠普新年新实惠 至2003年3月28日,用户以正常渠道价格购买任意一款Compaq Presario,Compaq EvoN1000v或Compaq Evo N800v惠普笔记本产品,即可免费获得价值499元的HP Deskjet 3323喷墨打印机一台。同时,至3月28日,用户以正常渠道价格购买任意一款Compaq Evo N610c或Compaq Evo N410c惠普笔记本产品。展开更多
The present study reports a highly selective and stable catalytic approach for producing tetralin, an important chemical, solvent, and H2 storage material. Transition metal phosphides （MOP, Ni2P, Co2P, and Fe2P） wer...The present study reports a highly selective and stable catalytic approach for producing tetralin, an important chemical, solvent, and H2 storage material. Transition metal phosphides （MOP, Ni2P, Co2P, and Fe2P） were prepared by wet impregnation and temperature-programmed reduction and characterized by X-ray diffraction （XRD）, energy dispersive X-ray spectroscopy （EDX）, EDX mapping, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, brunauer-emmett- teller （BET）, temperature-programmed desorption of ammonia （NH3-TPD）, and fourier transform infrared spectroscopy of pyridine （pyridine-FTIR）. Of all the transition metal phosphides MoP was formed at a lower reduction temperature, which resuited in smaller particle size that enhanced the overall surface area of the catalyst. The existence of weak, moderate, and Lewis acidic sites over MoP were responsible for its high tetralin selectivity （90%） and stability during the 100 h reaction on-stream in a fixed-bed reactor.展开更多
MoO3 nanobelts （NBs） having different properties have been synthesized via a physical vapor deposition （PVD） method. The crystallographic structures and morphologies of the NBs were characterized by X-ray diffract...MoO3 nanobelts （NBs） having different properties have been synthesized via a physical vapor deposition （PVD） method. The crystallographic structures and morphologies of the NBs were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Electrical measurements were performed and the profound piezoresistive effect in MoO3 experimentally studied and verified. Factors that influence the gauge factor, such as NB size, doping concentration and atmosphere composition, are discussed and analyzed. Gas sensing performance was also tested in devices and it was demonstrated that by applying strain to the gas sensor, its sensing performance could be effectively tuned and enhanced. This study provides the first demonstration of significant piezoresistivity in MoO3 NBs and the first illustration of a generic mechanism by means of which this effect can be coupled with other electronic modulation measures to afford better device performance and broader material functionality.展开更多
文摘惠普新年新实惠 至2003年3月28日,用户以正常渠道价格购买任意一款Compaq Presario,Compaq EvoN1000v或Compaq Evo N800v惠普笔记本产品,即可免费获得价值499元的HP Deskjet 3323喷墨打印机一台。同时,至3月28日,用户以正常渠道价格购买任意一款Compaq Evo N610c或Compaq Evo N410c惠普笔记本产品。
基金financial support from the Special Funds of the National Natural Science Foundation of China(21127011)National High Technology Research and Development Program of China(2011AA050606)National Natural Science Foundation of China(Petrochemical Joint Fund,U1162106)
文摘The present study reports a highly selective and stable catalytic approach for producing tetralin, an important chemical, solvent, and H2 storage material. Transition metal phosphides （MOP, Ni2P, Co2P, and Fe2P） were prepared by wet impregnation and temperature-programmed reduction and characterized by X-ray diffraction （XRD）, energy dispersive X-ray spectroscopy （EDX）, EDX mapping, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, brunauer-emmett- teller （BET）, temperature-programmed desorption of ammonia （NH3-TPD）, and fourier transform infrared spectroscopy of pyridine （pyridine-FTIR）. Of all the transition metal phosphides MoP was formed at a lower reduction temperature, which resuited in smaller particle size that enhanced the overall surface area of the catalyst. The existence of weak, moderate, and Lewis acidic sites over MoP were responsible for its high tetralin selectivity （90%） and stability during the 100 h reaction on-stream in a fixed-bed reactor.
文摘MoO3 nanobelts （NBs） having different properties have been synthesized via a physical vapor deposition （PVD） method. The crystallographic structures and morphologies of the NBs were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Electrical measurements were performed and the profound piezoresistive effect in MoO3 experimentally studied and verified. Factors that influence the gauge factor, such as NB size, doping concentration and atmosphere composition, are discussed and analyzed. Gas sensing performance was also tested in devices and it was demonstrated that by applying strain to the gas sensor, its sensing performance could be effectively tuned and enhanced. This study provides the first demonstration of significant piezoresistivity in MoO3 NBs and the first illustration of a generic mechanism by means of which this effect can be coupled with other electronic modulation measures to afford better device performance and broader material functionality.
