Vinyl acetate （VA） synthesis on Pd/Au（111） and Pd/Au（100） surfaces has been systematically investigated through first-principles density functional theory （DFT） calculations. The DFr results showed that for VA...Vinyl acetate （VA） synthesis on Pd/Au（111） and Pd/Au（100） surfaces has been systematically investigated through first-principles density functional theory （DFT） calculations. The DFr results showed that for VA synthesis, the ＇Samanos＇ reaction mechanism （i.e., direct coupling of coadsorbed ethylene and acetate species and subsequent/%hydride elimination to form VA） is more favorable than the ＇Moiseev＇ mechanism （i.e., ethylene first dehydrogenates to form vinyl species which then couple with the coadsorbed acetate species to form VA）. More importantly, it was found the surface coverage of acetate has a significant effect on the reactivity of VA synthesis, and the activation energy of the rate- controlling step on Pd/Au（100） surface is smaller than that on Pd/Au（111） surface （0.88 vs. 0.95 eV）, indicating the former is more active than the latter.展开更多
The dependence of high temperature shape memory effect on the pre-deformation tempera- ture of the Ti_(50)Ni_3Pd_(37) alloy has been studied.This alloy,of which the reverse transformation start temperature on heating ...The dependence of high temperature shape memory effect on the pre-deformation tempera- ture of the Ti_(50)Ni_3Pd_(37) alloy has been studied.This alloy,of which the reverse transformation start temperature on heating is 620 K,has both one-way and two-way shape memory effects. The maximum shape memory strain of the ahoy may be obtained under pre-deformation in the range of 620 to 640 K.This seems to be related to the minimum recoverable strain energy emerged from the above mentioned temperature range.展开更多
Total ionizing dose responses of different transistor geometries after being irradiated by ^（60）Co γ-rays, in 0.13-μm partially-depleted silicon-on-insulator（PD SOI） technology are investigated. The negative thr...Total ionizing dose responses of different transistor geometries after being irradiated by ^（60）Co γ-rays, in 0.13-μm partially-depleted silicon-on-insulator（PD SOI） technology are investigated. The negative threshold voltage shift in an n-type metal-oxide semiconductor field effect transistor（nMOSFET） is inversely proportional to the channel width due to radiation-induced charges trapped in trench oxide, which is called the radiation-induced narrow channel effect（RINCE）.The analysis based on a charge sharing model and three-dimensional technology computer aided design（TCAD） simulations demonstrate that phenomenon. The radiation-induced leakage currents under different drain biases are also discussed in detail.展开更多
Microstructure and phase transformation behaviors of the film annealed at different temperatures were studied by X-ray diffractometry （XRD）, transmission electron microscopy and differential scanning calorimeter （...Microstructure and phase transformation behaviors of the film annealed at different temperatures were studied by X-ray diffractometry （XRD）, transmission electron microscopy and differential scanning calorimeter （DSC）. Also tensile tests were examined. For increasing annealed temperature, multiple phase transformations, transformations via a B19-phase or direct martensite/austenite transformtion are observed. The TiNiPd thin film annealed at 750℃ had relatively uniform martensite/austenite transformtion and shape memory effect. Martensite/austenite transformtion was also found in strain-temperature curves. Subsequent annealing at 450℃ had minor effect on transformation temperatures of Ti-Ni-Pd thin films but resulted in more uniform transformation and improved shape memory effect.展开更多
基金supported by the State Key Program of Natural Science of Tianjin (Grant No. 13JCZDJC26800)the foundation of State Key Laboratory of Coal Conversion (Grant No. J13-14-908)
文摘Vinyl acetate （VA） synthesis on Pd/Au（111） and Pd/Au（100） surfaces has been systematically investigated through first-principles density functional theory （DFT） calculations. The DFr results showed that for VA synthesis, the ＇Samanos＇ reaction mechanism （i.e., direct coupling of coadsorbed ethylene and acetate species and subsequent/%hydride elimination to form VA） is more favorable than the ＇Moiseev＇ mechanism （i.e., ethylene first dehydrogenates to form vinyl species which then couple with the coadsorbed acetate species to form VA）. More importantly, it was found the surface coverage of acetate has a significant effect on the reactivity of VA synthesis, and the activation energy of the rate- controlling step on Pd/Au（100） surface is smaller than that on Pd/Au（111） surface （0.88 vs. 0.95 eV）, indicating the former is more active than the latter.
文摘The dependence of high temperature shape memory effect on the pre-deformation tempera- ture of the Ti_(50)Ni_3Pd_(37) alloy has been studied.This alloy,of which the reverse transformation start temperature on heating is 620 K,has both one-way and two-way shape memory effects. The maximum shape memory strain of the ahoy may be obtained under pre-deformation in the range of 620 to 640 K.This seems to be related to the minimum recoverable strain energy emerged from the above mentioned temperature range.
基金Project supported by the Weapon Equipment Pre-Research Foundation of China(Grant No.9140A11020114ZK34147)the Shanghai Municipal Natural Science Foundation,China(Grant No.15ZR1447100)
文摘Total ionizing dose responses of different transistor geometries after being irradiated by ^（60）Co γ-rays, in 0.13-μm partially-depleted silicon-on-insulator（PD SOI） technology are investigated. The negative threshold voltage shift in an n-type metal-oxide semiconductor field effect transistor（nMOSFET） is inversely proportional to the channel width due to radiation-induced charges trapped in trench oxide, which is called the radiation-induced narrow channel effect（RINCE）.The analysis based on a charge sharing model and three-dimensional technology computer aided design（TCAD） simulations demonstrate that phenomenon. The radiation-induced leakage currents under different drain biases are also discussed in detail.
基金supported by Science&Technology Commission of Shanghai Municipality(STCSM),China(No.02DJ14042)the Key Project of Chinese Ministry of Education(No.0307).
文摘Microstructure and phase transformation behaviors of the film annealed at different temperatures were studied by X-ray diffractometry （XRD）, transmission electron microscopy and differential scanning calorimeter （DSC）. Also tensile tests were examined. For increasing annealed temperature, multiple phase transformations, transformations via a B19-phase or direct martensite/austenite transformtion are observed. The TiNiPd thin film annealed at 750℃ had relatively uniform martensite/austenite transformtion and shape memory effect. Martensite/austenite transformtion was also found in strain-temperature curves. Subsequent annealing at 450℃ had minor effect on transformation temperatures of Ti-Ni-Pd thin films but resulted in more uniform transformation and improved shape memory effect.
