Recently several studies indicated possible deterioration of accuracy in the SuperDARN convection measurements at large distances （〉2 500 km）. In this study, the SuperDARN-derived convection was compared with ion d...Recently several studies indicated possible deterioration of accuracy in the SuperDARN convection measurements at large distances （〉2 500 km）. In this study, the SuperDARN-derived convection was compared with ion drift measurements given by the DMSP satellites, focused on SuperDARN far-range measurements, to investigate the above-mentioned problem. Two different procedures of SuperDARN convection estimation were applied. An overall reasonable agreement between two observation systems were found though individual points in some passes show significant differences. Besides, a tendency is also clear that the SuperDARN-derived velocities were slightly smaller than those of DMSP ion drift measurements. Potential factors contributing to the velocity differences were explained.展开更多
Anodic bonding of glass to Kovar alloy coated with Al film (Glass Al film/Kovar) was performed in the temperature range of 513 ～ 713?K under the static electric voltage of 500?V in order to investigate the interfacia...Anodic bonding of glass to Kovar alloy coated with Al film (Glass Al film/Kovar) was performed in the temperature range of 513 ～ 713?K under the static electric voltage of 500?V in order to investigate the interfacial phenomena of Al glass joint. The results reveal that Na and K ions within the glass are displaced by the applied field from the anode side surface of the glass to form depletion layers of them. The K ion depletion layer is narrow and followed by a K pile up layer, and both the two layers are formed within the Na depletion layer. The width of the Na and K depletion layers is increased with increasing bonding temperature and time. The activation energies for the growth of both depletion layers were close to that for Na diffusion in the glass. TEM observations reveal that Al film coated at the surface of Kovar alloy is oxidized to amorphous Al 2O 3 containing a few of Fe, Ni and Co by oxygen ions from the glass drifted by high electric field during bonding. The amount of Fe ions diffusing into the glass adjacent to the anode is significantly low due to the presence of Al film between Kovar alloy and the glass. As a result, the amorphous reaction layer of Fe Si O in the glass near the interface is avoided which is formed in Kovar glass joints.展开更多
As electron temperature T<sub>e</sub> is much higher than ion temperature T<sub>i</sub>, and electron driftspeed V<sub>d</sub> is larger than the critical value V<sub>dc</s...As electron temperature T<sub>e</sub> is much higher than ion temperature T<sub>i</sub>, and electron driftspeed V<sub>d</sub> is larger than the critical value V<sub>dc</sub> of V<sub>d</sub>, the ω=KV<sub>φ</sub> mode ion acoustic wave（IAW） will be instable. Under a long wave condition （Kλ<sub>D</sub>【【1, where λ<sub>D</sub> is Deby length,K is weve number）, the growing rate γ（K） of the IAW may be written展开更多
基金Supported by the National Natural Science Foundation of China (40504019)Open Fund Granted by the Key Laboratory (LOGEG) of Chinese Minis-try of Education
文摘Recently several studies indicated possible deterioration of accuracy in the SuperDARN convection measurements at large distances （〉2 500 km）. In this study, the SuperDARN-derived convection was compared with ion drift measurements given by the DMSP satellites, focused on SuperDARN far-range measurements, to investigate the above-mentioned problem. Two different procedures of SuperDARN convection estimation were applied. An overall reasonable agreement between two observation systems were found though individual points in some passes show significant differences. Besides, a tendency is also clear that the SuperDARN-derived velocities were slightly smaller than those of DMSP ion drift measurements. Potential factors contributing to the velocity differences were explained.
文摘Anodic bonding of glass to Kovar alloy coated with Al film (Glass Al film/Kovar) was performed in the temperature range of 513 ～ 713?K under the static electric voltage of 500?V in order to investigate the interfacial phenomena of Al glass joint. The results reveal that Na and K ions within the glass are displaced by the applied field from the anode side surface of the glass to form depletion layers of them. The K ion depletion layer is narrow and followed by a K pile up layer, and both the two layers are formed within the Na depletion layer. The width of the Na and K depletion layers is increased with increasing bonding temperature and time. The activation energies for the growth of both depletion layers were close to that for Na diffusion in the glass. TEM observations reveal that Al film coated at the surface of Kovar alloy is oxidized to amorphous Al 2O 3 containing a few of Fe, Ni and Co by oxygen ions from the glass drifted by high electric field during bonding. The amount of Fe ions diffusing into the glass adjacent to the anode is significantly low due to the presence of Al film between Kovar alloy and the glass. As a result, the amorphous reaction layer of Fe Si O in the glass near the interface is avoided which is formed in Kovar glass joints.
文摘As electron temperature T<sub>e</sub> is much higher than ion temperature T<sub>i</sub>, and electron driftspeed V<sub>d</sub> is larger than the critical value V<sub>dc</sub> of V<sub>d</sub>, the ω=KV<sub>φ</sub> mode ion acoustic wave（IAW） will be instable. Under a long wave condition （Kλ<sub>D</sub>【【1, where λ<sub>D</sub> is Deby length,K is weve number）, the growing rate γ（K） of the IAW may be written
