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Spatial heterogeneity of the driving forces of cropland change in china

Science china Earth sciences 2005年第12期48卷 2231-2240页

作者： LIU Xuhua1,2, WANG Jinfeng1, LIU Mingliang4,1 & MENG Bin1,2,3.1. Institute of Geographic sciences and Natural Resources Research, Chinese Academy of sciences, beijing 100101,{3. 2. Graduate School of the Chinese Academy of sciences, beijing 10003.,{3. 3. college of arts and sciences of beijing union university, beijing 100083,{3. 4. School of Forestry and Wildlife sciences, Auburn university, Auburn, Alabama, AL3.849, USA Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Graduate School of the Chinese Academy of sciences Beijing China School of Forestry and Wildlife sciences Auburn University Auburn Alabama USA college of arts and sciences of {3. union university Beijing China

By using digital satellite remote sensing data acquired in 1987―1989 and 1999―2000 and GIS combined with the natural and socio-economic data, this paper drew an integrated zonation of the cropland change and its driving forces in china. The results indicated that the cropland change in the study period was constrained by geographical factors and driven by cli-mate change as well as socio-economic system. Moreover, the regional differences of the drivers for cropland change were significant. In the midwest of china, natural condition changes and geographical background were the main constraints and drivers, while in Eastern china, social and economic changes and economic policies were the main driving forces. The cropland loss was nationwide. The dominant factors to cause this decrease included buildup of developing area to attract foreign capital and technologies, changes of industry structure due to urban in-fluence, the change of employment notions thanks to living standard improvement, rapid ur-banization due to the expansion of cities and towns, the diminished farming net income partly because of the global warming effects, and the rapid economic growth stimulated by the con-venient transportation system. These factors interact and interdepend with each other to cause the cropland loss in china recently. The reasons for the increase of cropland were primarily the cultivation and deforestation by the farmers who want to increase income. This study on the mechnism of LUCC relied on the cropland change integrated classification considering the natural or human factors both inside and outside the region, which provides a new approach to study the integrated regionalization and LUCC mechanism.

关键词： land use change, driving force, integrated classification, spatial statistics, cropland, china.

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A heuristic path-estimating algorithm for large-scale real-time traffic information calculating

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Science china(Technological sciences) 2008年第S1期51卷 165-174页

作者： L WeiFeng1,ZHU TongYu1,WU DongDong2,DAI Hong3.& HUANG Jian1 1 State Key Laboratory for Software Development Environment,Beihang university,beijing 100083,{3. 2 beijing Transportation Information Center,beijing 100055,{3. 3.college of arts & Science,beijing union university,beijing 100083,{3. State Key Laboratory for Software Development Environment Beihang University Beijing China beijing Transportation Information Center Beijing China college of arts & Science Beijing Union University Beijing China

As the original Global Position System (GPS) data in Floating Car Data have the accuracy problem,this paper proposes a heuristic path-estimating algorithm for large-scale real-time traffic information calculating. It uses the heuristic search method,imports the restriction with geometric operation,and makes comparison between the vectors composed of the vehicular GPS points and the special road network model to search the set of vehicular traveling route candidates. Finally,it chooses the most optimal one according to weight. Experimental results indicate that the algorithm has considerable efficiency in accuracy (over 92.7%) and com-putational speed (max 8000 GPS records per second) when handling the GPS tracking data whose sampling rate is larger than 1 min even under complex road network conditions.

关键词： path-estimating floating car data (FCD) road network vector GPS

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CONTROLLED RELEASE FROM PDMAEMA GELS PREPARED BY GAMMA RADIATION

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Chinese Journal of Polymer Science 2002年第5期20卷 409-412页

作者： Ning Liu Min Yi Shuang-ji Chen Hong-fei Ha college of Chemistry and Molecular Engineering Peking university beijing 100871,{3. Department of Biochemistry college of Applied arts and Science, beijing union university beijing 100083.{3. college of Chemistry and Molecular Engineering Peking University 北京 100871 Department of Biochemistry College of Applied Arts and Science Beijing Union University 北京 100083

Poly(N,N-dimethylaminoethyl methacrylate) (polyDMAEMA) hydrogels prepared by gamma-irradiation showed obvious temperature-sensitivity in a temperature range of 3.-40degreesC and pH-sensitivity at pH=2.5. They also showed electric response behavior although it was not typical. The hydrogels were used in controlled release at different pH, temperature, and electric voltage. The release rates of methylene blue (MB) from the gels at 52degreesC and pH=1.24 were faster than those at 20degreesC and pH=10.56, respectively. In addition, the release rate at a field voltage of 5.0 was also faster than that without electric field.

关键词： poly(N,N-dimethylaminoethyl methacrylate) environmental sensitivity hydrogel controlled release

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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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Effects of 3.4-DichIOrOaniline on Testicle Enzymes as Biological Markers in Rats

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Biomedical and Environmental sciences 2009年第1期22卷 40-43页

作者： Bo ZHANG~2 AND SEN LIN Department ofBiology,college ofApplied sciences and Humanities,beijing {3. university, beijing 100083,china

Objective To investigate the effects of 3.4-dichloroaniline （3.4-DCA） on activities of testicle enzymes as biological markers in rats. Methods Fifty male rats were randomly divided into 5 groups （n=10）. One group was left untreated and used as a solvent control （administered orally by corn oil）, while the other 4 groups were treated with 3. 4-DCA. Corn oil was used as a solvent, and 3.4-DCA was diluted into tested concentrations （3., 81, 170, and 3.7 mg/kg）. All the groups orally administered 3.4-DCA or corn oil, once a day for 4 weeks. The testicle tissue was homogenized in a 0.1 mol/L potassium phosphate buffer （0.1 mol/L, pH 7.2）. The crude homogenate was centrifuged at 6000 rpm for 5 min at 4 ~C. The supernatant obtained was used as an enzyme extract for determination of the enzyme activities. Results Compared with the control, the activities of ALP, ACP, and SDH were increased significantly at a lower level of 3.4-DCA, and decreased at a higher level of 3. 4-DCA, whreas the activities of LDH, LDH-X, and G6PDH were inhibited significantly with the increased 3.4-DCA concentration. Organ coefficient ＂organ weight/total body weight × 100＂ of testis, liver, and spleen increased significantly with the increased 3.4-DCA concentration. These results suggest that 3.4-DCA toxicity to the male reproductive system was associated with the activities of testicular enzymes which are the sensitive biochemical endpoints reflecting 3.4-DCA toxicity to the male reproductive system. Conclusion 3.4-DCA has toxicity to the reproductive system in male rats.

关键词： 3. 4-dichloraniline Rat Marker testicular enzymes

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Iterative implementation of the adaptive regularization yields optimality

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Science china Mathematics 2005年第4期48卷 485-492页

作者： MA Qinghua & WANG Yanfei Department of Information sciences, college of arts and Science of {3. union university, {3. 10003., china National Key Laboratory on Remote Sensing Science, Institute of Remote Sensing Applications, Chinese Academy of sciences, {3. 100101, china Department of Mathematics, university of Central Florida, P. O. Box 1613.4, Orlando, FL 3.816-13.4, USA Department of Information sciences College of Arts and Science of Beijing Union University Beijing China National Key Laboratory on Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing China

The adaptive regularization method is first proposed by Ryzhikov et al. for the deconvolution in elimination of multiples. This method is stronger than the Tikhonov regularization in the sense that itis adaptive, i.e. it eliminates the small eigenvalues of theadjoint operator when it is nearly singular. We will show in this paper that the adaptive regularization can be implemented iterately. Some properties of the proposed non-stationary iterated adaptive regularization method are analyzed. The rate of convergence for inexact data is proved. Therefore the iterative implementation of the adaptive regularization can yield optimality.

关键词： ill-posed problems, non-stationary iterated adaptive regularization, optimality.

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Quenched moderate deviations principle for random walk in random environment

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Science china Mathematics 2010年第8期53卷 1947-1956页

作者： HONG WenMing 1 & WANG HuaMing 1,2 1 Key Laboratory of Mathematics and Complex Systems of Ministry of Education & School of Mathematical sciences,beijing Normal university,beijing 100875,china 2 Department of Basic Courses,Business college,beijing union university,beijing 100025,china Key Laboratory of Mathematics and Complex Systems of Ministry of Education & School of Mathematical sciences Beijing Normal University Department of Basic Courses Business College Beijing Union University

We derive a quenched moderate deviations principle for the one-dimensional nearest random walk in random environment,where the environment is assumed to be stationary and *** approach is based on hitting time decompos... 详细信息

关键词： random walk in random environment moderate deviations principle hitting time

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Synthesis of Conformationally LockedIsonucleosides: 2'-Deoxy-2'-nucleobase-5'-deoxy-1', 4' : 3. , 6'-dianhydro-D-mannitol

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Chemical Research in Chinese Universities 2001年第2期17卷 178-185页

作者： TIAN Xiao-bing, ZHANG Ling, MIN Ji-mei and ZHANG Li-he (School of Pharmaceutical sciences, beijing Medical university,{3., P. R. china) LU Yang, JIANG Reng-wang and ZHENG Qi-tai (Institute of Materia Medica, Peking union Medical college &. Ch 北京大学北京 100083 中国医学科学院药物所北京 100050

Novel bicyclic isonucleosides, 2′-deoxy-2′ -nucleobase-5′-deoxy-1′ , 4′ : 3. , 6′ -dianhydro- D-mannitol 10a-10c, were synthesized from D-glucose. The computer-assisted molecular simu- lation indicated that the... 详细信息

关键词： Bicyclic isonucleoside Locked conformation Synthesis

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Sensing characterization of Sn/In/Ti nanocomplex oxides for CO, CH_4 and NO_2

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Science china(Technological sciences) 2007年第1期50卷 18-26页

作者： BAI ShouLi1, TONG ZhangFa2, LI DianQing1, HUANG XiaoWei3. LUO RuiXian1 & CHEN AiFan1 1 State Key Laboratory of Chemical Resource Engineering, beijing university of Chemical Technology, beijing 100029,{3. 2 School of Chemistry and Chemical Engineering, Guangxi university, Nanning 53.004,{3. 3.college of Biochemical Engineering, beijing union university, beijing 100023.{3. State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology

The nanocomplex oxides of Sn-In and Sn-In-Ti were prepared by controlled co-precipitation method as sensing materials of semiconductor gas sensors for detection of CO, CH4 and NO2. Through manipulating the Sn/In cation ratio, metal salt total concentration, precipitation pH value and aging time, the nanocrystalline powders were successfully derived with chemical homogeneity and superior thermal stability, compared with the single component oxides. The particle size and morphology, surface area, and thermal and phase stabilities were characterized using TEM, TG-DTA, BET and XRD. The sensing tests showed that the Sn-In com-posites exhibit high sensitivity and selectivity for CO and NO2. The introduction of TiO2 enhanced CH4 sensitivity and selectivity, particularly, additives of Pd and Al2O3.as a dopant and surface modification greatly enhanced the sensing properties. The sensitivity depended on the composition of composites, calcination temperature and operating temperature. The optimal values were (25%In2O3. 75%SnO2)-20%TiO2 for ternary composite, 600 and 3.0℃, respectively. Temperature-programmed de-sorption (TPD) studies were employed to explain the gas adsorption behavior dis-played by the surface of nanocomposites and X-ray photoelectron spectroscopic (XPS) analysis was used to confirm the electronic interactions existing between oxide components. The sensing mechanism of the nanocomposites was attributed to chemical and electronic synergistic effects.

关键词： SnO2-In2O3.TiO2 nanocomposites CO NO2 CH4 gas sensing

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Cu(Ⅱ) Potentiation of Alzheimer Aβ1-40 Cytotoxicity and Transition on its Secondary Structure

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Acta Biochimica et Biophysica Sinica 2006年第11期38卷 765-772页

作者： Xue-Ling DAI~1 Ya-Xuan SUN~2 Zhao-Feng JIANG~2* 1 college of Life Science,Capital Normal university,beijing 10003.,{3. 2 college of Applied sciences and Humanities,beijing union university,beijing 100083,{3. collegeofLifeScience CapitalNormalUniversityBeijing100037China collegeofAppliedsciencesandHumanities BeijingUnionUniversityBeijing100083China

Mounting evidence has shown that dyshomeostasis of the redox-active biometals such as Cuand Fe can lead to oxidative stress,which plays a key role in the neuropathology of Alzheimer's disease（AD）.Here we demonstrate that with the formation of Cu（Ⅱ）·Aβ1-40 complexes,copper markedly potentiatesthe neurotoxicity exhibited by β-amyloid peptide （Aβ）.A greater amount of hydrogen peroxide was releasedwhen Cu（Ⅱ）·Aβ1-40 complexes was added to the xanthine oxidase/xanthine system detected by potassiumiodide *** bound to Aβ1-40 was observed by electron paramagnetic resonance（EPR） *** dichroism （CD） studies indicated that copper chelation could cause a structuraltransition of Aβ.The addition of copper to Aβ introduced an increase on β-sheet as well as α-helix,whichmay be responsible for the aggregation of Aβ.We hypothesized that Aβ aggregation induced by copper maybe responsible for local injury in *** interaction between Cu2+and Aβ also provides a possible mechanismfor the enrichment of metal ions in amyloid plaques in the AD brain.

关键词： Alzheimer’s disease Cu(Ⅱ)·Aβ1-40 complex neuron injury Aβ secondary structure

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