The surface solar radiation(SSR) is of great importance to bio-chemical cycle and life activities.However,it is impossible to observe SSR directly over large areas especially for rugged surfaces such as the Qinghai-Ti...The surface solar radiation(SSR) is of great importance to bio-chemical cycle and life activities.However,it is impossible to observe SSR directly over large areas especially for rugged surfaces such as the Qinghai-Tibet Plateau.This paper presented an improved parameterized model for predicting all-sky global solar radiation on rugged surfaces using Moderate Resolution Imaging Spectroradiometer(MODIS) atmospheric products and Digital Elevation Model(DEM).The global solar radiation was validated using 11 observations within the plateau.The correlation coefficients of daily data vary between 0.67-0.86,while those of the averages of 10-day data are between 0.79-0.97.The model indicates that the attenuation of SSR is mainly caused by cloud under cloudy sky,and terrain is an important factor influencing SSR over rugged surfaces under clear sky.A positive relationship can also be inferred between the SSR and slope.Compared with horizontal surfaces,the south-facing slope receives more radiation,followed by the west-and east-facing slopes with less SSR,and the SSR of the north-facing slope is the least.展开更多
Yangbajing (YBJ) is located in the Tibetan Plateau, China. The characteristics of solar radiation and its relationship with clouds at YBJ from April 2009 to April 2010 were analyzed in this paper. The annual mean sola...Yangbajing (YBJ) is located in the Tibetan Plateau, China. The characteristics of solar radiation and its relationship with clouds at YBJ from April 2009 to April 2010 were analyzed in this paper. The annual mean solar radiation was 478.4 W m 2 , and the annual mean transmittance was 0.713. The atmospheric mean trans- mittance of clear skies reaches 0.828 when the solar elevation angle (SEA) is greater than 10 degrees. Comparisons with numerical simulations show that the atmosphere of YBJ is clean. Impacts from atmospheric conditions on solar radiation are similar for clear skies during the year because the standard deviation of transmittance in clear skies was less than 0.05 when the SEA was greater than 10 degrees. It is important to understand the impact of clouds on solar radiation without considering other impact factors. In the last part of this article, the authors analyzed and established a statistical quantitative relationship between surface solar radiation and cloud fraction.展开更多
This study reconstructs the long-term evolution of river terraces over large spatial scales along the Anning River, western Sichuan, and identifies external factors controlling terrace formation. Pollen record analysi...This study reconstructs the long-term evolution of river terraces over large spatial scales along the Anning River, western Sichuan, and identifies external factors controlling terrace formation. Pollen record analysis and terrace structure indicate that formation of the middle section of terraces I-III resulted from the interaction of changing climates and uplift of the margins of the Qinghai-Tibet Plateau. The relative influence of climate and uplift in terrace formation changes in different periods. The terraces reveal multiple, gradual uplift events on the eastern Qinghai-Tibet Plateau, which is of great significance for determining uplift mechanisms across the entire plateau.展开更多
Sodium-ion batteries （NIBs） show great prospect on the energy storage applications benefiting from thei low cost and the abundant Na resources despite the expected lower energy density compared wit lithium-ion batte...Sodium-ion batteries （NIBs） show great prospect on the energy storage applications benefiting from thei low cost and the abundant Na resources despite the expected lower energy density compared wit lithium-ion batteries （LIBs）. To further enhance the competitive advantage, especially in energy densit3 developing the high-capacity carbon anode materials can be one of the effective approaches to realiz this goal. Herein, we report a novel carbon anode made from charcoal with a high capacity of ~400 Ah g i, wherein about 85% （〉330 mAh g^-1） of its total capacity is derived from the long plateau regio below ~0.1 V. which differs fiom those of typical hard carbon materials （~300 mAh g^-l） in NIBs but i similar to the graphite anode in LIBs. When coupled with air-stable Nao.gCuo.22Feo.3oMno.4802 oxid cathode, a high-energy density of ~240 Wh kg^-1 is achieved with good rate capability and cyclin stability. The discovery of this promising carbon anode is expected to further improve the energy densit of NIBs towards large-scale electrical energy storage.展开更多
The electronic structure characters are calculated for the Zn1-∞MxO alloys with some Zn atoms in ZnO substituted by 3d transition-metal atoms （M）, in order to find out which of these alloys could provide an interme...The electronic structure characters are calculated for the Zn1-∞MxO alloys with some Zn atoms in ZnO substituted by 3d transition-metal atoms （M）, in order to find out which of these alloys could provide an intermediate band material used for fabricating high efficiency solar cell. Especially, among of these alloys, the electronic structure character and optical performance of Zn1-xCr∞ 0 alloys clearly show an intermediate band filled partially and isolated from the VB and the CB in energy band structure of ZnO host, and the intermediate band characters can be preserved with increasing Cr concentrations no more than 8.33% in Zn1-xCrxO alloys, at the same time, the ratio 0.52 of Eg^FC to EVE in Zn1-xCrxO, （x = 4.16%） alloy is closest to the optimal ratio of 0,57. Besides, compared to the ZnO, the optical absorption does indicate a great improved absorption below the calculated band gap of the ZnO and an enhancement of the optical absorption in the whole solar spectral energy range.展开更多
基金Under the auspices of Knowledge Innovation Programs of the Chinese Academy of Sciences (No KZCX2-YW-308)National Natural Science Foundation of China (No 40771172, 40901223)
文摘The surface solar radiation(SSR) is of great importance to bio-chemical cycle and life activities.However,it is impossible to observe SSR directly over large areas especially for rugged surfaces such as the Qinghai-Tibet Plateau.This paper presented an improved parameterized model for predicting all-sky global solar radiation on rugged surfaces using Moderate Resolution Imaging Spectroradiometer(MODIS) atmospheric products and Digital Elevation Model(DEM).The global solar radiation was validated using 11 observations within the plateau.The correlation coefficients of daily data vary between 0.67-0.86,while those of the averages of 10-day data are between 0.79-0.97.The model indicates that the attenuation of SSR is mainly caused by cloud under cloudy sky,and terrain is an important factor influencing SSR over rugged surfaces under clear sky.A positive relationship can also be inferred between the SSR and slope.Compared with horizontal surfaces,the south-facing slope receives more radiation,followed by the west-and east-facing slopes with less SSR,and the SSR of the north-facing slope is the least.
基金support from the National Special Fund for the Commonweal Industry (Meteorology)of China (Grant No. GYHY200806031)
文摘Yangbajing (YBJ) is located in the Tibetan Plateau, China. The characteristics of solar radiation and its relationship with clouds at YBJ from April 2009 to April 2010 were analyzed in this paper. The annual mean solar radiation was 478.4 W m 2 , and the annual mean transmittance was 0.713. The atmospheric mean trans- mittance of clear skies reaches 0.828 when the solar elevation angle (SEA) is greater than 10 degrees. Comparisons with numerical simulations show that the atmosphere of YBJ is clean. Impacts from atmospheric conditions on solar radiation are similar for clear skies during the year because the standard deviation of transmittance in clear skies was less than 0.05 when the SEA was greater than 10 degrees. It is important to understand the impact of clouds on solar radiation without considering other impact factors. In the last part of this article, the authors analyzed and established a statistical quantitative relationship between surface solar radiation and cloud fraction.
基金supported by National Basic Research Program of China (Grant No. 2004CB418401)
文摘This study reconstructs the long-term evolution of river terraces over large spatial scales along the Anning River, western Sichuan, and identifies external factors controlling terrace formation. Pollen record analysis and terrace structure indicate that formation of the middle section of terraces I-III resulted from the interaction of changing climates and uplift of the margins of the Qinghai-Tibet Plateau. The relative influence of climate and uplift in terrace formation changes in different periods. The terraces reveal multiple, gradual uplift events on the eastern Qinghai-Tibet Plateau, which is of great significance for determining uplift mechanisms across the entire plateau.
基金supported by the National Key Technologies R&D Program(2016YFB0901500)National Natural Science Foundation of China(51725206,51421002,51232005,and 51372131)
文摘Sodium-ion batteries （NIBs） show great prospect on the energy storage applications benefiting from thei low cost and the abundant Na resources despite the expected lower energy density compared wit lithium-ion batteries （LIBs）. To further enhance the competitive advantage, especially in energy densit3 developing the high-capacity carbon anode materials can be one of the effective approaches to realiz this goal. Herein, we report a novel carbon anode made from charcoal with a high capacity of ~400 Ah g i, wherein about 85% （〉330 mAh g^-1） of its total capacity is derived from the long plateau regio below ~0.1 V. which differs fiom those of typical hard carbon materials （~300 mAh g^-l） in NIBs but i similar to the graphite anode in LIBs. When coupled with air-stable Nao.gCuo.22Feo.3oMno.4802 oxid cathode, a high-energy density of ~240 Wh kg^-1 is achieved with good rate capability and cyclin stability. The discovery of this promising carbon anode is expected to further improve the energy densit of NIBs towards large-scale electrical energy storage.
基金Supported by the State Key Program for Basic Research of China under Grant No.2006CB921803Project of High Technology Research&Development of China(Project No.2007AA03Z404)+1 种基金National Natural Science Foundation of China under Grant Nos.61274058,60990312,and 61025020Natural Science Foundation of Anhui Province under Grant No.1208085QF116
文摘The electronic structure characters are calculated for the Zn1-∞MxO alloys with some Zn atoms in ZnO substituted by 3d transition-metal atoms （M）, in order to find out which of these alloys could provide an intermediate band material used for fabricating high efficiency solar cell. Especially, among of these alloys, the electronic structure character and optical performance of Zn1-xCr∞ 0 alloys clearly show an intermediate band filled partially and isolated from the VB and the CB in energy band structure of ZnO host, and the intermediate band characters can be preserved with increasing Cr concentrations no more than 8.33% in Zn1-xCrxO alloys, at the same time, the ratio 0.52 of Eg^FC to EVE in Zn1-xCrxO, （x = 4.16%） alloy is closest to the optimal ratio of 0,57. Besides, compared to the ZnO, the optical absorption does indicate a great improved absorption below the calculated band gap of the ZnO and an enhancement of the optical absorption in the whole solar spectral energy range.
