以金属钨为研究对象,研究了不同能量的He+辐照对钨中He泡形成的影响。在600℃下分别用12ke V和20 ke V的He+辐照,辐照剂量为5×1020He+/m2,通过透射电镜(TEM)对辐照前后样品的微观结构进行表征。研究结果表明,钨在2个能量的He+辐照...以金属钨为研究对象,研究了不同能量的He+辐照对钨中He泡形成的影响。在600℃下分别用12ke V和20 ke V的He+辐照,辐照剂量为5×1020He+/m2,通过透射电镜(TEM)对辐照前后样品的微观结构进行表征。研究结果表明,钨在2个能量的He+辐照后都有He泡的产生,在12 ke V的He+辐照下,氦泡的平均尺寸约为2.19 nm,数密度为1.5×1023/m3;在20 ke V的He+辐照下,氦泡的尺寸约为1.52 nm,数密度为3.0×1023/m3。随着He+辐照能量增加,钨中He泡的平均尺寸减小,但体密度变大。展开更多
[ Objective ]The aim of this study was to discuss the feasibility of breeding cabbage with high Vc by 532 nm laser.[ Method ] With the material of cabbage, the embryo of cabbage seeds was irradiated by frequency doubl...[ Objective ]The aim of this study was to discuss the feasibility of breeding cabbage with high Vc by 532 nm laser.[ Method ] With the material of cabbage, the embryo of cabbage seeds was irradiated by frequency doubled Nd ：YAG laser with different power densities and time, and the effects of laser mode on functional leaf area, chlorophyll and Vc contents in cabbage seedlings were also studied. [Result] The results showed that functional leaf area and chlorophyll content were related to laser power density and time when laser power density was 2 -20 mW/mm^2, while the optimal effect was observed at 14 mW/mm^2 for 1 min. The content of Vc in cabbage seedlings was related to dosage of laser irradiation when irradiating time ranged from 1 to 5 min, and the optimal effect was observed at 2.8 J （20 mW/mm^2, 3 min）. [Conclusion] Irradiating the embryo of cabbage seeds with proper irradiation dosage of 532 nm laser can increase its effect on the Vc content significantly.展开更多
Development of a reactive nanocement is a new approach to improve the physical and chemical properties of construction materials. However, due to the decreased size of cement particles, beam damage during transmission...Development of a reactive nanocement is a new approach to improve the physical and chemical properties of construction materials. However, due to the decreased size of cement particles, beam damage during transmission electron microscope （TEM） observation becomes more severe than in conventional cement. In this work, irradiation damage to nano-C2S （dicalcium silicate） is observed and studied by in-situ evolution of diffraction patterns （DP）, high resolution TEM （HRTEM）, and electron energy-loss spectroscopy （EELS）. The results show that the damage to nano-C2S occurs through a decomposition reaction. Nano-C2S is first amorphized, and then re-crystallized into CaO nano-crystals with average size of 7 nm surrounded by an amorphous matrix of Si and SiO2. During this process, C2S particles exhibit volume shrinkage. The damage energy causing the reaction was analyzed and electron-electron inelastic scattering produced radiolysis and heat, leading to the observed phenomena.展开更多
Recent satellite data analysis has provided improved data sets relevant to the surface energy budget in the Arctic Ocean. In this paper, surface radiation properties in the Arctic Ocean obtained from the Surface Radia...Recent satellite data analysis has provided improved data sets relevant to the surface energy budget in the Arctic Ocean. In this paper, surface radiation properties in the Arctic Ocean obtained from the Surface Radiation Budget（SRB3.0） and the International Satellite Cloud Climatology Project（ISCCP-FD） during 1984– 2007 are analyzed and compared. Our analysis suggests that these datasets show encouraging agreement in basin-wide averaged seasonal cycle and spatial distribution of surface albedo; net surface shortwave and all-wave radiative fluxes; and shortwave, longwave, and all-wave cloud radiative forcings. However, a systematic large discrepancy is detected for the net surface longwave radiative flux between the two data sets at a magnitude of ~ 23 W m–2, which is primarily attributed to significant differences in surface temperature, particularly from April to June. Moreover, the largest difference in surface shortwave and all-wave cloud radiative forcings between the two data sets is apparent in early June at a magnitude of 30 W m–2.展开更多
文摘以金属钨为研究对象,研究了不同能量的He+辐照对钨中He泡形成的影响。在600℃下分别用12ke V和20 ke V的He+辐照,辐照剂量为5×1020He+/m2,通过透射电镜(TEM)对辐照前后样品的微观结构进行表征。研究结果表明,钨在2个能量的He+辐照后都有He泡的产生,在12 ke V的He+辐照下,氦泡的平均尺寸约为2.19 nm,数密度为1.5×1023/m3;在20 ke V的He+辐照下,氦泡的尺寸约为1.52 nm,数密度为3.0×1023/m3。随着He+辐照能量增加,钨中He泡的平均尺寸减小,但体密度变大。
基金Supported by Fund from Jilin Provincial Science & Technology Department(20090541)Project from Department of Education ofJilin Province(200828)~~
文摘[ Objective ]The aim of this study was to discuss the feasibility of breeding cabbage with high Vc by 532 nm laser.[ Method ] With the material of cabbage, the embryo of cabbage seeds was irradiated by frequency doubled Nd ：YAG laser with different power densities and time, and the effects of laser mode on functional leaf area, chlorophyll and Vc contents in cabbage seedlings were also studied. [Result] The results showed that functional leaf area and chlorophyll content were related to laser power density and time when laser power density was 2 -20 mW/mm^2, while the optimal effect was observed at 14 mW/mm^2 for 1 min. The content of Vc in cabbage seedlings was related to dosage of laser irradiation when irradiating time ranged from 1 to 5 min, and the optimal effect was observed at 2.8 J （20 mW/mm^2, 3 min）. [Conclusion] Irradiating the embryo of cabbage seeds with proper irradiation dosage of 532 nm laser can increase its effect on the Vc content significantly.
文摘Development of a reactive nanocement is a new approach to improve the physical and chemical properties of construction materials. However, due to the decreased size of cement particles, beam damage during transmission electron microscope （TEM） observation becomes more severe than in conventional cement. In this work, irradiation damage to nano-C2S （dicalcium silicate） is observed and studied by in-situ evolution of diffraction patterns （DP）, high resolution TEM （HRTEM）, and electron energy-loss spectroscopy （EELS）. The results show that the damage to nano-C2S occurs through a decomposition reaction. Nano-C2S is first amorphized, and then re-crystallized into CaO nano-crystals with average size of 7 nm surrounded by an amorphous matrix of Si and SiO2. During this process, C2S particles exhibit volume shrinkage. The damage energy causing the reaction was analyzed and electron-electron inelastic scattering produced radiolysis and heat, leading to the observed phenomena.
基金supported by the National Basic Research Program of China(2011CB30970)the National Natural Science Foundation of China(41176169 and 40930848)
文摘Recent satellite data analysis has provided improved data sets relevant to the surface energy budget in the Arctic Ocean. In this paper, surface radiation properties in the Arctic Ocean obtained from the Surface Radiation Budget（SRB3.0） and the International Satellite Cloud Climatology Project（ISCCP-FD） during 1984– 2007 are analyzed and compared. Our analysis suggests that these datasets show encouraging agreement in basin-wide averaged seasonal cycle and spatial distribution of surface albedo; net surface shortwave and all-wave radiative fluxes; and shortwave, longwave, and all-wave cloud radiative forcings. However, a systematic large discrepancy is detected for the net surface longwave radiative flux between the two data sets at a magnitude of ~ 23 W m–2, which is primarily attributed to significant differences in surface temperature, particularly from April to June. Moreover, the largest difference in surface shortwave and all-wave cloud radiative forcings between the two data sets is apparent in early June at a magnitude of 30 W m–2.
