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夭国与散国族姓问题之辩说 被引量:2
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作者 杨亚长 《中原文物》 北大核心 2007年第5期38-41,共4页
夭国与散国曾是西周时期两个较著名的方国,对于其各自的族姓学术界存在不同的看法。但依据相关铜器铭文和文献记载,夭国为姜姓、散国为姬姓的观点应较为符合实际。
关键词 散国 姜姓 姬姓
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脉冲电阻分压器的性能分析和电感补偿 被引量:1
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作者 高华东 徐志跃 《电子设计工程》 2013年第19期65-68,共4页
在自动检测领域,高压窄脉冲的测量是非常重要的,脉冲分压器结合AD采集卡是常用的测量系统的主要组成部分。电阻分压器因其结构简单、性能优良、使用方便等特性而具有广泛的应用。本文讨论了电阻元件杂散电容对脉冲电阻分压器性能的影响... 在自动检测领域,高压窄脉冲的测量是非常重要的,脉冲分压器结合AD采集卡是常用的测量系统的主要组成部分。电阻分压器因其结构简单、性能优良、使用方便等特性而具有广泛的应用。本文讨论了电阻元件杂散电容对脉冲电阻分压器性能的影响,引入传递函数的概念对其进行理论分析,提出了电感补偿的方法。实验结论和理论计算结果一致,验证了电感补偿的可行性。 展开更多
关键词 电阻分压器 电容 传递函数 电感补偿
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β-diversity Patterns of Plant Community in Fragmented Habitat in a Degenerated Meadow in Songnen Plain,China 被引量:11
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作者 HAN Dayong LI Haiyan YANG Yunfei 《Chinese Geographical Science》 SCIE CSCD 2009年第4期375-381,共7页
A number of isolated islands of Leymus chinensis + herbosa community were investigated in fragmented habitat islands, by Braun-Blanquet field survey approach, in a degenerated meadow in the Songnen Plain, China in 20... A number of isolated islands of Leymus chinensis + herbosa community were investigated in fragmented habitat islands, by Braun-Blanquet field survey approach, in a degenerated meadow in the Songnen Plain, China in 2007. These islands were classified as large, medium, and small scales on the basis of the island area (100-1000m2, large island; 50-100m2, middle island; 10-50m2, small island). Each scale of the investigation involved eight islands. The responses ofβ-diversity patterns of plant taxon to the habitat fragmentation at local community and metacommunity levels were analyzed on different scales of 24 isolated islands. The results indicated that at the local community level, there were 57 species belonging to 20 families and 49 genera in large islands, 49 species belonging to 16 families and 40 genera in middle islands, and 27 species belonging to eight families and 23 genera in small islands, β-diversity indexes for species, genus and family in large, middle, and small islands varied greatly, and the highest value of the indexes was not noted in the largest island. However, the average of the data obtained at the three scales showed that across large islands, Whittaker indexes were low and Bray-Curtis similarity indexes were high, while across small islands, Whittaker indexes were high and Bray-Curtis similarity indexes were low. At the metacommunity level, Whittaker indexes for species and genus showed a great significantly negative double logarithmic correlation (p〈0.01) with the island area, whereas the Bray-Curtis indexes for species, genus and family showed a great significantly positive double logarithmic correlation (p〈0.01) with the island area. At both local community and metacommunity levels, tumovers of species and genus could respond more sensitively to spatial changes of plant diversity patterns than that of family. Hence, the species and the genus could be used for the analysis offl-diversity patterns of plant community. 展开更多
关键词 habitat fragmentation local community METACOMMUNITY plant taxon β-diversity
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Variations in Optical Scattering and Backscattering by Organic and Inorganic Particulates in Chinese Lakes of Taihu, Chaohu and Dianchi 被引量:2
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作者 LYU Heng WANG Qiao +3 位作者 WU Chuanqing ZHU Li LI Yunmei HUANG Jiazhu 《Chinese Geographical Science》 SCIE CSCD 2015年第1期26-38,共13页
This study presents an investigation of the scattering and backscattering properties of the particulates in three Chinese inland lakes(the Taihu Lake, the Chaohu Lake and the Dianchi Lake) based on in situ measurement... This study presents an investigation of the scattering and backscattering properties of the particulates in three Chinese inland lakes(the Taihu Lake, the Chaohu Lake and the Dianchi Lake) based on in situ measurements taken at 119 sites. We modeled the particulate scattering spectra using a wavelength-dependent power-law function, finding that the power-law exponents in the Taihu Lake and the Chaohu Lake differ from those in the Dianchi Lake but are similar to the values in the U.S. coastal waters. In contrast to the open ocean, the backscattering properties in the three lakes can not be determined only from chlorophyll-a concentration. The backscattering ratio spectra exhibit a wavelength dependence feature in all three lakes, generally decreasing with the increasing wavelength. Analysis results of the correlations between the backscattering ratio and the individual water quality parameters clearly show that there are distinctive relations among the three lakes, attributed primarily to different compositions of optically active materials in the three lakes. Analysis of the mass-specific scattering and backscattering coefficients shows that the coefficients at wavelength 532 nm in the Taihu Lake and Chaohu Lake are similar, but they are apparently different from those in the Dianchi Lake. Lastly, Model I multiple linear regressions were adopted to partition the mass-specific cross-sections for scattering and backscattering into organic and inorganic cross-sections to further interpret the scattering and backscattering properties. The relative contribution of organic and inorganic particulates to scattering and backscattering is clearly different among the three lakes. The scattering and backscattering properties of the particulates in the three inland lakes vary significantly based on our collected data. The results indicated that the existing semi-analytical water quality retrieval models of the Taihu Lake can not be applied perfectly to the Chaohu Lake and the Dianchi Lake. 展开更多
关键词 scattering/backscattering coefficient backscattering ratio mass-specific cross-section organic/inorganic particulates Chinese inland lakes
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Kinetic Energy Budget Equations of Rotational and Divergent Flow in Terrain-following Coordinates 被引量:1
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作者 CAO Jie SUN Ji-Song +1 位作者 GAO Shou-Ting CUI Xiao-Peng 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第3期149-153,共5页
In this study, kinetic energy budget equations of rotational and divergent flow in pressure coordinates are derived on terrain-following coordinates. The new formulation explicitly shows the terrain effects and can be... In this study, kinetic energy budget equations of rotational and divergent flow in pressure coordinates are derived on terrain-following coordinates. The new formulation explicitly shows the terrain effects and can be applied directly to model-simulated dynamic and thermodynamic fields on the model's original vertical grid. Such application eliminates interpolation error and avoids errors in virtual weather systems in mountainous areas. These advantages and their significance are demonstrated by a numerical study in terrain-following coordinates of a developing vortex after it moves over the Tibetan Plateau in China. 展开更多
关键词 terrain-following coordinates kinetic energy southwest vortex streamfunction velocity potential
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Intestinal disease of scattered mirror carp Cyprinus carpio caused by Thelohanellus kitauei and notes on the morphology and phylogeny of the myxosporean from Sichuan Province,southwest China 被引量:4
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作者 叶灵通 卢明淼 +5 位作者 权可艳 李文祥 邹红 吴山功 王江勇 王桂堂 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第3期587-596,共10页
The mass mortality of pond-reared scattered mirror carp, Cyprinus carpio, caused by Thelohanellus kitauei, occurred at fish farms in Sichuan Province, southwest China. Morphological and molecular analyses were supplem... The mass mortality of pond-reared scattered mirror carp, Cyprinus carpio, caused by Thelohanellus kitauei, occurred at fish farms in Sichuan Province, southwest China. Morphological and molecular analyses were supplemented with histological evaluation of infected tissues to better understand the route of infection and the pathological effects of 1". kitauei on the fish host. The intestine of the diseased host was full of large cysts of the myxosporean. The cysts range from 2 cm to 3.6 cm in diameter. Histopathology indicated that T. kitauei first invaded the submucosa of the host intestine and then moved into the mucosa layers with the development of their spores, finally entering into the enteric cavity of the hosts after the disruption of mucosa layers. The pyriform spores of T. kitauei were surrounded by the transparent spore sheath, measuring 25.98/μm±0.95 μm in body length, 8.72 μm±0.51μm body width, and 7.86 μm±0.26 μm in body thickness. The single polar capsule was pyriform, measuring 14.73 μm±0.92μm in length and 6.82 μm±0.45μm in width, with eight to 10 turns of filament coils winding inside. Phylogenetic analysis based on the 18S small-subunit ribosomal DNA sequences indicated that minimal genetic differences were present between T. kitauei samples from South Korea and from China. Close affinity was found between the genus Thelohanellus and Myxobolus. Additionally, two polar capsule nuclei were found at the anterior end of the single polar capsule in spores of T. kitauei stained with hematoxylin and eosin, which suggested the separation of the genus Thelohanellus from Myxobolus. 展开更多
关键词 intestinal disease scattered mirror carp Thelohanellus kitauei host-specific tropism MORPHOLOGY PHYLOGENY
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China's adjustment of climate change policies:what lessons can be learned from the US? 被引量:2
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作者 Liu Mingming Zhao Xiusheng 《Ecological Economy》 2009年第3期228-237,共10页
From the US New Energy Plan, personnel appointment, and diplomatic activities, etc., we can see that US is now on the way to returning to the negotiation table and undertaking the leadership in addressing climate chan... From the US New Energy Plan, personnel appointment, and diplomatic activities, etc., we can see that US is now on the way to returning to the negotiation table and undertaking the leadership in addressing climate change. What US has done puts tremendous challenges on China, which emits large amount of greenhouse gas into the atmosphere. However, different from US, China is undergoing rapid development, and huge energy consumption is unavoidable. China has to make a balance between developing economy and addressing climate change. This paper focuses on the US climate change policies and its greenhouse gas emissions, and its influences on China climate change policy. China greenhouse gas emissions and relative policies are also analyzed to see what situation China is in, and what challenges that China is facing. Consequently, combing China's local situation, we propose several solutions for China to address climate change, i.e. moving towards a low carbon economy, struggling for emitting more, enhancing China-US cooperation, and implementing different climate change policies based on local situation. Meanwhile, the achievements that China has made are also introduced. 展开更多
关键词 Address climate change Climate change policy China and US Kyoto Protocol CO2 emissions Low carbon economy
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Optimal Forward-Scattering Angles of Atmospheric Aerosols in North China 被引量:1
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作者 JIA Sheng-Jie Lü Da-Ren 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第3期236-242,共7页
The accurate understanding of atmospheric aerosol extinction coefficients is very important for at- mospheric science research. To achieve a fast and simple method for determining the parameters, the selection of opti... The accurate understanding of atmospheric aerosol extinction coefficients is very important for at- mospheric science research. To achieve a fast and simple method for determining the parameters, the selection of optimal forward-scattering angles of atmospheric aerosols is required. In this paper, the authors introduce the detec- tion basis of forward-scattering of atmospheric aerosols, and the authors verify the sensitivity of the phase function to the real part of the complex refractive index. The au- thors use the Jaenicke urban aerosol model to determine that forward-scattering angles near 33° are suitable. However, the optimal forward-scattering angles in North China are between 37° and 40°. Numerical simulation shows that certain types of particle size distribution of newly generated particles and pollution have limited in- fluences on the selection of forward-scattering angles. But the ranges of these insensitive angles shift - 10 degrees for dust intrusion, and the relative deviations of the phase function are less than 5.0% within extra angles of 0° to 3°. This study can serve as a reference for the selection of optimal forward-scattering angles for visibility meters and Present Weather Identifiers (PWIs) in addition to the de- tection of forward-scattering optical properties. 展开更多
关键词 forward-scattering anglesphase function complex refractive index visibility meters
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Air Pollution Concentration Approach to Potential Area Selection of the Air Quality Monitoring Station in Nakhon Ratchasima Municipality, Thailand 被引量:1
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作者 Patiwat Littidej Sunya Sarapirome Warunee Aunphoklang 《Journal of Environmental Science and Engineering(A)》 2012年第4期484-494,共11页
The purpose of the study is to generate traffic air information system) to determine a proper zone of AQMS (air analyzed were carbon monoxide (CO), and nitrogen oxides (NOx) pollution map using mathematical mode... The purpose of the study is to generate traffic air information system) to determine a proper zone of AQMS (air analyzed were carbon monoxide (CO), and nitrogen oxides (NOx) pollution map using mathematical model and GIS (geographic quality monitoring station) in municipality area. The pollutants which can be harmful to people living in the area. The three steps of mapping process were performed under the GIS environment using the existing vehicle emission rates and pollutant dispersion model. First, traffic volume, road network, and the emission rates of road segments varying with types of vehicle were collected from existing data. Second, the pollutant concentrations were calculated by use of CALINE4, a tool with Gaussian dispersion model. The model parameters include emission rate, wind directions and speeds, ambient temperature and observed pollutant concentration, and atmospheric stability during all seasons from the January 1, 2010 to May 31,2011 with regardless the rainy season. This resulted in concentrations at many receptor points along links of the road network. Third, distributions of pollution concentrations were generated by means of the spatial interpolation of those from receptors. The results of pollution raster-based maps are used for determining frequency of violence and combined pollution map. The resulting frequency of violence and intensity concentration will be further integrated to determine a potential area of AQMS. Finally, achieving pollution potential area of AQMS can be located as helpful basic data for efficient traffic and transportation planning. 展开更多
关键词 Frequency of violence intensity concentration AQMS (air quality monitoring station) dispersion model CALINE4 Nakhon Ratchasima Thailand.
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Risk-analysis-based research and application of land use planning
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作者 Cao Zheng Li Qingshui +2 位作者 Liu Mao Zhang Xiuhua Lv Yan 《Engineering Sciences》 EI 2010年第3期90-96,共7页
The establishments which produce,store and use kinds of inflammable,explosive or toxic materials may induce accident,such as fire,explosion or poisonous gas dispersion,etc. Therefore,there is a need to locate these es... The establishments which produce,store and use kinds of inflammable,explosive or toxic materials may induce accident,such as fire,explosion or poisonous gas dispersion,etc. Therefore,there is a need to locate these establishments appropriately and conduct land use planning in the vicinity of these establishments based on risk analysis. Consulting advanced experience which obtained from land-use planning in European countries,this paper studied on locating hazardous establishment based on risk index,land-use planning based on consequence-probability,and land-use planning based on individual risk. Frameworks and procedures of the three approaches above were determined and applied to a proposed LNG station. The results show three methods are feasible when major projects' location and their surrounding buildings or establishments' layout are considered. 展开更多
关键词 risk analysis land use planning risk index individual risk
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Annual and Interannual Variability of Scatterometer Ocean Surface Wind over the South China Sea 被引量:1
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作者 ZHANG Guosheng XU Qing +3 位作者 GONG Zheng CHENG Yongcun WANG Lei JI Qiyan 《Journal of Ocean University of China》 SCIE CAS 2014年第2期191-197,共7页
To investigate the annual and interaunual variability of ocean surface wind over the South China Sea (SCS), the vector empirical orthogonal function (VEOF) method and the Hilbert-Huang transform (HHT) method wer... To investigate the annual and interaunual variability of ocean surface wind over the South China Sea (SCS), the vector empirical orthogonal function (VEOF) method and the Hilbert-Huang transform (HHT) method were employed to analyze a set of combined satellite scatterometer wind data during the period from December 1992 to October 2009. The merged wind data were generated from European Remote Sensing Satellite (ERS)-1/2 Scatterometer, NASA Scatterometer (NSCAT) and NASA's Quick Scatterometer (QuikSCAT) wind products. The first VEOF mode corresponds to a winter-summer mode which accounts for 87.3% of the total variance and represents the East Asian monsoon features. The second mode of VEOF corresponds to a spring-autumn oscil- lation which accounts for 8.3% of the total variance. To analyze the interannual variability, the annual signal was removed from the wind data set and the VEOFs of the residuals were calculated. The temporal mode of the ftrst intcrannual VEOF is correlated with the Southern Oscillation Index (SOI) with a four-month lag. The second temporal interannual VEOF mode is correlated with the SOI with no time lag. The time series of the two interannual VEOFs were decomposed using the HI-IT method and the results also show a correlation between the interannual variability and El Nino-Southern Oscillation (ENSO) events. 展开更多
关键词 ocean surface wind annual and interannual variability SCATTEROMETER South China Sea
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Genetic characteristics and pathogenicity of human hepatitis E virus in Nanjing,China 被引量:5
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作者 lia-Bao Geng Mao-Rong Wang +4 位作者 Jie Wang Zhi-Guo Yang Yan Cheng Fei Qiao Min Wang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第9期965-970,共6页
AIM: To investigate the genetic characteristics and pathogenicity of hepatitis E virus (HEV) and assess the potential risk factors for sporadic hepatitis E.
关键词 GENOTYPE Hepatitis E virus Liver failure Zoo-notic transmission PATHOGENICITY
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The Discrete Horizontal Complex on Lattice Space
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作者 ZHOU Hui-qian LIU Zhen LI Qi-sheng 《Chinese Quarterly Journal of Mathematics》 CSCD 2009年第4期561-567,共7页
We define discrete total differential forms on lattice space by. changing coefficients of discrete differential forms from functions only of n to functions also of dependent variables un and their partial differences.... We define discrete total differential forms on lattice space by. changing coefficients of discrete differential forms from functions only of n to functions also of dependent variables un and their partial differences. And the discrete exterior derivative extends to be discrete total differential map which is also nilpotent. Then a discrete horizontal complex can be derived and be proved to be exact by constructing homotopy operators. 展开更多
关键词 discrete horizontal complex noncommutative differential calculus discrete higher Euler operator homotopy operator
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Currents and mixing in the northern South China Sea 被引量:3
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作者 刘军亮 蔡树群 王盛安 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第5期974-980,共7页
We investigated the vertical distribution of current velocity data of the entire water column at a site on the continental shelf of the northern South China Sea(SCS) from August 4 to September 6,2007,and found that th... We investigated the vertical distribution of current velocity data of the entire water column at a site on the continental shelf of the northern South China Sea(SCS) from August 4 to September 6,2007,and found that the characteristics of barotropic and baroclinic tides are mainly diurnal.During the observation period,we also estimated the mixing before and after the passage of Typhoon Pabuk.We found that the internal-wave-scale dissipation rate,the turbulent dissipation rate,and the mixing rate in every water layer increased by about an order of magnitude after the typhoon passage.We analyzed a case of abrupt strong current and calculated the mixing rate before,during,and after the typhoon event.The results show that the internal-wave-scale dissipation rate and the mixing rate in every water layer increased by about two orders of magnitude during the event,while the turbulent dissipation rate increased by about an order of magnitude.Passage of the abrupt strong current could also have increased the mixing rate of affected seawater by more than an order of magnitude.However,the passage of the typhoon differed in that there was an increase in mixing only in the lower layer where the abrupt strong current was particularly strong.The variation of the mixing rate may help us to understand the effects of typhoons and abrupt strong currents on the mixing of seawater. 展开更多
关键词 current field TYPHOON abrupt strong current mixing rate South China Sea (SCS)
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Estimation of Regional Evapotranspiration in Alpine Area and Its Response to Land Use Change:A Case Study in Three-River Headwaters Region of Qinghai-Tibet Plateau,China 被引量:6
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作者 LI Huixia LIU Guohua FU Bojie 《Chinese Geographical Science》 SCIE CSCD 2012年第4期437-449,共13页
Three-River Headwaters (TRH) region involved in this paper refers to the source region of the Changjiang (Yangtze) River, the Huanghe (Yellow) River and the Lancang River in China. Taking the TRH region of the Q... Three-River Headwaters (TRH) region involved in this paper refers to the source region of the Changjiang (Yangtze) River, the Huanghe (Yellow) River and the Lancang River in China. Taking the TRH region of the Qing- hai-Tibet Plateau as a case, the annual evapotranspiration (ET) model developed by Zhang et al. (2001) was applied to evaluate mean annual ET in the alpine area, and the response of annual ET to land use change was analyzed. The plant-available water coefficient (w) of Zhang's model was revised by using vegetation-temperature condition index (VTCI) before annual ET was calculated in alpine area. The future land use scenario, an input of ET model, was spa- tially simulated by using the conversion of land use and its effects at small regional extent (CLUE-S) to study the re- sponse of ET to land use change. Results show that the relative errors between the simulated ET and that calculated by using water balance equation were 3.81% and the index of agreement was 0.69. This indicates that Zhang's ET model based on revised plant-available water coefficient is a scientific and practical tool to estimate the annual ET in the al- pine area. The annual ET in 2000 in the study area was 221.2 ram, 11.6 mm more than that in 1980. Average annual ET decreased from southeast to northwest, but the change of annual ET between 1980 and 2000 increased from southeast to northwest. As a vast and sparsely populated area, the population in the TRH region was extremely unbalanced and land use change was concentrated in very small regions. Thus, land use change had little effect on total annual ET in the study area but a great impact on its spatial distribution, and the effect of land use change on ET decreased with in- creasing precipitation. ET was most sensitive to the interconversion between forest and unused land, and was least sen- sitive to the interconversion between cropland and low-covered grassland. 展开更多
关键词 evapotranspiration (ET) land use change plant-available water coefficient alpine area Three-RiverHeadwaters (TRH) region Qinghai-Tibet Plateau
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Atmosphere Transmission Performance for 0.4 μm~0.8 μm Ray Radiation in Middle Latitude of China
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作者 WU Jian-hui YANG Kun-tao XIANG Qiao-lian ZHANG Nan-yang 《Semiconductor Photonics and Technology》 CAS 2009年第1期34-40,共7页
This paper researched on the atmospheric transmission performance of 0.4 μm~0.8 μm ray radiation based on the characteristic of the middle latitude atmosphere in China.By analysis of the characteristic of the actua... This paper researched on the atmospheric transmission performance of 0.4 μm~0.8 μm ray radiation based on the characteristic of the middle latitude atmosphere in China.By analysis of the characteristic of the actual atmosphere,the absorption of molecular and the scattering of the steam and ozone,as well as the aerosol scattering(big granule scattering) are play a leading role to the 0.4 μm~0.8 μm ray radiation.Then a better atmospheric transmission formula in horizontal path has been deducted.The result of computer simulation indicates that this equation can best calculate the transmission performance of 0.4 μm~0.8 μm visible radiation in the middle latitude area of China.This computing result was applied to the nuclear explosion parameter detection system based on 0.4 μm~0.8 μm visible radiation.Through nuclear explosion simulator to produce ray radiation,the tested result indicates that this method has the better measuring precision than the traditional method with the software of LOWTRAN.The calculation result of this formula not only can apply directly to each kind of optoelectronics detecting system,but also to the optical wireless communication system based on the 0.4 μm~0.8 μm ray radiation. 展开更多
关键词 middle latitude atmosphere atmospheric transmission radiation detection ABSORPTION SCATTERING
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Evapotranspiration and ratio of soil evaporation to evapotranspiration of winter wheat and maize in north China
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作者 Zheng Wei Yu Liu +1 位作者 Di Xu Jiabing Cai 《International Journal of Technology Management》 2013年第2期100-103,共4页
Evapotranspiration (ETc) is an important quantity for hydrological cycle. This study shows evapotranspiration, the ratio of evaporation to evapotranspiration (E/ETc) of winter wheat and maize in north China. Sever... Evapotranspiration (ETc) is an important quantity for hydrological cycle. This study shows evapotranspiration, the ratio of evaporation to evapotranspiration (E/ETc) of winter wheat and maize in north China. Several relationships, namely, E/ET0 and soil surface moisture, E/ET0 and leaf area index (LAI), are also analyzed. The average seasonal ETc values for winter wheat, maize (2008) and maize (2009) are 431.21,456.3 and 341.4mm. The value of E/ET0 varied from 1 at initial growth stage to 0.295 at the later growth for winter wheat, and from 1 to 0.492, from 1 to 0.566 for maize (2008) and maize (2009). The relationship between E/ET0 and surface soil water content, and E/ET0 and LAI are fitted to a quadratic parabola equation with significant correlation coefficients, respectively, for wheat and maize. These results should help the precise planning and efficient management of irrigation for these crops in this region. 展开更多
关键词 EVAPOTRANSPIRATION soil evaporation surface soil water content winter wheat MAIZE
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The Multi-Polar Structure and New Balance of the China-US Relationship
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作者 Cui Liru 《Contemporary International Relations》 2017年第6期51-70,共20页
The multi-polar structure is a new international relationship structure, which differs greatly from both the bi-polar and uni-polar structures in both structure and nature, mainly emerging from the evolution of two as... The multi-polar structure is a new international relationship structure, which differs greatly from both the bi-polar and uni-polar structures in both structure and nature, mainly emerging from the evolution of two aspects: first, the meaning of "polar" has undergone a major change; and second, beyond the power structure, the relationship structure between nations is much different from the past and is inflicting an increasingly important impact on core implication of the multi-polar the structure. Decentralization is the structure. In the current reality of international politics, decentralization refers to the dissolution of US hegemony, as different nations and power centers are busy competing and cooperating with one another at different levels in accordance with their own advantages and characteristics. Globally, the multi-polar structure manifests a state in which the current power structure is loosening, while international relationships have become more diversified due to their ongoing development. This is the development of a new relationship structure that is of great significance and what calls for our closest attention. 展开更多
关键词 Multi-Polar Structure BALANCE China-US Relationship
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The Seasonal Variations of Aerosols over East Asia as Jointly Inferred from MODIS and OMI 被引量:5
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作者 LIU Qi DING Wei-Dong FU Yun-Fei 《Atmospheric and Oceanic Science Letters》 2011年第6期330-337,共8页
Data on aerosol optical thickness(AOT) and single scattering albedo(SSA) derived from Moderate Resolution Imaging Spectrometer(MODIS) and Ozone Monitoring Instrument(OMI) measurements,respectively,are used jointly to ... Data on aerosol optical thickness(AOT) and single scattering albedo(SSA) derived from Moderate Resolution Imaging Spectrometer(MODIS) and Ozone Monitoring Instrument(OMI) measurements,respectively,are used jointly to examine the seasonal variations of aerosols over East Asia.The seasonal signals of the total AOT are well defined and nearly similar over the land and over the ocean.These findings indicate a natural cycle of aerosols that originate primarily from natural emissions. In contrast,the small-sized aerosols represented by the fine-mode AOT,which are primarily generated over the land by human activities,do not have evident seasonalscale fluctuations.A persistent maximum of aerosol loadings centered over the Sichuan basin is associated with considerable amounts of fine-mode aerosols throughout the year.Most regions exhibit a general spring maximum. During the summer,however,the aerosol loadings are the most marked over north central China.This occurrence may result from anthropogenic fine particles,such as sulfate and nitrate.Four typical regions were selected to perform a covariation analysis of the monthly gridded AOT and SSA.Over southwestern and southeastern China,if the aerosol loadings are small to moderate they are composed primarily of the highly absorptive aerosols. However,more substantial aerosol loadings probably represent less-absorptive aerosols.The opposite covariation pattern occurring over the coastal-adjacent oceans suggests that the polluted oceanic atmosphere is closely correlated with the windward terrestrial aerosols.North central China is strongly affected by dust aerosols that show moderate absorption.This finding may explain the lower variability in the SSA that accompanies increasing aerosol loadings in this region. 展开更多
关键词 aerosol optical thickness single scattering albedo seasonal variation Moderate Resolution Imaging Spectrometer Ozone Monitoring Instrument
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Chemical Composition of Summertime PM_(2.5) and Its Relationship to Aerosol Optical Properties in Guangzhou,China 被引量:7
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作者 Tao Jun Cheng Tian-Tao Zhang Ren-Jian 《Atmospheric and Oceanic Science Letters》 2012年第2期88-94,共7页
Urban aerosols have a large effect on the deterioration of air quality and the degradation of atmospheric visibility.Characterization of the chemical composition of PM 2.5 and in situ measurements of the optical prope... Urban aerosols have a large effect on the deterioration of air quality and the degradation of atmospheric visibility.Characterization of the chemical composition of PM 2.5 and in situ measurements of the optical properties of aerosols were conducted in July 2008 at an urban site in Guangzhou,Southern China.The mean PM 2.5 concentration for the entire period was 53.7±23.2 μg m 3.The mean PM 2.5 concentration (82.7±25.4 μg m 3) on hazy days was roughly two times higher than that on clear days (38.8±8.7 μg m 3).The total water-soluble ion species and the total average carbon accounted for 47.9%±4.3% and 35.2%±4.5%,respectively,of the major components of PM 2.5.The increase of secondary and carbonaceous aerosols,in particular ammonium sulfate,played an important role in the formation of haze pollution.The mean absorption and scattering coefficients and the single scattering albedo over the whole period were 53±20 M m 1,226±111 M m 1,and 0.80±0.04,respectively.PM 2.5 had a high linear correlation with the aerosol extinction coefficient,elemental carbon (EC) was correlated with aerosol absorption,and organic carbon (OC) and SO 4 2 were tightly linked to aerosol scattering. 展开更多
关键词 fine aerosol particle chemical composition aerosol optical coefficient
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