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The gravity wave instability induced by photochemistry in summer polar mesopause region

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chinese science Bulletin 2000年第3期45卷 267-272页

作者： Center for space science and Applied research, chinese academy of sciences, beijing 100080, china Laboratory of Numeric study of Heliospheric Physics, chinese academy of sciences, beijing 100080, china Center for space science and Applied research Chinese Academy of Sciences Beijing China Laboratory of Numeric study of Heliospheric Physics Chinese Academy of Sciences Beijing China

The effect of diabatic process due to the photochemical heating and cooling on the gravity wave propagation in middle atmosphere is studied. A linear gravity wave model which considers the diabatic process is established. The unstable region and the growth rate of the gravity wave caused by photochemistry are calculated. And the comparison between the model and the adiabatic gravity wave theory of pure dynamics is made. The results indicate that the photochemical heating process can induce the instability of gravity wave at mesopause. The intensity of the instability becomes stronger as the temperature decreases. The temperature feature and the altitude characteristics of the instability are consistent with the observation. Therefore, the instability of the gravity wave induced by photochemistry may be an important mechanism in polar mesopause region in summer.

关键词： photochemistry instability gravity wave growth rate.

Reconstruction of temperature series in china for the last 5000 years

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Progress in Natural science:Materials International 2006年第8期16卷 838-845页

作者： GE Quansheng, WANG shunbing and ZHENG Jingyun (Institute of Geographical sciences and Natural Resources research, chinese academy of sciences, beijing 100101, china Graduate school of the chinese academy of sciences, beijing 100039, china) [a]chinese academy of sciences Institute of Geographical Sciences and Natural Resources Research Beijing China [b]Graduate school of the chinese academy of sciences Beijing China

A temperature series with a 100 year resolution for the last 5000 years in china has been reconstructed by using 31 longterm temperature proxy series selected from recent publications in the last 20 years. The proxy records include pollens, stalagmites, lake-sediments, peat, ice cores and historical documents. The result reveals that in the millennial scale temperature variation it was warm in 3050-250 BC and it was cold in 250 BC-1950 AD. In the above two periods there were many stages of sub-scale temperature fluctuations. The result also shows an obvious temperature discrepancy on the century to multi-century scale between the Eastern Monsoon Region, the Qinghai-Tibet Region and the Northwestern Region in 2850 BC, 2350 BC, 1350 BC, 950-350 BC, 50-250 AD, and 550 AD. A comparison between the reconstructed series of this paper and some North Hemisphere temperature series indicates that in the longterm scale change, the temperature change in china is in phrase with that of the Northern Hemisphere during the last 5000 years, while on the century to multi-century scale there are differences at the beginning and end times, which may imply that temperature change does not occur simultaneously in different regions.

关键词： temperature series the last 5000 years china.

Adjoint method for the optimum planning of industrial pollutant sources

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science china Earth sciences 2005年第8期48卷 1270-1279页

作者： LIU Feng1,2, HU Fei2 & ZHU Jiang2 1. College of environmental sciences, Peking University, beijing 100871, china 2. LAPC, Institute of Atmospheric Physics, chinese academy of sciences, beijing 100029, china 1. College of environmental sciences Peking University 100871 Beijing China 2. LAPC Institute of Atmospheric Physics Chinese Academy of Sciences 100029 Beijing China

The optimum planning of industrial pollutant sources, which optimizes the economic object without violating environmental constraints, is an important and hard task to be conquered. In this paper, an adjoint method is developed to solve the problem. The penalty function is in-troduced to deal with the environmental inequality constraints, and Lagrange function is con-structed to derive the adjoint equation and the gradient of the object function. In this means, the gradient of the object function can be calculated by solving the adjoint equation, and the infor-mation from the gradient is used to make the object function descend and approach to an optimal solution after some iterations. A two-dimensional, simplified model is used for numerical experi-ments. The theoretical derivations are verified by the results of the experiments. Furthermore, the adjoint method is shown to be of excellent convergence and efficiency, which is adaptive to the fast development of air quality numerical models and super computers.

关键词： optimum planning, industrial pollutant sources, adjoint equation, penalty function, gradient.

Meteorological observations on Mount Everest in 2005

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Progress in Natural science:Materials International 2007年第7期17卷 828-837页

作者： Xie Aihong~(1**) Qin Dahe~1 Ren Jiawen~1 Qin Xiang~1 Xiao Cunde~(1,2) Hou shugui~1 Kang shichang~(1,3) Yang Xingguo~(1,4) Jiang Youyan~1 (1.Key Laboratory of Cryosphere and Environment,Cold and Arid Regions Environment and Engineering research Institute,chinese academy of sciences,Lanzhou 730000,china 2.chinese academy of Meteorological science,beijing 100081,china 3.Institute of Tibetan Plateau research,chinese academy of sciences,beijing 100085,china 4.Gansu Provincial Meteorological Bureau,Lanzhou 730000,china) [a]Key Laboratory of Cryosphere and Environment Cold and Arid Regions Environment and Engineering Research Institute Chinese Academy of Sciences Lanzhou China [b]chinese academy of Metoorological science Beijing China [c]Institute of Tibetan Plateau research Chinese Academy of Sciences Beijing China [d]Gansu Provincial Meteorological Bureau Lanzhou China

Mount Everest,the highest point on the Earth is often referred to as the earth's third pole as such the place is relatively inaccessible and little is known about its *** April 2005,an automatic weather station was installed at the mountain's North Col(6523 m a.s.l.).According to the observational 10-minute mean and daily records,the meteorological characteristics were analyzed. All the meteorological elements displayed obvious diurnal variations during May 1 to July 22,*** monthly variation of daily meteo- rological elements on Mount Everest coincided with that on Dingri,the closest routine meteorological station,with the high correlation co- efficients of 0.928,0.877,0.682,0.755,0.826 and 0.676(n=83,pssure and wind speed,***,the vertical mean gradient of temperature was above 0.6℃/100 m,especially for the daily maximum *** weather events on Mount Everest prominently appeared on the same day as those on Dingri,especially those from daily mean pressure,temperature and relative humidity with the cross-correlation coeffi- cients of 0.673,0.485 and 0.487(n=83,ps on Mount Everest lagged one-day be- hind those on ***,forecasting of the weather events on Mount Everest from pressure on Dingri was more reliable than those from the other meteorological *** conclusions are much important for research on meteorology and climate changes in the region.

关键词： Mount Everest meteorological observation Dingri County radiation air temperature relative humidity air pressure wind

Trophic transfer of mercury and methylmercury in an aquatic ecosystem impacted by municipal sewage effluents in beijing, china

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Journal of environmental sciences 2010年第8期22卷 1189-1194页

作者： Jianjie Fu, Yawei Wang, Qunfang Zhou, Guibin Jiang state Key Laboratory of environmental Chemistry and Ecotoxicology, research Center for Eco-environmental sciences, chinese academy of sciences, beijing 100085, china. [a] state Key Laboratory of environmental Chemistry Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Gaobeidian Lake, located in beijing, china, serves as a recipient lake for efluents from a large municipal sewage treatment plant （MsTP）. In order to evaluate the effects of discharging MsTP efluent on the mercury contamination of the local aquatic ecosystem, sediment cores, water, plankton, fish, and turtle samples were collected from Gaobeidian Lake for mercury speciation analysis. High concentrations of total mercury （T-Hg） were detected in sediment cores （5.24–17.0 μg/g dry weight （dw）, average： 10.1 μg/g）. The ratio of methylmercury （MeHg） to T-Hg was less than 0.3% in sediments and ranged from 35% to 76% in biota samples. The highest level of T-Hg and MeHg were found in aquatic bryophyte and crucian carp （3673 and 437 ng/g dw, respectively）. The relative contents of MeHg were significantly correlated with trophic levels （R2 = 0.5506, p 0.001）, which confirmed that MeHg can be bio-transferred and biomagnified via food chain in this aquatic ecosystem.

关键词： methylmercury total mercury trophic levels aquatic ecosystem municipal sewage treatment plants

Relationships between tree-ring width index and NDVI of grassland in Delingha

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chinese science Bulletin 2006年第9期51卷 1106-1114页

作者： HE Jicheng1,3 & sHAO Xuemei1,21. Institute of Geographical sciences and Natural Resources research, chinese academy of sciences, beijing 100101, china 2. Institute of Tibetan Plateau research, chinese academy of sciences, beijing 100085, china 3. Graduate school of chinese academy of sciences, beijing 100039, china Institute of Geographical sciences and Natural Resources research Chinese Academy of Sciences Beijing China Graduate school of chinese academy of sciences Beijing China Institute of Tibetan Plateau research Chinese Academy of Sciences Beijing China

Using five well-replicated Qilian juniper (sabina przewalskii Kom.) tree-ring width index se- ries, monthly normalized difference vegetation index (NDVI) of grassland, and climatic data from 1982 to 2001, the relationships between tree-ring width index, NDVI of grassland, and climatic data were analyzed firstly. Then, the relationship between tree-ring width index and NDVI of grassland was explored. The re- sults showed that: (1) Temperature and precipitation in June influenced tree-ring width index and NDVI of grassland deeply in Delingha. (2) There were sig- nificant relationships between five tree-ring width index series (DLH1-DLH5) and monthly NDVI of grassland from June to september, with the most significant relationship being between tree-ring width index series and NDVI of grassland in August. (3) The PC1 (the first principal component derived from DLH1-DLH5 series) exhibited good agreement with monthly NDVI of grassland in the grass growth sea- son (from June to september) and the averaged NDVI in the growth season, which was attributed to their common responses to water-supply limit in Delingha. This study may allow an increase in studying the past dynamics of grassland in Delingha in that the variation of grassland NDVI during the last millennium has been reconstructed from PC1.

关键词：圆柏祁连山 NDVI 草原年轮宽度指数

single crystal β-Ga_2O_3: Cr grown by floating zone technique and its optical properties

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science china(Technological sciences) 2007年第1期50卷 51-56页

作者： ZHANG JunGang1, 2, LI Bin3, XIA ChangTai1, XU Jun1, DENG Qun4, XU XiaoDong1, WU Feng1, XU Wusheng4, sHI Hongsheng4, PEI GuangQing1, 2 & WU YongQing1,2 1 shanghai Institute of Optics and Fine Mechanics, chinese academy of sciences, shanghai 201800, china 2 Graduate school of the chinese academy of sciences, beijing 100039, china 3 shanghai Institute of Applied Physics, chinese academy of sciences, shanghai 201800, china 4 GE (china) research and Development Center Co. Ltd., shanghai 201203, china 1. shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China 2. Graduate school of the chinese academy of sciences Beijing 100039 China 3. shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China 4. GE (china) research and Development Center Co. Ltd. Shanghai 201203 China

β-Ga2O3: Cr single crystals were grown by floating zone technique. Absorption spectra and fluorescence spectra were measured at room temperature. The values of field splitting parameter Dq and Racah parameter B were obtained by the peak values of absorption spectra. The value 10Dq/B=23.14 manifests that in β-Ga2O3 crystals Cr3+ ions are influenced by low energy crystal field. After high temperature annealing in air, the Cr3+ intrinsic emission was enhanced and the green lumines-cence disappeared. The strong and broad 691 nm emission was obtained at 420 nm excitation due to the electron transition occurred from 4T2 to 4A2. The studies manifest that the β-Ga2O3 crystals have the potential application for tunable laser.

关键词： β-Ga2O3: Cr single crystals floating zone technique tunable laser spectrum.

Evaluation of phosphorus removal from wastewater by soils in rural areas in china

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Journal of environmental sciences 2010年第1期22卷 15-22页

作者： Hanwen Liang, Junxin Liu, Yuansong Wei, Xuesong Guoresearch Center for Eco-environmental sciences, chinese academy of sciences, beijing 100085, china [a] research Center for Eco-environmental sciences Chinese Academy of Sciences Beijing 100085 China

Low-cost, easy-maintenance and high-efficiency decentralized wastewater treatment technologies are urgently needed in rural areas of china. Processes with high potential for phosphorus removal are of great interest. However, commonly used treatment methods often do not meet the strict criteria for removing phosphorus from rural wastewater. In order to search an economic and simple technology for phosphorus removal from the common bit-technologies effluent, seven soil types collected from different rural areas in china were investigated for their ability to remove phosphorus. X-ray diffraction （XRD） was used to analyse the mineral structure, and inductively coupled plasma optical emission spectrometer （ICP-OEs） was used to analyse the geochemical composition of the soil samples. Three primary minerals - quartz, albite and montmorillonite - were clearly detected. The samples were divided into two soil types, acidic soils and alkaline soils, based on their pH values. The geochemical composition study indicated that a higher percentage of Ca and Mg occurred in alkaline soils （pH 〉 8） than in acidic soils （pH 〈 6.5）. Adsorption isotherms from batch experiments fitted the Langmuir and Freundlich models well, the maximum P adsorption capacities ranged from 0.256 to 1.598 mg P/g, indicating a high phosphorus removal potential for all of these soils. The P fractions extracted revealed that the sum of NaOH-extracted inorganic P （NaOH-Pi） was the major P component in the acidic soils, and CaCO3-bound phosphorus （Ca-P） in the alkaline soils. Dynamic adsorption simulation showed that these soils have the ability to remove phosphorus from wastewater.

关键词： adsorption phosphorus removal rural areas wastewater treatment

Discrepancy between infrared and optical emission in some Be stars

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chinese science Bulletin 2002年第18期47卷 1511-1513页

作者： LIU Qingzhong & WEI JianyanPurple Mountain Observatory, chinese academy of sciences, Nanjing210008, china National Astronomical Observatories, chinese academy of sciences, beijing 100012, china Purple Mountain Observatory Chinese Academy of Sciences Nanjing China National Astronomical Observatories Chinese Academy of Sciences Beijing China

An expanding ring model is put forward to investigate the original regions of Ha line emission and infrared excess emission in Be stars, by taking optical depth into account. We find that the two regions depend strongly on the physical properties of the envelope of Be stars such as the initial density and density structure. This model can be used to qualitatively interpret the disagreement between the near infrared excess and the equivalent width (EW) of Ha emission line, as observed in some Be stars.

关键词： Be star emission line near infrared excess.