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Land cover changes based on plant successions: Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed

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Science china Earth sciences 2005年第12期48卷 2214-2230页

作者： YAN Jianzhong1,2,3, ZHANG Yili1, BAI Wanqi1, LIU Yanhua4, BAO Weikai5. LIU Linshan1, 2 & ZHENG Du1 1. institute of Geographic sciences and Natural Resources Research, chinese academy of sciences, Beijing 100101, china 2. Graduate School of the chinese academy of sciences, Beijing 100039, china 3. College of Resources and Environment, Southwest Agricultural University, Chongqing 400716, china 4. The Ministry of Science and Technology, P. C. china, Beijing 100862, china 5. chengdu institute of biology, chinese academy of sciences, chengdu 61004., china 1. institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. Graduate School of the chinese academy of sciences 100039 Beijing China 3. College of Resources and Environment Southwest Agricultural University 400716 Chongqing China 4. The Ministry of Science and Technology P. C. China 100862 Beijing China 5. chengdu institute of biology Chinese Academy of Sciences 610041 Chengdu China

To link regional land use/cover changes with environmental effects, land cover changes are required to reflect vegetation successions, whereas the land cover classification systems commonly used nowadays cannot serve this purpose. In this paper, a new land cover classification system is established in which land covers are classified by the vegetation succes-sions, taking Zamtang County, Barkam County and Jinchuan County in the upper Dadu River watershed as a study area. Using multi-temporal remote sensing images, the land cover data of 1967, 1986 and 2000 are obtained by means of integration of unsupervised classification and visual interpretation methods. The database facilitates the study of land use/cover changes, en-vironmental effects and ecological construction. Land cover changes reflect the main ecological processes in the upper Dadu River watershed. The landscape composed mainly of grasslands, wildwoods and alpine scrubs in 1967 was changed to that of grasslands, secondary forests, al-pine scrubs, fragmentary wildwoods, artificial forests, secondary scrubs in 2000, meanwhile, the landscape got more fragmentized. The total area of the forests decreased by 9.43%. Study results have shown the process of restoration of logged areas in forest centers. From 1967 to 2000, only 6.86 percents of logged areas were converted to shrubs, meadows or crop-lands, and the rest were converted into artificial forests or secondary forests. So the ecological shelter functions will be restored, stage by stage. Firewood collection, charcoal production and overgrazing are the three major triggers for the extensive degradation of alpine oak forests, Sa-bina tibetica forests and meadows. The arid valley grasslands expanded too. The degradation of vegetation in the southern slopes impairs ecological shelter functions and affects livelihood of local residents, so it is essential to find effective measures for ecological restoration and recon-struction. Field investigations have found

关键词： land use/cover classification, upper Dadu River watershed, vegetation successions, GIS, RS.

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PREPARATION OF Fe_3O_4/PSt MAGNETIC PARTICLES IN THE PRESENCE OF MAGNETIC FLUID IN ETHANOL/WATER MIXTURE

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chinese Journal of Polymer Science 1999年第2期17卷 129-134页

作者： Xiao-bin Ding Zong-hua Sun Guo-xiang Wan Ying-yan Jiang chengdu institute of Organic Chemistry, Chinesc academy of sciences, chengdu 61004.,{5. institute of Chemistry, chinese academy of sciences, Beijing 100080,{5. chinese Acad Sci Chengdu Inst Organ Chem Chengdu 610041 Peoples R China chinese Acad Sci Inst Chem Beijing 100080 Peoples R China

Fe_3O_4/Polystyrene(PSt) magnetic particles with core/shell structure have been prepared in thepresence of Fe_3O_4 magnetic fluid in ethanol/water medium by dispersion polymeriation of styrene. A Fe_3O_4particle formation mechanism was proposed. According to this mechanism, the size of particle nuclei isdetermined by the extent of aggregation of Fe_3O_4 /oligomer. Magnetic particles with diameter ranging from 5.o 200 μm were prepared under different reaction conditions. Some polymerization parameters such as theconcentration of monomer, stabilizer, initiator, and ethanol which affect particle size and size distribution arediscussed and their effect on particle formation are explained by the proposed mechanism.

关键词： Fe_3O_4 magnetic fluid Magnetic particle Polystyrene Polymerization Mechanism

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SYNTHESIS OF SOAP-FREE ACRYLIC HYDROSOLS

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chinese Journal of Polymer Science 2002年第6期20卷 531-536页

作者： Li Jia Zong-hui Liu De-qing Wei Chengd institute of Organic Chemistry chinese academy of sciences, chengdu 61004., china chinese Acad Sci Chengdu Inst Organ Chem Chengdu 610041 Peoples R China

Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-free polymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of reaction condition on the morphology and particle size of the hydrosols was investigated. The minimum amount of acrylic acid in the hydrosols is 2%. The maximum weight average molecular weight (M-w) of polymer that assures soap-free emulsion conversion into hydrosol is about 1.2 x 10(5.-1.3 x 10(5.. The particle transforming process was investigated, and an obvious change of particle diameter and morphology was observed.

关键词： hydrosol acrylic resin water-borne resin soap-free polymerization

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A Novel Pregnane Glycoside from Biondia chinensis

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chinese Chemical Letters 2003年第10期14卷 1027-1028页

作者： Xing Gen TAN, Shu Lin PENG, Xun LIAO, Jian LIANG, Li Sheng DING chengdu institute of biology, chinese academy of sciences, chengdu 61004. chengdu institute of biology Chinese Academy of Sciences Chengdu 610041

A novel pregnane glycoside, biondianoside E, was isolated from the roots of Biondia chinensis. By the spectroscopic and chemical methods, this structure was elucidated as 3B, 5., 14B, 205. 21-pentahydroxypregnane 3-O-... 详细信息

关键词： Biondia chinensis pregnane glycoside biondianoside E.

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Soil N Pools and Transformation Rates Under Different Land Uses in a Subalpine Forest-Grassland Ecotone

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Pedosphere 2005年第1期15卷 52-58页

作者： SUNGeng WUNing LUOPeng chengduinstituteofbiology ChineseAcademyofSciencesChengdu610041China

Soil nitrogen pools (NP), denitrification (DN), gross nitrification (GN), N2O and CO2 flux rates with their responses to temperature increases were determined under five different land uses and managements in a subalpine forest-grassland ecotone of the eastern Tibetan Plateau. Land uses consisted of 1) sparse woodland, 2) shrub-land, 3) natural pasture, 4)fenced pasture, and 5. tilled pasture mimicking a gradient degenerating ecosystem under grazing impacts. The NO3--N content was higher than the NH4+-N content. Comparing tilled pasture with fenced pasture showed that higher intensive management (tillage) led to a significant decrease of soil organic matter (SOM) (P ＜ 0.05. in the soils, which was in contrast to the significant increases (P ＜0.05. of DN, GN, N2O and CO2 flux rates. GN (excluding tilled pasture) and CO2 flux rates increased with a temperature rise, but DN and N2O flux rates normally reached their maximum values at 12-14 ℃ with tilled pasture (the highest management intensity) being very sensitive to temperature increases. There was a difference between net nitrification and GN, with GN being a betterindicator of soil nitrification.

关键词： denitrification gross nitrification land use subalpine forest-grassland ecotone Tibetan Plateau

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Evaluation of Sustainable Land Management and Diagnosis of Obstacle at County Scale in Sichuan Basin:Taking Lezhi County as Example

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Wuhan University Journal of Natural sciences 2006年第4期11卷 1046-1051页

作者： CHEN Guangjian 1, 2, 3 , LIU Qing 1 1. chengdu institute of biology, chinese academy of sciences, chengdu 61004., Sichuan,{5. 2. Graduate University of chinese academy of sciences, Beijing 100049, china 3. academy of Land Reconnaissance and Layout of Sichuan Province , chengdu 610031, Sichuan, china chengdu institute of biology Chinese Academy of Sciences Chengdu Sichuan China Graduate University of chinese academy of sciences Beijing China academy of Land Reconnaissance and Layout of Sichuan Province Chengdu Sichuan China

This paper established sustainable land resources evaluating indicators fit for hilly area in Sichuan Basin, Southwest of china, and evaluated the case of sustainable land management of Lezhi County from 1990 to 2001. The result showed that the land resource sustainable utilization ability in Lezhi County is belong to Second level （better sustainable）. Secondly, this paper diagnosed some years obstacles of sustainable land management of Lezhi County from base period to goal period and compared the obstacles factors in the indicators system. There were 16 indexes orderly become major affect factor to land sustainable utilization of Lezhi county in indicator system, of which there are 8 obstacles indexes exist both in 1990 and 2001. The value of obstacles degree of five indicators exceeded 5.in 1990, but in 2001, only two indicators＇ values were more than 5.

关键词： land resources sustainable land management assessment indicators diagnosis of obstacle

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A Proposed Mechanism of Photocatalytic Oxidation of Trichloroethylene in Gas Phase

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chinese Chemical Letters 2000年第1期11卷 31-34页

作者： Gong Hu LI Hu Lan MA Wei Zhu AN (chengdu institute of Organic Chemistry, The chinese academy of sciences, chengdu 61004.) chinese Acad Sci Chengdu Inst Organ Chem Chengdu 610041 Peoples R China

GC/MS has been used to identify gas phase products and intermediates formed during the gas phase photocatalytic oxidation of trichloroethylene (TCE) on TiO(2) with low BET surface area. A new byproduct, oxalyl choloride (ClCOCOCl) was detected together with other byproducts such as COCl(2), CHCl(3), DCAC and C(2)HCl(5.. Firstly the method of perturbation on the reaction system was conducted. Very little amount of water was carried into the feed gas and subsequent changes were observed. The discussion based on the product distribution changes led to a postulated mechanism consisting of two stages.

关键词： photocatalytic oxidation trichloroethylene product distribution

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Land Use of the Three Gorges Reservoir Area and the Effect on Its Landscape Pattern in the Recent 5. Years

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Wuhan University Journal of Natural sciences 2006年第4期11卷 910-914页

作者： HUANG Zhiqin 1,2,3 , ZHOU Wancun 1 ,ZHOU Jieming 4 , ZHU Mingcang 3,5.1. institute of Mountain Hazards and Environment, chinese academy of sciences , chengdu 61004., Sichuan, china 2. Graduate University of chinese academy of sciences, Beijing 100049, china 3. Sichuan institute of Land Resource Management, chengdu 61004., Sichuan , china 4. Department of Resources and Environment Science, Sichuan Normal University , chengdu 610061, Sichuan, china 5. College of Information Engineering, chengdu University of Technology, chengdu 61005., Sichuan, china institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu Sichuan China Graduate University of chinese academy of sciences Beijing China Sichuan institute of Land Resource Management Chengdu Sichuan China Department of Resources and Environment Science Sichuan Normal University Chengdu Sichuan China College of Information Engineering Chengdu University of Technology Chengdu Sichuan China

The paper makes detailed analysis on the changing processes of the main types of land use in Three Gorges Reservoir Area through the techniques of RS （Remote Sense） and GIS （Geography Information System）. Based on the theory of landscape ecology, many types of landscape pattern indexes are calculated and made correlation analysis. The results indicate that： in 1995.the ecological environment of Three Gorges Reservoir Area was the most vulnerable in the recent 5. years, but resumed in 2002; the landscape pattern diversity index, fractal dimension index and fragmentation index has close correlation with the area of land use/cover change （LUCC）. The research also releases that the increase of the cultivated land, grassland and construction land deteriorates the landscape ecological pattern, while the increase of forest land area will help restore the landscape ecological pattern to its original state. The rapid change of grassland is an important index of the change of landscape pattern, because it has the most effect on change of landscape pattern index.

关键词： the Three Gorges Reservoir Area land use/cover change landscape pattern.

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Modifications of Norditerpenoid Alkaloids:Ⅲ. Preparation of 7 ,17-seco Yunnaconitine Derivatives via Rearrangement of Chloroamine

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chinese Chemical Letters 1999年第5期10卷 379-382页

作者： Fend Pane WANG Ju Zheng FAN Xi Xian JIAN Bo Gang LI(Department of Chemistry of Medicinal Natural Products. School of Pharmacy. West china University of Medical sciences. chengdu 61004. chengdu institute of {5.. chinese academy of sciences. chengdu Dept. of Chem. of Med. Nat. Products School of Pharmacy W. China Univ. of Medical Sciences Chengdu 610041 China chengdu institute of biology Chinese Academy of Sciences Chengdu 610041 China

Preparation of both 7. 17-seco yunnaconitine derivatives 6 starting from yunnaconitine 3via rearrangement of choroamine 5.is described.

关键词： Norditerpenoid Alkaloids 7. 17-seco ynnaconitine

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Susceptibility Assessment of Landslides Caused by the Wenchuan Earthquake Using a Logistic Regression Model

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Journal of Mountain Science 2010年第3期7卷 234-245页

作者： SU Fenghuan Key Laboratory of Mountain Hazards and Land Surface Processes Chinese Academy of Sciences Chengdu China institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China Graduate University of the chinese academy of sciences Beijing China

The Wenchuan earthquake on May 12,2008 caused numerous collapses,landslides,barrier lakes,and debris *** susceptibility mapping is important for evaluation of environmental capacity and also as a guide for post-earthquake *** this paper,a logistic regression model was developed within the framework of GIS to map landslide *** County,a heavily affected area,was selected for the *** of landslides was prepared by interpretation of multi-temporal and multi-resolution remote sensing images(ADS40 aerial imagery,SPOT5.imagery and TM imagery,etc.) and field *** Certainly Factor method was used to find the influencial factors,indicating that lithologic groups,distance from major faults,slope angle,profile curvature,and altitude are the dominant factors influencing *** weight of each factor was determined using a binomial logistic regression *** susceptibility mapping was based on spatial overlay analysis and divided into five *** faults have the most significant impact,and landslides will occur most likely in areas near the *** of the area has a high or very high susceptibility,located in the northeast,south and southwest,including 65.3% of all landslides coincident with the *** susceptibility map can reveal the likelihood of future failures,and it will be useful for planners during the rebuilding process and for future zoning issues.

关键词： Landslide susceptibility WenchuanEarthquake GIS logistic regression certainty factor

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