检索结果-南通市图书馆

Progress in natural Science:Materials International 2004年第8期 90-96页

作者： ZHENG Jingyun*, HAO Zhixin and ge quansheng(institute of geographic sciences and natural resources research, chinese academy of sciences, beijing 100101, china) institute of geographic sciences and natural resources research Chinese Academy of Sciences Beijing 100101 China

Two methods to reconstruct seasonal precipitation are developed in terms of the soil surface water balance and field infiltration experiment by artificial rainfall. Seasonal and annual precipitation for the period of 1736～1910 are reconstructed from snow and rainfall archives in the Qing Dynasty through both methods. The seasonal precipitation series from 1736 to 2000 is also established. The results show that the time series of seasonal precipitation obtained from both methods are statistically significant and consistent, implying that the seasonal precipitation can be reconstructed accurately from snow and rainfall archives in the Qing Dynasty by the above two methods, and thus the chinese precipitation data in a large area would be extended to the early 18th century from 20th century (instrumental observation period).

关键词： seasonal precipitation reconstruction snow and rainfall archives physical model field experiment reliability.

Quantifying soil erosion with GIS-based RUSLE under different forest management options in Jianchang Forest Farm

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国科学：技术科学英文版 2006年第z1期49卷 160-166页

作者： ZHANG Hengming, WANG Qingli, dai Limin, Guofan Shao, TANG Una, WANG Shunzhong & GU Huiyan 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, Lafayette IN47901, USA Northeast Forestry University, Harbin 150040, china institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China Graduate University of chinese academy of sciences Beijing 100101 China Department of Forestry natural resources Purdue University Lafayette IN 47901 USA Northeast Forestry University Harbin 150040 China

Quantitatively estimating soil erosion with an integration of geographic information system (GIS) and the revised universal soil loss equation (RUSLE) under four different exposed soil proportion scenarios caused by forest management practices was studied at Jianchang Forest Farm. The GIS provided means of input data generation required by RUSLE model and allowed a spatial assessment of the erosion hazard over the study area. Four exposed soil proportion scenarios of 5%, 10%, 20% and 30% were tested with the GIS-based RUSLE model to evaluate soil erosion hazard. The predicted soil erosion potentials were classified into five categories in order to provide valuable aids for management planning.

关键词： geographic information system, RUSLE, soil erosion, forest management.

Excitonic Instability in Ta2Pd3Te5 Monolayer

在线全文

学校读者我要写书评

暂无评论

chinese Physics Letters 2024年第9期41卷 57-62页

作者： Jingyu Yao Haohao Sheng Ruihan Zhang Rongtian Pang Jin-Jian Zhou quansheng Wu Hongming Weng Xi dai Zhong Fang Zhijun Wang beijing National Laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing 100190China University of chinese academy of sciences Beijing 100049China Centre for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE)School of PhysicsBeijing Institute of TechnologyBeijing 100081China Department of Physics Hong Kong University of Science and TechnologyHong Kong 999077China

By systematic theoretical calculations,we reveal an excitonic insulator(EI)in the Ta_(2)Pd_(3)Te_(5)*** bulk Ta_(2)Pd_(3)Te_(5)is a van der Waals(vdW)layered compound,whereas the vdW layer can be obtained through exfoliation or molecular-beam ***-principles calculations show that the monolayer is a nearly zero-gap semiconductor with the modified Becke–Johnson *** to the same symmetry of the band-edge states,the two-dimensional polarization 2D would be finite as the band gap goes to zero,allowing for an EI state in the *** the first-principles many-body perturbation theory,the GW plus Bethe–Salpeter equation calculation reveals that the exciton binding energy is larger than the single-particle band gap,indicating the excitonic *** computed phonon spectrum suggests that the monolayer is dynamically stable without lattice *** findings suggest that the Ta_(2)Pd_(3)Te_(5) monolayer is an excitonic insulator without structural distortion.

关键词： monolayer principles calculations

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

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 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.

On the major proposals for carbon emission reduction and some related issues

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2010年第12期53卷 159-172页

作者： DING ZhongLi1,DUAN XiaoNan2,ge quansheng3 & ZHANG ZhiQiang4 1 CAS Key Lab of Cenozoic geology and Environment,institute of geology and geophysics,chinese academy of sciences,beijing 100029,china 2 The general Office of chinese academy of sciences,beijing 100864,china 3 institute of geographic sciences and natural resources research,chinese academy of sciences,beijing 100101,china 4 The Lanzhou Branch of the National Science Library,Scientific Information Center for resources and Environment of CAS,Lanzhou 730000,china 1. CAS Key Lab of Cenozoic geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China2. The General Office of Chinese Academy of Sciences Beijing 100864 China3. Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China4. The Lanzhou Branch of the National Science Library Scientific Information Center for Resources and Environment of CAS Lanzhou 730000 China

We evaluated and ran simulations for seven proposals for the reduction of global CO2 emissions (e.g.,those of the Intergovernmental Panel on Climate Change (IPCC),United Nations Development Program,and Organization for Economic Cooperation and Development).All the proposals ignored the fact that the cumulative CO2 emissions per capita for developed countries were 7.54 times those for developing countries in the historical period of *** proposals further deliberately allocate 2006-2050 emission quotas to developed countries that are 2.3-6.7 times those to developing *** will seriously violate the development rights of developing *** paper clearly states that proposals such as that of the IPCC are not suitable references for future international climate change negotiations as they violate the fundamentals of fairness and equity in international relationships and the UNFCCC principle of "common but differentiated responsibilities".Comparing estimates of emissions in china in the scenario of rapid development with low-CO2-emission technology in the period 2006-2050 with estimates for other countries and groups,we find that china can logically and morally argue for equivalent emission rights even in the case of the strict CO2 concentration target of 450-470 ppmv.

关键词： CO2 emission reduction cumulative CO2 emission per capita emission rights

同方期刊数据库

Farming and forestry land use changes in china and their driving forces from 1900 to 1980

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2005年第10期48卷 1747-1757页

作者： ge quansheng dai junhu institute of geographic sciences and natural resources research Chinese Academy of Sciences Beijing 100101 China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

A variety of agricultural and forestry land use materials, especially those in the first half of 20th century, were collected. According to land use change in this period, the whole country is demarcated into seven regions, Northeast china, North china, Northwest and Loess Plateau, Southeast and Coastal Region, Southwest china, Qinghai-Tibetan Plateau, Inner Mongolia and Xinjiang, in proper order by using Cluster Analysis. The farming and forestry land use change in these regions were analyzed. The results show that the total cultivated land areas increased in this period, especially in the 1950s and 1960s the cultivated land area increased more significantly, but differed in different regions, and the most rapid increasing rate was 2.63 percent a year. On the other hand, the forestry land area was increasing in most parts of this period, especially after 1949. But in most regions, the decrease of forestry land area at the end of 1970s is also very obvious. It is regarded that the population increase, food production, natural disasters and some related government policies were among the main driving factors for farming and forestry land use change.

关键词： land use change, cultivated land, forestry land, driving factors, 20th century.

Mapping forest fire risk zones with spatial data and principal component analysis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science china(Technological sciences) 2006年第z1期49卷 140-149页

作者： XU Dong, Guofan Shao, dai Limin, HAO Zhanqing, TANG Lei & WANG Hui institute of Applied Ecology, chinese academy of sciences, Shenyang 110016, china Graduate University of chinese academy of sciences, beijing 100039, china Department of Forestry and natural resources, Purdue University, West Lafayette, IN 47907, USA Department of Management, Shenyang institute of Aeronautical Engineering, Shenyang 110034, china Department of City Development, Jinan University, Jinan 250002, china 1. institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China2. Graduate University of Chinese Academy of Sciences Beijing 100039 China3. Department of Forestry and Natural Resources Purdue University West Lafayette IN 47907 USA4. Department of Management Shenyang Institute of Aeronautical Engineering Shenyang 110034 China5. Department of City Development Jinan University Jinan 250002 China

By integrating forest inventory data with remotely sensed data, new data layers for factors that affect forest fire potentials were generated for Baihe Forestry Bureau in Jilin Province of china. The principle component analysis was used to sort out the relationships between forest fire potentials and environmental factors. The classifications of these factors were performed with GIS, generating three maps: a fuel-based fire risk map, a topography-based fire risk map, and an anthropogenic-factor fire risk map. These three maps were then synthesized to generate the final fire risk map. The linear regression method was used to analyze the relationship between an area-weighted value of forest fire risks and the frequency of historical forest fires at each forest farm. The results showed that the most important factor contributing to forest fire ignition was topography, followed by anthropogenic factors.

关键词： wildfire risk, regression analysis, geographic information system, remote sensing, Baihe Forestry Bureau.

The spatiotemporal characteristics of spring phenophase changes of Fraxinus chinensis in china from 1952 to 2007

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2012年第6期55卷 991-1000页

作者： WANG HuanJiong dai junhu ge quansheng institute of geographic sciences and natural resources research Chinese Academy of Sciences Beijing 100101 China Graduate School of chinese academy of sciences Beijing 100049 China

We selected widely distributed and well observed plant species Fraxinus chinensis to study the formation mechanism of geographical distribution of the plant phenophase changes and revealed their spatiotemporal dynamics in china. Based on the first leaf date （FLD） data at 12 sites derived from chinese Phenological Observation Network （CPON） and related meteoro- logical data, we developed and validated the process-based model of FLD for Fraxinus chinensis. After reconstructing data series of FLD for Fraxinus chinensis over the study area from 1952 to 2007, we analyzed different spatiotemporal patterns of phenophase changes of this species. The results suggested that the process-based model was able to simulate the FLD accu- rately for Fraxinus chinensis on large spatial and temporal scales, because of the consideration of different budding rate re- sponded to the air temperatures during the dormancy and the quiescence in accordance with the physiological mechanism of plants. The geographical distribution of the spring phenology in temperate regions was determined by the spatial pattern of daily average air temperature. The changes of FLD for Fraxinus chinensis revealed significant phenological advances in most areas. However, it showed delayed trends in a few sites. The overall average change trend was -1 .l days/decade. This result was consistent with the advanced trend in other regions of the North Hemisphere. The changes of FLD showed a noticeable regional variation with clearer advance in the north than in the south. The FLD in northern china showed an average ad- vance as high as -2.0 days/decade （P〈0.01）. And the advance in northeastern and northwestern china was respectively -1.5 and -1.4 days/decade （P〈0.01）. Furthermore, eastern and central regions showed a minor trend, which was -1.0 days/decade （P〈0.05）. The smallest and non-significant advance appeared in southwestern and southern china.

关键词： phenophases phenological model first leaf Fraxinus chinensis

Environmental ethics and regional sustainable development

在线全文

学校读者我要写书评

暂无评论

Journal of geographical sciences 2012年第1期22卷 86-92页

作者：郑度戴尔阜 institute of geographic sciences and natural resources research CAS

The scientific environmental ethics plays a key role in the recognition of the human-environment interactions. Modern environmental ethics is the philosophical re-thinking of modern human race environmental behavior. The development of environmental ethics theory, as well as its application in reality, determines the viewpoints of environmental ethics. Sustainable development implies harmony on human-environment interactions and inter-generation responsibility, with emphasis on a harmonious relationship among population, resources, environment and development, so as to lay a sustainable and healthy foundation of resources and environment for future generations. The harmonious society construction in china that is raised by the chinese central government should be covered by environmental ethics. The connotation of open environmental ethics includes a respect for nature, care for the individual human race, and respect for the development of future generations, which means giving consideration to natural values, individual and human race benefits and welfare across generations. The role of environmental ethics in regional development consists of cognition, criticism, education, inspiration, adjusting, legislation and promoting environmental regulations. The major problems in regional development are extensive resource exploration, fast population growth, irrational industrial structure, unfair welfare distribution and the twofold effects of science and technology development. The formulation of environmental ethics that aims at regional sustainable development, can not only harmonize the relationship of population, resource, environment and economic development, but also guide behavior selection, push social and political system transformation, strengthen the legal system, and raise environmental awareness of the public.

关键词： environmental ethics value of nature responsibility of human race sustainable development

Spatiotemporal differentiation of changes in wheat phenology in china under climate change from 1981 to 2010

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2018年第8期61卷 1088-1097页

作者： Yujie LIU Qiaomin CHEN quansheng ge junhu dai Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences' and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China University of chinese academy of sciences Beijing 100049 China

Phenology is a reliable biological indicator for reflecting climate change. An examination of changes in crop phenology and the mechanisms driving them is critical for guiding regional agricultural activities in attempts to adapt to climate change. Due to a lack of records based on continuous long-term observation, studies on changes in multiple consecutive phenological stages throughout a whole growing season on a national scale are rarely found, especially with regard to the spatiotemporal differentiation of phenological changes. Using a long-term dataset(1981-2010) of wheat phenology collected from 48 agro-meteorological stations in china, we qualified the spatiotemporal changes of 10 phenological stages as well as the length of wheat growth phases. Results showed that climate and wheat phenology changed significantly during the growing seasons from 1981 to 2010. On average, on a national scale, dates of sowing(0.19 d a-1), emergence(0.06 d a-1), trefoil(0.05 d a-1), and milk ripe(0.06 d a-1) showed a delaying trend, whereas dates of tillering(-0.02 d a-1), jointing(-0.15 d a-1),booting(-0.21 d a-1), heading(-0.17 d a-1), anthesis(-0.19 d a-1), and maturity(-0.10 d a-1) showed an advancing ***, the vegetative growth phase and growing season were shortened by 0.23 and 0.29 d a-1, respectively, whereas the reproductive growth phase was lengthened by 0.06 d a-1. Trends in dates of phenological stages or length of growing phases varied across wheat-planting regions. Moreover, spatiotemporal differentiation of sensitivity in growing season length(GSL) to variations in climatic factors during the growing season between spring and winter wheat were remarkable. The GSL of spring(winter) wheat decreased(increased) with an increase in average temperature during the growing season. In all wheat-planting regions, the GSL increased with the increasing of total precipitation and sunshine duration during the growing season. In particular, the sensitivity of GSL to

关键词： Wheat phenology Spatiotemporal differentiation Climate change china