This article takes traditional residential buildings in Ningxia region as the starting point,and through field research and data analysis,demonstrates the specific elements of the spatial composition of traditional re...This article takes traditional residential buildings in Ningxia region as the starting point,and through field research and data analysis,demonstrates the specific elements of the spatial composition of traditional residential buildings and the common forms of courtyard space.The study summarizes the regional cultural characteristics of traditional residential buildings in the region,laying a foundation for subsequent research and providing some reference basis.展开更多
In view of the aging population in the country,college communities can better meet the needs of the elderly in the community by developing hardware facilities,environmental resources,and management systems.However,in ...In view of the aging population in the country,college communities can better meet the needs of the elderly in the community by developing hardware facilities,environmental resources,and management systems.However,in China,the research on elderly care in colleges is still in its infancy.The paper presents an analysis on the characteristics of the elderly group,outdoor activities,and space characteristics in college communities through the field survey of a university in the north,questionnaire survey and interview with the elderly.Suggestions for optimizing the outdoor activities space of the elderly in college communities are then provided,hoping to provide some reference for relevant research.展开更多
Based on the connotation of urban resilience and the main contradictions of China's urbanization,urban resilience is placed within the main daily activities contradictory scene of the urban man-land system to buil...Based on the connotation of urban resilience and the main contradictions of China's urbanization,urban resilience is placed within the main daily activities contradictory scene of the urban man-land system to build a theoretical framework of urban activity resilience.Relying on geographic big data,this study identifies the spatial characteristics of activity resilience,reveals the impact of activity environment on activity resilience in Nanjing,and proposes countermeasures.The main conclusions are as follows.1)Activity resilience presents a composite spatial structure of circles and clusters,and most areas are resilient but at a low level.2)There are significantly positive and negative global autocorrelation between activity resilience and activity scale,and activity stability.Simultaneously,there also exists a local spatial autocorrelation with the opposite positive and negative trends.3)Activity environment has a significant effect on activity resilience,and the degree and direction of influence among different dimensions and regions are heterogeneous.4)For activity resilience,it is necessary to increase the matching degree between the scale and stability of activities,and reduce the excessive concentration and flow of activities.For the activity environment,it is necessary to improve the accessibility of the ecological environment,strengthen the high-quality supply of the infrastructure environment,optimize the balance of the location environment,and promote the inclusiveness of the social environment.展开更多
Traditional Chinese architecture can be regarded as the building of culture, i.e. image of the architecture can be considered as a certain externalized means of traditional culture. And space as a hero of architecture...Traditional Chinese architecture can be regarded as the building of culture, i.e. image of the architecture can be considered as a certain externalized means of traditional culture. And space as a hero of architecture refl ects characteristics of culture using its form and content. This research explored the common architectural element—gallery from cultural perspective, and proposed gallery as a kind of fuzzy intermediary space, then analyzed its intermediary nature from the perspective of fuzziness, transition, boundary, and placeness, and also its spatial order from the perspective of directivity, dynamics, diachronism and orderliness. On this basis, spatial characteristics of gallery beneath the surface were explored.展开更多
This paper, based on the autonomy concept, continues to investigate hierarchical forms and spatial structure of ecosystems. The former can lead to limits for the selection of the component parts of an ecosystem and a ...This paper, based on the autonomy concept, continues to investigate hierarchical forms and spatial structure of ecosystems. The former can lead to limits for the selection of the component parts of an ecosystem and a distinction between its endogenous and exogenous variables; and the latter can be lead to a hypothesis of the space of an ecosystem: the space of an ecosystem = its habitat area + supporting area + impact area, and two characteristics of ecosystems, space-overlapping and the area of ecosystem space, have been further studied referring to human activities.展开更多
The temporal and spatial characteristics of seasonal hydrogen storage will play a very important role in the coupling of multi-energy systems.This essay believes that there are several key issues worth noting in the s...The temporal and spatial characteristics of seasonal hydrogen storage will play a very important role in the coupling of multi-energy systems.This essay believes that there are several key issues worth noting in the seasonal hydrogen storage coupled multi-energy system,namely,hydrogen storage methods,coupling models,and benefit evaluation.Through research,this article innovatively divides seasonal hydrogen storage into two types:space transfer hydrogen storage technology and time transfer physical property conversion hydrogen storage technology.Then sort out the two most typical seasonal hydrogen storage multi-energy system application scenarios and their hydrogen storage unit models.Finally,it is shown that hydrogen storage methods should be selected according to different periods of time and regions,and the benefits should be evaluated before they can be used in practice.This review study is applicable to the process of coupling seasonal hydrogen storage in multi-energy systems.Hydrogen energy is used as an intermediate energy link for the selection,evaluation and modeling of the optimal selection and rational utilization.展开更多
[Objective] The research aimed to study temporal and spatial characteristics of climate variation in Hebei area during 1956-2007. [Method] Based on the data from 23 weather stations evenly distributed over Hebei area ...[Objective] The research aimed to study temporal and spatial characteristics of climate variation in Hebei area during 1956-2007. [Method] Based on the data from 23 weather stations evenly distributed over Hebei area (included Beijing and Tianjin) during 1956-2007, by using statistical analytic method, the temporal and spatial variation characteristics of main meteorological factors (temperature and precipitation, etc.) in the area were analyzed. The variation fact and evolution rule of climate in the area in 52 years were discussed. [Result] In Hebei area during 1956-2007, the annual and four-season temperatures both presented wavy rise trends. The temperature increment in winter was the maximum, contributing the most to the annual temperature elevation in this area. The temperatures in the whole district all presented rise trends, and the variation difference had regularity. The annual and four-season rainfalls both had large fluctuation amplitudes, following different linear variation trends. The annual rainfall overall presented wavy decrease trends. The spatial difference of rainfall variation was significant. The rainfalls in the whole district all presented decrease trends. The decrease amplitude presented low-high-low pattern from the northeast to the southwest. The potential evaporation capacity over the whole district was the highest in the 1960s, and decreased ever since instead of increasing with the temperature. The potential evaporation capacities of each season also presented decline trends. Except in Fengning and Yuxian, the evaporation capacities of other stations in the whole district all presented decline trends. The relative humidity slightly decreased as time, with the exception of Chengde, Qinhuangdao and Nangong. The sunshine hours had a clear decrease trends. [Conclusion] The research provided scientific basis for realizing regional sustainable development, improving ecological environment and people’s life quality.展开更多
Settlement of the minorities is a particular heterogeneous space in a metropolis,and such spaces exist as inseparable parts of the city for historical,social and geopolitical reasons.Taking Tibetan settlement in Wuhou...Settlement of the minorities is a particular heterogeneous space in a metropolis,and such spaces exist as inseparable parts of the city for historical,social and geopolitical reasons.Taking Tibetan settlement in Wuhou District,Chengdu City for example,this study analyzed spatial features and evolution history of minority settlements,and explored how to respect and accept historic signifi cance and cultural value of these heterogeneous spaces during the rapid urban development,and then use them reasonably and reform creatively,so as to maintain their original spatial features and integrate the spaces into the overall urban structure.展开更多
The physical space and viewing perception of streets and lanes in traditional towns of Sichuan and Chongqing in China are deeply influenced by the terrain conditions of the area.The adaptation of the geographical envi...The physical space and viewing perception of streets and lanes in traditional towns of Sichuan and Chongqing in China are deeply influenced by the terrain conditions of the area.The adaptation of the geographical environment with the change of the terrain height difference creates rich spatial rhythm changes in the spatial continuity and opening and closing processing of streets and lanes.The aspect ratio of building elevation and street front of frontage makes the street and lane scale adapt to the different functional requirements of business and life.At the same time,the changeable terrain height difference creates the composition level of street landscape perception of close shot,medium shot and long shot,which constitutes the unique regional charm of streets and lanes in traditional towns of Sichuan and Chongqing.展开更多
Defensive traditional architecture research is critical to the understanding of the ethnic history and multiethnic villages.Currently,there are few studies on the combination of traditional architecture and multiethni...Defensive traditional architecture research is critical to the understanding of the ethnic history and multiethnic villages.Currently,there are few studies on the combination of traditional architecture and multiethnicity,and most of the defensive traditional buildings in multiethnic villages of Guangxi are facing the plight of being destroyed and abandoned.The aim of this research is to identify the spatial characteristics,commonalities,and differences of Guangxi’s defensive traditional architecture with Mozhuang Village and Guxietun Village as the examples,in order to preserve the architectural and ethnic components of these villages.This research uses the four research methods:literature review,field research,observation and space syntax analysis,and it summarizes the three results from the five aspects:plan,elevation,construction material,masonry and decoration.Results showed that the spatial characteristics are dominated by the ethnic group with the higher technological,cultural or economic level,and there are both commonalities and differences in defensive traditional architecture in multiethnic villages.Based on the three study results,this research proposes some overall suggestions toward traditional villages and architecture improvement in ethnic areas.展开更多
Through literature research, field research and urban design analysis methods, based on the self-organization theory, the evolution characteristics of the settlement space of Anju Ancient Town with significant charact...Through literature research, field research and urban design analysis methods, based on the self-organization theory, the evolution characteristics of the settlement space of Anju Ancient Town with significant characteristics of traditional mountain settlements were analyzed, and then its internal and external influencing factors were summarized. Finally, appropriate protection and development strategies were proposed, such as reasonably planning functional zones, breaking through the single structure, and creating a good living cultural environment. The innovation of this study is that it integrates the self-organization theory into the cognition of traditional mountain settlement space, and discusses the connection between the mountain settlement space and the traditional regional context under the modern development concept, so as to seek the benign protection and reasonable development of traditional mountain settlement space.展开更多
Based on the monthly precipitation data for the period 1960-2008 from 616 rainfall stations and the phenology data of main grain crops, the spatial characteristics of drought hazard in China were investigated at a 10 ...Based on the monthly precipitation data for the period 1960-2008 from 616 rainfall stations and the phenology data of main grain crops, the spatial characteristics of drought hazard in China were investigated at a 10 km×10 km grid-cell scale using a GIS-based drought hazard assessment model, which was constructed by using 3-month Standard Precipitation Index (SPI). Drought-prone areas and heavy drought centers were also identified in this study. The spatial distribution of drought hazard in China shows apparent east-west difference, with the eastern part of China being far more hazardous than the western part. High hazard areas are common in the eastern and central parts of Inner Mongolian Plateau, the central part of Northeast China Plain, the northern part of Heilongjiang, the southeastern part of Qinghai-Tibet Plateau, the central and southern parts of Loess Plateau, the southern part of North China Plain, the northern and southern parts of Yangtze River Plain, and Yun- nan-Guizhou Plateau. Furthermore, obvious differences in drought hazard were found both within and between different agricultural zonings.展开更多
In this article, results obtained from wideband multiple-input multiple-output channel measurements at 4.9 GHz are presented. Measurements were performed in an indoor hotspot scenario with both line-of-sight and non-l...In this article, results obtained from wideband multiple-input multiple-output channel measurements at 4.9 GHz are presented. Measurements were performed in an indoor hotspot scenario with both line-of-sight and non-line-of-sight propagation conditions. Vertical polarized uniform linear arrays (ULAs) with different antenna spacing and orientation were utilized for investigating the impact of antenna configurations on the system performance. Based on measured channel impulse responses, the spatial correlation of ULA is analyzed and compared with the theoretical values calculated from the power azimuth spectrum. Following that, the eigenvalue statistics and capacity with respect to antenna spacing and orientation are given and compared. The diversity-multiplexing tradeoff (DMT) of measured channels at operational signal-to-noise ratio (SNR) is also presented. The reason why the DMT of measured channels is much lower than that ofi.i.d. Rayleigh channels is specified.展开更多
Spatial characteristic is an important indicator of remote sensor performance,and space-borne infrared hyperspectral sounder is the frontier of atmospheric vertical sounding technology.In this paper,the formation mech...Spatial characteristic is an important indicator of remote sensor performance,and space-borne infrared hyperspectral sounder is the frontier of atmospheric vertical sounding technology.In this paper,the formation mechanism of the vertical spatial characteristics involved in the space-borne infrared hyperspectral sounding data are analyzed in detail,which shows that the vertical spatial characteristics of sounding data depends not only on the spectral channels and their waveband coverage,but also the specific atmospheric parameter and its specific variation interested.The indicators of vertical spatial characteristics are defined and their mathematical models are established based on the mechanism analyses.These models are applied to the vertical spatial characteristic evaluation of atmospheric temperature sounding for FY-4A GIIRS,which is the first space-borne infrared hyperspectral atmospheric sounder in geostationary orbit.It is concluded that FY-4A GIIRS can sound the vertical temperature distribution in whole troposphere and lower stratosphere with height<35 km.This study can provide basic information to support the improvement of infrared hyperspectral sounder and the trace of vertical spatial characteristics of atmospheric inversion products.展开更多
As cultural facilities,physical bookstore is an important part of urban infrastructure.Influenced by the development of social economy and the internet,physical bookstores also have become a combination of cultural sp...As cultural facilities,physical bookstore is an important part of urban infrastructure.Influenced by the development of social economy and the internet,physical bookstores also have become a combination of cultural space and tourism experience.In this case,it is necessary to explore the spatial characteristics and influencing factors of physical bookstores.This study uses Density-Based Spatial Clustering of Applications with Noise(DBSCAN),spatial analysis and geographical detectors to calculate the spatial distribution pattern and factors influencing physical bookstores in national central cities/municipality(hereafter using cities)in western China.Based on spatial data,population density,road density and other data,this study constructed a data set of the influencing factors of physical bookstores,consisting of 11 factors along 6 dimensions for 3 national central cities in western China.The results are as follows:first,the spatial distribution pattern of physical bookstores in Xi’an,Chengdu,and Chongqing is unbalanced.The spatial distribution of physical bookstores in Xi’an and Chongqing is from southwest to northeast and are relatively clustered,while those in Chengdu are relatively discrete.Second,the spatial distribution pattern of physical bookstores has been formed under the influence of different factors.The intensity and significance of influencing factors differ in the case cities.However,in general,the social factor,business factor,the density of research facilities,tourism factor and road density are the main driving factors in the three cities.There is a synergistic relationship between public libraries and physical bookstores.Third,the explanatory power becomes stronger after the interaction between various factors.In Xi’an and Chengdu,the density of communities and the density of research facilities have stronger explanatory power for the dependent variable after interacting with other factors.However,in Chongqing,the traffic factors have stronger explanatory power for the dependent variable after interacting with other factors.The results could provide a practical reference for the sustainable development of physical bookstores and encourage a love of reading among the public.展开更多
In response to the strategic call for the " Great Protection" of the Yangtze River Economic Belt and to fulfill the important historical tasks assigned by the state to the provinces and cities of the area,th...In response to the strategic call for the " Great Protection" of the Yangtze River Economic Belt and to fulfill the important historical tasks assigned by the state to the provinces and cities of the area,the Yangtze River Economic Belt is adjusting the agricultural industry structure,optimizing the input-output ratio,and ensuring stable and sustainable agricultural production. Based on the combination of the three-stage Data Envelopment Analysis( DEA) model and cluster analysis,this study examined the Yangtze River Economic Belt from 2008 to 2018 to measure its agricultural production efficiency and to analyze its temporal and spatial characteristics. Studies showed that exogenous environmental factors significantly( P < 5%) impacted agricultural production efficiency in the Yangtze River Economic Zone,and there were temporal and spatial differences. These included:(1) after excluding environmental factors,the overall agricultural production efficiency of the Yangtze River Economic Zone had improved. Sichuan Province and Jiangsu Province were at the forefront of efficiency,whereas the agricultural production efficiency of Shanghai had declined obviously.(2) The agricultural production efficiency of the Yangtze River Economic Belt varied year by year,with fluctuating development. The middle reaches of the Yangtze River had advanced agricultural production efficiency more than the upstream and downstream regions,and the agricultural production efficiency of the individual provinces did not match their economic and social development.(3) Increases in labor,land,irrigation,and other input factors increased agriculture production efficiency,and there was no correlation between fiscal investment,per capita gross domestic product( GDP) and agricultural production efficiency,while the disaster-affected area had a significantly negative impact on agricultural production efficiency.展开更多
As significant evidence of permafrost degradation,thermokarst lakes play an important role in the permafrost regions by regulating hydrology,ecology,and biogeochemistry.In the Sources Area of the Yellow River(SAYR),pe...As significant evidence of permafrost degradation,thermokarst lakes play an important role in the permafrost regions by regulating hydrology,ecology,and biogeochemistry.In the Sources Area of the Yellow River(SAYR),permafrost degradation has accelerated since the 1980s,and numerous thermokarst lakes have been discovered.In this paper,we use Sentinel-2 images to extract thermokarst lake boundaries and perform a regional-scale study on their geometry across the permafrost region in the SAYR.We also explored the spatiotemporal variations and potential drivers from the perspectives of the permafrost,climate,terrain and vegetation conditions.The results showed that there were 47,518 thermokarst lakes in 2021 with a total area of 190.22×106 m^(2),with an average size of 4,003.3 m^(2).The 44,928 ponds(≤10,000 m^(2))predominated the whole lake number(94.1%)but contributed to a small portion of the total lake area(28.8%).With 2,590 features(5.9%),small-sized(10,000 to 100,000 m^(2))and large-sized lakes(>100,000 m^(2))constituted up to 71.2%of the total lake area.Thermokarst lakes developed more significantly in warm permafrost regions than in cold permafrost areas;74.1%of lakes with a total area of 119.6×106 m^(2)(62.9%),were distributed in warm permafrost regions.Most thermokarst lakes were likely to develop within the elevation range of 4,500~4,800 m,on flat terrain(slope<10°),on SE and S aspects and in alpine meadow areas.The thermokarst lakes in the study region experienced significant shrinkage between 1990 and 2021,characterized by obvious lake drainage;the lake numbers decreased by 5418(56.1%),with a decreasing area of 58.63×106 m^(2)(49.0%).This shrinkage of the thermokarst lake area was attributable mainly to the intensified degradation of rich-ice permafrost thawing arising from continued climate warming,despite the wetting climatic trend.展开更多
The distribution characteristics of park green space in Wuhan City were studied by standard deviation ellipse(SDE)method,average nearest neighbor index,kernel density estimation(KDE)method and scale index method.At th...The distribution characteristics of park green space in Wuhan City were studied by standard deviation ellipse(SDE)method,average nearest neighbor index,kernel density estimation(KDE)method and scale index method.At the same time,the influencing factors of its distribution were discussed from three aspects of nature,social economy and culture with a geographical detector.The results show that(1)the distribution of park green space in Wuhan was relatively concentrated,and the directionality was not strong.The distribution mode was clustered mode.There were four main aggregation centers,which were located in Jianghan District,Qingshan District,Dongxihu District and Wuchang District respectively.Among them,the scale index of Jianghan District was the highest,up to 0.5902,while that of Xinzhou district was the lowest,only 0.0047.(2)The order of interpretation intensity of park green space distribution in Wuhan was population density(0.382)>regional GDP(0.278)>location of historical relics(0.165)>urbanization rate(0.136)>watershed zoning(0.069)>altitude(0.012).(3)The interaction of population density and watershed zoning had the strongest explanation for the distribution of park green space in Wuhan.Except for the influence of population density,the interaction of urbanization rate and regional GDP had the strongest explanation for the distribution of park green space in Wuhan.展开更多
With a focus on the difficulty of quantitatively describing the degree of nonuniformity of temporal and spatial distributions of water resources, quantitative research was carried out on the temporal and spatial distr...With a focus on the difficulty of quantitatively describing the degree of nonuniformity of temporal and spatial distributions of water resources, quantitative research was carried out on the temporal and spatial distribution characteristics of water resources in Guangdong Province from 1956 to 2000 based on a cloud model. The spatial variation of the temporal distribution characteristics and the temporal variation of the spatial distribution characteristics were both analyzed. In addition, the relationships between the numerical characteristics of the cloud model of temporal and spatial distributions of water resources and precipitation were also studied. The results show that, using a cloud model, it is possible to intuitively describe the temporal and spatial distribution characteristics of water resources in cloud images. Water resources in Guangdong Province and their temporal and spatial distribution characteristics are differentiated by their geographic locations. Downstream and coastal areas have a larger amount of water resources with greater uniformity and stronger stability in terms of temporal distribution. Regions with more precipitation possess larger amounts of water resources, and years with more precipitation show greater nonuniformity in the spatial distribution of water resources. The correlation between the nonuniformity of the temporal distribution and local precipitation is small, and no correlation is found between the stability of the nonuniformity of the temporal and spatial distributions of water resources and precipitation. The amount of water resources in Guangdong Province shows an increasing trend from 1956 to 2000, the nonuniformity of the spatial distribution of water resources declines, and the stability of the nonuniformity of the spatial distribution of water resources is enhanced.展开更多
The spatial distributions of the electron density and the mean electron energy of argon radio frequency (rf) glow discharge plasma in a plasma-enhanced chemical vapour deposition (PECVD) system have been investiga...The spatial distributions of the electron density and the mean electron energy of argon radio frequency (rf) glow discharge plasma in a plasma-enhanced chemical vapour deposition (PECVD) system have been investigated using an established movable Langmuir probe. The results indicate that in the axial direction the electron density tends to peak at midway between the two electrodes while the axial variation trend of mean electron energy is different from that of the electron density, the mean electron energy is high near the electrodes. And the mean electron energy near the cathode is much higher than that near the anode. This article focuses on the radial distribution of electron density and mean electron energy. A proposed theoretical model distribution agrees well with the experimental one: the electron density and the mean electron energy both increase from the centre of the glow to the edge of electrodes. This is useful for better understanding the discharge mechanism and searching for a better deposition condition to improve thin film quality.展开更多
基金The National Social Science Foundation of the Arts Key Project“Research on the Architecture Art and Folk Culture of Chinese Traditional Houses on the Land“Silk Road”(Number:18AH008)”Project entrusted by the Ministry of Culture and Tourism:“Yellow River Culture and Chinese Civilization:Rescue Research on Shaanxi Traditional Residential Buildings and Residential Folk Culture” (No.21HH02)Shaanxi Province High-level Talents Special Support Program.
文摘This article takes traditional residential buildings in Ningxia region as the starting point,and through field research and data analysis,demonstrates the specific elements of the spatial composition of traditional residential buildings and the common forms of courtyard space.The study summarizes the regional cultural characteristics of traditional residential buildings in the region,laying a foundation for subsequent research and providing some reference basis.
文摘In view of the aging population in the country,college communities can better meet the needs of the elderly in the community by developing hardware facilities,environmental resources,and management systems.However,in China,the research on elderly care in colleges is still in its infancy.The paper presents an analysis on the characteristics of the elderly group,outdoor activities,and space characteristics in college communities through the field survey of a university in the north,questionnaire survey and interview with the elderly.Suggestions for optimizing the outdoor activities space of the elderly in college communities are then provided,hoping to provide some reference for relevant research.
基金Under the auspices of National Social Science Fund of China(No.20AZD040)the Program B for Outstanding PhD Candidate of Nanjing University(No.202002B103)。
文摘Based on the connotation of urban resilience and the main contradictions of China's urbanization,urban resilience is placed within the main daily activities contradictory scene of the urban man-land system to build a theoretical framework of urban activity resilience.Relying on geographic big data,this study identifies the spatial characteristics of activity resilience,reveals the impact of activity environment on activity resilience in Nanjing,and proposes countermeasures.The main conclusions are as follows.1)Activity resilience presents a composite spatial structure of circles and clusters,and most areas are resilient but at a low level.2)There are significantly positive and negative global autocorrelation between activity resilience and activity scale,and activity stability.Simultaneously,there also exists a local spatial autocorrelation with the opposite positive and negative trends.3)Activity environment has a significant effect on activity resilience,and the degree and direction of influence among different dimensions and regions are heterogeneous.4)For activity resilience,it is necessary to increase the matching degree between the scale and stability of activities,and reduce the excessive concentration and flow of activities.For the activity environment,it is necessary to improve the accessibility of the ecological environment,strengthen the high-quality supply of the infrastructure environment,optimize the balance of the location environment,and promote the inclusiveness of the social environment.
基金Sponsored by 2015 Special Fund for Young Teachers’Teaching Reform in Liaoning University of Science and Technology(QNJJ–2015–09)
文摘Traditional Chinese architecture can be regarded as the building of culture, i.e. image of the architecture can be considered as a certain externalized means of traditional culture. And space as a hero of architecture refl ects characteristics of culture using its form and content. This research explored the common architectural element—gallery from cultural perspective, and proposed gallery as a kind of fuzzy intermediary space, then analyzed its intermediary nature from the perspective of fuzziness, transition, boundary, and placeness, and also its spatial order from the perspective of directivity, dynamics, diachronism and orderliness. On this basis, spatial characteristics of gallery beneath the surface were explored.
文摘This paper, based on the autonomy concept, continues to investigate hierarchical forms and spatial structure of ecosystems. The former can lead to limits for the selection of the component parts of an ecosystem and a distinction between its endogenous and exogenous variables; and the latter can be lead to a hypothesis of the space of an ecosystem: the space of an ecosystem = its habitat area + supporting area + impact area, and two characteristics of ecosystems, space-overlapping and the area of ecosystem space, have been further studied referring to human activities.
基金funded by two projects of Science and Technology Commission of Shanghai Municipality,Grant Nos.20DZ1206300,18DZ1203304,18DZ1203403.
文摘The temporal and spatial characteristics of seasonal hydrogen storage will play a very important role in the coupling of multi-energy systems.This essay believes that there are several key issues worth noting in the seasonal hydrogen storage coupled multi-energy system,namely,hydrogen storage methods,coupling models,and benefit evaluation.Through research,this article innovatively divides seasonal hydrogen storage into two types:space transfer hydrogen storage technology and time transfer physical property conversion hydrogen storage technology.Then sort out the two most typical seasonal hydrogen storage multi-energy system application scenarios and their hydrogen storage unit models.Finally,it is shown that hydrogen storage methods should be selected according to different periods of time and regions,and the benefits should be evaluated before they can be used in practice.This review study is applicable to the process of coupling seasonal hydrogen storage in multi-energy systems.Hydrogen energy is used as an intermediate energy link for the selection,evaluation and modeling of the optimal selection and rational utilization.
基金Supported by Science and Technology Plan Item of Hebei Academy of Sciences (10115,09927,07108)Plan Item of Hebei Science and Technology Department (09276722)
文摘[Objective] The research aimed to study temporal and spatial characteristics of climate variation in Hebei area during 1956-2007. [Method] Based on the data from 23 weather stations evenly distributed over Hebei area (included Beijing and Tianjin) during 1956-2007, by using statistical analytic method, the temporal and spatial variation characteristics of main meteorological factors (temperature and precipitation, etc.) in the area were analyzed. The variation fact and evolution rule of climate in the area in 52 years were discussed. [Result] In Hebei area during 1956-2007, the annual and four-season temperatures both presented wavy rise trends. The temperature increment in winter was the maximum, contributing the most to the annual temperature elevation in this area. The temperatures in the whole district all presented rise trends, and the variation difference had regularity. The annual and four-season rainfalls both had large fluctuation amplitudes, following different linear variation trends. The annual rainfall overall presented wavy decrease trends. The spatial difference of rainfall variation was significant. The rainfalls in the whole district all presented decrease trends. The decrease amplitude presented low-high-low pattern from the northeast to the southwest. The potential evaporation capacity over the whole district was the highest in the 1960s, and decreased ever since instead of increasing with the temperature. The potential evaporation capacities of each season also presented decline trends. Except in Fengning and Yuxian, the evaporation capacities of other stations in the whole district all presented decline trends. The relative humidity slightly decreased as time, with the exception of Chengde, Qinhuangdao and Nangong. The sunshine hours had a clear decrease trends. [Conclusion] The research provided scientific basis for realizing regional sustainable development, improving ecological environment and people’s life quality.
基金Sponsored by Youth Program of National Natural Science Fund(51108379)
文摘Settlement of the minorities is a particular heterogeneous space in a metropolis,and such spaces exist as inseparable parts of the city for historical,social and geopolitical reasons.Taking Tibetan settlement in Wuhou District,Chengdu City for example,this study analyzed spatial features and evolution history of minority settlements,and explored how to respect and accept historic signifi cance and cultural value of these heterogeneous spaces during the rapid urban development,and then use them reasonably and reform creatively,so as to maintain their original spatial features and integrate the spaces into the overall urban structure.
文摘The physical space and viewing perception of streets and lanes in traditional towns of Sichuan and Chongqing in China are deeply influenced by the terrain conditions of the area.The adaptation of the geographical environment with the change of the terrain height difference creates rich spatial rhythm changes in the spatial continuity and opening and closing processing of streets and lanes.The aspect ratio of building elevation and street front of frontage makes the street and lane scale adapt to the different functional requirements of business and life.At the same time,the changeable terrain height difference creates the composition level of street landscape perception of close shot,medium shot and long shot,which constitutes the unique regional charm of streets and lanes in traditional towns of Sichuan and Chongqing.
文摘Defensive traditional architecture research is critical to the understanding of the ethnic history and multiethnic villages.Currently,there are few studies on the combination of traditional architecture and multiethnicity,and most of the defensive traditional buildings in multiethnic villages of Guangxi are facing the plight of being destroyed and abandoned.The aim of this research is to identify the spatial characteristics,commonalities,and differences of Guangxi’s defensive traditional architecture with Mozhuang Village and Guxietun Village as the examples,in order to preserve the architectural and ethnic components of these villages.This research uses the four research methods:literature review,field research,observation and space syntax analysis,and it summarizes the three results from the five aspects:plan,elevation,construction material,masonry and decoration.Results showed that the spatial characteristics are dominated by the ethnic group with the higher technological,cultural or economic level,and there are both commonalities and differences in defensive traditional architecture in multiethnic villages.Based on the three study results,this research proposes some overall suggestions toward traditional villages and architecture improvement in ethnic areas.
基金the General Project of National Natural Science Foundation of China(51778078)General Project of Natural Science Foundation of Chongqing City(cstc2021jcyj-msxmX1055).
文摘Through literature research, field research and urban design analysis methods, based on the self-organization theory, the evolution characteristics of the settlement space of Anju Ancient Town with significant characteristics of traditional mountain settlements were analyzed, and then its internal and external influencing factors were summarized. Finally, appropriate protection and development strategies were proposed, such as reasonably planning functional zones, breaking through the single structure, and creating a good living cultural environment. The innovation of this study is that it integrates the self-organization theory into the cognition of traditional mountain settlement space, and discusses the connection between the mountain settlement space and the traditional regional context under the modern development concept, so as to seek the benign protection and reasonable development of traditional mountain settlement space.
基金National Natural Science Foundation of China, No.40601091 No.40801216+1 种基金 National Key Technology R&D Program of China, No.2006BAD20B02 No.2006BAC 18B06
文摘Based on the monthly precipitation data for the period 1960-2008 from 616 rainfall stations and the phenology data of main grain crops, the spatial characteristics of drought hazard in China were investigated at a 10 km×10 km grid-cell scale using a GIS-based drought hazard assessment model, which was constructed by using 3-month Standard Precipitation Index (SPI). Drought-prone areas and heavy drought centers were also identified in this study. The spatial distribution of drought hazard in China shows apparent east-west difference, with the eastern part of China being far more hazardous than the western part. High hazard areas are common in the eastern and central parts of Inner Mongolian Plateau, the central part of Northeast China Plain, the northern part of Heilongjiang, the southeastern part of Qinghai-Tibet Plateau, the central and southern parts of Loess Plateau, the southern part of North China Plain, the northern and southern parts of Yangtze River Plain, and Yun- nan-Guizhou Plateau. Furthermore, obvious differences in drought hazard were found both within and between different agricultural zonings.
基金supported by the China Important National Science and Technology Specific Projects (2009ZX03007-003-01)Hi-Tech Research and Development Program of China (2009AA011502)
文摘In this article, results obtained from wideband multiple-input multiple-output channel measurements at 4.9 GHz are presented. Measurements were performed in an indoor hotspot scenario with both line-of-sight and non-line-of-sight propagation conditions. Vertical polarized uniform linear arrays (ULAs) with different antenna spacing and orientation were utilized for investigating the impact of antenna configurations on the system performance. Based on measured channel impulse responses, the spatial correlation of ULA is analyzed and compared with the theoretical values calculated from the power azimuth spectrum. Following that, the eigenvalue statistics and capacity with respect to antenna spacing and orientation are given and compared. The diversity-multiplexing tradeoff (DMT) of measured channels at operational signal-to-noise ratio (SNR) is also presented. The reason why the DMT of measured channels is much lower than that ofi.i.d. Rayleigh channels is specified.
文摘Spatial characteristic is an important indicator of remote sensor performance,and space-borne infrared hyperspectral sounder is the frontier of atmospheric vertical sounding technology.In this paper,the formation mechanism of the vertical spatial characteristics involved in the space-borne infrared hyperspectral sounding data are analyzed in detail,which shows that the vertical spatial characteristics of sounding data depends not only on the spectral channels and their waveband coverage,but also the specific atmospheric parameter and its specific variation interested.The indicators of vertical spatial characteristics are defined and their mathematical models are established based on the mechanism analyses.These models are applied to the vertical spatial characteristic evaluation of atmospheric temperature sounding for FY-4A GIIRS,which is the first space-borne infrared hyperspectral atmospheric sounder in geostationary orbit.It is concluded that FY-4A GIIRS can sound the vertical temperature distribution in whole troposphere and lower stratosphere with height<35 km.This study can provide basic information to support the improvement of infrared hyperspectral sounder and the trace of vertical spatial characteristics of atmospheric inversion products.
基金Under the auspices of National Natural Science Foundation of China(No.41271179)。
文摘As cultural facilities,physical bookstore is an important part of urban infrastructure.Influenced by the development of social economy and the internet,physical bookstores also have become a combination of cultural space and tourism experience.In this case,it is necessary to explore the spatial characteristics and influencing factors of physical bookstores.This study uses Density-Based Spatial Clustering of Applications with Noise(DBSCAN),spatial analysis and geographical detectors to calculate the spatial distribution pattern and factors influencing physical bookstores in national central cities/municipality(hereafter using cities)in western China.Based on spatial data,population density,road density and other data,this study constructed a data set of the influencing factors of physical bookstores,consisting of 11 factors along 6 dimensions for 3 national central cities in western China.The results are as follows:first,the spatial distribution pattern of physical bookstores in Xi’an,Chengdu,and Chongqing is unbalanced.The spatial distribution of physical bookstores in Xi’an and Chongqing is from southwest to northeast and are relatively clustered,while those in Chengdu are relatively discrete.Second,the spatial distribution pattern of physical bookstores has been formed under the influence of different factors.The intensity and significance of influencing factors differ in the case cities.However,in general,the social factor,business factor,the density of research facilities,tourism factor and road density are the main driving factors in the three cities.There is a synergistic relationship between public libraries and physical bookstores.Third,the explanatory power becomes stronger after the interaction between various factors.In Xi’an and Chengdu,the density of communities and the density of research facilities have stronger explanatory power for the dependent variable after interacting with other factors.However,in Chongqing,the traffic factors have stronger explanatory power for the dependent variable after interacting with other factors.The results could provide a practical reference for the sustainable development of physical bookstores and encourage a love of reading among the public.
基金Supported by the Strategic Leading Science and Technology Project (Class A)of Chinese Academy of Sciences (XDA23020101)the National Natural Science Foundation of China (41801129)。
文摘In response to the strategic call for the " Great Protection" of the Yangtze River Economic Belt and to fulfill the important historical tasks assigned by the state to the provinces and cities of the area,the Yangtze River Economic Belt is adjusting the agricultural industry structure,optimizing the input-output ratio,and ensuring stable and sustainable agricultural production. Based on the combination of the three-stage Data Envelopment Analysis( DEA) model and cluster analysis,this study examined the Yangtze River Economic Belt from 2008 to 2018 to measure its agricultural production efficiency and to analyze its temporal and spatial characteristics. Studies showed that exogenous environmental factors significantly( P < 5%) impacted agricultural production efficiency in the Yangtze River Economic Zone,and there were temporal and spatial differences. These included:(1) after excluding environmental factors,the overall agricultural production efficiency of the Yangtze River Economic Zone had improved. Sichuan Province and Jiangsu Province were at the forefront of efficiency,whereas the agricultural production efficiency of Shanghai had declined obviously.(2) The agricultural production efficiency of the Yangtze River Economic Belt varied year by year,with fluctuating development. The middle reaches of the Yangtze River had advanced agricultural production efficiency more than the upstream and downstream regions,and the agricultural production efficiency of the individual provinces did not match their economic and social development.(3) Increases in labor,land,irrigation,and other input factors increased agriculture production efficiency,and there was no correlation between fiscal investment,per capita gross domestic product( GDP) and agricultural production efficiency,while the disaster-affected area had a significantly negative impact on agricultural production efficiency.
基金supported by the Natural Science Foundation of Qinghai Province,China(No.2021-ZJ940Q)the Open Project of State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University(No.2022-ZZ-02)。
文摘As significant evidence of permafrost degradation,thermokarst lakes play an important role in the permafrost regions by regulating hydrology,ecology,and biogeochemistry.In the Sources Area of the Yellow River(SAYR),permafrost degradation has accelerated since the 1980s,and numerous thermokarst lakes have been discovered.In this paper,we use Sentinel-2 images to extract thermokarst lake boundaries and perform a regional-scale study on their geometry across the permafrost region in the SAYR.We also explored the spatiotemporal variations and potential drivers from the perspectives of the permafrost,climate,terrain and vegetation conditions.The results showed that there were 47,518 thermokarst lakes in 2021 with a total area of 190.22×106 m^(2),with an average size of 4,003.3 m^(2).The 44,928 ponds(≤10,000 m^(2))predominated the whole lake number(94.1%)but contributed to a small portion of the total lake area(28.8%).With 2,590 features(5.9%),small-sized(10,000 to 100,000 m^(2))and large-sized lakes(>100,000 m^(2))constituted up to 71.2%of the total lake area.Thermokarst lakes developed more significantly in warm permafrost regions than in cold permafrost areas;74.1%of lakes with a total area of 119.6×106 m^(2)(62.9%),were distributed in warm permafrost regions.Most thermokarst lakes were likely to develop within the elevation range of 4,500~4,800 m,on flat terrain(slope<10°),on SE and S aspects and in alpine meadow areas.The thermokarst lakes in the study region experienced significant shrinkage between 1990 and 2021,characterized by obvious lake drainage;the lake numbers decreased by 5418(56.1%),with a decreasing area of 58.63×106 m^(2)(49.0%).This shrinkage of the thermokarst lake area was attributable mainly to the intensified degradation of rich-ice permafrost thawing arising from continued climate warming,despite the wetting climatic trend.
文摘The distribution characteristics of park green space in Wuhan City were studied by standard deviation ellipse(SDE)method,average nearest neighbor index,kernel density estimation(KDE)method and scale index method.At the same time,the influencing factors of its distribution were discussed from three aspects of nature,social economy and culture with a geographical detector.The results show that(1)the distribution of park green space in Wuhan was relatively concentrated,and the directionality was not strong.The distribution mode was clustered mode.There were four main aggregation centers,which were located in Jianghan District,Qingshan District,Dongxihu District and Wuchang District respectively.Among them,the scale index of Jianghan District was the highest,up to 0.5902,while that of Xinzhou district was the lowest,only 0.0047.(2)The order of interpretation intensity of park green space distribution in Wuhan was population density(0.382)>regional GDP(0.278)>location of historical relics(0.165)>urbanization rate(0.136)>watershed zoning(0.069)>altitude(0.012).(3)The interaction of population density and watershed zoning had the strongest explanation for the distribution of park green space in Wuhan.Except for the influence of population density,the interaction of urbanization rate and regional GDP had the strongest explanation for the distribution of park green space in Wuhan.
基金supported by the National Science and Technology Major Project of Water Pollution Control and Treatment(Grants No.2014ZX07405002,2012ZX07506007,2012ZX07506006,and 2012ZX07506002)the Natural Science Foundation of the Anhui Higher Education Institutions of China(Grant No.KJ2016A868)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘With a focus on the difficulty of quantitatively describing the degree of nonuniformity of temporal and spatial distributions of water resources, quantitative research was carried out on the temporal and spatial distribution characteristics of water resources in Guangdong Province from 1956 to 2000 based on a cloud model. The spatial variation of the temporal distribution characteristics and the temporal variation of the spatial distribution characteristics were both analyzed. In addition, the relationships between the numerical characteristics of the cloud model of temporal and spatial distributions of water resources and precipitation were also studied. The results show that, using a cloud model, it is possible to intuitively describe the temporal and spatial distribution characteristics of water resources in cloud images. Water resources in Guangdong Province and their temporal and spatial distribution characteristics are differentiated by their geographic locations. Downstream and coastal areas have a larger amount of water resources with greater uniformity and stronger stability in terms of temporal distribution. Regions with more precipitation possess larger amounts of water resources, and years with more precipitation show greater nonuniformity in the spatial distribution of water resources. The correlation between the nonuniformity of the temporal distribution and local precipitation is small, and no correlation is found between the stability of the nonuniformity of the temporal and spatial distributions of water resources and precipitation. The amount of water resources in Guangdong Province shows an increasing trend from 1956 to 2000, the nonuniformity of the spatial distribution of water resources declines, and the stability of the nonuniformity of the spatial distribution of water resources is enhanced.
文摘The spatial distributions of the electron density and the mean electron energy of argon radio frequency (rf) glow discharge plasma in a plasma-enhanced chemical vapour deposition (PECVD) system have been investigated using an established movable Langmuir probe. The results indicate that in the axial direction the electron density tends to peak at midway between the two electrodes while the axial variation trend of mean electron energy is different from that of the electron density, the mean electron energy is high near the electrodes. And the mean electron energy near the cathode is much higher than that near the anode. This article focuses on the radial distribution of electron density and mean electron energy. A proposed theoretical model distribution agrees well with the experimental one: the electron density and the mean electron energy both increase from the centre of the glow to the edge of electrodes. This is useful for better understanding the discharge mechanism and searching for a better deposition condition to improve thin film quality.