检索结果-南通市图书馆

The Epimerization of 10-Deacetylbaccatin Ⅲ by Microsphaeropsis Onychiuri a Fungus from Taxus Yunnanensis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

chinese Chemical Letters 1997年第1期8卷 47-48页

作者： Jun Zeng ZHANG Fu TU Li He ZHANG(The National Research Laboratories of Natural and Biomimetic Drugs, School of pharmaceutical sciences,beijing Medical University, beijing 100083)De You QIU(The Research institute of forestry, chinese academy of forestry, Natl. Res. Labs. Nat. Biomimetic D. School of Pharmaceutical Sciences Beijing Medical University Beijing 100083 China Research institute of forestry Chinese Academy of Forestry Beijing 100091 China

: The microbiological transformaion of a natural taxoid 10-deacetylbaccatin III into its C-7 epimer, 10-deacetylbaccatin V with Microsphaeropsis onychiuri, a fungus isolated from the inner bark of Taxus yunnanensis is... 详细信息

关键词： The Epimerization of 10-Deacetylbaccatin by Microsphaeropsis Onychiuri a Fungus from Taxus Yunnanensis

State and Trend Analysis of Industrial Plantation Development in Foreign Countries

在线全文

学校读者我要写书评

暂无评论

chinese forestry Science and Technology 2010年第2期9卷 40-49页

作者： HU Yanjie1 WANG Fang2.1. Research institute of forestry Policy and Information,{2. academy of forestry, beijing 100091, P. R. China 2. School of Forest Resources, beijing forestry University, beijing 100083, P. R. China

The paper firstly reviewed industrial plantation development in the main forestry countries worldwide, and then summarized the state and trend of the R & D of industrial plantation in foreign countries in terms of genetic improvement, breeding techniques, site evaluation techniques, density control techniques, long-term productivity maintenance techniques and diseases and pests control techniques. In the meantime, the three management models employed in industrial plantations abroad was introduced, i.e. intensive management, oriented management, and enterprise-based management and integration of forest, industry and paper-making, based on which four suggestions were proposed through summarizing the successful experiences in industrial plantation development abroad to facilitate the development of fast-growing and high-yield plantation in China from the technical perspective.

关键词： plantation fast-growing and high-yield plantation management technique management model reference

Digitally determining forest inventory units with an ecological classification system

在线全文

学校读者我要写书评

暂无评论

Science China(Technological sciences) 2006年第z1期49卷 118-127页

作者： TANG Una, WANG Qingli, Guofan Shao, DAI Limin, WANG Shunzhong, LI Xiufen & XU Dong institute of Applied Ecology, chinese{2. of sciences, Shenyang 110016, China Graduate University of chinese{2. of sciences, beijing 100101, China Department of forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA 1. institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China 2. Graduate University of chinese academy of{2. Beijing 100101 China 3. Department of forestry and Natural Resources Purdue University West Lafayette IN 47907 USA

Management-level forest resource data in China were obtained with a combination of two forest inventories. However, inconsistencies in the spatial attributes of forest data vary between the two inventory types and between two inventories of the same type. The inconsistencies make it inconvenient for long-term forest management planning with digital technologies. Ecological Land Types (ELTs) and Ecological Land Type Phases (ELTPs) have been mapped in selected forestry regions in northeast China, where important forest industries are located. The boundaries of ELTs are determined by geomorphic conditions, which are quantified by Digital Elevation Models (DEM); ELTPs are classified by overlaying ELTs with forest vegetation data layers that are obtained with both remotely sensed and ground data. The ELTPs represent the divisions of land in terms of both natural and human-induced forest conditions, and therefore they are reliable units for forest inventories and management. This paper introduces a case study for digitally determining forest inventory units in Benxi City, Liaoning Province, northeast China. The general objective of the study was to explain how a compatible forest inventory system should be designed and why the compatible forest inventory system was significant to digital forestry in China.

关键词： forest inventory, ecological classification, ELT mapping, ELTP mapping, geographic information systems, forest management.

Monitoring the Cultivated Slope Land in the Three Gorges Reservoir Area Based on Remote Sensing and GIS

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural sciences 2006年第4期11卷 915-921页

作者： ZHOU Jieming1, ZHOU Qigang 2. 3 ,HUANG Zhiqin 2. 3, 4 1. The Faculty of Geography and Resources Science, Sichuan Normal University, Chengdu 610066, Sichuan, China 2. institute of Mountain Hazards and Environment, chinese{2. of sciences, Chengdu 610041, Sichuan, China 3. Graduate University of the chinese{2. of sciences, beijing 100049, China 4. Information Center of Land and Resources Department of Sichuan Province, Chengdu 610041, Sichuan, China The Faculty of Geography Resources Science Sichuan Normal University 610066 Chengdu Sichuan China institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China Graduate University of the chinese academy of{2. 100049 Beijing China Information Center of Land Resources Department of Sichuan Province 610041 Chengdu Sichuan China

By means of combining auto-extraction with manual interpretation, the current distribution information about cultivated land is obtained. The distribution information of 1992.is extracted from the dynamic polygons of 2.02. The monitoring mini-system of the cultivated slope land is established. In the system, detailed surveys, focused on the resources of cultivated slope land, are carried out. The results indicate that the area of the cultivated slope land is very large. Meanwhile, there are lots of cultivated steep slopes with gradient above 35°. The areas of steep land cultivated had been slowly reduced from 1992.to 2.02. At the same time, the pressures of returning farm land to forestry are great in all counties. The conflicts between population growth, insufficient grain supply and stagnant economic development sharpen increasingly. It is inevitable to improve the agricultural structure.

关键词： slope land cultivated remote sensing geography information system (GIS) the pressure of returning farm land to forestry Three Gorges Reservoir Area

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

在线全文

学校读者我要写书评

暂无评论

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,{2. 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 1. Department of forestry and Natural Resources Purdue University West Lafayette IN 47907 USA 2. institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China 3. Inner Mongolia Agriculture University Hohhot 010019 China 4. academy of Forest Inventory and Planning State Forestry Administration Beijing 100714 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.

Spatial and environmental effects on plant communities in the Yellow River Delta,Eastern China

在线全文

学校读者我要写书评

暂无评论

Journal of forestry Research 2009年第2期20卷 117-122页

作者： SONG Chuang-ye1, 2. LIU Gao-huan1, LIU Qing-sheng1 1 institute of Geographic sciences and Nature Resources Research,{2. academy of sciences, beijing 100101, China 2.Graduated School of{2. academy of sciences, beijing 100039, China institute of Geographic sciences and Nature Resources Research Chinese Academy of Sciences Beijing 100101 China Graduated School of chinese academy of{2. Beijing 100039 China

Types and structure of plant communities in the Yellow River Delta were investigated by using detrended canonical correspon-dence analyses(DCCAs) and a two-way indicator species analysis(TWINSPAN).The distribution pattern and influential factors of the plant communities were also analyzed by testing elevation, slope, soil characteristics, longitude and latitude of 134 vegetation samples collected by representative plot sampling *** showed that all the 134 vegetation samples could be divided into seven vegetation groups, separately dominated by Robinia pseucdoacacia, Imperata cylindrical, Miscanthus saccharifleus, Suaeda salsa, Aeluropus sinensis, Phragmites australis and Tamarix *** vegetation distribution pattern was mainly related to elevation, ground water depth and soil characteristics such as salinity and soluble *** the factors affecting distribution pattern of the plant communities, the species matrix explained by non-spatial environmental variation accounts for 45.2. of total *** variation and spatial-structured environmental variation explain 11.8%, and 2.2., *** 40.8% of undetermined variation is attributed to biological and stochastic factors.

关键词： detrended canonical correspondence analyses environmental factors plant communities spatial factors Yellow River Delta two-way indicator species analysis

Improvement of a 3D radar backscattering model using matrix-doubling method

在线全文

学校读者我要写书评

暂无评论

Science China Earth sciences 2010年第7期53卷 1029-1035页

作者： NI WenJian1,2. GUO ZhiFeng1 & SUN GuoQing3 1 State Key Laboratory of Remote Sensing Science, jointly sponsored by the institute of Remote Sensing Applications of chinese{2. of sciences and beijing Normal University, beijing 100101, China 2.Graduate University of chinese{2. of sciences, beijing 100049, China 3 Department of Geography, University of Maryland, College Park, MD 2.042. USA 1. State Key Laboratory of Remote Sensing Science jointly sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Department of Geography University of Maryland College Park MD 27042 USA

Radiative transfer models have been widely used to simulate the radar backscattering from forested areas. A three-dimensional radar backscatter model of forest canopy developed in previous studies takes full account of spatial position of trees in a forest stand, and the interactions among crown, trunk and ground surface. The model predicted well for the co-polarized backscatter measurements, but underestimated the backscattering for cross-polarization, primarily because only the first-order scattering within tree crowns was considered in the model. The backscattering at cross-polarization depends strongly on multiple scatter- ing within tree crowns. To produce good estimations for cross-polarized component, the matrix-doubling method is employed here to compute multiple-scattering within the crown. The modified model is compared with the original model, and the field forest measurements and AIRSAR data are used for validation of the modified model. The cross-polarization backscattering is improved in different degrees for different crown structures and at different bands.

关键词： remote sensing forestry electromagnetic propagation radar backscattering model matrix-doubling

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

在线全文

学校读者我要写书评

暂无评论

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 Planning,State forestry Administration,{2. 100714,China 2.institute of Zoology,the chinese academy of sciences,{2. 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

BASIC CONNOTATION OF MODERN forestry AND DEVELOPING TREND IN CHINA

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

chinese forestry Science and Technology 2009年第3期8卷 10-18页

作者： WANG Dengju Research institute of forestry Policy and Information,{2. academy of forestry, beijing 100091, P. R. China

The basic connotation of current modern forestry in China was deeply analyzed, and the main characteristics of modern forestry were pointed out. The goals and tasks of{2. modern forestry development in the curren... 详细信息

关键词： modern forestry connotation characteristics goal task