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GIS-based analysis of forest degradations in Baihe forestry Bureau,northeast china

science china(Technological sciences) 2006年第z1期49卷 167-176页

作者： ZHOU Li, DAI Limin , Guofan Shao, XU Dong, WANG Hui & BAI Jianwei institute of Applied Ecology, chinese academy of sciences, Shenyang 110016, china Graduate University of chinese academy of sciences, beijing 100101, china Department of forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA Department of City Development, Jinan University, Jinan 250002, china academy of Forest Inventory and Planning, State forestry Administration, beijing 100714, china 1. institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China 2. Graduate University of chinese academy of sciences Beijing 100101 China 3. Department of forestry and Natural Resources Purdue University West Lafayette IN 47907 USA 4. Department of City Development Jinan University Jinan 250002 China 5. academy of Forest Inventory and Planning State Forestry Administration Beijing 100714 China

Forests in the Changbai Mountains are important timber sources for economic development of the society and provide ecological services in northeast china. In order to strengthen forest resource management, this paper analyzed management-induced changes in forest structure, tree species composition and forest landscape pattern from 1987 to 2000 for Baihe forestry Bureau in Jilin Province based on digitized forest parcel maps and forest survey data. The results suggested that the area of Mature, High-Stocking, and Close-Canopy Forests decreased by 31.4%, 55.9% and 10.7% respectively; volume of Mixed Forest, the native forest vegetation type, decreased by 17.8%;the number of patches increased tremendously but the mean patch density decreased sharply for Mature, High-Stocking, Close-Canopy, and Mixed Forests. All the changes in forest structure, species composition, and landscape pattern indicated severe degradations going on with the forests in Baihe forestry Bureau. Because of the effect of degradation to forest services, restoring forest resources and protecting biodiversity has become urgently important. The strategies of sustainable forest management need to be worked out and implemented.

关键词： geographic information system, forest management, Changbai Mountains, forest change, forest decline.

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VISCOELASTIC BEHAVIOR OF THE NON-HOOKE DEFORMATION BEFORE YIELDING IN UNIAXIAL DRAWING OF AMORPHOUS POLY(ETHYLENE TEREPHTHALATE)

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chinese Journal of Polymer science 2001年第4期19卷 399-405页

作者： Zhen-hua Yuan De-yan Shen Ren-yuan Qian Polymer Physics Laboratory Center for Molecular science, institute of Chemistry chinese academy of sciences, beijing 100080 china chinese Acad Sci Inst Chem Ctr Mol Sci Polymer Phys Lab Beijing 100080 Peoples R China

Viscoelastic behavior of the non-Hooke deformation of amorphous PET film before yield was investigated in the temperature region 74-80.5 degreesC around the glass transition temperature. The film specimen was drawn to yield point followed by unloading to zero stress, then the residual deformation was held constant; while the subsequent evolution of the stress was recorded. An induction period was found in the course of stress evolution followed by a stress step-increase. The induction period decreases with increasing drawing temperature with an activation energy of 1.10 MJ/mol.K, which is attributed to the time needed for the relaxation of rubbery deformation through cooperative internal rotations. At temperatures lower than 74 degreesC, there is no stress increase or the induction period becomes too long to be observed. Thus the nature of anelasticity in the non-Hooke region before yielding is attributed to stress induced rubbery deformation. The experimental results are interpreted in terms of Perez' theological model of a series connected Hooks spring and a Voigt element consisting of a parallel connected elastic spring and a dashpot.

关键词： pre-yield deformation PET uniaxial drawing non-Hooke deformation viscoelasticity stress induced rubbery deformation

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A Dynamic Solution for Document Redundancies in Multiple Sources

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现代图书情报技术 2002年第S1期 129-133,149页

作者： Gong Zhiguo(Faculty of science and Technology University of Macao,Macao 3001,china)Zhou Longxiang (institute of Mathematics chinese academy of science beijing 100080 china) FacultyofscienceandTechnologyUniversityofMacauMacau30010china instituteofMathematicschineseacademyofsciencebeijing100080china

With the development of IT,more andmore document resources are available over the *** to facilitate users’retrieval of the digital documents,Integrations of the multi source systems are necessary,Sincethe individual sources collect their information independently,the same papers may be stored in different source *** traditional solutions to the redundancy problems in thedistributed environments are usually based on the globalcatalogs which keep the redundancy information for thesyst...

关键词： A Dynamic Solution for Document Redundancies in Multiple Sources

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A shortest path algorithm for moving objects in spatial network databases

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Progress in Natural science:Materials International 2008年第7期18卷 893-899页

作者： Xiaolan Yin a,b,*, Zhiming Ding c, Jing Li a a Technology Center of Software Engineering, institute of Software, chinese academy of science, P.O. Box 8718, beijing 100080, china b Graduate University, chinese academy of sciences, beijing 100049, china c Technology Center of Basic Software, institute of Software, chinese academy of sciences, beijing 100080, china Technology Center of Software Engineering Institute of Software Chinese Academy of Science P.O. Box 8718 Beijing 100080 China Graduate University Chinese Academy of Sciences Beijing 100049 China Technology Center of Basic Software Institute of Software Chinese Academy of Sciences Beijing 100080 China

One of the most important kinds of queries in Spatial Network Databases (SNDB) to support location-based services (LBS) is the shortest path query. Given an object in a network, e.g. a location of a car on a road network, and a set of objects of interests, e.g. hotels, gas station, and car, the shortest path query returns the shortest path from the query object to interested objects. The studies of shortest path query have two kinds of ways, online processing and preprocessing. The studies of preprocessing suppose that the interest objects are static. This paper proposes a shortest path algorithm with a set of index structures to support the situation of moving objects. This algorithm can transform a dynamic problem to a static problem. In this paper we focus on road networks. However, our algorithms do not use any domain specific information, and therefore can be applied to any network. This algorithm’s complexity is O(klog2i), and traditional Dijkstra’s complexity is O((i + k)2).

关键词： Moving object Spatial network databases Shortest path index Shortest path

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Occurrence and Culture of Mycorrhizal Fungi Associated with Oaks in Dandong Region, Liaoning Province

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Pedosphere 2005年第2期15卷 232-237页

作者： WANGHui DAILi-Min YANGBao-Shan LANGQing-Long GUHui-Yan instituteofAppliedEcology ChineseAcademyofSciencesShenyang110016（China）／／GraduateSchoolofChineseAcademyofSciencesBeijing100039（China） instituteofAppliedEcology ChineseAcademyofSciencesShenyang110016（China） instituteofLiaoningSericulturalscience Fengcneng118100（China） instituteofAppliedEcology ChineseAcademyofSciencesShenyang110016（China）／／CollegeofForestryNortheastForestryUniversityHarbin150040（China）

With both field investigation and pure culture experiments, the occurrence and optimal essential growth of mycorrhizal fungi with oaks in Dandong Region of Liaoning Province, china were investigated from 1997-2002 A total of 36 species of mycorrhizal fungi associated with oaks were observed. The results showed that the occurrence of mycorrhizal fungi was related to tree species, tree ages, and months of the year, with at least 20 fungi species being associated with more than two oak species. The highest Sim…

关键词： mycorrhizal fungi rnycorrhizal relationship oak pure culture

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Comparative analysis of temperature and CO2 fluxes for winter wheat in Tibetan Plain and North china Plain using the EMD method

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Progress in Natural science:Materials International 2006年第10期16卷 1066-1071页

作者： JIANG Zhaoyang, YU Qiang, LEI Shuhe, WANG Tianduo, SUN Xiaomin and ZHANG Renhua ( chinese academy of Meteorological science, beijing 100081, china institute of Geographic sciences and Natural Resources Research, chinese academy of sciences, beijing 100101, china Mathematics Department, Ocean University of china, Qingdao 266071, china Shanghai institute of Plant Physiology and Ecology, chinese academy of sciences, Shanghai 200032, china) [a]chinese academy of Meteorological science Beijing China [b]chinese academy of sciences Institute of Geographic sciences and Natural Resources Research Beijing China [c]Mathematics Department Ocean University of China Qingdao China [d]chinese academy of sciences Shanghai Institute of Plant Physiology and Ecology Shanghai China

Comparative study of spectral properties of temperature and CO2 fluxes measured by eddy covariance method at Yucheng (36°57'N, 116°36'E, 28 m a.s.l., in the North china Plain) and at Lhasa (29°41'N, 91°20'E, 3688 m a.s. 1., on the Tibetan Plateau) is described using the empirical mode decomposition (EMD) method. The main results are: (1) The intrinsic oscillation modes or intrinsic mode functions (IMFs) were extracted from data of temperature ( T) and CO2 fluxes (F) measured at Yucheng ( T1 and F1) and Lhasa ( T2 and F2) . (2) Hilbert transform was applied to these IMF components, then the Hubert-Huang spectra and the marginal spectra of these data were obtained. (3) Comparison of temperature and CO2 fluxes in North china Plain and on Tibetan Plain illustrated that the characteristic frequencies corresponding to T1, F1, T2 and F2 are 0.05 Hz, 0.03 Hz, 0.014 Hz and 0.005 Hz, respectively.

关键词： empirical mode decomposition (EMD) intrinsic mode function (IMF) flux Hilbert transform wheat Tibet.

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Formation of Ultrafine Metal Particles and Metal Oxide Precursor on Anodized Al by Electrolysis Deposition

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Journal of Materials science & Technology 2000年第1期16卷 50-54页

作者： Lingchuan LI (institute of Chemical Metallurgy, chinese academy of sciences, beijing 100080, china) institute of Chemical Metallurgy Chinese Academy of Sciences Beijing 100080 China

Nickel was deposited by ac electrolysis deposition in the pores of the porous oxide film of Al produced by anodizing in phosphoric acid. Ultrafine rod-shaped Ni particles were formed in the pores. At the same time a film of Ni oxide precursor was developed on the surface of the porous oxide film. The Ni particles and the Ni oxide precursor were examined by SEM, TEM and X-ray diffraction. The thickness of the barrier layer of the porous oxide film was thin and it attributed to the formation of the metal particles, while the formation of the oxide precursor was associated with the surface pits which were developed in the pretreatment of Al.

关键词： Al Formation of Ultrafine Metal Particles and Metal Oxide Precursor on Anodized Al by Electrolysis Deposition

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Exploration of combined adjustment laws about IGV,stator and rotational speed in off-design conditions in an axial compressor

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中国科学：技术科学英文版 2010年第4期53卷 969-975页

作者： HU YanMing1,2 & NIE ChaoQun1 1 Key Laboratory of Advanced Energy and Power Technology,institute of Engineeting Thermophysics,chinese academy of science,beijing 100190,china 2 Graduate School of chinese academy of sciences,beijing 100190,china 1. Key Laboratory of Advanced Energy and Power Technology Institute of Engineeting Thermophysics Chinese Academy of Science Beijing 100190 China2. Graduate School of Chinese Academy of Sciences Beijing 100190 China

Experimental investigations are performed in a three-stage low-speed axial compressor with variable inlet guide vanes(IGV) and adjustable *** characteristics of the compressor,especially the efficiency and stall margin,are analyzed in design and off-design operation conditions by adjusting stagger angles of IGV and stators as well as changing the rotational *** experimental results show that the off-design performance of the multistage axial compressor is improved by restaggering of IGV and stators related to rotational *** the background of engineering applications,digital signal processing(DSP) technique is used to realize online adjustment of stagger angles according to the corresponding relations between incidence angles of rotor and rotational speed.

关键词： axial compressor IGV surge DSP techniques off-design

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SUPERCONVERGENCES OF THE ADINI'S ELEMENT FORSECOND ORDER EQUATION

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Journal of Computational Mathematics 1999年第6期17卷 569-574页

作者： Ping Luo(Department of Computer science and Technology, Qinghua University, beijing 100084,china)Qun Lin(institute of Systems science, Academia Sinica, beijing, 100080, china) Tsing Hua Univ Dept Comp Sci & Technol Beijing 100084 Peoples R China Acad Sinica Inst Syst Sci Beijing 100080 Peoples R China

n this papers the asymptotic error expansions of Adini's element for the secondorder imhomogeneous Neumann problem are given and the superconvergence estimations are obtained. Moreover, a numerical example to support ... 详细信息

关键词： Adini's element Superconvergence estimation Asymptotic expansion.

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Bilevel Programs with Multiple Potential Reactions

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Systems science and Systems Engineering 1994年第3期4卷 269-278页

作者： WANG Qian and WANG Shouyang institute of Systems science,chinese academy of science.beijing 100080,china

In this paper,we study linear bilevel programming without the assumption that the reaction set of the follower is a *** properties of the feasible region of the leader are presented.A new solution concept is introduced to deal with the uncertainty resulting from multiple potential reactions of the *** solve a bilevel program with multiple potential reactions,we propose,meadod to transform the original problem into a bilevel programming proproblem which can be solved by some known algorithms.

关键词： Bilevel programming point-to-set mapping open mapping linear programming

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