The wind and snow environment outside the planned space plays a key role in the comfort and safety of the human habitat in severe cold regions. Traditional studies of the external environment of human settlements, how...The wind and snow environment outside the planned space plays a key role in the comfort and safety of the human habitat in severe cold regions. Traditional studies of the external environment of human settlements, however, frequently overlook the combined impacts of wind and snow environments. Furthermore, in urban meteorological studies, it is impossible to accurately assess the wind and snow environment in specific areas or locations. In this study, a refined Computational Fluid Dynamics(CFD) multiphase flow numerical method was used to simulate a planning space's wind and snow environment. The study classified the Snowstorm Weather Grade(SWG) by incorporating the Snowstorm Weather Index(SWI) to generate calculation results of the wind environment and snow environment. In particular, 150 measurement points in the planning space were chosen for analysis and evaluation of their wind and snow environments. The results demonstrated that the SWI index can effectively correlate to the wind and snow environment calculation results. In addition, the graph of SWI showed that 55% of the measurement points had a moderate wind and snow grade SWI, which exceeds the average grade for the entire region. The practical application shows that the wind and snow environment assessment indexes and technical methods developed in this paper can be successfully applied to wind and snow environment studies in other cold cities.展开更多
Urbanization has profound impacts on ecological environments. Green spaces are a vital component of urban ecosystems and play a crucial role in maintaining ecological balance and enhancing sustainability. This study a...Urbanization has profound impacts on ecological environments. Green spaces are a vital component of urban ecosystems and play a crucial role in maintaining ecological balance and enhancing sustainability. This study aimed to investigate the community composition characteristics of butterflies in urban green spaces within the context of rapid urbanization. Simultaneously, it explored the status and differences in butterfly taxonomic diversity, functional diversity, and functional traits among different types of urban green spaces, regions, and urban gradients to provide relevant insights for further improving urban green space quality and promoting biodiversity conservation. We conducted a year-long survey of 80 green spaces across different urban regions and ring roads within Hefei City, Anhui Province, with monthly sampling intervals over 187 transects. A total of 4822 butterflies, belonging to 5 families, 17 subfamilies, 40 genera, and 55 species were identified. The species richness, Shannon, Simpson, functional richness, and Rao's quadratic entropy indices of butterflies in urban park green spaces were all significantly higher than those in residential and street green spaces(P < 0.05). Differences in butterfly diversity and functional traits among different urban regions and ring roads were relatively minor, and small-sized, multivoltine, and long flying duration butterflies dominated urban green spaces. Overall, these spaces offer more favorable habitats for butterflies. However, some residential green spaces and street green spaces demonstrate potential for butterfly conservation.展开更多
This paper studies the problem of the space station short-term mission planning, which aims to allocate the executing time of missions effectively, schedule the corresponding resources reasonably and arrange the time ...This paper studies the problem of the space station short-term mission planning, which aims to allocate the executing time of missions effectively, schedule the corresponding resources reasonably and arrange the time of the astronauts properly. A domain model is developed by using the ontology theory to describe the concepts, constraints and relations of the planning domain formally, abstractly and normatively. A method based on time iteration is adopted to solve the short-term planning problem. Meanwhile, the resolving strategies are proposed to resolve different kinds of conflicts induced by the constraints of power, heat, resource, astronaut and relationship. The proposed approach is evaluated in a test case with fifteen missions, thirteen resources and three astronauts. The results show that the developed domain ontology model is reasonable, and the time iteration method using the proposed resolving strategies can successfully obtain the plan satisfying all considered constraints.展开更多
Path planning for space vehicles is still a challenging problem although considerable progress has been made over the past decades.The major difficulties are that most of existing methods only adapt to static environm...Path planning for space vehicles is still a challenging problem although considerable progress has been made over the past decades.The major difficulties are that most of existing methods only adapt to static environment instead of dynamic one,and also can not solve the inherent constraints arising from the robot body and the exterior environment.To address these difficulties,this research aims to provide a feasible trajectory based on quadratic programming(QP) for path planning in three-dimensional space where an autonomous vehicle is requested to pursue a target while avoiding static or dynamic obstacles.First,the objective function is derived from the pursuit task which is defined in terms of the relative distance to the target,as well as the angle between the velocity and the position in the relative velocity coordinates(RVCs).The optimization is in quadratic polynomial form according to QP formulation.Then,the avoidance task is modeled with linear constraints in RVCs.Some other constraints,such as kinematics,dynamics,and sensor range,are included.Last,simulations with typical multiple obstacles are carried out,including in static and dynamic environments and one of human-in-the-loop.The results indicate that the optimal trajectories of the autonomous robot in three-dimensional space satisfy the required performances.Therefore,the QP model proposed in this paper not only adapts to dynamic environment with uncertainty,but also can satisfy all kinds of constraints,and it provides an efficient approach to solve the problems of path planning in three-dimensional space.展开更多
In May 2019,the construction of the land and space planning system was officially launched.The Ministry of Natural Resources of the State Council issued the Notice on Comprehensively Implementing Land and Space Planni...In May 2019,the construction of the land and space planning system was officially launched.The Ministry of Natural Resources of the State Council issued the Notice on Comprehensively Implementing Land and Space Planning,which clearly requires all regions to comprehensively launch the land and space planning and puts forward specific work requirements[1].Later,in order to guide the preparation and implementation of land and space planning,various technical standards were successively issued.The dual-assessment technical guidelines,land use classification standards,and the compilation guidelines for provincial,city and county planning were gradually submitted for review and trial implementation.In this context,there have been more and more planning theories and practical studies based on the background of land and space planning.For tourist service towns,how to protect the style and features of the towns under the land and space planning system and preserve the local characteristics is a problem that needs to be solved urgently[2].展开更多
Based on the generalized landscape perspective, regional connotation of urban river landscape is expanded. The area connotation of urban river landscape is expanded based on the generalized landscape perspective. In a...Based on the generalized landscape perspective, regional connotation of urban river landscape is expanded. The area connotation of urban river landscape is expanded based on the generalized landscape perspective. In addition to natural and functional attributes, river landscape should be regarded as a regional space element based on heterogeneous space scale. First, as for research method system, the space research models(including ecological footprint, space planning, and landscape pattern index, etc.) coupled with different angle scales and interdisciplinary theory, are utilized to study different correlations and results formed by urban river landscape elements and other regional space elements from the perspective of the regional ecological space, and the overall development goal of the urban river landscape pattern based on the goals of the regional ecological space planning is obtained. Second, the oriented urban river landscape planning and the "M" type close-tonature design strategy are evaluated through the city function zoning orientation and micro-scale urban river landscape pattern index. The research realizes the compatibility of overall goals in terms of the regional ecology, the development of urban functional areas, and the river landscape planning, without losing micro difference and maneuverability based on the urban river landscape planning and design oriented strategy, which innovates the new approach of urban river landscape planning and design with sustainable and balanced development of regional resources, multi-scale, and multiple objectives.展开更多
Cultivated land is the most important strategic resource to ensure food security.The newly constructed quality classification system of cultivated land resources considers the cultivated land health index for the firs...Cultivated land is the most important strategic resource to ensure food security.The newly constructed quality classification system of cultivated land resources considers the cultivated land health index for the first time.How the new classification and grading index system and the quality classification results of cultivated land resources to effectively guide the preparation of municipal land space planning has become a key research direction.This paper expounds the overall design idea for quality classification of cultivated land resources and classification index system.Taking Chongzuo City as an example,through the analysis of the quality classification results of cultivated land resources in the study area,using GIS spatial analysis and factor pairwise comparison method,this paper explores the application ideas and methods of quality classification research results of cultivated land resources in the formulation of cultivated land retention target,the delineation of dominant areas of cultivated land protection,the delineation of three control lines,the comprehensive improvement of land,and ecological restoration zoning in the municipal land space planning.展开更多
Low carbon landscape development is an emerging approach of landscape design,which aims to promote sustainable development,and reduce energy consumption and environmental impact by reducing carbon emissions.As an impo...Low carbon landscape development is an emerging approach of landscape design,which aims to promote sustainable development,and reduce energy consumption and environmental impact by reducing carbon emissions.As an important component of low carbon landscape construction,the construction of urban pocket park system based on mini-parks plays a crucial role in improving the urban greening level,increasing the urban green space,alleviating the urban pressure,improving the living and healthy environment of urban residents,and promoting the urban ecological balance.Taking Chaowai district of Beijing as an example,this paper calculates the ecological value of trees including energy contribution,carbon sequestration,ability to improve rainfall runoff and aesthetic value by collecting the information of trees and the plot on which the trees are located through the i-Tree platform,which provides important reference value for the urban pocket park system planning to create low carbon comprehensive benefits.展开更多
The fourth CAST Space Technology Forum was held on November 29, 2012 with the theme of Progress of China's Manned Space Station Project. Scientists, experts and government officials gathered to discuss the scheme,...The fourth CAST Space Technology Forum was held on November 29, 2012 with the theme of Progress of China's Manned Space Station Project. Scientists, experts and government officials gathered to discuss the scheme, technical issues of the project, which consists of thirteen systems. CASC is in charge of the construction of seven systems through its subsidiaries. CALT is assigned to the building of LM-2F, LM-5 and LM-7 launch vehicles and CAST is assigned to the R&D of a space laboratory,展开更多
China's urbanization has been over the medium-term process,which has made great achievements,but also triggered a huge problem of air pollution. Air pollution has become a big problem after the water pollution in Chi...China's urbanization has been over the medium-term process,which has made great achievements,but also triggered a huge problem of air pollution. Air pollution has become a big problem after the water pollution in China,and a serious threat to people's life and health. Under the background of " the construction of beautiful China" and rapid urbanization,how to build a beautiful home has become the focus of attention. Taking Shenyang as an example,the author contrastively analyses the spatial distribution of the main air pollutants( PM10,PM2. 5,and SO2) and the present situation of land use,and thus finds out the rules between pollutants distribution and land use. Then combining the urban planning scheme and the rules obtained above,reasonable suggestions are proposed for the scheme to improve the air quality,and reduce or avoid air pollution,and providing the basis for the construction of a piece of blue sky. The conclusions are as follows: 1 air pollutants concentration above Light Oil Gas Making Factory in south vice city of Shenyang reaches the peak value,and industrial point source is the main air pollutants emission source; 2 pollutants concentration above greenbelt is the lowest; 3 the overall spatial structure of urban planning can insulate the industrial agglomeration areas to some extent; greenbelt planning covers 40%- 50% of the area with high concentration of air pollutants,and it is suggested to achieve full coverage; traffic planning can achieve shunt most of the pollutants in many regions,but it can also expand the scope of pollutants in some certain regions,in such regions,it should reduce the road density.展开更多
This paper investigates the motion planning of redundant free-floating manipulators with seven prismatic joints. On the earth, prismatic-jointed manipulators could only position their end-effectors in a desired way. H...This paper investigates the motion planning of redundant free-floating manipulators with seven prismatic joints. On the earth, prismatic-jointed manipulators could only position their end-effectors in a desired way. However, in space, the end-effectors of free-floating manipulators can achieve both the desired orientation and desired position due to the dynamical coupling between manipulator and satellite movement, which is formally expressed by linear and angular momentum conservation laws. In this study, a tractable algorithm particle swarm optimization combined with differential evolution (PSODE) is provided to deal with the motion planning of redundant free-floating prismatic-jointed manipulators, which could avoid the pseudo inverse of the Jacobian matrix. The polynomial functions, as argument in sine functions are used to specify the joint paths. The co- efficients of the polynomials are optimized to achieve the desired end-effector orientation and position, and simulta- neously minimize the unit-mass-kinetic energy using the redundancy. Relevant simulations prove that this method pro- vides satisfactory smooth paths for redundant free-floating prismatic-jointed manipulators. This study could help to recognize the advantages of redundant prismatic-jointed space manipulators.展开更多
In recent years, with the large increase in the number of motor vehicles in colleges and universities and the lag in campus planning, the relative shortage of parking spaces on campus has become increasingly serious. ...In recent years, with the large increase in the number of motor vehicles in colleges and universities and the lag in campus planning, the relative shortage of parking spaces on campus has become increasingly serious. Taking Baoding College as an example, this article analyzes the current situation of static traffic on campus and finds out the problem of parking on campus through questionnaire surveys and field surveys. Analyze the growth trend of the number of motor vehicles based on the data, use the GM (1, 1) model and the linear fitting model to predict the number of motor vehicles in the future, and determine the size and layout of the parking lot based on the campus size, functional zoning, and road layout. The big campus-based parking system planning method based on big data can effectively solve the problems of small sample data, low accuracy, and poor timeliness of traditional methods, which improves the practicability and scientificity of planning results.展开更多
Under the background of the new round of land and space planning,the research on rural planning in China is undergoing positive changes.Based on the past emphasis on engineering thinking and planning technology,it has...Under the background of the new round of land and space planning,the research on rural planning in China is undergoing positive changes.Based on the past emphasis on engineering thinking and planning technology,it has entered the field of planning strategy and planning guidance.The extended development trend shows a research trend of intensified integration with public management disciplines and government governance theories.The intervention of government regulation research will provide a solid theoretical guarantee for the rural revitalization strategy that focuses on planning and planning first.In order to study the rural planning hotspots and trends in the context of territorial and spatial planning,using CiteSpace software to map rural areas from the perspectives of the number of articles,authors,publishing organizations,keyword co-occurrence networks,keyword clustering analysis,hotspot evolution,prominent word analysis,etc.The knowledge map was planned and visualized comparative analysis was carried out.展开更多
At present,the moon and Mars are the main focus of deep space exploration,scientific pursuits are the initial goal,and extensive cooperation leads to a greater prospect.China has made many scientific achievements and ...At present,the moon and Mars are the main focus of deep space exploration,scientific pursuits are the initial goal,and extensive cooperation leads to a greater prospect.China has made many scientific achievements and built considerable infrastructure through its lunar and Mars exploration activities.In the future,China will continue to carry out deep space exploration activities with scientific goals as the driving force,develop the International Lunar Research Station,explore the sun,inner planets and asteroids,discover exoplanets and build an asteroid defence system.In order to support future deep space exploration missions,China will construct an integrated communication,navigation and remote sensing constellation and develop heavy-lift launch vehicles.China offers a wide range of opportunities for cooperation,upholds the central role of Committee on the Peaceful Uses of Outer Space(UNCOPUOS),and welcomes all countries in the world to participate in deep space exploration activities.展开更多
With the accelerating development of modern residential districts and the improvement of living levels, the requirement of people on environment is increasingly enhanced as well as the demand for culture. Based on peo...With the accelerating development of modern residential districts and the improvement of living levels, the requirement of people on environment is increasingly enhanced as well as the demand for culture. Based on people-oriented principle, this design utilized Chinese 'Fu' (blessings) culture to express people’s eager for a better life and the atmosphere of good fortune. It also produced the image of ecological environment by designing water landscapes and plant landscapes, created active space like squares for activity and active water system and developed the characteristics of residential districts by designing landscape sketches and plant landscapes.展开更多
[提示]刚刚获得最高国家科学技术奖的中国工程院院士、中国载人航天工程总设计师王永志向外界透露了"神六"计划,Yahoo上马上刊登了此激动人心的消息。王永志说:……the launch of the two-person Shenzhou VI craft were proc...[提示]刚刚获得最高国家科学技术奖的中国工程院院士、中国载人航天工程总设计师王永志向外界透露了"神六"计划,Yahoo上马上刊登了此激动人心的消息。王永志说:……the launch of the two-person Shenzhou VI craft were proceeding smoothly.展开更多
基金Sponsored by the National Natural Science Foundation of China (Grant No. 51708151)。
文摘The wind and snow environment outside the planned space plays a key role in the comfort and safety of the human habitat in severe cold regions. Traditional studies of the external environment of human settlements, however, frequently overlook the combined impacts of wind and snow environments. Furthermore, in urban meteorological studies, it is impossible to accurately assess the wind and snow environment in specific areas or locations. In this study, a refined Computational Fluid Dynamics(CFD) multiphase flow numerical method was used to simulate a planning space's wind and snow environment. The study classified the Snowstorm Weather Grade(SWG) by incorporating the Snowstorm Weather Index(SWI) to generate calculation results of the wind environment and snow environment. In particular, 150 measurement points in the planning space were chosen for analysis and evaluation of their wind and snow environments. The results demonstrated that the SWI index can effectively correlate to the wind and snow environment calculation results. In addition, the graph of SWI showed that 55% of the measurement points had a moderate wind and snow grade SWI, which exceeds the average grade for the entire region. The practical application shows that the wind and snow environment assessment indexes and technical methods developed in this paper can be successfully applied to wind and snow environment studies in other cold cities.
基金funded by the National Non Profit Research Institutions of the Chinese Academy of Forestry(CAFYBB2020ZB008)National Natural Science Foundation of China(32371936)the Research Projects in Anhui Universities in 2022(natural sciences)(2022AH051874).
文摘Urbanization has profound impacts on ecological environments. Green spaces are a vital component of urban ecosystems and play a crucial role in maintaining ecological balance and enhancing sustainability. This study aimed to investigate the community composition characteristics of butterflies in urban green spaces within the context of rapid urbanization. Simultaneously, it explored the status and differences in butterfly taxonomic diversity, functional diversity, and functional traits among different types of urban green spaces, regions, and urban gradients to provide relevant insights for further improving urban green space quality and promoting biodiversity conservation. We conducted a year-long survey of 80 green spaces across different urban regions and ring roads within Hefei City, Anhui Province, with monthly sampling intervals over 187 transects. A total of 4822 butterflies, belonging to 5 families, 17 subfamilies, 40 genera, and 55 species were identified. The species richness, Shannon, Simpson, functional richness, and Rao's quadratic entropy indices of butterflies in urban park green spaces were all significantly higher than those in residential and street green spaces(P < 0.05). Differences in butterfly diversity and functional traits among different urban regions and ring roads were relatively minor, and small-sized, multivoltine, and long flying duration butterflies dominated urban green spaces. Overall, these spaces offer more favorable habitats for butterflies. However, some residential green spaces and street green spaces demonstrate potential for butterfly conservation.
基金supported by the National Natural Science Foundation of China(11402295)the Science Project of National University of Defense Technology(JC14-01-05)the Hunan Provincial Natural Science Foundation of China(2015JJ3020)
文摘This paper studies the problem of the space station short-term mission planning, which aims to allocate the executing time of missions effectively, schedule the corresponding resources reasonably and arrange the time of the astronauts properly. A domain model is developed by using the ontology theory to describe the concepts, constraints and relations of the planning domain formally, abstractly and normatively. A method based on time iteration is adopted to solve the short-term planning problem. Meanwhile, the resolving strategies are proposed to resolve different kinds of conflicts induced by the constraints of power, heat, resource, astronaut and relationship. The proposed approach is evaluated in a test case with fifteen missions, thirteen resources and three astronauts. The results show that the developed domain ontology model is reasonable, and the time iteration method using the proposed resolving strategies can successfully obtain the plan satisfying all considered constraints.
基金supported by National Natural Science Foundation of China (Grant Nos. 61035005,61075087)Hubei Provincial Natural Science Foundation of China (Grant No. 2010CDA005)Hubei Provincial Education Department Foundation of China (Grant No.Q20111105)
文摘Path planning for space vehicles is still a challenging problem although considerable progress has been made over the past decades.The major difficulties are that most of existing methods only adapt to static environment instead of dynamic one,and also can not solve the inherent constraints arising from the robot body and the exterior environment.To address these difficulties,this research aims to provide a feasible trajectory based on quadratic programming(QP) for path planning in three-dimensional space where an autonomous vehicle is requested to pursue a target while avoiding static or dynamic obstacles.First,the objective function is derived from the pursuit task which is defined in terms of the relative distance to the target,as well as the angle between the velocity and the position in the relative velocity coordinates(RVCs).The optimization is in quadratic polynomial form according to QP formulation.Then,the avoidance task is modeled with linear constraints in RVCs.Some other constraints,such as kinematics,dynamics,and sensor range,are included.Last,simulations with typical multiple obstacles are carried out,including in static and dynamic environments and one of human-in-the-loop.The results indicate that the optimal trajectories of the autonomous robot in three-dimensional space satisfy the required performances.Therefore,the QP model proposed in this paper not only adapts to dynamic environment with uncertainty,but also can satisfy all kinds of constraints,and it provides an efficient approach to solve the problems of path planning in three-dimensional space.
文摘In May 2019,the construction of the land and space planning system was officially launched.The Ministry of Natural Resources of the State Council issued the Notice on Comprehensively Implementing Land and Space Planning,which clearly requires all regions to comprehensively launch the land and space planning and puts forward specific work requirements[1].Later,in order to guide the preparation and implementation of land and space planning,various technical standards were successively issued.The dual-assessment technical guidelines,land use classification standards,and the compilation guidelines for provincial,city and county planning were gradually submitted for review and trial implementation.In this context,there have been more and more planning theories and practical studies based on the background of land and space planning.For tourist service towns,how to protect the style and features of the towns under the land and space planning system and preserve the local characteristics is a problem that needs to be solved urgently[2].
基金Sponsored by National Natural Science Foundation of China(NSFC)(51208428)Applied Basic Research Program of Sichuan Province(2013JY0038)+1 种基金Sichuan Research Center for Landscape and Recreation Research Project(JGYQ201419)Central University Fundamental Research Funds for Science and Technology Innovation Project(SWJTU11CX158)
文摘Based on the generalized landscape perspective, regional connotation of urban river landscape is expanded. The area connotation of urban river landscape is expanded based on the generalized landscape perspective. In addition to natural and functional attributes, river landscape should be regarded as a regional space element based on heterogeneous space scale. First, as for research method system, the space research models(including ecological footprint, space planning, and landscape pattern index, etc.) coupled with different angle scales and interdisciplinary theory, are utilized to study different correlations and results formed by urban river landscape elements and other regional space elements from the perspective of the regional ecological space, and the overall development goal of the urban river landscape pattern based on the goals of the regional ecological space planning is obtained. Second, the oriented urban river landscape planning and the "M" type close-tonature design strategy are evaluated through the city function zoning orientation and micro-scale urban river landscape pattern index. The research realizes the compatibility of overall goals in terms of the regional ecology, the development of urban functional areas, and the river landscape planning, without losing micro difference and maneuverability based on the urban river landscape planning and design oriented strategy, which innovates the new approach of urban river landscape planning and design with sustainable and balanced development of regional resources, multi-scale, and multiple objectives.
文摘Cultivated land is the most important strategic resource to ensure food security.The newly constructed quality classification system of cultivated land resources considers the cultivated land health index for the first time.How the new classification and grading index system and the quality classification results of cultivated land resources to effectively guide the preparation of municipal land space planning has become a key research direction.This paper expounds the overall design idea for quality classification of cultivated land resources and classification index system.Taking Chongzuo City as an example,through the analysis of the quality classification results of cultivated land resources in the study area,using GIS spatial analysis and factor pairwise comparison method,this paper explores the application ideas and methods of quality classification research results of cultivated land resources in the formulation of cultivated land retention target,the delineation of dominant areas of cultivated land protection,the delineation of three control lines,the comprehensive improvement of land,and ecological restoration zoning in the municipal land space planning.
基金Sponsored by General Project of Natural Science Foundation of Beijing City(8202017)Youth Talent Support Program of 2018 Beijing Municipal University Academic Human Resources Development(PXM2018_014212_000043).
文摘Low carbon landscape development is an emerging approach of landscape design,which aims to promote sustainable development,and reduce energy consumption and environmental impact by reducing carbon emissions.As an important component of low carbon landscape construction,the construction of urban pocket park system based on mini-parks plays a crucial role in improving the urban greening level,increasing the urban green space,alleviating the urban pressure,improving the living and healthy environment of urban residents,and promoting the urban ecological balance.Taking Chaowai district of Beijing as an example,this paper calculates the ecological value of trees including energy contribution,carbon sequestration,ability to improve rainfall runoff and aesthetic value by collecting the information of trees and the plot on which the trees are located through the i-Tree platform,which provides important reference value for the urban pocket park system planning to create low carbon comprehensive benefits.
文摘The fourth CAST Space Technology Forum was held on November 29, 2012 with the theme of Progress of China's Manned Space Station Project. Scientists, experts and government officials gathered to discuss the scheme, technical issues of the project, which consists of thirteen systems. CASC is in charge of the construction of seven systems through its subsidiaries. CALT is assigned to the building of LM-2F, LM-5 and LM-7 launch vehicles and CAST is assigned to the R&D of a space laboratory,
文摘China's urbanization has been over the medium-term process,which has made great achievements,but also triggered a huge problem of air pollution. Air pollution has become a big problem after the water pollution in China,and a serious threat to people's life and health. Under the background of " the construction of beautiful China" and rapid urbanization,how to build a beautiful home has become the focus of attention. Taking Shenyang as an example,the author contrastively analyses the spatial distribution of the main air pollutants( PM10,PM2. 5,and SO2) and the present situation of land use,and thus finds out the rules between pollutants distribution and land use. Then combining the urban planning scheme and the rules obtained above,reasonable suggestions are proposed for the scheme to improve the air quality,and reduce or avoid air pollution,and providing the basis for the construction of a piece of blue sky. The conclusions are as follows: 1 air pollutants concentration above Light Oil Gas Making Factory in south vice city of Shenyang reaches the peak value,and industrial point source is the main air pollutants emission source; 2 pollutants concentration above greenbelt is the lowest; 3 the overall spatial structure of urban planning can insulate the industrial agglomeration areas to some extent; greenbelt planning covers 40%- 50% of the area with high concentration of air pollutants,and it is suggested to achieve full coverage; traffic planning can achieve shunt most of the pollutants in many regions,but it can also expand the scope of pollutants in some certain regions,in such regions,it should reduce the road density.
基金supported by the National Natural Science Foundation of China (11072122)
文摘This paper investigates the motion planning of redundant free-floating manipulators with seven prismatic joints. On the earth, prismatic-jointed manipulators could only position their end-effectors in a desired way. However, in space, the end-effectors of free-floating manipulators can achieve both the desired orientation and desired position due to the dynamical coupling between manipulator and satellite movement, which is formally expressed by linear and angular momentum conservation laws. In this study, a tractable algorithm particle swarm optimization combined with differential evolution (PSODE) is provided to deal with the motion planning of redundant free-floating prismatic-jointed manipulators, which could avoid the pseudo inverse of the Jacobian matrix. The polynomial functions, as argument in sine functions are used to specify the joint paths. The co- efficients of the polynomials are optimized to achieve the desired end-effector orientation and position, and simulta- neously minimize the unit-mass-kinetic energy using the redundancy. Relevant simulations prove that this method pro- vides satisfactory smooth paths for redundant free-floating prismatic-jointed manipulators. This study could help to recognize the advantages of redundant prismatic-jointed space manipulators.
文摘In recent years, with the large increase in the number of motor vehicles in colleges and universities and the lag in campus planning, the relative shortage of parking spaces on campus has become increasingly serious. Taking Baoding College as an example, this article analyzes the current situation of static traffic on campus and finds out the problem of parking on campus through questionnaire surveys and field surveys. Analyze the growth trend of the number of motor vehicles based on the data, use the GM (1, 1) model and the linear fitting model to predict the number of motor vehicles in the future, and determine the size and layout of the parking lot based on the campus size, functional zoning, and road layout. The big campus-based parking system planning method based on big data can effectively solve the problems of small sample data, low accuracy, and poor timeliness of traditional methods, which improves the practicability and scientificity of planning results.
文摘Under the background of the new round of land and space planning,the research on rural planning in China is undergoing positive changes.Based on the past emphasis on engineering thinking and planning technology,it has entered the field of planning strategy and planning guidance.The extended development trend shows a research trend of intensified integration with public management disciplines and government governance theories.The intervention of government regulation research will provide a solid theoretical guarantee for the rural revitalization strategy that focuses on planning and planning first.In order to study the rural planning hotspots and trends in the context of territorial and spatial planning,using CiteSpace software to map rural areas from the perspectives of the number of articles,authors,publishing organizations,keyword co-occurrence networks,keyword clustering analysis,hotspot evolution,prominent word analysis,etc.The knowledge map was planned and visualized comparative analysis was carried out.
文摘At present,the moon and Mars are the main focus of deep space exploration,scientific pursuits are the initial goal,and extensive cooperation leads to a greater prospect.China has made many scientific achievements and built considerable infrastructure through its lunar and Mars exploration activities.In the future,China will continue to carry out deep space exploration activities with scientific goals as the driving force,develop the International Lunar Research Station,explore the sun,inner planets and asteroids,discover exoplanets and build an asteroid defence system.In order to support future deep space exploration missions,China will construct an integrated communication,navigation and remote sensing constellation and develop heavy-lift launch vehicles.China offers a wide range of opportunities for cooperation,upholds the central role of Committee on the Peaceful Uses of Outer Space(UNCOPUOS),and welcomes all countries in the world to participate in deep space exploration activities.
文摘With the accelerating development of modern residential districts and the improvement of living levels, the requirement of people on environment is increasingly enhanced as well as the demand for culture. Based on people-oriented principle, this design utilized Chinese 'Fu' (blessings) culture to express people’s eager for a better life and the atmosphere of good fortune. It also produced the image of ecological environment by designing water landscapes and plant landscapes, created active space like squares for activity and active water system and developed the characteristics of residential districts by designing landscape sketches and plant landscapes.
文摘[提示]刚刚获得最高国家科学技术奖的中国工程院院士、中国载人航天工程总设计师王永志向外界透露了"神六"计划,Yahoo上马上刊登了此激动人心的消息。王永志说:……the launch of the two-person Shenzhou VI craft were proceeding smoothly.