期刊文献+
共找到2,859篇文章
< 1 2 143 >
每页显示 20 50 100
Spatio-temporal Evaluation of Multi-scale Cultivated Land System Resilience in Black Soil Region from 2000 to 2019:A Case Study of Liaoning Province,Northeast China
1
作者 WANG Yue JIANG Yuting ZHU Guoxu 《Chinese Geographical Science》 SCIE CSCD 2024年第1期168-180,共13页
It is of great significance to systematically analyze the cultivated land system resilience(CLSR) for the black soil protection and national food security.The CLSR is impacted by planting structure adjustment and cult... It is of great significance to systematically analyze the cultivated land system resilience(CLSR) for the black soil protection and national food security.The CLSR is impacted by planting structure adjustment and cultivated land quality decline,posing major hidden dangers to food security.It is urgent to evaluate the CLSR at multiple spatio-temporal scales.This study took Liaoning Province in the black soil region of Northeast China as an example.Based on the resilience theory,this study constructed the CLSR evaluation system from the input-feedback perspective at the provincial-scale and the city-scale,and used the rank-sum ratio comprehensive evaluation method(RSR) to analyze the key influencing factors of CLSR in Liaoning Province and its 14 cities from 2000 to 2019.The results showed that:1) the time series changes of CLSR at the provincial-scale and the city-scale in Liaoning Province were similar,both showing an increasing trend.2) The CLSR in Liaoning Province presented a spatial pattern of ‘high in the west and low in the east’ at the city-scale.3) There were seven and six main influencing factors of CLSR at the provincial-scale and the city-scale,respectively.In addition to the net income per capita of rural households,other influencing factors of CLSR were different at the provincial-scale and the city-scale.The feedback factors were dominant at the provincial-scale,and the input factors and feedback factors were dominant at the city-scale.The results could provide a reference for the utilization of black soil and draw on the experience of regional agricultural planning and adjustment. 展开更多
关键词 cultivated land system resilience(CLSR) rank-sum ratio comprehensive evaluation(RSR) multi-scales influencing factors black soil region Liaoning Province china
下载PDF
Research on the Renovation of Rural Buildings Suitable for Aging Populations Based on Cross-Analysis
2
作者 Zhengming Zhu Feiyan Li 《Journal of Architectural Research and Development》 2024年第6期17-23,共7页
Based on the intersection of“Implementing the National Strategy to Actively Cope with Population Aging”and“Guiding Opinions on Future Rural Construction”in Zhejiang Province,this study constructed the evaluation i... Based on the intersection of“Implementing the National Strategy to Actively Cope with Population Aging”and“Guiding Opinions on Future Rural Construction”in Zhejiang Province,this study constructed the evaluation index system of rural age-appropriate building space.This is done by analyzing the current situation locally and internationally,summarizing the existing problems,and optimizing countermeasures.The cross-analysis method is adopted by fully listening to the opinions of the elderly and introducing a professional team to transform the physical,psychological,and rural natural environment of the elderly.The renovation strategies of building layout,indoor and outdoor space,and supporting facilities for the elderly are put forward.Looking to the future,including the application of intelligent technology,the development of a community pension model,and multi-party cooperation,it aims to create a comfortable,safe,and convenient living environment for rural elderly people,improve the quality of life,promote rural revitalization and actively respond to the challenges of population aging. 展开更多
关键词 Cross-analysis china Aging population Rural building renovation
下载PDF
Probability Distribution of Ratio of China Aviation Network Edge Vertices Degree and Its Evolutionary Trace Based on Complex Network
3
作者 Cheng Xiangjun Yang Fang Wei Liying 《Journal of Traffic and Transportation Engineering》 2024年第3期119-129,共11页
In order to reveal the complex network characteristics and evolution principle of China aviation network, the probability distribution and evolution trace of ratio of China aviation network edge vertices degree were s... In order to reveal the complex network characteristics and evolution principle of China aviation network, the probability distribution and evolution trace of ratio of China aviation network edge vertices degree were studied based on the statistics data of China civil aviation network in 1988, 1994, 2001, 2008 and 2015. According to the theory and method of complex network, the network system was constructed with the city where the airport was located as the network node and the route between cities as the edge of the network. Based on the statistical data, the ratio of edge vertices degree in China aviation network in 1988, 1994, 2001, 2008 and 2015 were calculated. Using the probability statistical analysis method and regression analysis approach, it was found that the ratio of edge vertices degree had linear probability distribution and the two parameters of the probability distribution had linear evolution trace. 展开更多
关键词 Complex network china aviation network ratio of edge vertices degree linear probability distribution linear evolution trace.
下载PDF
Concentration and Characterization of Colored Dissolved Organic Matter in the Surface Microlayer and Subsurface Water of the Yellow Sea and the East China Sea 被引量:5
4
作者 ZHANG Jing ZHAO Junjie +1 位作者 YANG Guipeng LIU Weifeng 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第2期383-393,共11页
The distribution and chemical properties of colored dissolved organic matter(CDOM) in the Yellow Sea and the East China Sea during December 2011-January 2012 were investigated. The input of freshwater and biological a... The distribution and chemical properties of colored dissolved organic matter(CDOM) in the Yellow Sea and the East China Sea during December 2011-January 2012 were investigated. The input of freshwater and biological activities had an evident influence on the CDOM levels(characterized by the light absorption coefficient at the wavelength of 355 nm a_(355)) in the study area. The spatial distribution of CDOM levels displayed a gradually decreasing trend from the coastal waters(0.37 m^(-1)) to the open sea(0.18 m^(-1)). The spectral slope ratio(the slope ratio S_R defined as S_(275-295):S_(350-400)) during the cruise was correlated with salinity, and exhibited a large variation from inshore(average of 2.515) to offshore sites(average of 5.327) compared with the distribution of a_(355). The values of S_R were related to CDOM molecular weight(MW). The a_(355), S_R, and chlorophyll a in 37 samples collected from the surface microlayer were significantly correlated with those in the corresponding subsurface water samples, implying a strong exchange action between the microlayer and bulk water. The a_(355) and S_R of CDOM exhibited significant microlayer enrichment, with mean enrichment factors(EFs) of 1.72 and 1.62, respectively. 展开更多
关键词 COLORED dissolved organic matter(CDOM) absorption coefficient spectral SLOPE ratio YELLOW SEA East china SEA
下载PDF
Crustal Poisson's ratio anomalies in the eastern part of North China and their origins 被引量:4
5
作者 Wencai Yang Chen Qu Changqing Yu 《Geoscience Frontiers》 SCIE CAS 2011年第3期313-321,共9页
Seismic tomography can provide both fine P-wave and S-wave velocity structures of the crust and upper mantle. In addition, with proper computation, Poisson's ratio images from the seismic velocities can be determined... Seismic tomography can provide both fine P-wave and S-wave velocity structures of the crust and upper mantle. In addition, with proper computation, Poisson's ratio images from the seismic velocities can be determined. However, it is unknown whether Poisson's ratio images have any advantages when compared with the P-wave and S-wave velocity images. For the purposes of this study, high- resolution seismic tomography under the eastern part of North China region was used to determine detailed 3-D crustal P- and S-wave seismic velocities structure, as well as Poisson's ratio images. Results of Poisson's ratio imaging show high Poisson's ratio (high-PR) anomalies located in the Hengshan-North Taihang-Zhangjiakou (H-NT-Z) region, demonstrating that Poisson's ratio imaging can provide new geophysical constraints for regional tectonic evolution. The H-NT-Z region shows a prominent and continuous high-PR anomaly in the upper crust. Based on Poisson's ratio images at different depths, we find that this high-PR anomaly is extending down to the middle crust with thickness up to about 26 kin. According to rock physical property measurements and other geological data, this crustal Poisson's ratio anomaly can be explained by Mesozoic partial melting of the upper mantle and basaltic magma underplating related to the lithospheric thinning of the North China craton. 展开更多
关键词 Seismic tomography North china Craton crust Poisson's ratio anomaly Magma underplating
下载PDF
Impact of Green Buildings( LEED and Estidama) in the Middle East and China 被引量:1
6
作者 Mayuko Totsuka Jourdan Younis 《施工技术》 CAS 北大核心 2014年第10期76-77,81,共3页
0 Introduction The growing number of accredited green buildings reflects the development and adoption of various green building rating systems in our building construction industry globally and within the Middle East ... 0 Introduction The growing number of accredited green buildings reflects the development and adoption of various green building rating systems in our building construction industry globally and within the Middle East over the past 5 years.While the US based LEED system,Leadership in Energy and Environmental Design,has been widely utilized as an international 展开更多
关键词 LEED and Estidama in the Middle East and china Impact of Green buildings
下载PDF
Layouts and Aesthetic Characteristics of Buildings in the Period of Republic of China along Zhongshan Road in Nanjing City
7
作者 ZHOU Pei 《Journal of Landscape Research》 2014年第5期40-42,共3页
Zhongshan Road in Nanjing City was formerly known as "Meridian of the Republic of China", signif icant buildings of the Republic of China were mostly distributed along this modern avenue. The diversifi ed st... Zhongshan Road in Nanjing City was formerly known as "Meridian of the Republic of China", signif icant buildings of the Republic of China were mostly distributed along this modern avenue. The diversifi ed styles and types of these buildings refl ect the historical changes of modern Chinese buildings, and also record history of that age. The buildings are intangible cultural heritages of not only Nanjing, but also China. Study on and protection of these buildings is a process of reviewing modern architectural history of China, and also rethinking the inheritance and development of traditional Chinese cultures. In addition, the research promotes the coordinated development of modern urban construction and social cultures. 展开更多
关键词 buildings of the Republic of china Zhongshan Road Architectural style New ethnic style
下载PDF
Effects of Groundwater with Various Salinities on Evaporation and Redistribution of Water and Salt in Saline-sodic Soils in Songnen Plain,Northeast China
8
作者 ZHU Wendong ZHAO Dandan +6 位作者 YANG Fan WANG Zhichun DONG Shide AN Fenghua MA Hongyuan ZHANG Lu TIBOR Tóth 《Chinese Geographical Science》 SCIE CSCD 2023年第6期1141-1152,共12页
Groundwater mineralization is one of the main factors affecting the transport of soil water and salt in saline-sodic areas.To investigate the effects of groundwater with different levels of salinity on evaporation and... Groundwater mineralization is one of the main factors affecting the transport of soil water and salt in saline-sodic areas.To investigate the effects of groundwater with different levels of salinity on evaporation and distributions of soil water and salt in Songnen Plain,Northeast China,five levels of groundwater sodium adsorption ration of water(SARw)and total salt content(TSC mmol/L)were conducted in an oil column lysimeters.The five treated groundwater labeled as ST0:0,ST0:10,ST5:40,ST10:70 and ST20:100,were prepared with NaCl and CaCl2 in proportion,respectively.The results showed the groundwater evaporation(GWE)and soil evaporation(SE)increased firstly and then decreased with the increase of groundwater salinity.The values of GWE and SE in ST10:70 treatment were the highest,which were 2.09 and 1.84 times the values in the ST0:0 treatment with the lowest GWE and SE.There was a positive linear correlation between GWE and the Ca^(2+)content in groundwater,with R^(2)=0.998.The soil water content(SWC)of ST0:0 treatment was significantly(P<0.05)less than those of other treatments during the test.The SWC of the ST0:0 and ST0:10 treatments increased with the increase of soil depth,while the other treatments showed the opposite trend.Statistical analysis indicated the SWC in the 0–60 cm soil layer was positively correlated with the groundwater TSC and its ion contents during the test.Salt accumulation occurred in the topsoil and the salt accumulation in the 0–20 cm soil layer was significantly(P<0.05)greater than that in the subsoil.This study revealed the effects of the salinity level of groundwater,especially the Ca^(2+)content and TSC of groundwater,on the GWE and distributions of soil water and salt,which provided important support for the prevention and reclamation of soil salinization and sodificaton in shallow groundwater regions. 展开更多
关键词 groundwater evaporation sodium adsorption ratio total salt content ion composition soil salinization water and salt dynamics Songnen Plain china
下载PDF
Slenderness Ratio Influence on the Structural Behavior of Residential Concrete Tall Buildings
9
作者 Tarek A. Awida 《Journal of Civil Engineering and Architecture》 2011年第6期527-534,共8页
The main concern of this paper is to study the influence of the building slenderness ratio on the structural behavior of the residential concrete tall buildings aiming to deepen structure and architect designers under... The main concern of this paper is to study the influence of the building slenderness ratio on the structural behavior of the residential concrete tall buildings aiming to deepen structure and architect designers understanding for such type of buildings. The study is emphasized only on Kuwait city design conditions for wind and seismic loadings. The paper presents an actual case study for adding two thirty stories residential towers with two different slenderness ratios to an existing residential complex. Wind loading is considered using both code values and wind tunnel results. Three dimensional finite element techniques through ETABS software are used in conducting analysis for structures presented here. A serviceability study is performed to ensure that buildings have sufficient stability to limit lateral drift and peak acceleration within the acceptable range of occupancy comfort. In addition, an ultimate strength study is carried out to verify that all the structural elements are designed to withstand factored gravity and lateral loads in a safe manner according to the international building codes. Analysis results are presented and discussed. A brief idea about foundation design of the new towers and its connection to the existing foundation is presented. Finally conclusions are summarized as guidelines for the structural professions of concrete residential tall buildings. 展开更多
关键词 Slenderness ratio residential tall buildings finite element reinforced concrete analysis and design.
下载PDF
CARBON EMISSION-BASED MEASUREMENT OF FLOOR AREA RATIO BONUS FOR RESIDENTIAL GREEN BUILDINGS IN CHINA
10
作者 Yanhui Mao Xuemei Gong Yun Ye 《Journal of Green Building》 2018年第2期84-97,共14页
Green building development in China relies mainly on compulsory measures that lack incentive policies to motivate the enthusiasm of real estate developers.A floor area ratio bonus is encouraged by the Chinese State Co... Green building development in China relies mainly on compulsory measures that lack incentive policies to motivate the enthusiasm of real estate developers.A floor area ratio bonus is encouraged by the Chinese State Council.In order to ensure the feasibility of a reward quota,residential buildings that met the requirement for energy efficiency during the official assessment in Ningbo in 2014 were selected as research objects.The amount of energy and water savings in terms of the Assessment Standard for Green Building is converted into carbon emissions.Carbon emissions of different star-rated green buildings are then measured in accordance with the actual water and power consumption of residential dwellings in 2014.A regression equation is set up concerning the floor area ratio and index for residential land per capita.A carbon emission-based method is proposed for measuring the reward quota associated with floor area ratio and recommendations are given for development using green building. 展开更多
关键词 green building carbon emission index for residential land per capita floor area ratio
原文传递
Hand in Hand East and West to Build a Glorious Gansu——Talk on the cooperation between the East and West of China by Mr.Cui Zhenghua,vice governor of Gansu Province
11
作者 Xiao Qiang,staff reporter 《China's Foreign Trade》 1996年第11期16-16,共1页
To implement the CPC CentralCommittee’s strategy of slanting theeconomic construction to the Midand West of China and to further promote thedevelopment and cooperation of economyand trade between the East and West, t... To implement the CPC CentralCommittee’s strategy of slanting theeconomic construction to the Midand West of China and to further promote thedevelopment and cooperation of economyand trade between the East and West, theEast-West Business and Trade Talks wereheld by the China Council for the Promotionof International Trade (CCPIT). At theconference, Mr. Cui Zhenghua, vice governorof Gansu Province and concurrently chairmanof the Gansu Subcouncil of the CCPIT,delivered a speech on the economiccooperation and development between theEast and West of China. 展开更多
关键词 West in Hand in Hand East and West to Build a Glorious Gansu Talk on the cooperation between the East and West of china by Mr.Cui Zhenghua vice governor of Gansu Province
下载PDF
Predictive Ability of Hypertriglyceridemic Waist,Hypertriglyceridemic Waist-to-Height Ratio,and Waist-to-Hip Ratio for Cardiometabolic Risk Factors Clustering Screening among Chinese Children and Adolescents
12
作者 XIAO Tian Li YUAN Shu Qian +6 位作者 GAO Jing Yu Julien SBaker YANG Yi De WANG Xi Jie ZHENG Chan Juan DONG Yan Hui ZOU Zhi Yong 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第3期233-241,共9页
Objective Hypertriglyceridemic waist(HW),hypertriglyceridemic waist-to-height ratio(HWHtR),and waist-to-hip ratio(WHR)have been shown to be indicators of cardiometabolic risk factors.However,it is not clear which indi... Objective Hypertriglyceridemic waist(HW),hypertriglyceridemic waist-to-height ratio(HWHtR),and waist-to-hip ratio(WHR)have been shown to be indicators of cardiometabolic risk factors.However,it is not clear which indicator is more suitable for children and adolescents.We aimed to investigate the relationship between HW,HWHtR,WHR,and cardiovascular risk factors clustering to determine the best screening tools for cardiometabolic risk in children and adolescents.Methods This was a national cross-sectional study.Anthropometric and biochemical variables were assessed in approximately 70,000 participants aged 6–18 years from seven provinces in China.Demographics,physical activity,dietary intake,and family history of chronic diseases were obtained through questionnaires.ANOVA,χ2 and logistic regression analysis was conducted.Results A significant sex difference was observed for HWHtR and WHR,but not for HW phenotype.The risk of cardiometabolic health risk factor clustering with HW phenotype or the HWHtR phenotype was significantly higher than that with the non-HW or non-HWHtR phenotypes among children and adolescents(HW:OR=12.22,95%CI:9.54-15.67;HWHtR:OR=9.70,95%CI:6.93-13.58).Compared with the HW and HWHtR phenotypes,the association between risk of cardiometabolic health risk factors(CHRF)clustering and high WHR was much weaker and not significant(WHR:OR=1.14,95%CI:0.97-1.34).Conclusion Compared with HWHtR and WHR,the HW phenotype is a more convenient indicator with higher applicability to screen children and adolescents for cardiovascular risk factors. 展开更多
关键词 Hypertriglyceridemic waist Waist-to-hip ratio Children and adolescents china Hypertriglyceridemic waist-to-height ratio Cardiovascular risk factors
下载PDF
Study on Greening Design for Spatial Landscape in Southern Yuejin District of South China Agricultural Univeristy 被引量:3
13
作者 张锦泉 沈创之 《Journal of Landscape Research》 2009年第3期30-34,共5页
General situations of South China Agricultural University were introduced in this study,while planning conditions and ideas were also analyzed,which put forward the correspondingly planning and designing idea.
关键词 South china AGRICULTURAL Univeristy SOUtheRN Yuejin DISTRICT LANDSCAPE space Building cluster integration
下载PDF
Integrating Virtual Reality and Energy Analysis with BIM to Optimize Window-to-Wall Ratio and Building’s Orientation for Age-in-Place Design at the Conceptual Stage
14
作者 Vafa Rostamiasl Ahmad Jrade 《Open Journal of Civil Engineering》 2024年第3期305-333,共29页
This study unfolds an innovative approach aiming to address the critical role of building design in global energy consumption, focusing on optimizing the Window-to-Wall Ratio (WWR), since buildings account for approxi... This study unfolds an innovative approach aiming to address the critical role of building design in global energy consumption, focusing on optimizing the Window-to-Wall Ratio (WWR), since buildings account for approximately 30% of total energy consumed worldwide. The greatest contributors to energy expenditure in buildings are internal artificial lighting and heating and cooling systems. The WWR, determined by the proportion of the building’s glazed area to its wall area, is a significant factor influencing energy efficiency and minimizing energy load. This study introduces the development of a semi-automated computer model designed to offer a real-time, interactive simulation environment, fostering improving communication and engagement between designers and owners. The said model serves to optimize both the WWR and building orientation to align with occupants’ needs and expectations, subsequently reducing annual energy consumption and enhancing the overall building energy performance. The integrated model incorporates Building Information Modeling (BIM), Virtual Reality (VR), and Energy Analysis tools deployed at the conceptual design stage, allowing for the amalgamation of owners’ inputs in the design process and facilitating the creation of more realistic and effective design strategies. 展开更多
关键词 Building information Modeling (BIM) Virtual Reality (VR) Game Engine Energy Analysis Window-to-Wall ratio Building Orientation Computer integration and Automation
下载PDF
Crustal Composition of China Continent Constrained from Heat Flow Data and Helium Isotope Ratio of Underground Fluid 被引量:10
15
作者 WANG Yang SUN Zhiming 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2010年第1期178-184,共7页
Based on conservation of energy principle and heat flow data in China continent, the upper limit of 1.3 μW/m3 heat production is obtained for continental crust in China. Furthermore, using the data of heat flow and h... Based on conservation of energy principle and heat flow data in China continent, the upper limit of 1.3 μW/m3 heat production is obtained for continental crust in China. Furthermore, using the data of heat flow and helium isotope ratio of underground fluid, the heat productions of different tectonic units in China continent are estimated in range of 0.58-1.12 μW/m3 with a median of 0.85 μW/m3. Accordingly, the contents of U, Th and K20 in China crust are in ranges of 0.83-1.76 μg/g, 3.16-6.69 μg/g, and 1.0%-2.12%, respectively. These results indicate that the abundance of radioactive elements in the crust of China continent is much higher than that of Archean crust; and this fact implies China's continental crust is much evolved in chemical composition. Meanwhile, significant lateral variation of crustal composition is also exhibited among different tectonic units in China continent. The crust of eastern China is much enriched in incompatible elements such as U, Th and K than that of western China; and the crust of orogenic belts is more enriched than that of platform regions. It can also be inferred that the crusts of eastern China and orogenic belts are much felsic than those of western China and platform regions, respectively, derived from the positive correlation between the heat production and SiO2 content of bulk crust. This deduction is consistent with the results derived from the crustal seismic velocity data in China. According to the facts of the lower seismic velocity of China than the average value of global crust, and the higher heat production of China continent compared with global crust composition models published by previous studies, it is deduced that the average composition models of global continent crust by Rudnick and Fountain (1995), Rudnick and Gao (2003), Weaver and Tarney (1984), Shaw et al. (1986), and Wedepohl (1995) overestimate the abundance of incompatible elements such as U, Th and K of continental crust. 展开更多
关键词 crustal composition of continent heat flow helium isotope ratio china continent
下载PDF
The modification and optimizing of the CHEMTAX running in the South China Sea 被引量:8
16
作者 WANG Lei HUANG Bangqin +1 位作者 LIU Xin XIAO Wupeng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第2期124-131,共8页
In order to determine the phytoplankton community composition, the modification and optimizing of the CHEMical TAXonomy(CHEMTAX) running was carried out through samples grouping, successive run and evaluate the resu... In order to determine the phytoplankton community composition, the modification and optimizing of the CHEMical TAXonomy(CHEMTAX) running was carried out through samples grouping, successive run and evaluate the results for HPLC-pigment samples in the South China Sea(SCS). The vertical distribution of the ratio of pigment to total Chl a(TChl a) exhibited three different patterns, including increasing with depth pattern(e.g., But-Fuco), decreasing with depth pattern(e.g., Zea) and increasing at deep chlorophyll maximum(DCM) pattern(e.g., Hex-Fuco). The vertical profiles for Fuco/TChl a and Pras/TChl a was higher in coast than in the shelf and basin, and the Zea and Dv-Chl a expressed conversely. So the samples in the coastal stations must be separated for the cluster analysis group procedure in the SCS. Successive run was introduced into the CHEMTAX calculation and the output results were evaluated by the convergence of pigment/TChl a ratios. Most of the ratios were well converged at the fifth running, except Zea/TChl a for Prochlorococcus and Chl b/TChl a for prasinophytes and so on. To evaluate the fifth running's results, haptophytes_8 and chlorophytes were two phytoplankton groups with much uncertainty. But the fifth estimated value was better than running once was supported by the regression evidence between the measured pigment concentration and calculation values. Synechococcus was another component with much mutability, and the CHEMTAX's result should be compared to the flow cytometry's cell abundance. 展开更多
关键词 PHYTOPLANKTON CHEMTAX pigment/Chl a ratio successive run South china Sea
下载PDF
ECOLOGICAL AND SOCIO-ECONOMIC REHABILITATION IN THE KARST OF SOUTHWEST CHINA 被引量:6
17
作者 Cai Yunlong Department of Geography, Peking University, Beijing 100871 People’s Republic of China 《Journal of Geographical Sciences》 SCIE CSCD 1997年第2期24-32,共9页
The Karst of Southwest China is a typical representative of poverty stricken region with impoverishment-degradation spiral. To essentially break away from this vicious circle, the local ecology, economy and society s... The Karst of Southwest China is a typical representative of poverty stricken region with impoverishment-degradation spiral. To essentially break away from this vicious circle, the local ecology, economy and society should be rehabilitated, and hence to strengthen the self-development capacity building of the localities. Two considerations are stressed in this article: (1) Poverty alleviation is a system project with great complexities. Any single approach is difficult to success and integrated measures should be taken. (2) Some typical and feasible areas should be selected to demonstrate the project of poverty alleviation and ecological, socio-economic reconstruction. Then, they can be used as a model to promote the sustainable development of the whole region. Based upon these ideals, a project entitled “Reversal of Impoverishment-Degradation Spiral in the Karst of Southwest China' was proposed and has been listed in 《Priority Programme for China's Agenda 21》. 展开更多
关键词 poverty alleviation environmental degradation capacity building ecological and socio-economic rehabilitation karst areas Southwest china.
下载PDF
An assessment of the carrying capacity of groundwater resources in North China Plain region–Analysis of potential for development 被引量:4
18
作者 LIU Min NIE Zhen-long +2 位作者 WANG Jin-zhe WANG Li-fang TIAN Yan-liang 《Journal of Groundwater Science and Engineering》 2016年第3期174-187,共14页
Over-exploitation of groundwater in North China Plain(NCP) has resulted in a series of eco-environment problems. Sustainable use of groundwater resources in NCP, in particular management of groundwater resource carryi... Over-exploitation of groundwater in North China Plain(NCP) has resulted in a series of eco-environment problems. Sustainable use of groundwater resources in NCP, in particular management of groundwater resource carrying capacity(GRCC), faces an unprecedented challenge. Here we define GRCC, and a new assessment method is tentatively proposed and applied to evaluate GRCC based on the whole NCP, city administrative units and county administrative units. Our study divided the NCP into three zones, i.e. non-overexploited non-overloaded zone(NNZ), overexploited but non-overloaded zone(ONZ), and overexploited overloaded zone(OOZ). Results confirmed 27.6% of counties belonged to NNZ. However, 58.9% of counties and NCP as a whole belonged to ONZ, and 13.5% of counties belonged to OOZ. Spatially, NNZs were mainly distributed in Beijing, parts of eastern coastal cities and Henan Province. OOZs were mostly distributed in middle-eastern part of Cangzhou, parts of Dezhou, Tianjin and Binzhou, and the remaining areas belonged to ONZs. We suggest two approaches for enhancing GRCC, i) increasing the amount of available groundwater and ii) improving the water use efficiency. An increase of 11.0 billion cubic meters to the available groundwater levels combined with water use efficiency improvements up to 479 CNY per cubic meter of the world mean, the gross domestic product(GDP) sustained by groundwater in the NCP could reach 11.1 trillion CNY and maintain a 20 years of GDP development assuming the current rate of growth. 展开更多
关键词 North china Plain Groundwater resources carrying capacity Groundwater exploitation ratio Socio-economic development ratio
下载PDF
Clay minerals and geochemistry of the bottom sediments in the northwestern East China Sea 被引量:5
19
作者 Jeungsu YOUN Shouye YANG Yong Ahn PARK 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2007年第3期235-246,共12页
Clay minerals of 34 sediments collected from the northwestern continental shelf of the East China Sea have been determined by X-ray diffraction analysis. The clay mineral distribution is mainly controlled by the sedim... Clay minerals of 34 sediments collected from the northwestern continental shelf of the East China Sea have been determined by X-ray diffraction analysis. The clay mineral distribution is mainly controlled by the sediment source and the dominant circulation pattern. The predominant clay mineral in our study area is illite comprising more than 67% of the whole clay fraction. The highest concentration of illite (〉68%) is found in the southeastern offshore parts beyond the reach of terrigenous input from the Jeju Island. It means that these illites are largely transported by the Kuroshio Current from the South China Sea (SCS). Smectite is highly concentrated in the northwest middle part and in the outer-shelf mud patch. It seems to be due to the high supply of smectite transported from China where fine-grained sediments are discharged from modern and ancient Huanghe (Yellow) River. The relatively high abundant kaolinite is likely derived from the Changjiang (Yangtze) River via the Taiwan Warm Current. In contrast, large amounts of chlorite and high chlorite/kaolinite ratios occur in the northwestern area, reflecting the transportation by the Yellow Sea Coastal Current from the southern Yellow Sea. The discrimination diagrams clearly show that the sediments in the northwestern East China Sea are ultimately sourced from Chinese rivers, especially from the Huanghe River, whereas the sediment in the northeast part might come from the Jeju Island. The muddy sediments of the Changjiang River's submerged delta have much lower 87Sr/S6Sr ratios (0.716 2-0.718 0) than those of the Shandong Peninsular mud wedge (0.721 6-0.724 9), which are supposed to be originated from the Huanghe River, suggesting the distribution pattern of 87Sr/86Sr ratios as a new tracer to discriminate the provenance of shelf sediments in the study area. The 87Sr/86Sr ratios of the outer-shelf muddy sediments ranged from 0.7169 to 0.7216 in a wide range and was between those of the Huanghe River and Changjiang River sediments, suggesting multiple sources of the sediment in the area. 展开更多
关键词 clay minerals geochemical composition strontium isotopic ratio PROVENANCE northwestern East china Sea
下载PDF
Building Height Trends and Their Influencing Factors under China’s Rapid Urbanization:A Case Study of Guangzhou,1960–2017 被引量:3
20
作者 SUN Wu LI Tao 《Chinese Geographical Science》 SCIE CSCD 2020年第6期993-1004,共12页
Understanding the spatiotemporal patterns of three-dimensional urban forms,especially building height,can have important implications for improving urban air quality and mitigating the urban heat island effect by opti... Understanding the spatiotemporal patterns of three-dimensional urban forms,especially building height,can have important implications for improving urban air quality and mitigating the urban heat island effect by optimizing urban planning and management policies.This study investigated building height evolution and its influencing factors over approximately half a century(1960–2017)in Guangzhou,China.The results indicated that the logarithmic declines in height,quantity,and area of urban buildings followed Zapf’s law,which restricts the three-dimensional shape of the urban form.The urban building height decreased from the center to the periphery of the city and decreased with decreasing altitude and increasing distance from main roads.These characteristics constituted the three main spatial differentiation rules of building height in the central district of Guangzhou,and all exhibited a logarithmic decrease,which gradually strengthened over time.The development of a double-layered height structure of low-rise and high-rise buildings between 1990 and 2017 was a notable manifestation of the increase in vertical urban height over time.The three factors of city center,altitude,and accessibility,which represent centrality,low relief,proximity to water,and proximity to road networks,highlighted the roles of traffic accessibility and commercial attraction in building height evolution.The importance of location macroscopically depends on the combined effect of the geographical pattern,urban planning,and market forces of cities located on a plain near hill or by a river.The principle of profit orientation restricted spatiotemporal building height patterns. 展开更多
关键词 building height urban form ALTITUDE ROAD formative mechanism Guangzhou china
下载PDF
上一页 1 2 143 下一页 到第
使用帮助 返回顶部