Impoverished sub-Saharan Africa(SSA)is under increasing environmental pressure from global environmental changes.It is now generally accepted in academic circles that economic development in SSA countries can cause en...Impoverished sub-Saharan Africa(SSA)is under increasing environmental pressure from global environmental changes.It is now generally accepted in academic circles that economic development in SSA countries can cause environmental pressure in other countries.However,there is research gap on the impact of economic assistance on environmental pressure in SSA countries and whether economic assistance causes spatial spillovers of environ-mental pressure between SSA countries.To better understand the impact of economic assistance on environmental pressures in SSA,a dynamic spatial Dubin panel model was developed.It helped us explore the spatial spillover effects of economic assistance on environmental pressures in recipient countries based on the panel data from 34 SSA countries.The results show that economic assistance had a positive stimulating effect on environmen-tal pressures of recipient countries,which means that the degree of human disturbance to the environment has deepened.Due to the regional correlation effect,neighboring countries were saddled with environmental pres-sures from the target country.Moreover,environmental pressures have time inertia,which can easily produce a snowball effect.The decomposition of effects shows that the impact of economic assistance on environmental pressures is relatively minor.Environmental pressures have spillover effects,so to deal with diffuse risks,joint regional prevention and control policies should be developed.展开更多
Group living animals form striking aggregation patterns and display synchronization,polarization,and collective intelligence.Though many col-lective behavioral studies have been conducted on small animals like insects...Group living animals form striking aggregation patterns and display synchronization,polarization,and collective intelligence.Though many col-lective behavioral studies have been conducted on small animals like insects and fish,research on large animals is still rare due to the limited availability of field collective data.We used drones to record videos and analyzed the decision-making and behavioral spatial patterns in orienta-tion of Kiang(Tibetan wild ass,Equus kiang).Leadership is unevenly distributed among Kiang,with the minority initiating majority behavior-shift decisions.Decisions of individual to join are driven by imitation between group members,and are largely dependent on the number of members who have already joined.Kiang respond to the behavior and position of neighbors through different strategies.They strongly polarize when moving,therefore adopting a linear alignment.When vigilant,orientation deviation increases as they form a tighter group.They remain scattered while feeding and,in that context,adopt a side-by-side alignment.This study reveals partially-shared decision-making among Kiang,whereby copying neighbors provides the wisdom to thrive in harsh conditions.This study also suggests that animals'spatial patterns in orientation depend largely ontheirbehavioral states inachieving synchronization.展开更多
.Nanochannel structures with a feature size deeply under the diffraction limit and a high aspect ratio hold huge biomedical significance,which is especially challenging to be realized on hard and brittle materials,suc....Nanochannel structures with a feature size deeply under the diffraction limit and a high aspect ratio hold huge biomedical significance,which is especially challenging to be realized on hard and brittle materials,such as silica,diamond,and sapphire.By simultaneously depositing the pulse energy on the surface and inside the sample,nanochannels with the smallest feature size of 18 nm(∼1∕30λ)and more than 200 aspect ratios are achieved inside silica,the mechanism of which can be concluded as the surface assisting material ejection effect.Both the experimental and theoretical results prove that the coaction of the superficial“hot domain”and internal hot domain dominates the generation of the nanochannels,which gives new insights into the laser-material interacting mechanisms and potentially promotes the corresponding application fields.展开更多
Remote mountainous villages are at risk of falling back into poverty,despite having been lifted out of extreme poverty.However,there has been a lack of focus on the factors contributing to povertyreturn in these villa...Remote mountainous villages are at risk of falling back into poverty,despite having been lifted out of extreme poverty.However,there has been a lack of focus on the factors contributing to povertyreturn in these villages,which making it difficult to understand the risks and their underlying causes.This study investigates the spatial distribution of 546 key assistance villages(KAVs)in the Liangshan mountainous region,a former poverty-stricken area,using the average nearest neighbor(ANN)and kernel density estimation(KDE)methods.Linear regression and geographically weighted regression(GWR)models are then employed to analyze the relationship between the KAVs'economy and potential povertyreturning factors.The results show that KAVs are primarily located in elevation ranges of 1800-2500 m(31.87%),with slopes of 6°-15°(42.67%)and 2-3 km from the township(28.94%).The distribution of KAVs exhibits distinct spatial clustering,forming four gathering areas.Several factors impact the KAVs'economy positively,including the normalized difference vegetation index(NDVI),built-up area,grassland,and education facilities,while elevation has a negative effect.The built-up area has the most critical impact on the rural economy,followed by NDVI and elevation.Additionally,education facilities and grassland areas also have significant effects.The study suggests promoting the Ex-situ Poverty Alleviation Relocation Program(ESPARP)and increasing rural built-up areas,grasslands,and educational facilities as practical measures for preventing poverty return and promoting economic development promotion in remote mountain villages.展开更多
In this article, our research aims to set up a geo-decisional system, more precisely we are particularly interested in the spatial analysis system of agricultural production in Madagascar. For this, we used the spatia...In this article, our research aims to set up a geo-decisional system, more precisely we are particularly interested in the spatial analysis system of agricultural production in Madagascar. For this, we used the spatial data warehouse technique based on the SOLAP spatial analysis tool. After having defined the concepts underlying these systems, we propose to address the research issues related to them from four points of view: needs study of the Malagasy Ministry of Agriculture, modeling of a multidimensional conceptual model according to the MultiDim model and the implementation of the system studied using GeoKettle, PostGIS, GeoServer, SPAGO BI and Géomondrian technologies. This new system helps improve the decision-making process for agricultural production in Madagascar.展开更多
In the remote sensing survey of the country land, cost and accuracy are a pair of conflicts, for which spatial sampling is a preferable solution with the aim of an optimal balance between economic input and accuracy o...In the remote sensing survey of the country land, cost and accuracy are a pair of conflicts, for which spatial sampling is a preferable solution with the aim of an optimal balance between economic input and accuracy of results, or in other words, acquirement of higher ac-curacy at less cost. Counter to drawbacks of previous application models, e.g. lack of compre-hensive and quantitative-comparison, the optimal decision-making model of spatial sampling is proposed. This model first acquires the possible accuracy-cost diagrams of multiple schemes through initial spatial exploration, then regresses them and standardizes them into a unified ref-erence frame, and finally produces the relatively optimal sampling scheme by using the discrete decision-making function (built by this paper) and comparing them in combination with the dia-grams. According to the test result in the survey of the arable land using remotely sensed data, the Sandwich model, while applied in the survey of the thin-feature and cultivated land areas with aerial photos, can better realize the goal of the best balance between investment and accuracy. With this case and other cases, it is shown that the optimal decision-making model of spatial sampling is a good choice in the survey of the farm areas using remote sensing, with its distin-guished benefit of higher precision at less cost or vice versa. In order to extensively apply the model in the surveys of natural resources, including arable farm areas, this paper proposes the prototype of development using the component technology, that could considerably improve the analysis efficiency by insetting program components within the software environment of GIS and RS.展开更多
基金This work is supported by National Natural Science Foundation of China(Grants No.72104246,71874203).
文摘Impoverished sub-Saharan Africa(SSA)is under increasing environmental pressure from global environmental changes.It is now generally accepted in academic circles that economic development in SSA countries can cause environmental pressure in other countries.However,there is research gap on the impact of economic assistance on environmental pressure in SSA countries and whether economic assistance causes spatial spillovers of environ-mental pressure between SSA countries.To better understand the impact of economic assistance on environmental pressures in SSA,a dynamic spatial Dubin panel model was developed.It helped us explore the spatial spillover effects of economic assistance on environmental pressures in recipient countries based on the panel data from 34 SSA countries.The results show that economic assistance had a positive stimulating effect on environmen-tal pressures of recipient countries,which means that the degree of human disturbance to the environment has deepened.Due to the regional correlation effect,neighboring countries were saddled with environmental pres-sures from the target country.Moreover,environmental pressures have time inertia,which can easily produce a snowball effect.The decomposition of effects shows that the impact of economic assistance on environmental pressures is relatively minor.Environmental pressures have spillover effects,so to deal with diffuse risks,joint regional prevention and control policies should be developed.
基金supported by Tibet Major Science and Technology Project(XZ201901-GA-06)National Natural Science Foundation of China(32101237&41871294)National key research and development program(2022YFC3202104).
文摘Group living animals form striking aggregation patterns and display synchronization,polarization,and collective intelligence.Though many col-lective behavioral studies have been conducted on small animals like insects and fish,research on large animals is still rare due to the limited availability of field collective data.We used drones to record videos and analyzed the decision-making and behavioral spatial patterns in orienta-tion of Kiang(Tibetan wild ass,Equus kiang).Leadership is unevenly distributed among Kiang,with the minority initiating majority behavior-shift decisions.Decisions of individual to join are driven by imitation between group members,and are largely dependent on the number of members who have already joined.Kiang respond to the behavior and position of neighbors through different strategies.They strongly polarize when moving,therefore adopting a linear alignment.When vigilant,orientation deviation increases as they form a tighter group.They remain scattered while feeding and,in that context,adopt a side-by-side alignment.This study reveals partially-shared decision-making among Kiang,whereby copying neighbors provides the wisdom to thrive in harsh conditions.This study also suggests that animals'spatial patterns in orientation depend largely ontheirbehavioral states inachieving synchronization.
基金supported by the National Natural Science Foundation of China under Grant Nos.12127806,62175195,and 61875158the International Joint Research Laboratory for Micro/Nano Manufacturing and Measurement Technologies,and the Fundamental Research Funds for the Central Universities.
文摘.Nanochannel structures with a feature size deeply under the diffraction limit and a high aspect ratio hold huge biomedical significance,which is especially challenging to be realized on hard and brittle materials,such as silica,diamond,and sapphire.By simultaneously depositing the pulse energy on the surface and inside the sample,nanochannels with the smallest feature size of 18 nm(∼1∕30λ)and more than 200 aspect ratios are achieved inside silica,the mechanism of which can be concluded as the surface assisting material ejection effect.Both the experimental and theoretical results prove that the coaction of the superficial“hot domain”and internal hot domain dominates the generation of the nanochannels,which gives new insights into the laser-material interacting mechanisms and potentially promotes the corresponding application fields.
基金supported by the Sichuan Province Science and Technology Support Program(Grant No.2020YFS0309)the Key Research Institution of Philosophy and Social Sciences in Sichuan Province:Research Center for Yi Culture(Grant No.YZWH 2303)the Key Research Institution of Philosophy and Social Sciences in Sichuan Province:Research Center of National Parks(Grant No.GJGY2023-YB001)。
文摘Remote mountainous villages are at risk of falling back into poverty,despite having been lifted out of extreme poverty.However,there has been a lack of focus on the factors contributing to povertyreturn in these villages,which making it difficult to understand the risks and their underlying causes.This study investigates the spatial distribution of 546 key assistance villages(KAVs)in the Liangshan mountainous region,a former poverty-stricken area,using the average nearest neighbor(ANN)and kernel density estimation(KDE)methods.Linear regression and geographically weighted regression(GWR)models are then employed to analyze the relationship between the KAVs'economy and potential povertyreturning factors.The results show that KAVs are primarily located in elevation ranges of 1800-2500 m(31.87%),with slopes of 6°-15°(42.67%)and 2-3 km from the township(28.94%).The distribution of KAVs exhibits distinct spatial clustering,forming four gathering areas.Several factors impact the KAVs'economy positively,including the normalized difference vegetation index(NDVI),built-up area,grassland,and education facilities,while elevation has a negative effect.The built-up area has the most critical impact on the rural economy,followed by NDVI and elevation.Additionally,education facilities and grassland areas also have significant effects.The study suggests promoting the Ex-situ Poverty Alleviation Relocation Program(ESPARP)and increasing rural built-up areas,grasslands,and educational facilities as practical measures for preventing poverty return and promoting economic development promotion in remote mountain villages.
文摘In this article, our research aims to set up a geo-decisional system, more precisely we are particularly interested in the spatial analysis system of agricultural production in Madagascar. For this, we used the spatial data warehouse technique based on the SOLAP spatial analysis tool. After having defined the concepts underlying these systems, we propose to address the research issues related to them from four points of view: needs study of the Malagasy Ministry of Agriculture, modeling of a multidimensional conceptual model according to the MultiDim model and the implementation of the system studied using GeoKettle, PostGIS, GeoServer, SPAGO BI and Géomondrian technologies. This new system helps improve the decision-making process for agricultural production in Madagascar.
基金the National Key Fundamental Research Development Planning Project(Grant No.KZCX1-Y-02)the High-tech Research and Development(863)Programme of the Ministry of Science and Technology(Grant No.2002AA135230)+1 种基金the Projects of the Chinese Academy of Sciences(Grant Nos.KZ951-A1-302,KZ951-A1-203, KJ951-B1-703) the National Natural Science Foundation of China(Grant Nos.49871064 , 69896250).
文摘In the remote sensing survey of the country land, cost and accuracy are a pair of conflicts, for which spatial sampling is a preferable solution with the aim of an optimal balance between economic input and accuracy of results, or in other words, acquirement of higher ac-curacy at less cost. Counter to drawbacks of previous application models, e.g. lack of compre-hensive and quantitative-comparison, the optimal decision-making model of spatial sampling is proposed. This model first acquires the possible accuracy-cost diagrams of multiple schemes through initial spatial exploration, then regresses them and standardizes them into a unified ref-erence frame, and finally produces the relatively optimal sampling scheme by using the discrete decision-making function (built by this paper) and comparing them in combination with the dia-grams. According to the test result in the survey of the arable land using remotely sensed data, the Sandwich model, while applied in the survey of the thin-feature and cultivated land areas with aerial photos, can better realize the goal of the best balance between investment and accuracy. With this case and other cases, it is shown that the optimal decision-making model of spatial sampling is a good choice in the survey of the farm areas using remote sensing, with its distin-guished benefit of higher precision at less cost or vice versa. In order to extensively apply the model in the surveys of natural resources, including arable farm areas, this paper proposes the prototype of development using the component technology, that could considerably improve the analysis efficiency by insetting program components within the software environment of GIS and RS.
