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Thresholds of geographic environmental elements in sediment yield of drainage basins

Science china Earth sciences 2005年第2期48卷 230-240页

作者： CHEN Hao, ZHOU Jinxing, CAI Qiangguo, LU Zhongchen & LI Zhongyan Institute of Geographic sciences and Natural Resources research, chinese academy of sciences, beijing 100101, china Institute of Forestry Science, chinese academy of Forestry Science, beijing 100091, china research center for eco-environment sciences, chinese academy of sciences, beijing 100085, china Computing Institute of Science and Engineering, North china Electric Power University, beijing 102206, china 1. Institute of Geographic sciences and Natural Resources research Chinese Academy of Sciences 100101 Beijing China 2. Institute of Forestry Science Chinese Academy of Forestry Science 100091 Beijing China 3. research center for eco-environment sciences Chinese Academy of Sciences 100085 Beijing China 4. Computing Institute of Science and Engineering North China Electric Power University 102206 Beijing China

Threshold of environmental elements in drainage basin sediment yield refers to, under effect of climate, underlying surface and human activity, a turning point of abrupt changes in drainage sediment yield related to environmental element characteristics. Previous studies on threshold of sediment yield of relevant drainage basins were mainly concentrated on impact of natural zones with a few researches on impact of other environmental elements. Particularly studies on compound environmental element threshold in drainage basin sediment yield remain blank today. Studies indicate that sediment yield in drainage basins is affected by compound interactions and complex actions. Based on single element analysis, the present paper gives quantitatively compound threshold of environmental elements affecting sediment yield of the drainage basin between Hekouzhen and Tongguan in the middle Yellow River by the method of multi-variant, polynomial formula regression analysis.

关键词： middle Yellow River, environmental element, sediment, sediment delivery mudule, threshold.

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新型一体化水族箱去除养鱼自用循环水中COD和BOD_5

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水处理技术 2010年第4期36卷 86-88页

作者：孙猛董莉莉张宝锋刘涛霍宏伟吉林大学环境与资源学院吉林长春130026 中国科学院环境生态研究中心北京100085

一体化的水族箱(含水处理器)采用物理过滤+生物降解+活性炭吸附工艺对养鱼自用水进行回收利用,研究了该工艺对养鱼自用水中的COD和BOD5降解效果及主要影响因素。结果表明,该工艺对养鱼自用循环水中的COD和BOD5去除率分别稳定在70%～85%... 详细信息

一体化的水族箱(含水处理器)采用物理过滤+生物降解+活性炭吸附工艺对养鱼自用水进行回收利用,研究了该工艺对养鱼自用水中的COD和BOD5降解效果及主要影响因素。结果表明,该工艺对养鱼自用循环水中的COD和BOD5去除率分别稳定在70%～85%和75%～90%,可以长期保证鱼类在水族箱中的正常生活。

关键词：一体化的水族箱 COD去除率 BOD5去除率生物膜

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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 sciences,chinese academy of sciences,beijing 100085,china [a]research center for eco-environmental sciences 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

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2023 Guideline for the management of hypertension in the elderly population in china

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Journal of Geriatric Cardiology 2024年第6期21卷 589-630页

作者： Hypertension Branch of chinese Geriatrics Society,beijing Hypertension Association,National Clinical research center of the Geriatric Diseases Qi HUA Li FAN Zeng-Wu WANG Jing LI 不详 Xuanwu Hospital Capital Medical UniversityBeijingChina chinese PLA General Hospital BeijingChina Fuwai Hospital Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

Preamble Hypertension is one of the most common chronic diseases and the primary risk factor for stroke,myocardial infarction and even cardiovascular *** than half of the elderly population has high blood *** people are a unique group,and strategies for the prevention,diagnosis,evaluation,and treatment of hypertension in elderly individuals differ significantly from those in the general population.

关键词： hypertension prevention diagnosis

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Cleaning method of the oil field wastewater treatment by UF process

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Journal of environmental sciences 2001年第3期13卷 365-367页

作者： WANG Jing rong, Xu Cheng(research center for eco environmental sciences, chinese academy of sciences, beijing 100085, china) research center for eco-environmental sciences Chinese Academy of Sciences Beijing 100085 China.

This article introduces experiments and researches of polysulphone ultrafiltration membrane's effect on oil field polluted water and approaches renewing oil field polluted water and approaches renewing of membrane's flux by different detergents and cleaning method. Good result has been achieved by doing experiments and the renewal rate of membrane is over 90%.

关键词： Detergents Membranes Oil fields Ultrafiltration Water pollution

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In situ adsorption-catalysis system for the removal of o-xylene over an activated carbon supported Pd catalyst

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Journal of environmental sciences 2009年第7期21卷 985-990页

作者： HUANG Shaoyong, ZHANG Changbin, HE Hong research 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

An activated carbon （AC） supported Pd catalyst was used to develop a highly efficient in situ adsorption-catalysis system for the removal of low concentrations of o-xylene. In this study, three kinds of Pd/AC catalysts were prepared and tested to investigate the synergistic efficiency between adsorption and catalysis for o-xylene removal. The Pd/AC catalyst was first used as an adsorbent to concentrate dilute o-xylene at low temperature. After saturated adsorption, the adsorbed o-xylene was oxidized to CO2 and H20 by raising the temperature of the catalyst bed. The results showed that more than 99% of the adsorbed o-xylene was completely oxidized to CO2 over a 5% Pd/AC catalyst at 140℃. Brunauer-Emmett-Teller （BET） analysis, scanning electron microscopy （SEM）, temperatureprogrammed desorption （TPD）, and temperature-programmed oxidation （TPO） were applied to investigate the physical properties of o-xylene adsorption-desorption and the in situ adsorption-catalysis activity of the AC support and Pd/AC catalyst. A synergistic relationship between the AC support and the active Pd species for the removal of low concentrations of o-xylene was established.

关键词： in situ adsorption-catalysis Pd/AC volatile organic compounds

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Dynamic analysis and assessment for sustainable development

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Journal of environmental sciences 2002年第1期14卷 88-94页

作者： SHI Xiao\|qing (Department of Systems ecology, research center for eco\|environmental sciences, chinese academy of sciences, beijing 100085, china. ) Department of Systems ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

The assessment of sustainable development is crucial for constituting sustainable development strategies. Assessment methods that exist so far usually only use an indicator system for making sustainable judgement. These indicators rarely reflect dynamic characteristics. However, sustainable development is influenced by changes in the social\|economic system and in the eco\|environmental system at different times. Besides the spatial character, sustainable development has a temporal character that can not be neglected; therefore the research system should also be dynamic. This paper focuses on this dynamic trait, so that the assessment results obtained provide more information for judgements in decision\|making processes. Firstly the dynamic characteristics of sustainable development are analyzed, which point to a track of sustainable development that is an upward undulating curve. According to the dynamic character and the development rules of a social, economic and ecological system, a flexible assessment approach that is based on tendency analysis, restrictive conditions and a feedback system is then proposed for sustainable development.

关键词： sustainable development assessment dynamic analysis

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Adsorption-desorption behavior of acetochlor to soils in the presence of some environmental substances

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Journal of environmental sciences 2002年第2期14卷 269-276页

作者： YE Chang ming, LEI Zhi fang (research center for eco environmental sciences, chinese academy of sciences, beijing 100085, china. research center for eco-environmental sciences Chinese Academy of Sciences Beijing 100085 Chin

The behavior of herbicide acetochlor adsorption desorption to soil in the presence of humic acid (HA), anionic surfactant sodium dodecylbenzene sulfonate (SDBS), cationic surfactant hexadecyltrimethyl ammonium bromide (HDAB) and NH 4NO 3 as a chemical fertilizer was studied. Observed acetochlor adsorption isotherm were well described using Freundlich isotherm equation, from which the desorption isotherm equation has been deduced. The deduced equation can more directly describe acetochlor desorption process. The results showed that the enhance of acetochlor adsorption capacity by solid HA was greater than by soluble HA. The presence of NH 4NO 3 can slightly enhance acetochlor adsorption to soil by comparison with that measured in NH 4NO 3 free solution. In soil water system, surfactant acetochlor interaction is very complex, and the surfactant adsorptions as well as acetochlor adsorption need to be considered. When acetochlor soil suspensions contained lower concentration SDBS or HDAB (40 mg/L), K f for acetochlor adsorption was decreased in comparison to that measured in SDBS or HDAB free solution. When acetochlor soil suspensions contained higher concentration SDBS or HDAB (corresponding 1400 mg/L or 200 mg/L), K f for acetochlor adsorption was increased in comparison to that measured in SDBS or HDAB free solution.

关键词： adsorption desorption acetochlor humic acid surfactants ammonium nitrate soil

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Combined toxicity of copper and cadmium to six rice genotypes (Oryza sativa L.)

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Journal of environmental sciences 2009年第5期21卷 647-653页

作者： HUANG Yizong, HU Ying, LIU Yunxia research 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

Accumulations of copper （Cu） and cadmium （Cd） in six rice cultivars （94D-22, 94D-54, 94D-64, Gui630, YY-1, and KY1360） were evaluated through exposure to heavy metal contamination （100 mg/kg Cu, 1.0 mg/kg Cd, and 100 mg/kg Cu ＋ 1.0 mg/kg Cd） in a greenhouse. The dry weights of shoot and root, concentrations of Cu and Cd in plant tissues and the Cu, Cd, P, Fe concentrations in the root surface iron plaques were analyzed eight weeks later after treatment. The results indicated that the plant biomass was mainly determined by rice genotypes, not Cu and Cd content in soil. Separated treatment with Cu/Cd increased each metal level in shoot, root and iron plaques. Soil Cu enhanced Cd accumulation in tissues. In contrast, Cu concentrations in shoot and root was unaffected by soil Cd. Compared to single metal contamination, combined treatment increased Cd content by 110.6%, 77.0%, and 45.2% in shoot, and by 112.7%, 51.2% and 18.4% in root for Gui630, YY-1, and KY1360, respectively. The content level of Cu or Cd in root surface iron plaques was not affected by their soil content. Cu promoted Fe accumulation in iron plaques, while Cd has no effect on P and Fe accumulation in it. The translocation of Cu and Cd from iron plaques to root and shoot was also discussed. These results might be beneficial in selecting cultivars with low heavy metal accumulation and designing strategies for soil bioremediation.

关键词： Cu Cd combined contamination soil uptake accumulation root surface iron plaques

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A tool model for predicting atmospheric chemical kinetics with sensitivity analysis

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Journal of environmental sciences 2001年第1期13卷 79-86页

作者： SHEN Ji (research center for eco\|environmental sciences, chinese academy of sciences, beijing 100085, china.E\|mail:shenji@***) research center for eco-environmental sciences Chinese Academy of Sciences Beijing 100085 China. shenji@***

A package(a tool model) for program of predicting atmospheric chemical kinetics with sensitivity analysis is presented. The new direct method of calculating the first order sensitivity coefficients using sparse matrix technology to chemical kinetics is included in the tool model, it is only necessary to triangularize the matrix related to the Jacobian matrix of the model equation. The Gear type procedure is used to integrate a model equation and its coupled auxiliary sensitivity coefficient equations. The FORTRAN subroutines of the model equation, the sensitivity coefficient equations, and their Jacobian analytical expressions are generated automatically from a chemical mechanism. The kinetic representation for the model equation and its sensitivity coefficient equations, and their Jacobian matrix is presented. Various FORTRAN subroutines in packages, such as SLODE, modified MA28, Gear package, with which the program runs in conjunction are recommended. The photo\|oxidation of dimethyl disulfide is used for illustration.

关键词： atmospheric chemical model chemical kinetics sensitivity analysis

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