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A density-dependent matrix model and its applications in optimizing harvest schemes

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Science china(Technological Sciences) 2006年第Z1期49卷 108-117页

作者： Guofan Shao, WANG Fei, DAI Limin, BAI Jianwei & LI Yingshan Department of forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, china Inner Mongolia Agriculture University, Hohhot 010019, china Academy of forest inventory and planning, state forestry administration, beijing 100714, china Department of forestry and Natural Resources Purdue University West Lafayette USA Institute of Applied Ecology Chinese Academy of Sciences Shenyang China Inner Mongolia Agriculture University Hohhot China Academy of forest inventory and {2. State Forestry Administration Beijing China

Based on temporal data collected from 36 re-measured plots, transition probabilities of trees from a diameter class to a higher class were analyzed for the broad-leaved-Korean pine forest in the Changbai Mountains. It was found that the transition probabilities were related not only to diameter size but also to the total basal area of trees with the diameter class. This paper demonstrates the development of a density-dependent matrix model, DM2. and a series of simulations with it for forest stands with different conditions under different harvest schemes. After validations with independent field data, this model proved a suitable tool for optimization analysis of harvest schemes on computers. The optimum harvest scheme(s) can be determined by referring to stand growth, total timbers harvested, and size diversity changes over time. Three user-friendly interfaces were built with a forest management decision support system forestAR?for easy operations of DM2.by forest managers. This paper also summarizes the advantages and disadvantages of DM2.

关键词： uneven-aged forestry, diameter transition model, harvesting intensity, diameter limit, sustainable forest management.

Microstructure and Strain Fatigue Dislocation Structure of 7075-RRA Aluminum Alloy

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Rare Metals 2001年第1期20卷 52-57页

作者： Yunqing Li (Department of planning and Developmet, state Nonferrous Metals Industry {2., beijing 100814, china) 中国有色金属工业总公司北京 100814

The microstructure and the strain fatigue dislocation substructure of 7075-RRA (Retrogression and Reaging) aluminum alloy have been studied by using transmission electron microscopy. From these, a competitive mechanism of cyclic microscopic softening/hardening is put forward to explain the relation between macroscopic cyclic stability behavior and microscopic substructure.

关键词： fatigue dislocation slip band aluminum alloy electron microscopic analysis

GIS-based analysis of forest degradations in Baihe forestry Bureau,northeast{2.

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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 2.0002. china Academy of forest inventory and planning, state forestry administration, beijing 100714, china Institute of Applied Ecology Chinese Academy of Sciences Shenyang China Graduate University of Chinese Academy of Sciences Beijing China Department of forestry and Natural Resources Purdue University West Lafayette USA Department of City Development Jinan University Jinan China Academy of forest inventory and {2. State Forestry Administration Beijing 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 2.00 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.

Important population viability analysis parameters for giant pandas(Aliuropoda melanoleuca)

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动物学研究 2012年第3期 18-24页

作者： Minghao GONG1,2.*,Yanling SONG2.Zhisong YANG3,Chen LIN1 1.Wildlife Monitoring Centre,Academy of forest inventory and {2.,state forestry administration,beijing 100714,china 2.Institute of Zoology,the Chinese Academy of Sciences,beijing 100101,china 3.Institute of Rare Animals and Plants,china West Normal University,Nanchong 637002.china

Population viability analysis(PVA) is a tool to evaluate the risk of extinction for endangered species and aid conservation *** quality of PVA output is dependent on parameters related to population dynamics and life-history;however,it has been difficult to collect this information for the giant panda(Aliuropoda melanoleuca),a rare and endangered mammal native to china,confined to some 30 fragmented habitat *** giant pandas are long-lived,mature late,have lower reproductive rates,and show little sexual dimorphism,obtaining data to perform adequate PVA has been ***,we develop a parameter sensitivity index by modeling the dynamics of six giant panda populations in the Minshan Mountains,in order to determine the parameters most influential to giant panda *** data shows that the giant panda populations are most sensitive to changes in four female parameters:initial breeding age,reproductive rate,mortality rate between age 0 and 1,and mortality rate of *** parameter sensitivity index strongly correlated with initial population size,as smaller populations were more sensitive to changes in these four *** model suggests that demographic parameters of females have more influence on the results of PVA,indicating that females may play a more important role in giant panda population dynamics than ***,reintroduction of female individuals to a small giant panda population should be a high priority for conservation *** findings form a technical basis for the coming program of giant panda reintroduction,and inform which parameters are crucial to successfully and feasibly monitoring wild giant panda populations.

关键词： Giant panda PVA Population parameter Parameter sensitivity index

Relay-assisted hierarchical adaptation scheme for multi-user scalable video delivery to heterogeneous mobile devices

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Science china(Information Sciences) 2012年第7期55卷 1541-1550页

作者： XIAO HongJiang 1,2.,JI XiangYang 1 & DAI QiongHai 1 1 Department of Automation,Tsinghua University,beijing 100084,china 2.Academy of Broadcasting {2.,state administration of Radio,Film and Television (SARFT),beijing 100866,china Department of Automation Tsinghua University Beijing China Academy of Broadcasting planning State Administration of Radio Film and Television (SARFT) Beijing China

In multi-user video (MUV) delivery scenarios,the available resources of receiver devices,such as processing capability,link packet error rate (PER),and bandwidth,are usually *** propose a relay-assisted hierarchical adaptation (RHA) scheme to maximize the total perceptual quality of all users when transmitting video streams coded via scalable video coding (SVC).First,MUV bitstreams are adaptively extracted under the constraints of network bandwidth and individual decoding ***,the relay links are introduced as substitutes of possible bad direct links for packets *** equal opportunity of transmission is allocated to each stream while the packets inside a stream are scheduled according to their *** priorities are determined by the links states and packets loss *** results show that our RHA scheme has significant performance improvements compared with other schemes.

关键词： scalable video relay multi-user scheduling decoding complexity

Evaluation of ecosystem services of Chinese pine forests in china

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Science china(Life Sciences) 2008年第7期51卷 662-666,668-670页

作者： GUO Hao ,WANG Bing,MA XiangQian,ZHAO GuangDong&LI ShaoNing Research Institute of forest Ecology Environment and Protection of CAF,Key Laboratory of forest Ecological Environment of{2.,beijing 100091,china Research Institute of forest Ecology Environment and Protection of CAF Key Laboratory of Forest Ecological Environment of State Forestry Administration Beijing China

Evaluation of forest ecosystem services is a hot topic,both in china and at abroad,but it has not yet obtained a consistency of evaluation indicator systems and evaluation *** the framework of evaluation criteria to be implemented for forest ecosystem services,years of consecutive observation data from Long Term Ecological Research Stations affiliated to Chinese forest Ecosystem Research Network(CFERN),forest resource inventory and public data were applied to carry out a detailed and dynamic evaluation on the physical quantity and value of ecosystem services of Chinese pine forests in *** results showed that the above services had the total value and unit value of 1144.9640 billion(1.1449640×10 12.)RMB and 52.074 thousand RMB per hectare per year,respectively during the 9th Five-year Plan(1996―2.00),and of 1190.5461 billion RMB and 52.101 thousand RMB per hectare per year,respectively,during the 10th Five-year Plan(2.01―2.05).For Chinese pine forests,water conservation was 40.40 hundred million cubic meters annually,soil conservation was 67 million tons and C fixation 9 million tons annually,production of healthful negative ions was 1.96×10 2. , absorption of SO2.was 5.02.hundred million kilograms and dust-catching was 759.10 hundred million kilograms. Among the 15 provinces of china with Chinese pine forests,the biggest beneficiary from ecosystem services was Liaoning Province;while Hunan Province was the smallest beneficiary between the 9th Five-year Plan.

关键词： ecosystem services physical quantity value evaluation Chinese pine

扫描电子显微镜及能谱分析技术在黄土微结构研究上的应用

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沈阳农业大学学报 2004年第3期35卷 216-219页

作者：宋菲国家林业局调查规划设计院北京100714

我国利用扫描电子显微镜研究黄土微结构的报道始于2.世纪的70年代。随着当代电子技术和计算机的发展,利用扫描电子显微镜和能谱分析技术,可以在观测微结构的同时,实现对微结构元素分析的目的。本研究介绍了扫描电子显微镜和能谱分析技... 详细信息

我国利用扫描电子显微镜研究黄土微结构的报道始于2.世纪的70年代。随着当代电子技术和计算机的发展,利用扫描电子显微镜和能谱分析技术,可以在观测微结构的同时,实现对微结构元素分析的目的。本研究介绍了扫描电子显微镜和能谱分析技术的原理,并从样品制作、处理、观察和结果分析等角度就二者在黄土微结构研究上的应用做了探讨。

关键词：扫描电子显微镜能谱分析技术黄土微结构

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镁基水冲压发动机三维两相反应流场研究

推进技术 2009年第1期30卷 52-56页

作者：胡凡张为华夏智勋朱艳国防科学技术大学航天与材料工程学院湖南长沙410073 国家林业局调查规划设计院北京100714

建立了镁基金属燃料/水冲压发动机三维两相反应流动模型,提出了采用燃烧效率修正一次燃烧温度的方法,对某试验发动机理想和实际工作状态进行了数值模拟,得到了发动机内流场分布趋势,并对计算与试验结果进行了对比,分析了产生误差的原因... 详细信息

建立了镁基金属燃料/水冲压发动机三维两相反应流动模型,提出了采用燃烧效率修正一次燃烧温度的方法,对某试验发动机理想和实际工作状态进行了数值模拟,得到了发动机内流场分布趋势,并对计算与试验结果进行了对比,分析了产生误差的原因。结果表明修正燃烧温度后模型更能反映发动机实际工作状态及内流场分布,雾化效果和发动机热损失是影响发动机性能的重要因素,实际工作过程中由于存在凝相金属镁使计算燃烧效率大于试验燃烧效率。

关键词：金属燃料/水冲压发动机+ 数值仿真两相流流动分布试验验证

Estimation of forest volumes by integrating Landsat TM imagery and forest {2. data

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Science china(Technological Sciences) 2006年第Z1期49卷 54-62页

作者： GU Huiyan, DAI Limin, WU Gang, XU Dong, WANG Shunzhong &WANG Hui Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, china School of forestry, Northeast forestry University, Harbin 150040, china state Key Lab of Systems Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, beijing 100085, china Graduate University of Chinese Academy of Sciences, beijing 100039, china Institute of Applied Ecology Chinese Academy of Sciences Shenyang China School of forestry Northeast Forestry University Harbin China state Key Lab of Systems Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of Sciences Beijing China

Accurate information about forest volumes is essential for forest management {2.. The survey interval of the forest Resource inventory of china (FRIC) is too long to meet the demand for timely decision-making required for forest protection, management, and utilization. Analysis of satellite imagery provides good potential for more frequent reporting of forest parameters. In this study, we describe an application of the k-nearest neighbors (kNN) method to Landsat TM imagery for improving estimation of forest volumes. Several spectral features were tested and compared in forest volume estimations, including normalized difference vegetation index, environmental vegetation index, and the combination of the spectral features. The combined index resulted in the most accurate volume estimations. The kNN estimator and the combined index were then used in forest volume estimation. The estimation error (RMSE) of the total volume was44.2., much lower than those for Larix forest (the RMSE was 51.7%) and those for the Korean pine and broadleaved forests (the estimation errors were over 71.7% and 88.19%,respectively). This preliminary study demonstrates the potential of forest volume estimations with remote sensing data to provide useful information for forest management if only limited ground information is available.

关键词： forest inventory, landsat TM, k-nearest neighbors, spectral extraction.