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基于地价质量协调度的城市理性地价研究——以全国35个重点监测城市住宅地价为例 被引量:1
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作者 梁彦庆 郝海青 +2 位作者 梁丽英 史思琪 葛京凤 《西南大学学报(自然科学版)》 CAS CSCD 北大核心 2018年第8期138-146,共9页
研究城市理性地价是城市土地资产核算和价值评估的客观需要,可为政府根据价格信号做出科学决策提供依据.以全国35个重点监测城市2008-2013年住宅地价为研究对象,采用多因素综合评价法测得城市地价质量,运用序列化比较检测城市地价间的... 研究城市理性地价是城市土地资产核算和价值评估的客观需要,可为政府根据价格信号做出科学决策提供依据.以全国35个重点监测城市2008-2013年住宅地价为研究对象,采用多因素综合评价法测得城市地价质量,运用序列化比较检测城市地价间的协调程度,并通过构建回归模型对城市理性地价进行判断.结果表明:(1)研究期间住宅地价总体呈平稳上升趋势,仅哈尔滨、南京等9市略有下降;(2)住宅地价处于基本合理范围内的城市约占60%,其余城市地价实际值与理论值差距较大;(3)以经济发展水平和地价水平进行衡量,东部沿海城市条件优越,形成双高型城市;中、西部地区相对较差,形成双低型城市;(4)地价较为合理的城市其地价与地价质量协调性也较好,二者匹配度较高. 展开更多
关键词 城市地价 地价质量 协调度 合理地价 理性地价
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基于县域尺度的河北省城市地价质量测度及空间差异研究 被引量:1
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作者 李博翀 李灿 +3 位作者 葛京凤 梁爽 徐晨曦 刘国君 《干旱区资源与环境》 CSSCI CSCD 北大核心 2019年第8期55-63,共9页
以河北省县域尺度城市为研究对象,基于系统论和地租地价理论,借鉴有关城镇化质量、土地质量、生态质量等系统质量的研究成果,引入"城市地价质量"概念,围绕地价影响因素构建城市地价质量指标体系,运用均方差决策法、协调度评... 以河北省县域尺度城市为研究对象,基于系统论和地租地价理论,借鉴有关城镇化质量、土地质量、生态质量等系统质量的研究成果,引入"城市地价质量"概念,围绕地价影响因素构建城市地价质量指标体系,运用均方差决策法、协调度评价模型等度量方法,从发展程度、主导类型和协调水平的角度对河北省县域尺度城市地价质量进行测度和空间差异分析。研究发现:1)河北省县域尺度城市地价质量发展程度存在地域差异,沿渤海湾环天津区域的城市地价质量发展程度高于冀中南平原区域,冀中南平原区域高于太行-燕山山地区域;2)在河北省县域尺度城市地价质量发展进程中,政府对土地市场的规划和调控供需占据主导地位,经济水平和基础设施有待提升和完善;3)河北省县域尺度下各城市在地价质量协调度和地价质量发展程度的排序中总体呈正向顺序关系,但也存在少数不符合规律的城市。 展开更多
关键词 城市地价质量 协调度 空间差异 河北省县域尺度
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Soil Environmental Quality Evaluation for Wasteland of Coalmine Tailing Polluted by Heavy Metals in Mingshan of Guangdong 被引量:1
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作者 刘德良 杨期和 《Agricultural Science & Technology》 CAS 2014年第10期1759-1763,共5页
ln order to appraise scientifical y the heavy metal contamination in waste-land of coalmine tailing in Mingshan of Guangdong, the 5 soil samples in wasteland of coalmine tailing were col ected in November 2010 to Marc... ln order to appraise scientifical y the heavy metal contamination in waste-land of coalmine tailing in Mingshan of Guangdong, the 5 soil samples in wasteland of coalmine tailing were col ected in November 2010 to March 2011. The 7 heavy metals content in the contaminated soil was measured by atomic absorption spec-trophotometry. The results showed the pH of the wasteland soil ranged from 2.87 to 6.16, and the soil was relatively infertile. The soil was mainly pol uted by Cd and Mn. The Cd content in wasteland soil ranged from 0.759 mg/kg to 3.109 mg/kg with an average content of 2.052 mg/kg, which was much higher than the standard content. The Mn content ranged from 387.057 to 488.660 mg/kg with an average content of 421.215 mg/kg, which was much higher than the standard content. The Nemerow integrated pol ution indexes showed the sample 1, sample 4 and sample 5 were of heavy pol ution, and sample 2 and sample 3 were of moderate pol ution. 展开更多
关键词 Heavy metal pol ution Wasteland of coalmine tailing Environmental quality evaluation Coalmine in Mingshan of Guangdong
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Annual Monitoring and Evaluation of the Grades of Arable Land Quality——Taking Lingchuan County as an Example 被引量:2
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作者 全坚 谭咪 《Agricultural Science & Technology》 CAS 2017年第6期1112-1119,共8页
With the increasing requirement for the protection of arable land, monitor- ing the grades of arable land quality is becoming more important, which can accu- rately and fully reflect the current situation and developm... With the increasing requirement for the protection of arable land, monitor- ing the grades of arable land quality is becoming more important, which can accu- rately and fully reflect the current situation and development trends of arable land quality. It is also an important measure for protecting the quality of arable land. in the present study, the distribution and changes of arable lands of different gradient types and grades in Lingchuan County, Guangxi Zhuang Autonomous Region in 2015 were monitored and evaluated, to analyze the trends and reasons for the changes in the quality and productivity of arable lands, and to provide references for dynamic monitoring of the quality of arable land. 展开更多
关键词 Arable land grades MONITORING Evaluation Lingchuan County
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GEOTHERMAL RESOURCES ASSESSMENT AND NUMERICAL SIMULATION IN TUANBO REGION
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作者 朱家玲 李春华 高天真 《Transactions of Tianjin University》 EI CAS 2001年第4期251-254,共4页
This paper mainly deals with the reservoir on the heat and mass transfer and mass and energy balance in a geothermal field.On the basis of briefing the general characteristics of the reservoir and the supposition of t... This paper mainly deals with the reservoir on the heat and mass transfer and mass and energy balance in a geothermal field.On the basis of briefing the general characteristics of the reservoir and the supposition of the reservoir modeling,the paper emphasizes the mathematical descriptions of hydra thermal transportation and convection by two methods according to the different models,such as lumped parameter model and distributed parameter model.It is effective to use these models in simulating the heterogeneous,and anisotropical fracture reservoir for the designed lifetime of 15 years. 展开更多
关键词 assessment of geothermal resources mass and energy balance lumped parameter model distributed parameter model
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Cultivated Land Quality Analysis of Karst Mountain Areas Based on GIS: A Case Study of Jingxi County 被引量:1
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作者 尹秋月 段正松 +1 位作者 李羡 陈兰康 《Agricultural Science & Technology》 CAS 2014年第8期1407-1409,1413,共4页
Agricultural land quality assessment of karst mountain areas is an impor-tant means to protect and manage cultivated land quality of karst mountain areas. With Jingxi County as a case, the data resources included achi... Agricultural land quality assessment of karst mountain areas is an impor-tant means to protect and manage cultivated land quality of karst mountain areas. With Jingxi County as a case, the data resources included achievements of cultivat-ed land grade, achievements of second land investigation, investigation of local con-ditions and the other data resources. With the overlay tool of MapGIS, attribute data of evaluation index were obtained, which can reflect agricultural land' characteris-tics, and agricultural land quality scores were calculated and land quality was grad-ed using the model of comprehensive evaluation of multiple factors to make further analysis on characteristics and spatial distribution. The results showed that used agricultural land is dominated by middle and high-grade lands in Jingxi County mainly, representing 68.58% of Jingxi County’s agricultural lands. On the other hand, the quality of paddy land is general y higher than that of dry land, and quality of agricultural land showed higher in middle and eastern Jingxi, and lower in north-western region, which provides references for national land management. 展开更多
关键词 GIS GIS Karst mountain areas Agricultural land Quality assessment Anal-ysis of characteristics
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The Gravitational Force Quantum and its Value 被引量:2
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作者 Tomas Kala 《Journal of Physical Science and Application》 2015年第4期288-290,共3页
Gravitation is one of the basic phenomena of the world. Tremendous number of theoretical works on origin, nature, essentials, consequences, etc. of the gravitation and related phenomena were published so far. The most... Gravitation is one of the basic phenomena of the world. Tremendous number of theoretical works on origin, nature, essentials, consequences, etc. of the gravitation and related phenomena were published so far. The most prominent ones are based on the Albert Einstein's general theory of relativity. The author of this communication based his approach to the gravitation on Isaac Newton's law of the universal gravitation and related quantities, i.e. gravitational forces of matter objects, distance and motion. Namely on the fact, that the gravitation force is - as well as the inertia, mass, space "occupied" and other properties are - principal features/attributes/properties of matter objects. Gravitation is an additive property of matter objects. Taking into account other positivistic quantities like mass of the Earth, standard acceleration of gravity, and the value of the atomic unit of mass, the author defined a gravitational force of atomic unit (or "the Gravitational Force Quantum") as a gravitational force which exerts one atomic unit of Earth's mass on 1 kilogram of a mass on Earth's surface, and he calculated its value: GFO = 1.4958 × 10^-54 N. This quantity can be useful for further development of the "quantum mechanical" approach to the description and general notion about the world. 展开更多
关键词 GRAVITATION gravitational force of atomic unit gravitational force quantum.
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Grey associated analysis of the underground water quality effected by the leaching water of dumping area or hillock of coal mine 被引量:4
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作者 卢国斌 张浪 刘志斌 《Journal of Coal Science & Engineering(China)》 2003年第2期70-73,共4页
The underground water has been contaminated seriously by the leaching water of dumping area or hillock. To determine the pollution limits of underground water, author took samples in the study area, analyzed samples f... The underground water has been contaminated seriously by the leaching water of dumping area or hillock. To determine the pollution limits of underground water, author took samples in the study area, analyzed samples for water quality, assessed the water quality of each monitoring point by the grey associated analysis method, and gave out the classifications of the underground water quality of the study area. Comparing with fuzzy comprehensive appraisal method, it is demonstrated that grey associated analysis method is applied easily, because of its clear concept, simple and convenient calculation and excellently operation. 展开更多
关键词 grey associated analysis underground water monitoring point environmental quality
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Evaluation and Trend Analysis of Surface Water Quality in Zhengzhou in 1998-2008 被引量:1
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作者 Du Xile Lu Changhe 《Chinese Journal of Population,Resources and Environment》 2012年第4期44-51,共8页
Water pollution is one of the major environmental prob- lems, especially in urban areas. Due to rapid urban expansion and industrialization, water pollution in Zhengzhou City, the capital of Henan Province in central ... Water pollution is one of the major environmental prob- lems, especially in urban areas. Due to rapid urban expansion and industrialization, water pollution in Zhengzhou City, the capital of Henan Province in central China has become a serious problem for its development. In this study, the surface water quality was evalu- ated using Nemerow Comprehensive Pollution Index (NCPI), and the change trend was calculated using methods of Mann-Kendall test and Sen's slope estimator, based on the monitoring data from 1998 to 2008. The results show that the NCP1 ranged from 3 to 50 in 70% of the monitoring cases, implying that most rivers were seriously polluted. However, this serious polltuon is expected to be gradually improved, as the concentration of water pollutants and NCPI declined significantly in most rivers. Water pollution in reservoirs was much lower than rivers, and the NCPI in the three monitored reservoirs was lower than 3 in most years, and shows a downward trend. Although the surface water quality was gradually improved, great efforts are still needed to enhance the protection and improvement of surface water environment. 展开更多
关键词 surface water water pollution TRENDS NCPI Mann- Kendall test Sen's method
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Assessment of Soil Quality Using Microarthropod Communities Under Different Land System: A Case Study in the Mid-Hills of Central Nepal
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作者 Farida Begum Roshan Man Bajracharya +1 位作者 Subodh Sharma Bishal K. Sitaula 《Journal of Life Sciences》 2011年第1期66-73,共8页
The study aimed to evaluate soil quality using microarthopods density, diversity and soil biological quality index (QBS-ar) under different land use systems and elevation gradients. A secondary aim was to determine ... The study aimed to evaluate soil quality using microarthopods density, diversity and soil biological quality index (QBS-ar) under different land use systems and elevation gradients. A secondary aim was to determine the relationship among soil biological and physiochemical indicators. Three groups of soil microarthropods were recognized viz. (1) Collembola (38%) (2) Acarina (33%) and (3) other microarthropods (29%). ANOVA indicated that total microarthropods densities differed significantly with land use and elevation. Population density of Acarina and other mieroarthropods were weakly significant different according to land use, while Collembola and Acarina densities showed highly significant difference with elevation. Total microarthropods, Acarina and Collembola densities were positively significantly correlated with soil organic carbon (SOC) and moisture but negatively correlated with bulk density, pH and temperature of the soil. SOC and soil moisture appeared to be good indicators of soil quality as reflected by the higher density and diversity of soil total microarthropods, Collembola, Acarina and other microarthropods group. The use of microarthropods for soil quality assessment could be effective and relatively inexpensive tool; however, further research is required to evaluate the impact of agricultural practices and elevation gradient on soil microarthropods density, diversity and species composition for the sustainable management of agro ecosystems. 展开更多
关键词 Assessment of soil quality ACARINA COLLEMBOLA soil organic carbon moisture monsoon.
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New methods of safety evaluation for rock/soil mass surrounding tunnel under earthquake 被引量:1
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作者 程选生 DOWDING Charles H 田瑞瑞 《Journal of Central South University》 SCIE EI CAS 2014年第7期2935-2943,共9页
The objective of this work is to obtain the seismic safety coefficient and fracture surface and proceed with the seismic safety evaluation for the rock mass or soil mass surrounding a tunnel,and the limitation of eval... The objective of this work is to obtain the seismic safety coefficient and fracture surface and proceed with the seismic safety evaluation for the rock mass or soil mass surrounding a tunnel,and the limitation of evaluating seismic stability is considered using the pseudo-static strength reduction.By using the finite element software ANSYS and the strength reduction method,new methods of seismic safety evaluation for the rock mass or soil mass surrounding a tunnel are put forward,such as the dynamic finite element static shear strength reduction method and dynamic finite element shear strength reduction method.In order to prove the feasibility of the proposed methods,the results of numerical examples are compared with that of the pseudo-static strength reduction method.The results show that 1) the two methods are both feasible,and the plastic zone first appears near the bottom corners; 2) the safety factor of new method Ⅱ is smaller than that of new method I but generally,and the difference is very small.Therefore,in order to ensure the safety of the structure,two new methods are proposed to evaluate the seismic stability of the rock mass or soil mass surrounding a tunnel.A theoretical basis is provided for the seismic stability of the rock mass or soil mass and the lining surrounding a tunnel and also provided for the engineering application. 展开更多
关键词 TUNNEL rock or soil mass surrounding tunnel earthquake stability safety evaluation
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Groundwater Quality Assessment for an Indian Urban Habitat: A GIS Approach
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作者 A. Saleem M.N. Dandigi +1 位作者 K. Vijaykumar P. Balakrishnan 《Journal of Environmental Science and Engineering》 2011年第12期1561-1569,共9页
Groundwater is an essential source of drinking water for many Indian urban habitats. Large numbers of people consume ground water instead of municipal tap water due to contamination of tap water. Groundwater is extrac... Groundwater is an essential source of drinking water for many Indian urban habitats. Large numbers of people consume ground water instead of municipal tap water due to contamination of tap water. Groundwater is extracted from thousands of bore wells, and used for potable purpose without proper testing and treatment. This paper describes a groundwater quality monitoring strategy and database model developed for Gulbarga city, located in Karnataka, India. Sampling wells are selected one each in 55 wards of the city corporation having easy access for regular sampling. Various attributes of sampling wells including their spatial coordinates, location address and a photograph are registered for ready recognition on site. Water samples are collected and analyzed for various physico-chemical parameters. Spatial coordinates and levels of sampling points are measured on site using a hand held GPS instrument. Gulbarga city map is digitized. A GIS database of the measured spatial and water quality data is developed using ArcGIS Desktop 9.3, and ground water quality maps are prepared which may serve as useful tools for developing policy, and regulatory mechanism for sustainable groundwater use. 展开更多
关键词 GROUNDWATER water quality GIS applications urban water supply drinking water.
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Rangeland degradation assessment in Kyrgyzstan:vegetation and soils as indicators of grazing pressure in Naryn Oblast
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作者 HOPPE Franziska ZHUSUI KYZY Taalaigul +1 位作者 USUPBAEV Adilet SCHICKHOFF Udo 《Journal of Mountain Science》 SCIE CSCD 2016年第9期1567-1583,共17页
Rangelands occupy more than 80% of the agricultural land in Kyrgyzstan. At least 30% of Kyrgyz pasture areas are considered to be subject to vegetation and soil degradation. Since animal husbandry is the economic basi... Rangelands occupy more than 80% of the agricultural land in Kyrgyzstan. At least 30% of Kyrgyz pasture areas are considered to be subject to vegetation and soil degradation. Since animal husbandry is the economic basis to sustain people's livelihoods, rangeland degradation presents a threat for the majority of the population. We present for the first time an ecological assessment of different pasture types in a remote area of the Naryn Oblast, using vegetation and softs as indicators of rangeland conditions. We analysed the current degree of utilization (grazing pressure), the amount of biomass, soil samples, and vegetation data, using cluster analysis as well as ordination techniques. Winter pastures (kyshtoo) are characterized by higher pH values (average of 7.27) and lower organic matter contents (average of 12.83%) compared to summer pastures (dzailoo) with average pH values of 6.03 and average organic matter contents of 21.05%. Additionally, summer pastures show higher above- ground biomass, and higher species richness and diversity. Our results support the hypothesis that winter pastures, which are located near settlements, suffer from over-utilisation, while the more distant summer pastures are subjected to much lower grazing pressure, 展开更多
关键词 Alpine meadows Alpine steppes Animalhusbandry Classification Grazing management Montane pastures ORDINATION Plant communities
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Mass Valuation and the Implementation Necessity of GIS (Geographic Information System) in Albania 被引量:1
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作者 Elfrida Shehu Elda Maci Vorpsi Alma Afezolli 《Journal of Civil Engineering and Architecture》 2015年第12期1506-1512,共7页
In the last decade, mass valuation system is applied in Albania in addition to individual valuation system for real estate valuation. This system is used for compiling the land value map and apartments value map. Due ... In the last decade, mass valuation system is applied in Albania in addition to individual valuation system for real estate valuation. This system is used for compiling the land value map and apartments value map. Due to the lack of experience in the compilation of these maps, the methodology of valuation is based on the experiences of other countries with similar development of real estate market. The mass assessment, which is applied in determining the values for specific purposes, such as expropriation, compensation and taxes for property transfer through the methodology adopted for this aim, is analyzed in the light of the finding of issues that accompany this application. The aim of this research is to highlight the problems to provide the ways of overcoming them in order to approximate the values of map values with market values. The mass appraisal process requires effective valuation models and proper management of resources. Its accuracy depends upon the extent and quality of property data available. Because of this reason, it is recommended the usage of the GIS (geographic information system), an automated system for collection and processing of the data necessary for valuation, as the first point of integration between two process of valuation, individual and mass valuation. 展开更多
关键词 Real estate mass valuation GIS map value.
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Potential of GIS Evaluation for Mass Wasting Processes in Mountain Ranges of South West Coast of India
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《Journal of Earth Science and Engineering》 2013年第6期416-423,共8页
The aim of the study is to monitor and assess landslide hazards by remote sensing data processing and GIS (Geographic Information Service) spatial analysis. Idukki district, the western Ghats of India was chosen as ... The aim of the study is to monitor and assess landslide hazards by remote sensing data processing and GIS (Geographic Information Service) spatial analysis. Idukki district, the western Ghats of India was chosen as test area, because of frequent destructive mass wasting processes. Western Ghats is a prominent orographic feature that runs parallel to the south west coast of India. Predicting landslide hazard on a regional scale, namely the assessment of actual and potential mass movement over large area is carried out using Remote Sensing and GIS. A numerical weightage to the causative factors of slope instability such as slope, relative relief, aspect, curvature, drainage density, drainage frequency, land use, road buffer and drainage buffer are assigned as per earlier workers for the purpose of landslide susceptibility zonation. A high degree of match is found between observed and predicted landslide hazard by the procedure employed in the study. 展开更多
关键词 Western Ghats mass wasting ARCGIS landslide susceptibility zonation.
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构建与农地流转市场相适应的农地价格体系 被引量:11
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作者 路燕 朱道林 《价格理论与实践》 北大核心 2006年第2期52-53,共2页
农用地流转方式决定了交易中存在的农地价格形式,农地价格是流转过程中产权经济关系的反映。为了控制和引导农地流转市场价格,在政府层面应建立包括农地质量基准地价、征地区片综合地价和标定地价在内的农地价格体系,实现国家对农地市... 农用地流转方式决定了交易中存在的农地价格形式,农地价格是流转过程中产权经济关系的反映。为了控制和引导农地流转市场价格,在政府层面应建立包括农地质量基准地价、征地区片综合地价和标定地价在内的农地价格体系,实现国家对农地市场的宏观管理。 展开更多
关键词 地价格体系 质量基准地价 征地区片综合地价 农地流转
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Use a Spatial Analysis Model to Assess Habitat Quality in Lashihai Watershed 被引量:6
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作者 LI Haiping QI Yanan QU Yunying 《Journal of Resources and Ecology》 CSCD 2018年第6期622-631,共10页
Habitat quality assessments are of great significance for protecting biodiversity.This study analyzes the changing habitat quality of Lashihai watershed based on SPOT satellite images.We extracted the land use data fo... Habitat quality assessments are of great significance for protecting biodiversity.This study analyzes the changing habitat quality of Lashihai watershed based on SPOT satellite images.We extracted the land use data for Lashihai watershed in Yunnan province for the years 2000 and 2015,and then used an INVEST model to evaluate habitat degradation,habitat quality and habitat scarcity in the study area from 2000 to 2015.Spatial statistical methods were used to determine changes to spatial dynamics.Results indicate that the number of areas with habitat degradation was generally small,and that both the number of areas with habitat degradation and the degree of degradation had fallen noticeably during the fifteen-year study period.In general,the quality of habitats was main- tained or improved,while the quality of habitats decreased in only a few areas.The scarcity of habitats for cultivated land had increased,the tension between people and land use was relatively prominent.The reason habitat quality in Lashihai watershed has improved can be attributed to three factors:1)The policy of returning farmland to forests since 2000 has been well implemented and has achieved remarkable results.Loss of forests from logging and deforestation has basically been eliminated,and great progress has been made restoring the ecological environment.2)High background value of quality habitat suitability benefits from the research area's high vegetation coverage.3)The development of the local tourism economy has transformed the area's ecological advantages into an economic bonus,greatly increasing the income level and living standards of residents.At the same time,the ecological resource bonus has increased the enthusiasm of residents for ecological protection and has helped to promote the protection of local eco-systems,both reducing ecological degradation and improving habitat quality.At the same time,increasing conflicts between land and people should be addressed.Support is needed to promote development of the ecological economy while continuously reducing ecological degradation and further increasing residents'income.There must be less reliance on industry and less pressure on both land and people,all the while ensuring that the local economy and ecology can more forward together in a sustainable way. 展开更多
关键词 Lashihai Watershed plateau wetland INVEST model habitat quality assessment spatial statistics
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RF and field measurements of the SSC-LINAC RFQ
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作者 LIU Ge LU YuanRong +15 位作者 YIN XueJun ZHANG XiaoHu DU Heng JIANG PeiYong LI ZhongShan LI XiaoNi HE Yuan WANG Zhi GAO ShuLi YANG YaQing ZHU Kun YAN XueQing CHEN JiaEr YUAN YouJin XIA JiaWen ZHAO HongWei 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第7期1311-1317,共7页
The 53.667 MHz continuous-wave heavy ion RFQ has been designed and manufactured for the SSC-LINAC project.This four-rod RFQ accelerates ions with maximum mass to charge ratio of 7 from 3.728 keV/u to 143 keV/u.Measure... The 53.667 MHz continuous-wave heavy ion RFQ has been designed and manufactured for the SSC-LINAC project.This four-rod RFQ accelerates ions with maximum mass to charge ratio of 7 from 3.728 keV/u to 143 keV/u.Measurements have been carried out to check the RF performance of the cavity and the quality of the electric field.The S11 of the power coupler is adjusted to better than-44 dB,and the Q0 of the cavity is 6440.The quality of the electric field is evaluated by the perturbation method.The measurement procedure and data analysis will be discussed in detail.The error due to gravity of the perturbation bead has been corrected by averaging the fields in different quadrants.As a result,the unflatness of the electric field is±2.5%,and the dipole field component distributes from 0%to 20%in different longitudinal positions,which indicates the asymmetry of the quadrupole field.The unflatness of the quadrupole field distribution represents a good agreement with the simulation results.High power RF test and beam commissioning of the RFQ are on schedule in early 2014. 展开更多
关键词 RFQ CONTINUOUS-WAVE heavy ion perturbation method field distribution
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Minimum Data Set for Assessing Soil Quality in Farmland of Northeast China 被引量:18
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作者 CHEN Yu-Dong WANG Huo-Yan +4 位作者 ZHOU Jian-Min XING Lu ZHU Bai-Shu ZHAO Yong-Cun CHEN Xiao-Qin 《Pedosphere》 SCIE CAS CSCD 2013年第5期564-576,共13页
Soil quality assessment provides a tool for agriculture managers and policy makers to gain a better understanding of how various agricultural systems affect soil resources. Soil quality of Hailun County, a typical soy... Soil quality assessment provides a tool for agriculture managers and policy makers to gain a better understanding of how various agricultural systems affect soil resources. Soil quality of Hailun County, a typical soybean (Glycine max L. Merill) growing area located in Northeast China, was evaluated using soil quality index (SQI) methods. Each SQI was computed using a minimum data set (MDS) selected using principal components analysis (PCA) as a data reduction technique. Eight MDS indicators were selected from 20 physical and chemical soil measurements. The MDS accounted for 74.9% of the total variance in the total data set (TDS). The SQI values for 88 soil samples were evaluated with linear scoring techniques and various weight methods. The results showed that SQI values correlated well with soybean yield (r = 0.658**) when indicators in MDS were weighted by the regression coefficient computed for each yield and index. Stepwise regression between yield and principal components (PCs) indicated that available boron (AvB), available phosphorus (AvP), available potassium (AvK), available iron (AvFe) and texture were the main factors limiting soybean yield. The method used to select an MDS could not only appropriately assess soil quality but also be used as a powerful tool for soil nutrient diagnosis at the regional level. 展开更多
关键词 norm value principal component analysis soil quality index stepwise regression
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