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Biologically effective ultraviolet radiation in beijing area

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Journal of environmental sciences 1993年第2期5卷 216-223页

作者： Wang Shaobin Su WeihanResearch Center for eco-environmental {2., {3., beijing 100085, china Research Center for eco-environmental {2. Chinese Academy of Sciences Beijing 100085 China. China

Ozone layer depletion implies the enhancement of solar ultraviolet radiation at the earth's surface. However, aerosol contributes to the scattering of solar radiation and leads to the reduction of UV-B radiation on the ground. In this paper, the model calculation shows that due to effects of atmospheric ozone and aerosol UV-B radiation in beijing in the past decade has decreased with the annual change rate of 0.7%, which is probably approximate to the measured values. The effects of three scenarios for long-term changes in atmospheric ozone and aerosol concentrations on UV-B radiation reaching the ground in are also discussed.

关键词： UV-B biological efftent zone aerosol beijing.

Determination of atmospheric concentrations of halocarbons in beijing area

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Journal of environmental sciences 1993年第1期5卷 76-82页

作者： Wang ShaobinResearch Center for eco-environmental {2., {3., beijing 100085, chinaPeng Lixin and Tang XiaoyanResearch Center of environmental {2., Peking University, beijing 100871, china Research Center for eco-environmental {2. Chinese Academy of Sciences Beijing 100085 China. China

Gas chromatography with ambient temperature injection and frozen-trapped techniques was used to determine the atmospheric concentrations of halocarbons over beijing. Halogenated compounds such as CFC-11, CFC-12. CHCl_3. CCl_4, CH_3.Cl_3. CHCl =CCl_2. and CCl2.CCl2.were measured and their concentrations are 109±8, 2.1}±13. 47±2., 97±2., 88±2., 11±1 and 17±3.(pptv), respectively.

关键词： GC-ECD atmospheric halocarbons beijing.

Distribution and health risk assessment of organochlorine pesticides(OCPs) in industrial site soils:A case study of urban renewal in beijing,china

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Journal of environmental sciences 2009年第3期21卷 366-372页

作者： YANG Wenrui,WANG Rusong,ZHOU Chuanbin,LI FengState key laboratory of Urban and Regional ecology,Research Center for eco-{2. {3.,chinese academy of sciences,beijing 100085,china. State key laboratory of Urban and Regional ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

A field survey was conducted in a contaminated industrial site of southern beijing, china to investigate the contents and distribution of the organochlorine pesticides （α-, β-, y-, δ-HCH, p,p＇-DDT, p,p＇-DDE, p,p＇-DDD and o,p＇-DDT） in the profiles of soil, and a health risk assessment was carded out with CalTOX multimedia exposure model. Results showed that mean concentrations of total hexachlorocyclohexane isomers （HCHs） and total dichlorodiphenyltrichloroethane isomers （DDXs） in soils were in the range of 1{2.2.- 148.71 mg/kg, and {2.02.67.4{2.mg/kg, respectively. Organochlorine pesticides （OCPs） content peaked in the surface and declined in soil profile with depth. The amounts of HCHs in three profiles of soil were larger than DDXs. Composition analysis indicated that there was a trend of degradation of OCPs in the site, but the mean of HCHs and DDXs concentration were over the state warning standard limit （HCHs, 0.50 mg/kg; DDXs, 0.50 mg/kg）. According to current land use development, health risk assessment with CalTOX and Monte Carlo analysis showed that health risks mainly came from two exposure pathways： dermal uptake and inhalation, and the total risk values all exceeded the general acceptable health risk value （10-6）. The sensitivity analysis indicated that five parameters significantly contributed to total risk.

关键词： pollution hexachlorocyclohexane isomers (HCHs) dichlorodiphenyltrichloroethane isomers (DDXs) soil profiles Monte Carlo sensitivity

Trophic transfer of mercury and methylmercury in an aquatic ecosystem impacted by municipal sewage effluents in beijing, {2.

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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. State Key Laboratory of environmental Chemistry and 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 {2.system, 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 （5.2.–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 3.% to 76% in biota samples. The highest level of T-Hg and MeHg were found in aquatic bryophyte and crucian carp （3.73.and 43. 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 {2.system.

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

Effect of external and internal phosphate status on arsenic toxicity and accumulation in rice seedlings

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Journal of environmental sciences 2009年第3期21卷 346-351页

作者： WANG Lihong,DUAN Guilan Research Center for eco-environmental {2.,{3.,beijing 100085,china Research Center for eco-environmental {2. Chinese Academy of Sciences Beijing 100085 China

Phosphorus （P） deficiency is thought to exacerbate the arsenic （As） phytotoxicity in paddy rice. The experiments were conducted to investigate the effects of external phosphate supply on As accumulation in rice and its toxicity under phosphate deficiency conditions. Rice seedlings pretreated with a phosphorus deficient nutrient solution （-P） for 14 d accumulated more As than those pretreated with a normal phosphorus supply nutrient solution （＋P）. Rice protreated with -P showed As toxicity symptoms after being exposed to 50 μmol/L arsenate for 4 h, while ＋P rice did not show any toxicity symptoms. Arsenic toxicity symptoms can be alleviated by increasing external P concentrations. The arsenate uptake rate and accumulation corresponded with the As toxicity in rice plants. Arsenic concentrations in rice roots decreased with increasing external phosphate concentrations. The lowest As accumulation and the highest P accumulation were found when the external P concentration reached 100μmol/L. In short, P deficiency increased the sensitivity of rice to arsenate and increasing of external phosphate supply could alleviate As toxicity.

关键词： phosphorus arsenate arsenic toxicity arsenic accumulation rice seedlings

Dynamic pursuing ecological model concerning the nitrogen cycle in the environment of chinese mainland

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Journal of environmental sciences 1993年第1期5卷 108-123页

作者： Kang Demeng and Chen LidingResearch Center for eco-environmental {2., {3., beijing 100085, china Research Center for eco-environmental {2. Chinese Academy of Sciences Beijing 100085 China. China

The paper gives a special dynamic pursuing ecological model on the bio-geochemical cycle of nitrogen in the whole range 9.6 million square kilometers of chinese mainland, basing on the reservoir-content and flux-rate of nitrogen and among the four spheres: atmosphere, pedosphere, biosphere, and hydrosphere, and the law of bio-geochemical cycle of nitrogen, the model predicted the size of reservoir capacities and fluxes of nitrogen in each sphere. Through tested and verified, the model was proven reasonable and reliable.

关键词： nitrogen cycle: fluxes flux-rate reservoir-content of nitrogen dynamic pursuing model.

Field measurements of dissociation of ammonium nitrate at a beijing site

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Journal of environmental sciences 1998年第3期10卷 95-101页

作者：  Shen Ji, Zhao Qianxue Research Center for ecoenvironmental {2., {3., beijing 100085, china 

The atmospheric nitric acid, ammonia and ammonium nitrate aerosol were determined simultaneously in a beijing site to test the equilibrium prediction. Rather good agreement between measurements and theory was found at ambient temperature above 9℃ at relative humidity below 70%. Below 9 ℃ the kinetic constraints preventing rapid attainment equilibrium were observed. A procedure for calculation of dependence of NH_4NO_3.aerosol dissociation constants on temperature and relative humidity was given. The seasonal variation of concentrations of NH_3. total NH_4^+ and HNO_3.was observed. The seasonal variation of concentrations of HNO_3.was caused by dissociation of NH_4NO_3.aerosol. The concentrations of NH_3.were 1-2.order higher than those of HNO_3. For formation of NH_4NO_3.aerosol the HNO_3.was the control reagent. Any increase of HNO_3. formed from NO_x would react with NH_3.to form NH4NO_3.aerosol in beijing area except for someday in summer time. 

关键词： ammonium nitrate aerosol nitric acid ammonia beijing.

Fractal properties of patch perimeters in a disturbed montane landscape,beijing,china

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Journal of environmental sciences 1999年第2期11卷 68-72页

作者： Ma Ke ming, Fu Bo jie Research Center for eco environmental {2., {3., beijing 100085, china

The forest landscape has been highly fragmented in Donglingshan montane region, beijing, china, where the folding degree of patch perimeters considerately influenced the spatial distribution of biological diversity, therefore the quantitative description to it is very helpful to conservation biology studies. The fractal dimensions of landscape patch perimeters of this region were estimated and compared. The results showed that fractal dimensions of all the landscape types were between 1.00 and 1.58. The fractal dimensions of natural vegetation types were higher than that of artificial vegetation type. Where forests (1 2.) and shrubs (1.2.) are near to farmland (1.12., so they were both highly disturbed by human activities regarding the smallest mean patch areas. But the grassland (1.58) had the largest mean patch area, its disturbance intensity was the lowest in this region. The fractal dimension of the overall landscape was 1.2., which was near to those of forests and shrubs, and obviously different from those of farmland and grassland. The fractal dimension of the overall landscape was 1.1{2.in small scales, and that was 1.65 in large scales. Which means that a large number of small area patches had regular perimeters, their fragment degrees were higher; whereas the large area patches had folding perimeters, their fragment degrees were lower, they had smaller patch numbers, however occupied most of the landscape area. Large areas and highly folded perimeters were the main property of the landscape patch in Donglingshan montane region.

关键词： beijing Dongling montane region landscape fragmentation patch perimeter fractal dimension.

Regional pattern of mercury wet deposition in beijing

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Journal of environmental sciences 2000年第S1期12卷 77-84页

作者： LIU Jun hua, WANG Wen hua, PENG An (SKLEAC, Research Center for eco-environmental {2., {3., beijing 100085, china)

The regional pattern of mercury were deposition in beijing was studied. The Hg concentrations in precipitation were detected in 0—0.83.ng/ml(summer) and in 0.3.1—1.73.ng/ml(winter), under extreme condition up to 3.4 ng/ml in heating periods. The sum of Hg wet deposition was 101.52.μg/(m 2.a) within Nov. 1994— Nov. 1995 and 12.1}09 μg/(m 2.a) within Nov. 1995 — Nov. 1996. The more precipitation fall down, the more Hg was removed from atmosphere, especially in heating periods. Burning coal for heating was thought as the reason of a baseline seasonable with highest Hg levels in winter. The Hg concentration in rainfall decreased with the raining duration, which clearly shows the efficiency of washouting Hg by wet deposition.

关键词： mercury wet deposition beijing