On the line of multi-molecule-formed transition state mechanism,reactionof ClONO2 with HCl on ice surface was investigated with model system by theoretical ab initio calculations.In the gas phase,the barrier of reacti...On the line of multi-molecule-formed transition state mechanism,reactionof ClONO2 with HCl on ice surface was investigated with model system by theoretical ab initio calculations.In the gas phase,the barrier of reaction of ClONO2 with HCl is 240.2kJ·mol-1at MP2HF/6-31G(d) level.The barriers drop substantially with the involvement of water molecules. The barrier of reaction of ClONO2 with 2H2O·HCl is 4.6kJ·mol-1 at the same theoretical level which suggests that the reaction of ClONO2 with HcCl can occur readily on ice surface,. The detailed accont will be published in near future.展开更多
Total ozone observations from the Total Ozone Unit （TOU） aboard the Chinese second generation polar orbiting mete- orological satellite, Fengyun-3/A （FY-3/A）, revealed that total column ozone over the Arctic decli...Total ozone observations from the Total Ozone Unit （TOU） aboard the Chinese second generation polar orbiting mete- orological satellite, Fengyun-3/A （FY-3/A）, revealed that total column ozone over the Arctic declined rapidly from the beginning of March 2011. An extensive region of low column amount formed around mid March; monthly mean total column ozone in March 2011 was about 30% lower than the average observed during 1979-2010. Daily total column density of ozone near the center of low ozone area in mid March was less than 240 Dobson units, about half the total column ozone amount observed during the same period of the prior 10 years. We analyzed total column ozone data from different satellites during 1979-2011. Results show that the Arctic depletion of ozone in spring 2011 was initiated by the cold polar vortex in the lower stratosphere. The March mean total ozone over the Arctic has shown a decreasing trend over the past 32 years, and its variation is strongly correlated with the polar vortex. A similar low ozone process of spring 1997 was compared to that of 2011, but daily variations of total ozone in March over the Northern Hemisphere in 1997 and 2011 have different patterns.展开更多
The Antarctica 'Ozone Hole' was discovered in 1985 by Farman’s group When theystudied the history （from 1957 to 1984） records of total ozone column abundance at HalleyBay（75.5°S,26.3°W） Station....The Antarctica 'Ozone Hole' was discovered in 1985 by Farman’s group When theystudied the history （from 1957 to 1984） records of total ozone column abundance at HalleyBay（75.5°S,26.3°W） Station. Later, observations from TOMS also confirmed the factthat the ozone depletion did happen over the Antarctica continent during the Australspring.Since then, more intensive research programs have been performed by somecountries such as the USA, Britain, Japan at their stations in Antarctica. The first researchof China in this field has been done with the work of measurements of O<sub>3</sub>,UV-B展开更多
Despite of the small amount in the atmosphere,ozone is one of the most critical atmospheric component as it protects human beings and any other life on the earth from the sun's high frequency ultraviolet radiation...Despite of the small amount in the atmosphere,ozone is one of the most critical atmospheric component as it protects human beings and any other life on the earth from the sun's high frequency ultraviolet radiation. In recent decades,the global ozone depletion caused by human activities is w ell know n and produces an " ozone hole",the most direct consequence of w hich is the increase in ultraviolet radiation,w hich w ill affect human survival,climatic environment,ecological environment and other important adverse impacts. Due to the implementation of the M ontreal protocol and other agreement,the total amount of ozone depleting substance in the atmosphere has been prominent reduced,w hich w ill lead to a new round of regional climate change.Therefore,predicting the changes of the total ozone in the future w ill have an important guiding significance for predicting the future climate change and making reasonable measures to deal w ith the climate change. In this paper,based on the ozone data of 1979 to 2016 in the southern hemisphere and ARIM A model algorithm,using time series analysis,w e obtain prediction effect of ARIM A model is good by Ljung-Box Q-test and R^2,and the model can be used to predict the future ozone change. With the help of SPSS softw are,the future trend of the total ozone can be predicted in the future 50 years. Based on the above experiment results,the global ozone change in the future 50 years can be forecasted,namely the atmospheric ozone layer w ill return to its 1980's standard by the middle of this century at the global scale.展开更多
Changes in the climate of the Arctic and of the Antarctic have been of great concern to the international scientific and social communities since the release in 2007 of the Intergovernmental Panel on Climate Change Fo...Changes in the climate of the Arctic and of the Antarctic have been of great concern to the international scientific and social communities since the release in 2007 of the Intergovernmental Panel on Climate Change Fourth Assessment Report （IPCC AR4）. Since then, many new findings have been reported from observations and research carried out in the Arctic and Antarctic during the fourth International Polar Year （IPY）. There is evidence that global warming is inducing rapid changes in the Arctic and Antarctic, in both a quantitative and qualitative sense, and that these regional changes could be used as indicators of global climate change. Declining Arctic sea ice could affect winter snowfall across much of the Northern Hemisphere by bringing harsher winters. Projections suggest that summertime Arctic sea ice will disappear by 2037. By the 2070s, the Antarctic ozone hole will recover to the level of the early 1980s, following the ban on the production of Freon earlier this century. With the loss of the shielding effect of the ozone hole, Antarctic surface temperatures will increase, ice sheets in East Antarctica will begin to melt, and the Antarctic sea ice will retreat. Therefore, sea level rise will become an increasingly serious issue this century. As sea surface temperature rises, the Southern Ocean will become less effective as a sink for atmospheric CO2 and the increase of surface CO2 will be faster than that in the atmosphere. Increased surface CO2 would lead to ocean acidification and affect ecological systems and food chains.展开更多
Doping can improve the band alignment at the metal-semiconductor interface to modify the corresponding Schottky barrier,which is crucial for the realization of high-performance logic components.Here,we systematically ...Doping can improve the band alignment at the metal-semiconductor interface to modify the corresponding Schottky barrier,which is crucial for the realization of high-performance logic components.Here,we systematically investigated a convenient and effective method,ultraviolet ozone treatment,for p-type doping of MoTe2 field-effect transistors to enormously enhance the corresponding electrical performance.The resulted hole concentration and mobility are near 100 times enhanced to be〜1.0×10^13 cm^-2 and 101.4 cm^2/(V·s),respectively,and the conductivity is improved by 5 orders of magnitude.These values are comparable to the highest ones ever obtained via annealing doping or non-lithographic fabrication methods at room temperature.Compared with the pristine one,the photoresponsivity(522 mA/W)is enhanced approximately 100 times.Such excellent performances can be attributed to the sharply reduced Schottky barrier because of the surface charge transfer from MoTe2 to MoOx(x<3),as proved by photoemission spectroscopy.Additionally,the p-doped devices exhibit excellent stability in ambient air.Our findings show significant potential in future nanoelectronic and optoelectronic applications.展开更多
IN ref.[1],a preliminary analysis was reported on the change characteristics of total ozoneduring the Antarctic'ozone hole'period in 1993,revealing that there is a very obvious dailychange of total ozone over ...IN ref.[1],a preliminary analysis was reported on the change characteristics of total ozoneduring the Antarctic'ozone hole'period in 1993,revealing that there is a very obvious dailychange of total ozone over Zhongshan Station and suggesting that this change would be relatedto the position of Zhongshan Station on the rim of the ozone hole influenced by the polar vortexvacillation and the expanding and contracting processes in Antarctic stratosphere.In this note,展开更多
This paper investigated the information about Ice sheet melt and Ozone hole variations during three solar cycles. After performing the inquiry on the data, the final results pointed out that both phenomena varying acc...This paper investigated the information about Ice sheet melt and Ozone hole variations during three solar cycles. After performing the inquiry on the data, the final results pointed out that both phenomena varying accord with Earth’s seasonality. The sea melt extension depends on the season and if the ocean waters are warmer around the polar caps. We checked the suggestion that anthropogenic perturbations could influence the variations in both phenomena.展开更多
文摘On the line of multi-molecule-formed transition state mechanism,reactionof ClONO2 with HCl on ice surface was investigated with model system by theoretical ab initio calculations.In the gas phase,the barrier of reaction of ClONO2 with HCl is 240.2kJ·mol-1at MP2HF/6-31G(d) level.The barriers drop substantially with the involvement of water molecules. The barrier of reaction of ClONO2 with 2H2O·HCl is 4.6kJ·mol-1 at the same theoretical level which suggests that the reaction of ClONO2 with HcCl can occur readily on ice surface,. The detailed accont will be published in near future.
文摘Total ozone observations from the Total Ozone Unit （TOU） aboard the Chinese second generation polar orbiting mete- orological satellite, Fengyun-3/A （FY-3/A）, revealed that total column ozone over the Arctic declined rapidly from the beginning of March 2011. An extensive region of low column amount formed around mid March; monthly mean total column ozone in March 2011 was about 30% lower than the average observed during 1979-2010. Daily total column density of ozone near the center of low ozone area in mid March was less than 240 Dobson units, about half the total column ozone amount observed during the same period of the prior 10 years. We analyzed total column ozone data from different satellites during 1979-2011. Results show that the Arctic depletion of ozone in spring 2011 was initiated by the cold polar vortex in the lower stratosphere. The March mean total ozone over the Arctic has shown a decreasing trend over the past 32 years, and its variation is strongly correlated with the polar vortex. A similar low ozone process of spring 1997 was compared to that of 2011, but daily variations of total ozone in March over the Northern Hemisphere in 1997 and 2011 have different patterns.
基金Project supported by the National Committee of Antarctica Program.
文摘The Antarctica 'Ozone Hole' was discovered in 1985 by Farman’s group When theystudied the history （from 1957 to 1984） records of total ozone column abundance at HalleyBay（75.5°S,26.3°W） Station. Later, observations from TOMS also confirmed the factthat the ozone depletion did happen over the Antarctica continent during the Australspring.Since then, more intensive research programs have been performed by somecountries such as the USA, Britain, Japan at their stations in Antarctica. The first researchof China in this field has been done with the work of measurements of O<sub>3</sub>,UV-B
基金supported by the key laboratory fund of Hubei province (Grant No. 2015KLA0,DZ-2016-01-H )graduate research innovation Project of NCIAE (No. YKY2016-08 )the science and technology research projects of Hebei province (Grant No. ZD 2016 106 )
文摘Despite of the small amount in the atmosphere,ozone is one of the most critical atmospheric component as it protects human beings and any other life on the earth from the sun's high frequency ultraviolet radiation. In recent decades,the global ozone depletion caused by human activities is w ell know n and produces an " ozone hole",the most direct consequence of w hich is the increase in ultraviolet radiation,w hich w ill affect human survival,climatic environment,ecological environment and other important adverse impacts. Due to the implementation of the M ontreal protocol and other agreement,the total amount of ozone depleting substance in the atmosphere has been prominent reduced,w hich w ill lead to a new round of regional climate change.Therefore,predicting the changes of the total ozone in the future w ill have an important guiding significance for predicting the future climate change and making reasonable measures to deal w ith the climate change. In this paper,based on the ozone data of 1979 to 2016 in the southern hemisphere and ARIM A model algorithm,using time series analysis,w e obtain prediction effect of ARIM A model is good by Ljung-Box Q-test and R^2,and the model can be used to predict the future ozone change. With the help of SPSS softw are,the future trend of the total ozone can be predicted in the future 50 years. Based on the above experiment results,the global ozone change in the future 50 years can be forecasted,namely the atmospheric ozone layer w ill return to its 1980's standard by the middle of this century at the global scale.
基金supported by the National Natural Science Foundation of China (Grant nos.40531007,41230529)the National High-tech Research & Development Program of China (Grant no.2008AA121703)+3 种基金the International Cooperation Project supported by Ministry of Science and Technology of China (Grant no.2009DFA22920)the International Cooperation Project supported by Chinese Arctic and Antarctic Administration (Grant nos.IC201013,IC201114,IC201201,and IC201308)the Chinese Polar Environmental Comprehensive Investigation and Assessment Programs (Grant nos.CHINARE2012-01-04-02,CHINARE2012-02-01,and CHINARE2012-03-04-02)the Ocean Public Welfare Scientific Research Project of China (Grant no.2004DIB5J178)
文摘Changes in the climate of the Arctic and of the Antarctic have been of great concern to the international scientific and social communities since the release in 2007 of the Intergovernmental Panel on Climate Change Fourth Assessment Report （IPCC AR4）. Since then, many new findings have been reported from observations and research carried out in the Arctic and Antarctic during the fourth International Polar Year （IPY）. There is evidence that global warming is inducing rapid changes in the Arctic and Antarctic, in both a quantitative and qualitative sense, and that these regional changes could be used as indicators of global climate change. Declining Arctic sea ice could affect winter snowfall across much of the Northern Hemisphere by bringing harsher winters. Projections suggest that summertime Arctic sea ice will disappear by 2037. By the 2070s, the Antarctic ozone hole will recover to the level of the early 1980s, following the ban on the production of Freon earlier this century. With the loss of the shielding effect of the ozone hole, Antarctic surface temperatures will increase, ice sheets in East Antarctica will begin to melt, and the Antarctic sea ice will retreat. Therefore, sea level rise will become an increasingly serious issue this century. As sea surface temperature rises, the Southern Ocean will become less effective as a sink for atmospheric CO2 and the increase of surface CO2 will be faster than that in the atmosphere. Increased surface CO2 would lead to ocean acidification and affect ecological systems and food chains.
基金We acknowledge the financial support from the National Natural Science Foundation of China(Nos.11874427,11874423).Dr.H an H uang acknowledges support from the Innovation-Driven project of Central South University(No.2017CX018)and from the Natural Science Foundation of H unan province(No.2016JJ1021).Mr.Xiaoming Zheng acknowledges the support from the Fundamental Research Funds for the Central Universities of Central South University(No.2017zzts066).
文摘Doping can improve the band alignment at the metal-semiconductor interface to modify the corresponding Schottky barrier,which is crucial for the realization of high-performance logic components.Here,we systematically investigated a convenient and effective method,ultraviolet ozone treatment,for p-type doping of MoTe2 field-effect transistors to enormously enhance the corresponding electrical performance.The resulted hole concentration and mobility are near 100 times enhanced to be〜1.0×10^13 cm^-2 and 101.4 cm^2/(V·s),respectively,and the conductivity is improved by 5 orders of magnitude.These values are comparable to the highest ones ever obtained via annealing doping or non-lithographic fabrication methods at room temperature.Compared with the pristine one,the photoresponsivity(522 mA/W)is enhanced approximately 100 times.Such excellent performances can be attributed to the sharply reduced Schottky barrier because of the surface charge transfer from MoTe2 to MoOx(x<3),as proved by photoemission spectroscopy.Additionally,the p-doped devices exhibit excellent stability in ambient air.Our findings show significant potential in future nanoelectronic and optoelectronic applications.
文摘IN ref.[1],a preliminary analysis was reported on the change characteristics of total ozoneduring the Antarctic'ozone hole'period in 1993,revealing that there is a very obvious dailychange of total ozone over Zhongshan Station and suggesting that this change would be relatedto the position of Zhongshan Station on the rim of the ozone hole influenced by the polar vortexvacillation and the expanding and contracting processes in Antarctic stratosphere.In this note,
文摘This paper investigated the information about Ice sheet melt and Ozone hole variations during three solar cycles. After performing the inquiry on the data, the final results pointed out that both phenomena varying accord with Earth’s seasonality. The sea melt extension depends on the season and if the ocean waters are warmer around the polar caps. We checked the suggestion that anthropogenic perturbations could influence the variations in both phenomena.
