We produced and analyzed oasis structure information, and evaluated oasis functional stability using the multiple indicators based on Remote Sensing(RS) and Geographical Information System(GIS) in the arid region of C...We produced and analyzed oasis structure information, and evaluated oasis functional stability using the multiple indicators based on Remote Sensing(RS) and Geographical Information System(GIS) in the arid region of China in 2015. The results showed that the oases area was 193,734 km^2, accounting for 8.17% of the arid region of China. The spatial difference in the functional stability of oases was obvious. The Beijiang zone had the highest functional stability and was relatively stable state, and the Hexi Corridor-Alashan Plateau zone had the lowest functional stability and was relatively unstable. The functional stability is dominated by production and ecological functions, which have regional differences. Increasing oasis agricultural output, strengthening highway infrastructure construction and paying attention to education will become important ways to improve oasis functional stability. Water resources determine the ecological function, thus affecting the oasis functional stability. The results provide references for the formulation of related policies according to local conditions.展开更多
In this study, argon and nitrogen were used as the discharge gases in radio-frequency （RF： 13.56 MHz） powered dielectric barrier atmospheric plasma. It was noticed that in single dielectric barrier discharge （DBD...In this study, argon and nitrogen were used as the discharge gases in radio-frequency （RF： 13.56 MHz） powered dielectric barrier atmospheric plasma. It was noticed that in single dielectric barrier discharge （DBD） with nitrogen as the discharge gas, or in argon plasma with a high applied power, micro-filament channels were easily formed. The channels in these two kinds of discharge were both constrictive on the bare metallic electrode and expansive on the opposite electrode covered with a quartz layer. The number of micro-channels was increased along with the input power, which caused the change in the I-V curve shape, i.e., the current kept increasing and the voltage fluctuated within a confined range. With double dielectric layers, however, no micro-channels appeared in the ICCD images, and the I-V curve demonstrated a totally different shape. It was assumed that micro-filaments exhibited a restraining effect on the discharge voltage. The mechanism of this restraining effect was explored in this work.展开更多
基金This work was supported by the National Key Research and Development Program of China (2017YFC0504301)the Strategic Priority Research Program of Chinese Academy of Sciences,Pan-Third Pole Environment Study for a Green Silk Road (Pan-TPE)
文摘We produced and analyzed oasis structure information, and evaluated oasis functional stability using the multiple indicators based on Remote Sensing(RS) and Geographical Information System(GIS) in the arid region of China in 2015. The results showed that the oases area was 193,734 km^2, accounting for 8.17% of the arid region of China. The spatial difference in the functional stability of oases was obvious. The Beijiang zone had the highest functional stability and was relatively stable state, and the Hexi Corridor-Alashan Plateau zone had the lowest functional stability and was relatively unstable. The functional stability is dominated by production and ecological functions, which have regional differences. Increasing oasis agricultural output, strengthening highway infrastructure construction and paying attention to education will become important ways to improve oasis functional stability. Water resources determine the ecological function, thus affecting the oasis functional stability. The results provide references for the formulation of related policies according to local conditions.
基金supported financially by National Natural Science Foundation of China (No.11175024)Beijing Natural Science Foundation(Nos.1112012), 2011BAD24B01+1 种基金Scientific Research Common Program of Beijing Municipal Commission of Education of China (KM201110015008, KM 201010015005)Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality (PHR20110516)
文摘In this study, argon and nitrogen were used as the discharge gases in radio-frequency （RF： 13.56 MHz） powered dielectric barrier atmospheric plasma. It was noticed that in single dielectric barrier discharge （DBD） with nitrogen as the discharge gas, or in argon plasma with a high applied power, micro-filament channels were easily formed. The channels in these two kinds of discharge were both constrictive on the bare metallic electrode and expansive on the opposite electrode covered with a quartz layer. The number of micro-channels was increased along with the input power, which caused the change in the I-V curve shape, i.e., the current kept increasing and the voltage fluctuated within a confined range. With double dielectric layers, however, no micro-channels appeared in the ICCD images, and the I-V curve demonstrated a totally different shape. It was assumed that micro-filaments exhibited a restraining effect on the discharge voltage. The mechanism of this restraining effect was explored in this work.
