Whether mining activity results in reduced flow of surface water in the Peace River Watershed of Florida has been the subject of much debate. With increased dependence of downstream users on surface water flow of the ...Whether mining activity results in reduced flow of surface water in the Peace River Watershed of Florida has been the subject of much debate. With increased dependence of downstream users on surface water flow of the Peace River as a source of drinking water for four coastal counties in Southwest Florida and problems of water security, the debate has been intensified. It is possible to assess relationships of mining with streamflow in the upper reaches of the Peace River Basin using hydrologic modeling and identify mined sub-basins. In this work, land-use change impacts were simulated by the Hydrological Simulation Program--Fortran （HSPF） model based on geographical information system （GIS） tools, to compare pre- and post-mining streamflows at a study site of the Peace River in west-central Florida. The purpose of this study was to determine if land-use changes caused by mining have negatively impacted streamflow in the Peace River. Changes of land use were identified before and after mining activities. A coupled volume-water depth-discharge （V-h-Q） model based on stage/storage and stage/discharge was applied using HSPF for the pre-mining and post-mining models, respectively. Daily simulated post-mining hydrographs from HSPF were plotted with the calibrated pre-mining results and streamflow hydrographs from the 18 gauging stations, to compare timing of peaks, low fows and flow trends. Analyses of percent ex- ceedances of flow frequency curves of the streams indicated that most streams had similar distributions for mined （reclaimed） and pre- mining periods. In the streamflow change analysis, streamflows actually increased in mining-affected basins at nearly half the stations. Streamflows at other stations diminished. Overall from this comprehensive study, there were declines in streamflow at most gauging stations on the mainstem of the Peace River and its tributaries. The results of this study suggest that regional planning is urgently needed to propose reclamation schemes that enhance regional hydrology.展开更多
Objectives:To investigate the focuses and trends of the studies on pediatric palliative care(PPC)and provide directions for future research.Methods:Relevant papers about PPC published from 2004 to 2018 were analyzed u...Objectives:To investigate the focuses and trends of the studies on pediatric palliative care(PPC)and provide directions for future research.Methods:Relevant papers about PPC published from 2004 to 2018 were analyzed using bibliometric analysis methods,including co-word analysis,biclustering analysis,and strategic diagram analysis.The included papers were divided into three groups based on the publication time,including 2004-2008,2009-2013,and 2014-2018.Results:A total of 1132 papers were published between 2004 and 2018,and there were 293 papers published between 2004 and 2008,396 between 2009 and 2013,and 443 between 2014 and 2018.There were 42 high-frequency MeSH terms/MeSH subheadings in papers published between 2004 and 2018,including 12 between 2004 and 2008,13 between 2009 and 2013,and 17 between 2014 and 2018.Conclusion:Studies on PPC were making progress,with the increasing number,expanding scope,and uneven global distribution.Integration palliative care into pediatrics,cancer treatments in pediatric oncology,education methods on PPC,and establishment of professional teams were the major themes during 2004e2008,then the themes changed into establishing interventions to enhance the quality of life of the patients and parents,building professional-family relationship,and investigating attitude of health personnel in PPC during 2009-2013 and subsequently turned into communication skills,end-oflife decision making,and guidelines making on PPC during 2014-2018.Underdeveloped and protential themes including effective approaches to deal with the ethical dilemmas,training programs on communication skills,family support and guideline making are worth studying in the future.展开更多
As an abstract study conception,most researches of ecological security generally are macro-scale theoretical study with a regional,national or global perspective.Micro-scale research mainly concentrates on ecological ...As an abstract study conception,most researches of ecological security generally are macro-scale theoretical study with a regional,national or global perspective.Micro-scale research mainly concentrates on ecological risk,ecosystem health and ecosystem safety.In order to assess regional ecological security and to accomplish the transition from micro-scale to macro-scale research,a Driving-Function-State-Output-Respond model framework(DFSOR model) is put forward in this paper according to the analyses on regional population,society,economy,re-sources,environment and ecological risks.In empirical research an index system is set out to evaluate ecological se-curity of land use.The DFSOR model comprises f ive group of indicators:(1) driving indicators,which include social population pressure and economic pressure;(2) function indicators,which include human function,hydrodynamic function,wind function and gravity function;(3) state indicators,which include soil resources,water resources and land use/land cover;(4) output indicators,which include production output and ecological risk output;(5) response indicators,which are composed of all sorts of policies and measures for improving production of ecosystem.The method and procedure for ecological security evaluation is put forward based on DFSOR model as well.In the case study,Yanchi,the ecotone between agriculture and animal husbandry,is chosen for the study.An index system is built to evaluate ecological security based on the evaluation of regional ecological risks which including sandif ica-tion,water erosion,soil salinization,soil pollution and shortage of water.The comprehensive evaluation result shows the regional ecological security index of land use in the research area increase obviously.But it is still in the state of low-graded danger.展开更多
We established a three-dimensional finite element model of the Anninghe-Zemuhe-Xiaojiang faults region using contact surfaces of different sizes to describe the spatial segmentation characteristics of the faults. Our ...We established a three-dimensional finite element model of the Anninghe-Zemuhe-Xiaojiang faults region using contact surfaces of different sizes to describe the spatial segmentation characteristics of the faults. Our model is based on constraints from GPS observations, models of the crust and upper mantle, precise earthquake locations, the tectonic stress field, the slip rate of the faults, and the rheology of the lithosphere in the Sichuan-Yunnan area. Considering the influence of strong earthquakes since A.D. 1327, we analyzed the main controlling factors of the characteristics of the strong earthquakes and also studied by numerical simulation the possible areas of future earthquake risk and their relationship with tectonic stress. The numerical results showed that the gravitational potential energy of the Qinghai-Tibet Plateau and the interaction of adjacent blocks are the main kinetic factors affecting the characteristics of the tectonic stress distribution. There appears to be some correspondence between the distribution of tectonic stress and the b value; however, we also found that some low b value locations correspond to regions of lower stress. This contradiction may be the result of some comprehensive factors, such as the release of strain energy caused by strong earthquakes.展开更多
This study reconstructs the long-term evolution of river terraces over large spatial scales along the Anning River, western Sichuan, and identifies external factors controlling terrace formation. Pollen record analysi...This study reconstructs the long-term evolution of river terraces over large spatial scales along the Anning River, western Sichuan, and identifies external factors controlling terrace formation. Pollen record analysis and terrace structure indicate that formation of the middle section of terraces I-III resulted from the interaction of changing climates and uplift of the margins of the Qinghai-Tibet Plateau. The relative influence of climate and uplift in terrace formation changes in different periods. The terraces reveal multiple, gradual uplift events on the eastern Qinghai-Tibet Plateau, which is of great significance for determining uplift mechanisms across the entire plateau.展开更多
基金National Natural Science Foundation of China(No.41271004)Beijing Municipal Science &Technology New Star Project Funds(No.2010B046)
文摘Whether mining activity results in reduced flow of surface water in the Peace River Watershed of Florida has been the subject of much debate. With increased dependence of downstream users on surface water flow of the Peace River as a source of drinking water for four coastal counties in Southwest Florida and problems of water security, the debate has been intensified. It is possible to assess relationships of mining with streamflow in the upper reaches of the Peace River Basin using hydrologic modeling and identify mined sub-basins. In this work, land-use change impacts were simulated by the Hydrological Simulation Program--Fortran （HSPF） model based on geographical information system （GIS） tools, to compare pre- and post-mining streamflows at a study site of the Peace River in west-central Florida. The purpose of this study was to determine if land-use changes caused by mining have negatively impacted streamflow in the Peace River. Changes of land use were identified before and after mining activities. A coupled volume-water depth-discharge （V-h-Q） model based on stage/storage and stage/discharge was applied using HSPF for the pre-mining and post-mining models, respectively. Daily simulated post-mining hydrographs from HSPF were plotted with the calibrated pre-mining results and streamflow hydrographs from the 18 gauging stations, to compare timing of peaks, low fows and flow trends. Analyses of percent ex- ceedances of flow frequency curves of the streams indicated that most streams had similar distributions for mined （reclaimed） and pre- mining periods. In the streamflow change analysis, streamflows actually increased in mining-affected basins at nearly half the stations. Streamflows at other stations diminished. Overall from this comprehensive study, there were declines in streamflow at most gauging stations on the mainstem of the Peace River and its tributaries. The results of this study suggest that regional planning is urgently needed to propose reclamation schemes that enhance regional hydrology.
文摘Objectives:To investigate the focuses and trends of the studies on pediatric palliative care(PPC)and provide directions for future research.Methods:Relevant papers about PPC published from 2004 to 2018 were analyzed using bibliometric analysis methods,including co-word analysis,biclustering analysis,and strategic diagram analysis.The included papers were divided into three groups based on the publication time,including 2004-2008,2009-2013,and 2014-2018.Results:A total of 1132 papers were published between 2004 and 2018,and there were 293 papers published between 2004 and 2008,396 between 2009 and 2013,and 443 between 2014 and 2018.There were 42 high-frequency MeSH terms/MeSH subheadings in papers published between 2004 and 2018,including 12 between 2004 and 2008,13 between 2009 and 2013,and 17 between 2014 and 2018.Conclusion:Studies on PPC were making progress,with the increasing number,expanding scope,and uneven global distribution.Integration palliative care into pediatrics,cancer treatments in pediatric oncology,education methods on PPC,and establishment of professional teams were the major themes during 2004e2008,then the themes changed into establishing interventions to enhance the quality of life of the patients and parents,building professional-family relationship,and investigating attitude of health personnel in PPC during 2009-2013 and subsequently turned into communication skills,end-oflife decision making,and guidelines making on PPC during 2014-2018.Underdeveloped and protential themes including effective approaches to deal with the ethical dilemmas,training programs on communication skills,family support and guideline making are worth studying in the future.
基金supported by the National Key Technologies R&D Program of China during the 10th Five-Year Plan Period (Grant No. 2002BA517A114)National Key Technologies R&D Program (Grant No. 2007BAB23C03).
文摘As an abstract study conception,most researches of ecological security generally are macro-scale theoretical study with a regional,national or global perspective.Micro-scale research mainly concentrates on ecological risk,ecosystem health and ecosystem safety.In order to assess regional ecological security and to accomplish the transition from micro-scale to macro-scale research,a Driving-Function-State-Output-Respond model framework(DFSOR model) is put forward in this paper according to the analyses on regional population,society,economy,re-sources,environment and ecological risks.In empirical research an index system is set out to evaluate ecological se-curity of land use.The DFSOR model comprises f ive group of indicators:(1) driving indicators,which include social population pressure and economic pressure;(2) function indicators,which include human function,hydrodynamic function,wind function and gravity function;(3) state indicators,which include soil resources,water resources and land use/land cover;(4) output indicators,which include production output and ecological risk output;(5) response indicators,which are composed of all sorts of policies and measures for improving production of ecosystem.The method and procedure for ecological security evaluation is put forward based on DFSOR model as well.In the case study,Yanchi,the ecotone between agriculture and animal husbandry,is chosen for the study.An index system is built to evaluate ecological security based on the evaluation of regional ecological risks which including sandif ica-tion,water erosion,soil salinization,soil pollution and shortage of water.The comprehensive evaluation result shows the regional ecological security index of land use in the research area increase obviously.But it is still in the state of low-graded danger.
基金supported by the National Science and Technology Program(Grant No.2012BAK15B01)China National Special Fund for Earthquake Scientific Research in Public Interest(Grant Nos.201008001 and 201308011)+1 种基金the"Basic Science Research Plan"of the Institute of Earthquake ScienceChina Earthquake Administration(Grant No.DQJB12C08)
文摘We established a three-dimensional finite element model of the Anninghe-Zemuhe-Xiaojiang faults region using contact surfaces of different sizes to describe the spatial segmentation characteristics of the faults. Our model is based on constraints from GPS observations, models of the crust and upper mantle, precise earthquake locations, the tectonic stress field, the slip rate of the faults, and the rheology of the lithosphere in the Sichuan-Yunnan area. Considering the influence of strong earthquakes since A.D. 1327, we analyzed the main controlling factors of the characteristics of the strong earthquakes and also studied by numerical simulation the possible areas of future earthquake risk and their relationship with tectonic stress. The numerical results showed that the gravitational potential energy of the Qinghai-Tibet Plateau and the interaction of adjacent blocks are the main kinetic factors affecting the characteristics of the tectonic stress distribution. There appears to be some correspondence between the distribution of tectonic stress and the b value; however, we also found that some low b value locations correspond to regions of lower stress. This contradiction may be the result of some comprehensive factors, such as the release of strain energy caused by strong earthquakes.
基金supported by National Basic Research Program of China (Grant No. 2004CB418401)
文摘This study reconstructs the long-term evolution of river terraces over large spatial scales along the Anning River, western Sichuan, and identifies external factors controlling terrace formation. Pollen record analysis and terrace structure indicate that formation of the middle section of terraces I-III resulted from the interaction of changing climates and uplift of the margins of the Qinghai-Tibet Plateau. The relative influence of climate and uplift in terrace formation changes in different periods. The terraces reveal multiple, gradual uplift events on the eastern Qinghai-Tibet Plateau, which is of great significance for determining uplift mechanisms across the entire plateau.
