This paper reports observations of significant synergistic effects between dielectric barrier discharge (DBD) plasmas and Cu-ZSM-5 catalysts for C2H4 selective reduction of NOx at 250 °C in the presence of excess...This paper reports observations of significant synergistic effects between dielectric barrier discharge (DBD) plasmas and Cu-ZSM-5 catalysts for C2H4 selective reduction of NOx at 250 °C in the presence of excess oxygen by using a one-stage plasma-over-catalyst (POC) reactor. With the reactant gas mixture of 530 ppm NO, 650 ppm C2H4, 5.8% O2 in N2 and GHSV = 12000 h-1, the pure catalytic, pure plasma-induced (discharges over fused silica pellets) and plasma- catalytic (in the POC reactor) NOx conversion are 39%, 1.5% and 79%, respectively. The in-situ optical emission spectra of the reactive systems imply some short-lived active species formed from plasma-induced and plasma-catalytic processes may be responsible to the observed synergistic effects in this one-stage POC system.展开更多
The microstructures of copper liners of shaped charges prepared byelectroforming technique were investigated by transmission electron microscopy (TEM). Meanwhile, theorientations distributing of the grains in the elec...The microstructures of copper liners of shaped charges prepared byelectroforming technique were investigated by transmission electron microscopy (TEM). Meanwhile, theorientations distributing of the grains in the electroformed copper liners of shaped charges wasexamined by the electron backscattering Kikuchi pattern (EBSP) technique. TEM observations haverevealed that these electroformed copper liners of shaped charges have the grain size of about 1-3mu m and the grains have a preferential orientation distribution along the growth direction. EBSPanalysis has demonstrated that the as-formed copper liners of shaped charges exhibit amicro-texture, i.e. one type of fiber texture, and the preferred growth direction is normal to thesurface of the liners.展开更多
The microstructures in the electroformed copper liners of shapedcharges after high-strain-rate plastic deformation were in-vestigated by transmission electron microscopy(TEM). Meanwhile, theorientation distribution of...The microstructures in the electroformed copper liners of shapedcharges after high-strain-rate plastic deformation were in-vestigated by transmission electron microscopy(TEM). Meanwhile, theorientation distribution of the grains in the recovered slug wasexamined by the electron backscattering Kikuchipattern(EBSP)technique. EBSP analysis illustrated that unlike theas-formed electro- formed copper liners of shaped charges the grainorientations in the recovered slug are distributed along randomly allthe directions after undergoing heavily strain deformation athigh-strain rate. Optical microscopy shows a typicalrecrystallization structure, and TEM exam- ination revealsdislocation cells existed in the thin foil specimen. These resultsindicate that dynamic recovery and recrystallization occur duringthis plastic deformation process, and the associated deformationtemperature is considered to be higher than 0.6 times the meltingpoint of copper.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.20077005)the National High Technology Research and Development Program("863 Programm”)of China(Grant No.2002AA649140)the Provincial Grants of Science and Technology of Liaoning,China(No.20022112).
文摘This paper reports observations of significant synergistic effects between dielectric barrier discharge (DBD) plasmas and Cu-ZSM-5 catalysts for C2H4 selective reduction of NOx at 250 °C in the presence of excess oxygen by using a one-stage plasma-over-catalyst (POC) reactor. With the reactant gas mixture of 530 ppm NO, 650 ppm C2H4, 5.8% O2 in N2 and GHSV = 12000 h-1, the pure catalytic, pure plasma-induced (discharges over fused silica pellets) and plasma- catalytic (in the POC reactor) NOx conversion are 39%, 1.5% and 79%, respectively. The in-situ optical emission spectra of the reactive systems imply some short-lived active species formed from plasma-induced and plasma-catalytic processes may be responsible to the observed synergistic effects in this one-stage POC system.
基金the National Natural Science Foundation of China (No. 59971008)
文摘The microstructures of copper liners of shaped charges prepared byelectroforming technique were investigated by transmission electron microscopy (TEM). Meanwhile, theorientations distributing of the grains in the electroformed copper liners of shaped charges wasexamined by the electron backscattering Kikuchi pattern (EBSP) technique. TEM observations haverevealed that these electroformed copper liners of shaped charges have the grain size of about 1-3mu m and the grains have a preferential orientation distribution along the growth direction. EBSPanalysis has demonstrated that the as-formed copper liners of shaped charges exhibit amicro-texture, i.e. one type of fiber texture, and the preferred growth direction is normal to thesurface of the liners.
基金financially supported by the National Natural Science Foundation of China (No.59971008).
文摘The microstructures in the electroformed copper liners of shapedcharges after high-strain-rate plastic deformation were in-vestigated by transmission electron microscopy(TEM). Meanwhile, theorientation distribution of the grains in the recovered slug wasexamined by the electron backscattering Kikuchipattern(EBSP)technique. EBSP analysis illustrated that unlike theas-formed electro- formed copper liners of shaped charges the grainorientations in the recovered slug are distributed along randomly allthe directions after undergoing heavily strain deformation athigh-strain rate. Optical microscopy shows a typicalrecrystallization structure, and TEM exam- ination revealsdislocation cells existed in the thin foil specimen. These resultsindicate that dynamic recovery and recrystallization occur duringthis plastic deformation process, and the associated deformationtemperature is considered to be higher than 0.6 times the meltingpoint of copper.
