2011-03-11日本福岛核电站放射性物质发生泄漏事件,本研究基于MASNUM(Laboratory of Marine Science and Numerical Modeling)海洋环流模式,建立了西北太平洋海洋放射性物质输运扩散模式,对事故释放的^(137)Cs在海洋中的输运和扩散过程...2011-03-11日本福岛核电站放射性物质发生泄漏事件,本研究基于MASNUM(Laboratory of Marine Science and Numerical Modeling)海洋环流模式,建立了西北太平洋海洋放射性物质输运扩散模式,对事故释放的^(137)Cs在海洋中的输运和扩散过程进行了20a的模拟与预测。根据与观测资料的比较,验证了所建立的模式具备模拟放射性物质在海洋中的输运扩散过程的能力。结果显示:至2015年,^(137)Cs表层活度浓度已经扩散至整个中国海域,活度浓度值在0.01Bq/m^3左右;事故发生10a后,研究海域^(137)Cs表层活度浓度趋于均匀,为0.20~0.60Bq/m^3左右;20a后,^(137)Cs在海洋表层的活度浓度要小于0.15Bq/m^3。垂向扩散的结果显示:事故发生10a后,黄海海域^(137)Cs垂向分布较为均匀,东海东部陆架海域活度浓度高于西部海域,且上层海水中^(137)Cs活度浓度高于底层海水,南海北部海域^(137)Cs活度浓度高于南部海域,且略小于黄海和东海;至2030年,中国近海^(137)Cs的活度浓度的垂向分布趋于均匀,南海略高于黄海和东海;日本海^(137)Cs活度浓度主要集中在表层,最大活度浓度出现在2016年,约为0.20Bq/m^3;西北太平洋海域^(137)Cs活度浓度要高于其他4个海域;2030年以后,整个海域^(137)Cs活度浓度在水平和垂向分布均趋于均匀,均小于0.15Bq/m^3。展开更多
The growth mode of 3,4,9,10-perylenetetra-carboxylic dianhydride(PTCDA) deposited on p-Si substrates can be deduced by X-ray Photoemission Spectroscopy(XPS). The spectrum and fine spectrum at the surface of specimen a...The growth mode of 3,4,9,10-perylenetetra-carboxylic dianhydride(PTCDA) deposited on p-Si substrates can be deduced by X-ray Photoemission Spectroscopy(XPS). The spectrum and fine spectrum at the surface of specimen are studied. Firstly, PTCDA molecules assemble at the defects to form lots of three-dimensional island-like PTCDA crystal nucleuses, and then by the action of delocalized big π bond, two adjacent layers of PTCDA molecules overlap to some extent and finally island-like structure forms. PTCDA molecules of benzene ring combine with Si atoms at the defects, and that of acid anhydride radicals combine with Si atoms at the perfect fraction of the surface. In the course of combination, although the structure of benzene ring doesn't change, the chemical reaction of acid anhydride radicals and Si occurs to break off C=O bond in acid anhydride, and then C-Si-O and silicon oxide might be produced.展开更多
A one-dimensional,self-consistent fluid model is developed for a computational investigation on discharge characteristics and dynamics of radio frequency(RF) glow discharges in atmospheric argon,which are demonstrated...A one-dimensional,self-consistent fluid model is developed for a computational investigation on discharge characteristics and dynamics of radio frequency(RF) glow discharges in atmospheric argon,which are demonstrated through the spatial and temporal profiles of plasma species,electric field,and mean electron energy.Furthermore,in the discharge current density range from 7.1 mA/cm2 to 119.5 mA/cm2,different discharge operation modes of α and γ are indicated by changing differential conductivity of voltage-current characteristics and sheath dynamics in terms of sheath voltage and sheath thickness.展开更多
文摘2011-03-11日本福岛核电站放射性物质发生泄漏事件,本研究基于MASNUM(Laboratory of Marine Science and Numerical Modeling)海洋环流模式,建立了西北太平洋海洋放射性物质输运扩散模式,对事故释放的^(137)Cs在海洋中的输运和扩散过程进行了20a的模拟与预测。根据与观测资料的比较,验证了所建立的模式具备模拟放射性物质在海洋中的输运扩散过程的能力。结果显示:至2015年,^(137)Cs表层活度浓度已经扩散至整个中国海域,活度浓度值在0.01Bq/m^3左右;事故发生10a后,研究海域^(137)Cs表层活度浓度趋于均匀,为0.20~0.60Bq/m^3左右;20a后,^(137)Cs在海洋表层的活度浓度要小于0.15Bq/m^3。垂向扩散的结果显示:事故发生10a后,黄海海域^(137)Cs垂向分布较为均匀,东海东部陆架海域活度浓度高于西部海域,且上层海水中^(137)Cs活度浓度高于底层海水,南海北部海域^(137)Cs活度浓度高于南部海域,且略小于黄海和东海;至2030年,中国近海^(137)Cs的活度浓度的垂向分布趋于均匀,南海略高于黄海和东海;日本海^(137)Cs活度浓度主要集中在表层,最大活度浓度出现在2016年,约为0.20Bq/m^3;西北太平洋海域^(137)Cs活度浓度要高于其他4个海域;2030年以后,整个海域^(137)Cs活度浓度在水平和垂向分布均趋于均匀,均小于0.15Bq/m^3。
文摘The growth mode of 3,4,9,10-perylenetetra-carboxylic dianhydride(PTCDA) deposited on p-Si substrates can be deduced by X-ray Photoemission Spectroscopy(XPS). The spectrum and fine spectrum at the surface of specimen are studied. Firstly, PTCDA molecules assemble at the defects to form lots of three-dimensional island-like PTCDA crystal nucleuses, and then by the action of delocalized big π bond, two adjacent layers of PTCDA molecules overlap to some extent and finally island-like structure forms. PTCDA molecules of benzene ring combine with Si atoms at the defects, and that of acid anhydride radicals combine with Si atoms at the perfect fraction of the surface. In the course of combination, although the structure of benzene ring doesn't change, the chemical reaction of acid anhydride radicals and Si occurs to break off C=O bond in acid anhydride, and then C-Si-O and silicon oxide might be produced.
基金National Natural Science Foundations of China (No. 10835004,No. 10905010)Shanghai Shuguang Program,China (No.08SG31)
文摘A one-dimensional,self-consistent fluid model is developed for a computational investigation on discharge characteristics and dynamics of radio frequency(RF) glow discharges in atmospheric argon,which are demonstrated through the spatial and temporal profiles of plasma species,electric field,and mean electron energy.Furthermore,in the discharge current density range from 7.1 mA/cm2 to 119.5 mA/cm2,different discharge operation modes of α and γ are indicated by changing differential conductivity of voltage-current characteristics and sheath dynamics in terms of sheath voltage and sheath thickness.
