Using a sample of 14 prefecture-level cities in Liaoning Province, this study first explored the spatial hierarchy and structural characteristics of energy efficiency from the following three viewpoints： energy techn...Using a sample of 14 prefecture-level cities in Liaoning Province, this study first explored the spatial hierarchy and structural characteristics of energy efficiency from the following three viewpoints： energy technical efficiency based on data envelopment analysis, energy consumption per unit of GDP, and energy utilization efficiency combining the previous two indexes After measuring and analyzing the advancement, rationality, and concentration of the industrial structure in each city, we made some generalizations about the coupling features of the energy efficiency and industrial structure in Liaoning, using the coupling degree rating model Some of our conclusions are as follows： （1） The 14 cities differ significantly in their en- ergy efficiency, with Shenyang, Dalian, Anshan, and Jinzhou enjoying the highest energy effi- ciency. Northwestern Liaoning and other heavy-industrial cities such as Fushun and Benxi belong to low-efficiency and high-consumption areas. （2） In areas with higher efficiency, the spatial patterns of the energy technical efficiency, energy consumption per unit of GDP, and energy utilization efficiency are, respectively, ＂π ＂-, ＂Ⅱ＂- and ＂H＂- shaped. Geographically, the energy utilization efficiency shows different trends from east to west and from north to south. Factors such as the binuclear structure of economic development have a major effect on this spatial pattern of energy efficiency. （3） Southeastern Liaoning enjoys a highly advanced in- dustrial structure. Areas with a highly rational industrial structure form an ＂H＂ shape, with Shenyang and Dalian at the two poles. The urban agglomerations in middle and southern Liaoning have a highly concentrated industrial structure. （4） Overall, the coupling between energy efficiency and industrial structure is low in Liaoning, except for Shenyang and Dalian at both ends, where the coupling between an advanced industrial structure and energy efficiency is higher than in other cities.展开更多
Wheat is an important agricultural crop in the Loess region of China, where there is drought stress and low availability of soil nitrogen and phosphorus. Using a pulse modulation fluorometer, we studied the effects of...Wheat is an important agricultural crop in the Loess region of China, where there is drought stress and low availability of soil nitrogen and phosphorus. Using a pulse modulation fluorometer, we studied the effects of water, nitrogen, and phosphorus on the kinetic parameters of chlorophyll fluorescence in winter wheat. The wheat was grown in layered columns of Eum-Orthic Anthrosol （Cinnamon soil）, with the water content and nutrient composition of each layer controlled. The results showed that the kinetic parameters of chlorophyll fluorescence were sensitive to water stress. The basic fluorescence （F0） of leaves was higher in the dry treatment （0-30 cm layer at 40-45% of field capacity, 30-90 cm at 75-80% of field capacity） compared to the wet treatment （entire soil column at 75-80% of field capacity）. The maximal fluorescence （Fm）, the variable fluorescence （Fv）, the photochemical efficiency （Fv/Fm） and potential activites （Fv/F0） of photosystem 2 （PS2） were significantly lower in the dry treatment. Although drought stress impaired PS2 function, this effect was significantly ameliorated by applying P or NP fertilizer, but not N alone. P application increased FJFm, both in well-watered and water stressed plants, especially when fertilizer was applied throughout the column or within the top 30 em of soil. A combined fertilizer improved photosynthesis in well watered plants, with Fm and F,fFm being the highest when fertilizer was applied throughout the columns. For drought stressed, plants FJFm was significantly greater when combined fertilizer was added within the top 30 cm of soil. We concluded that, when growing winter wheat in both arid and semi-arid parts of the Loess region of China, it is important to guarantee the nutrient supply in the top 30 cm of the soil.展开更多
Given the great number of studies focusing on the temporal interaction between economic and environmental subsystems, it is useful to perform a quantitative spatial as- sessment of these subsystems. In this paper, com...Given the great number of studies focusing on the temporal interaction between economic and environmental subsystems, it is useful to perform a quantitative spatial as- sessment of these subsystems. In this paper, comprehensive assessment indicators for re- gional economic development and environmental pollution subsystems are constructed. Then the degree of coupling and coordination of the regional economy-environment system is calculated for 350 prefectural units in China. It is found that the economic development and environmental pollution in most prefectural units is still at a low level of coupling and coordi- nation. According to the coupling and coordination values, the Chinese territory can be di- vided into four types of area: economy-environment harmonious area, economy-environ- ment gearing area, economy-environment rivaling area and low coupling degree of econ- omy-environment area. Based on a structural analysis of the industrial sector in the four types of areas, there is a spatial relationship between the regional industrial sector structure and the coupling-coordination level. In the economy-environment harmonious area, the sectors of manufacturing of high-technology and high value-added products, such as com- munications, computer and electronic equipment, transport equipment and electrical ma- chinery, account for a large proportion of the value of local industrial output. The industrial value of the economy-environment gearing area is concentrated on the manufacturing of machinery and equipment, and. contains a few polluting sectors such as ferrous and non-ferrous metallurgy, chemical manufacturing and electricity generation. The econ- omy-environment rivaling area is the type of area where polluting sectors concentrate, such as iron and steel, petrifaction, coal mining, building materials and electricity generation. In the low coupling degree of economy-environment area, its industry is concentrated on the pro- duction and processing of primary products.展开更多
The spatial distribution of overburden strata failure is of significant importance to affect the safety of underground mining. Because the traditional methods cannot be applied in all coal mines due to geological cond...The spatial distribution of overburden strata failure is of significant importance to affect the safety of underground mining. Because the traditional methods cannot be applied in all coal mines due to geological conditions or mining structures, a method of coupling FLAC3D with GIS was presented to calculate the spatial distribution of overburden strata failure in longwall coal mines. After building the spatio-temporal database from the calculation results of FLAC3D, the height of the mining-induced fractured zone in the overburden strata can be calculated by using the given height function. The results of case study show that the height of the fractured zone reached the maximum value at the face advance equal to about the panel width. The outcome of the work presented will be helpful in practice to improve safety in the production.展开更多
Addressing the issue of the healthy and coordinated development of the population and economic factors in rural areas will not only help consolidate and expand the achievements of poverty alleviation,but will also lay...Addressing the issue of the healthy and coordinated development of the population and economic factors in rural areas will not only help consolidate and expand the achievements of poverty alleviation,but will also lay a foundation for comprehensive rural revitalization.In this paper,the spatial coupling relationship between the population and economic factors in rural areas in the QinlingDaba Mountains,China,is explored to provide a reference for rural revitalization and regional sustainable development in poverty areas.Sixty-eight county units in rural areas in the Qinling-Daba Mountains,as well as the population and economic factors in rural areas,are used to study the spatial coupling relationship between population and economy,as well as the driving mechanism,in rural areas in the Qinling-Daba Mountains from 2010 to 2020.The results show that a population contraction phenomenon occurred in the rural areas in the Qinling-Daba Mountains,and the spatial agglomeration trends of the population and economic factors were consistent.The agglomeration was mainly located in the suburban areas of the municipal area,and the agglomeration degree was significantly higher in these areas than in other areas.In terms of the spatial distribution,the economic development level of the rural areas in the northeastern part of the Qinling-Daba Mountains was generally higher than that in the central and western parts,and the unbalanced trends of the population and economic spatial differentiation in the eastern and western regions were significant.The spatial coupling relationship between the population and economy changed from coordinated development to economic advancement.This was mainly due to the mutual restriction and joint actions of the industrial structure,capital situation,natural environment,policies,and institutional regulations,among which the industrial structure and capital status had significant effects.展开更多
The development of Qingzang national park cluster is part of China’s efforts to establish a major ecological civi-lization project in the Qingzang Plateau,in line with global sustainable development goals.Based on pr...The development of Qingzang national park cluster is part of China’s efforts to establish a major ecological civi-lization project in the Qingzang Plateau,in line with global sustainable development goals.Based on preliminary scientific investigation and research in the Qingzang Plateau,the construction of the park cluster will include 21 national parks.To mitigate the conflict between conservation of the national park cluster and the develop-ment of local communities,this study proposes an analysis framework to identify the spatial coupling features between the national park cluster and sustainable development of communities.Four elements were selected to construct the analysis framework,including natural conditions,geographic location,cultural background,and national policies.This framework was applied to the 457 township communities within the 21 national parks.Results show the weak influence of the construction of the national park cluster for approximately 304 township communities,without significant spatial coupling traits,while the remaining 153 communities demonstrated significant spatial coupling features.These latter townships had developed four types of spatial coupling with na-tional parks,including eco-migrants,transportation hubs,characteristic cultures,and border development,which account for 17.4%,35.3%,19.8%,and 27.5%of the 153 townships respectively.A composite type with more than one spatial coupling feature was also found for 14 communities within the 153 townships.This provides a reference for policy making towards four major types of interactive modes between townships and the national park construction for the sustainable development of Qingzang Plateau.展开更多
The uneven distribution of medical resources has led to increasingly frequent patient mobility;however, the interaction between this phenomenon and the healthcare supply-demand relationship remains underexplored. The ...The uneven distribution of medical resources has led to increasingly frequent patient mobility;however, the interaction between this phenomenon and the healthcare supply-demand relationship remains underexplored. The present study constructed the 2023Cross-City Patient Mobility Network in China using one million patient mobility data records obtained from online healthcare platforms. We applied urban network analysis to uncover mobility patterns and used the coupling coordination degree model to assess healthcare supply-demand relationships before and after patient mobility. Explainable machine learning further revealed the impact of supply-demand coupling on patient mobility. The results indicated the following: Patient mobility followed administrative boundaries, although megacities serve areas beyond provincial borders;The scale of healthcare supply and demand displayed a multi-centric spatial pattern with a general decline from east to west, and these characteristics of demand distribution were further solidified by patient mobility;Cities with low supply-demand coupling and undersupply experienced patient outflows, while cities with high coupling and oversupply attracted them. In turn, patient mobility helped balance healthcare supply and demand, optimising the coupling relationship across cities. Thus, this research not only provides a methodological reference for understanding the interaction between patient mobility and healthcare systems but also offers empirical insights for public health policy.展开更多
At present, gas hydrates are known to occur in continental high latitude permafrost regions and deep sea sediments. For middle latitude permafrost regions of the Tibetan Plateau, further research is required to ascert...At present, gas hydrates are known to occur in continental high latitude permafrost regions and deep sea sediments. For middle latitude permafrost regions of the Tibetan Plateau, further research is required to ascertain its potential development of gas hydrates. This paper reviewed pertinent literature on gas hydrates in the Tibetan Plateau. Both geological and ge- ographical data are synthesized to reveal the relationship between gas hydrate formation and petroleum geological evo- lution, Plateau uplift, formation of permafrost, and glacial processes. Previous studies indicate that numerous residual basins in the Plateau have been formed by original sedimentary basins accompanied by rapid uplift of the Plateau. Ex- tensive marine Mesozoic hydrocarbon source rocks in these basins could provide rich sources of materials forming gas hydrates in permafrost. Primary hydrocarbon-generating period in the Plateau is from late Jurassic to early Cretaceous, while secondary hydrocarbon generation, regionally or locally, occurs mainly in the Paleogene. Before rapid uplift of the Plateau, oil-gas reservoirs were continuously destroyed and assembled to form new reservoirs due to structural and thermal dynamics, forcing hydrocarbon migration. Since 3.4 Ma B.P., the Plateau has undergone strong uplift and extensive gla- ciation, periglacier processes prevailed, hydrocarbon gas again migrated, and free gas beneath ice sheets within sedi- mentary materials interacted with water, generating gas hydrates which were finally preserved under a cap formed by frozen layers through rapid cooling in the Plateau. Taken as a whole, it can be safely concluded that there is great temporal and spatial coupling relationships between evolution of the Tibetan Plateau and generation of gas hydrates.展开更多
Although the complex structure-preserving method presented in our previous studies can be used to investigate the orbit–attitude–vibration coupled dynamic behaviors of the spatial flexible damping beam,the simulatio...Although the complex structure-preserving method presented in our previous studies can be used to investigate the orbit–attitude–vibration coupled dynamic behaviors of the spatial flexible damping beam,the simulation speed still needs to be improved.In this paper,the infinite-dimensional dynamic model describing the orbit–attitude–vibration coupled dynamic problem of the spatial flexible damping beam is pretreated by the method of separation of variables,and the second-level fourth-order symplectic Runge–Kutta scheme is constructed to investigate the coupling dynamic behaviors of the spatial flexible damping beam quickly.Compared with the simulation speed of the complex structure-preserving method,the simulation speed of the symplectic Runge–Kutta method is faster,which benefits from the pretreatment step.The effect of the initial radial velocity on the transverse vibration as well as on the attitude evolution of the spatial flexible damping beam is presented in the numerical examples.From the numerical results about the effect of the initial radial velocity,it can be found that the appearance of the initial radial velocity can decrease the vibration frequency of the spatial beam and shorten the evolution interval for the attitude angle to tend towards a stable value significantly.In addition,the validity of the numerical results reported in this paper is verified by comparing with some numerical results presented in our previous studies.展开更多
Urban spatial morphology(USM)optimization is critical to balancing biodiversity conservation and sustainable urbanization.However,previous studies predominantly focused on the socio-economic efficiency and static ecol...Urban spatial morphology(USM)optimization is critical to balancing biodiversity conservation and sustainable urbanization.However,previous studies predominantly focused on the socio-economic efficiency and static ecological metrics and rarely addressed the dynamic USM optimization across spatial scales.Here,we developed a multi-level ecological network(MEN)framework to resolve the tension between urban expansion and ecological integrity.By integrating the cost-weighted distance analysis with a hierarchical network transmission mechanism,we established a cross-scale spatial optimization system,which coordinated the regional ecological corridors and local habitat patches.Comparative experiments with conventional single-scale approaches and scenario simulations using the PLUS model show that the MEN framework had superior performance in three dimensions:(1)spatial governance:the primary-level network(peri-urban natural reserves)effectively contained urban sprawl,and the secondary-level network(intra-urban green corridors)mitigated habitat fragmentation and improved the built-environment;(2)scenario robustness:the model maintained an optimal compactness-loose balance in multiple development pathways;(3)landscape metrics:patch fragmentation decreased by 18.25%,and the internal landscape richness improved by 10.66%compared to the scenario without USM optimization.The findings provide new insight to establish a hierarchical ecological optimization framework as a nature-based spatial protocol to reconcile metropolitan growth with landscape sustainability.展开更多
The coupling of water and fertilizer is the only way for high yield, efficiency, sugar on sugarcane. On sugarcane production, the spatial and temporal controlling technology of fertigation is an important direction of...The coupling of water and fertilizer is the only way for high yield, efficiency, sugar on sugarcane. On sugarcane production, the spatial and temporal controlling technology of fertigation is an important direction of the sustainable and healthy development of ecological agriculture in cane area of China. This paper reviews main achievements and advances on the coupling effect of water and fertilizer on sugarcane from time and space at home or abroad in recent years, analyzes the application prospects of the temporal and spatial coupling effect of water and fertilizer on sugarcane and puts forward some problems which need further research in future.展开更多
The spatial relationships between traffic accessibility and supply and demand(S&D)of ecosystem services(ESs)are essential for the formulation of ecological compensation policies and ESs regulation.In this study,an...The spatial relationships between traffic accessibility and supply and demand(S&D)of ecosystem services(ESs)are essential for the formulation of ecological compensation policies and ESs regulation.In this study,an ESs matrix and coupling analysis method were used to assess ESs S&D based on land-use data for 2000,2010,and 2020,and spatial regression models were used to analyze the correlated impacts of traffic accessibility.The results showed that the ESs supply and balance index in the middle reaches of the Yangtze River urban agglomeration(MRYRUA)continuously decreased,while the demand index increased from 2000 to 2020.The Gini coefficients of these indices continued to increase but did not exceed the warning value(0.4).The coupling degree of ESs S&D continued to increase,and its spatial distribution patterns were similar to that of the ESs demand index,with significantly higher values in the plains than in the montane areas,contrasting with those of the ESs supply index.The results of global bivariate Moran’s I analysis showed a significant spatial dependence between traffic accessibility and the degree of coupling between ESs S&D;the spatial regression results showed that an increase in traffic accessibility promoted the coupling degree.The present results provide a new perspective on the relationship between traffic accessibility and the coupling degree of ESs S&D,representing a case study for similar future research in other regions,and a reference for policy creation based on the matching between ESs S&D in the MRYRUA.展开更多
The electrical performance of radomes on high-speed aircraft can be influenced by the thermal and mechanical loads produced during high-speed flight,which can affect the detection dis-tance and accuracy of the guidanc...The electrical performance of radomes on high-speed aircraft can be influenced by the thermal and mechanical loads produced during high-speed flight,which can affect the detection dis-tance and accuracy of the guidance system.This paper presents a new method that uses the Finite Difference Time Domain(FDTD)method to calculate the electrical performance of radomes under Thermo-Mechanical-Electrical(TME)coupling.This method can accurately characterize the effects of material dielectric temperature drift and structural deformation on the electrical performance of the radome under flight conditions,enabling high-precision full-wave calculations of the broadband electrical performance of the radome.The method initiates by utilizing a Finite Element Grid Model(FE-GM)of the radome to sequentially acquire the radome's response temperature field and structural deformation field through thermal and mechanical simulations.Subsequently,spatial mapping techniques are developed to accurately incorporate the dielectric temperature drift and structural deformation of the radome into its Yee grid Electromagnetic(EM)simulation model.A verification case was designed to test the proposed method,and the results confirmed its high computational accuracy.Additionally,the effectiveness and necessity of the method were further demonstrated by analyzing the electrical performance of a fused silica ceramic radome used on a high-speed aircraft.展开更多
The construction of a new type of urbanization is a necessary path for the development of modern cities,and a powerful support for coordinating the balanced development of urban and rural areas and promoting high-qual...The construction of a new type of urbanization is a necessary path for the development of modern cities,and a powerful support for coordinating the balanced development of urban and rural areas and promoting high-quality agricultural development.Based on the panel data of 30 provinces in China from 2004 to 2018,the article constructs a new urbanization and agricultural high-quality development evaluation system;then using the coupling coordination degree model and the spatial correlation analysis method,the paper empirically tests the coupling coordination of the two systems degree and its spatial relevance.The results of the study show that the average level of coupling and coordination between new urbanization and high-quality agricultural development in the period under study is at a barely coordinated level,with the highest level being moderately coordinated.There are significant inter-regional differences,with a higher level of coupling and coordination in the eastern regions and more room for improvement in the central and western regions.At this stage,the trend of"club convergence"is remarkable,with highhigh agglomeration and low-low agglomeration coexisting,and the polarization is serious.Therefore,comprehensively promoting the rural revitalization strategy,adhering to the integrated development of urban and rural areas,and enhancing inter-regional collaborative governance are powerful measures to promote the joint progress of new urbanization and high-quality agricultural development.展开更多
Based on combing the existing research on the production-living-ecological space,the paper quantitatively analyzes the evaluation system-development level-temporal and spatial evolution,future trend-influencing factor...Based on combing the existing research on the production-living-ecological space,the paper quantitatively analyzes the evaluation system-development level-temporal and spatial evolution,future trend-influencing factors of the production-living-ecological functions coupling and coordination in the Yellow River Basin from 2009 to 2018.Through multi-scale analysis and comparison,the paper tries to identify problem areas and put forward corresponding measures.The research results show that:(1)The coupling and coordination degree of the production-living-ecological functions in the Yellow River Basin both show an upward trend,and its future growth trend is relatively slow.(2)The spatial-temporal differential characteristics of the coordinated development level of the production-living-ecological functions are obvious,and gradually develop towards the direction of benign resonance in time,showing a spatial distribution pattern of“high in the northeast and low in the southwest”.(3)There is a big difference in the level of coordinated development of the production-living-ecological functions,and the coordination degree of the“production-living”function is the lowest.(4)Scientific and technological investment,economic development level,government capacity,and urbanization level have a significant positive impact on the spatial effect of the coordinated development of the production-living-ecological functions of the Yellow River Basin,and the same factor has different effects on different regions.展开更多
Three coupling coefficients are defined to describe spatiotemporal coupling in ultrashort pulses. With these coupling coefficients, the first-order spatiotemporal couplings of Gaussian pulse and beam are described ana...Three coupling coefficients are defined to describe spatiotemporal coupling in ultrashort pulses. With these coupling coefficients, the first-order spatiotemporal couplings of Gaussian pulse and beam are described analytically. Also, the first-order and the second-order spatiotemporal couplings caused by angular dispersion elements are studied using these coupling coefficients. It can be shown that these coupling coefficients are dimensionless and normalized, and readily indicate the severity of spatiotemporal coupling.展开更多
Based on the microscopic nonlocal optical response theory, the intersubband optical absorption properties in AlGa As/Ga As couple quantum wells（CQWs） are investigated for p-polarized states. The numerical results sh...Based on the microscopic nonlocal optical response theory, the intersubband optical absorption properties in AlGa As/Ga As couple quantum wells（CQWs） are investigated for p-polarized states. The numerical results show that spatial nonlocality of optical responses can induce a radiation shift on optical absorption spectra due to nonlocal effects. The dependence of the radiation shift on the CQW structure and the applied electric field is clarified. It is also demonstrated that the maximal radiation shift and the least optical absorbance can be obtained by adopting an appropriate CQW structure and a suitable applied electric field. This work may provide some methods of designing the nanomaterials with controllable nonlocality and observing the spatial nonlocal effects in experiment.展开更多
A rate-compatible spatially coupled repeat-accumulate (RC-SC-RA) code is proposed. Its protograph is obtained by extending a given (J, K, L) SC-RA coupled chain (denoted as the mother chain) with extra check nodes and...A rate-compatible spatially coupled repeat-accumulate (RC-SC-RA) code is proposed. Its protograph is obtained by extending a given (J, K, L) SC-RA coupled chain (denoted as the mother chain) with extra check nodes and parity bit nodes T times. At each time, the extension is realized via coupling the message bits in the same way as that in the mother chain. Rate-compatibility is achieved by adjusting the extension parameters and applying random puncturing technique. Density evolution analysis shows that the iterative decoding thresholds of all the member codes in the proposed RC-SC-RA code family are very close to Shannon limits over the binary erasure channel. Finite length simulation results are consistent with the thresholds well. Moreover, the proposed RC-SC-RA codes perform better than spatially coupled low density parity check (SC-LDPC) codes in decoding performance especially in lower-rate region.展开更多
The construction of a livable environment for the elderly is an important measure to address the challenges of aging and improve their livelihood and well-being.Based on China’s national conditions and combined with ...The construction of a livable environment for the elderly is an important measure to address the challenges of aging and improve their livelihood and well-being.Based on China’s national conditions and combined with the actual development needs of the cities,it is of great significance to explore the coupling and coordination characteristics and influencing factors within the livable environment system for the elderly for the coordination and stable development.This article was based on the three subsystems of’living service environment,socioeconomic environment and ecological livable environment’,following the research framework of’process-pattern-trend-impact’,constructs an evaluation index system for the livable environment for the elderly.Entropy weight-TOPSIS evaluation model,coupling coordination degree model,center of gravity and standard deviation ellipse model and the geographic detector model were used starting from the evolution of coupling coordination types to study the spatial and temporal pattern and dynamic trend characteristics and influencing factors of internal coupling coordination types in the livable environment system for the elderly from2010 to 2019.The results showed that:1)The coordinated development of life service environment system and ecological livable environment system(LE)and socioeconomic environment system and ecological livable environment system(SE)in the livable environment for the elderly decreased from the intermediate coordination level coordination areas to the low-level quality improvement and optimization areas:coordinated transition type.The overall development level of life service environment system and socioeconomic environment system(LS)was low,and it was always at a low level.2)The coupling degree of livable environment system for the elderly was high,the coupling coordination type shown a gradually decreasing layer structure with Zhejiang,Beijing and Guangdong high-level leading demonstration areas as the axis belt.3)The coupling coordination center of the elderly livable environment system was located in Henan,and the standard deviation ellipse was distributed in the northeast-southwest direction.The development center and the ellipse of the high-level leading demonstration areas and the intermediate coordination level areas were concentrated in the central and eastern regions,while the low-level coordination areas for improving quality and efficiency are mainly located in the western region.4)Urban development,green facilities,infrastructure,government macroscopic regulation and control,economic stimulus,and housing construction were all important factors affecting the coordinated development of the livable environment system for the elderly,exerting a varying degree of effect on the level of coordinated development of various types of systems.展开更多
This paper reports on investigations into capacity of ad hoc network whose nodes are equipped with multiple element antennas (MEAs). The investigation of this multi-user Multiple Input Multiple Output (MIMO) system ta...This paper reports on investigations into capacity of ad hoc network whose nodes are equipped with multiple element antennas (MEAs). The investigation of this multi-user Multiple Input Multiple Output (MIMO) system takes into account mutual coupling (MC) in addition to spatial correlation that is present in array antennas. A closed-form expression for an upper bound of mutual information (capacity) of MIMO ad hoc network is derived. An optimal signal transmission scheme is proposed to maximize the MIMO ad hoc network capacity. Simulation results for capacity of non-optimized and optimized cases of signal transmission are presented.展开更多
基金The MOE Project of Key Research Institute of Humanities and Social Sciences in University,No.14JJD790044Science and Technology Research Program Supported by the Education Department of Liaoning Province,No.L2013411
文摘Using a sample of 14 prefecture-level cities in Liaoning Province, this study first explored the spatial hierarchy and structural characteristics of energy efficiency from the following three viewpoints： energy technical efficiency based on data envelopment analysis, energy consumption per unit of GDP, and energy utilization efficiency combining the previous two indexes After measuring and analyzing the advancement, rationality, and concentration of the industrial structure in each city, we made some generalizations about the coupling features of the energy efficiency and industrial structure in Liaoning, using the coupling degree rating model Some of our conclusions are as follows： （1） The 14 cities differ significantly in their en- ergy efficiency, with Shenyang, Dalian, Anshan, and Jinzhou enjoying the highest energy effi- ciency. Northwestern Liaoning and other heavy-industrial cities such as Fushun and Benxi belong to low-efficiency and high-consumption areas. （2） In areas with higher efficiency, the spatial patterns of the energy technical efficiency, energy consumption per unit of GDP, and energy utilization efficiency are, respectively, ＂π ＂-, ＂Ⅱ＂- and ＂H＂- shaped. Geographically, the energy utilization efficiency shows different trends from east to west and from north to south. Factors such as the binuclear structure of economic development have a major effect on this spatial pattern of energy efficiency. （3） Southeastern Liaoning enjoys a highly advanced in- dustrial structure. Areas with a highly rational industrial structure form an ＂H＂ shape, with Shenyang and Dalian at the two poles. The urban agglomerations in middle and southern Liaoning have a highly concentrated industrial structure. （4） Overall, the coupling between energy efficiency and industrial structure is low in Liaoning, except for Shenyang and Dalian at both ends, where the coupling between an advanced industrial structure and energy efficiency is higher than in other cities.
基金supported by the National Natural Science Foundation of China (NSFC 50809068)the foundation of the State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,China (10502)+1 种基金the China Postdoctoral Science Foundation (20080441196)the West Light Foundation of the Chinese Academy of Science
文摘Wheat is an important agricultural crop in the Loess region of China, where there is drought stress and low availability of soil nitrogen and phosphorus. Using a pulse modulation fluorometer, we studied the effects of water, nitrogen, and phosphorus on the kinetic parameters of chlorophyll fluorescence in winter wheat. The wheat was grown in layered columns of Eum-Orthic Anthrosol （Cinnamon soil）, with the water content and nutrient composition of each layer controlled. The results showed that the kinetic parameters of chlorophyll fluorescence were sensitive to water stress. The basic fluorescence （F0） of leaves was higher in the dry treatment （0-30 cm layer at 40-45% of field capacity, 30-90 cm at 75-80% of field capacity） compared to the wet treatment （entire soil column at 75-80% of field capacity）. The maximal fluorescence （Fm）, the variable fluorescence （Fv）, the photochemical efficiency （Fv/Fm） and potential activites （Fv/F0） of photosystem 2 （PS2） were significantly lower in the dry treatment. Although drought stress impaired PS2 function, this effect was significantly ameliorated by applying P or NP fertilizer, but not N alone. P application increased FJFm, both in well-watered and water stressed plants, especially when fertilizer was applied throughout the column or within the top 30 em of soil. A combined fertilizer improved photosynthesis in well watered plants, with Fm and F,fFm being the highest when fertilizer was applied throughout the columns. For drought stressed, plants FJFm was significantly greater when combined fertilizer was added within the top 30 cm of soil. We concluded that, when growing winter wheat in both arid and semi-arid parts of the Loess region of China, it is important to guarantee the nutrient supply in the top 30 cm of the soil.
基金National Basic Research Program of China, No.2012CB95570002National Key Technology R&D Program,No.2012BAJ15B02
文摘Given the great number of studies focusing on the temporal interaction between economic and environmental subsystems, it is useful to perform a quantitative spatial as- sessment of these subsystems. In this paper, comprehensive assessment indicators for re- gional economic development and environmental pollution subsystems are constructed. Then the degree of coupling and coordination of the regional economy-environment system is calculated for 350 prefectural units in China. It is found that the economic development and environmental pollution in most prefectural units is still at a low level of coupling and coordi- nation. According to the coupling and coordination values, the Chinese territory can be di- vided into four types of area: economy-environment harmonious area, economy-environ- ment gearing area, economy-environment rivaling area and low coupling degree of econ- omy-environment area. Based on a structural analysis of the industrial sector in the four types of areas, there is a spatial relationship between the regional industrial sector structure and the coupling-coordination level. In the economy-environment harmonious area, the sectors of manufacturing of high-technology and high value-added products, such as com- munications, computer and electronic equipment, transport equipment and electrical ma- chinery, account for a large proportion of the value of local industrial output. The industrial value of the economy-environment gearing area is concentrated on the manufacturing of machinery and equipment, and. contains a few polluting sectors such as ferrous and non-ferrous metallurgy, chemical manufacturing and electricity generation. The econ- omy-environment rivaling area is the type of area where polluting sectors concentrate, such as iron and steel, petrifaction, coal mining, building materials and electricity generation. In the low coupling degree of economy-environment area, its industry is concentrated on the pro- duction and processing of primary products.
基金provided by the National Natural Science Foundation of China(No.51374046)State Key Laboratory for Geo Mechanics and Deep Underground Engineering at China University of Mining&Technology(SKLGDUEK1420)
文摘The spatial distribution of overburden strata failure is of significant importance to affect the safety of underground mining. Because the traditional methods cannot be applied in all coal mines due to geological conditions or mining structures, a method of coupling FLAC3D with GIS was presented to calculate the spatial distribution of overburden strata failure in longwall coal mines. After building the spatio-temporal database from the calculation results of FLAC3D, the height of the mining-induced fractured zone in the overburden strata can be calculated by using the given height function. The results of case study show that the height of the fractured zone reached the maximum value at the face advance equal to about the panel width. The outcome of the work presented will be helpful in practice to improve safety in the production.
基金Under the auspices of National Natural Science Foundation of China(No.42071220,42371223)China Postdoctoral Science Foundation(No.2021M701053)Postgraduate Cultivating Innovation and Quality Improvement Action Plan of Henan University(No.SYLYC2022017)。
文摘Addressing the issue of the healthy and coordinated development of the population and economic factors in rural areas will not only help consolidate and expand the achievements of poverty alleviation,but will also lay a foundation for comprehensive rural revitalization.In this paper,the spatial coupling relationship between the population and economic factors in rural areas in the QinlingDaba Mountains,China,is explored to provide a reference for rural revitalization and regional sustainable development in poverty areas.Sixty-eight county units in rural areas in the Qinling-Daba Mountains,as well as the population and economic factors in rural areas,are used to study the spatial coupling relationship between population and economy,as well as the driving mechanism,in rural areas in the Qinling-Daba Mountains from 2010 to 2020.The results show that a population contraction phenomenon occurred in the rural areas in the Qinling-Daba Mountains,and the spatial agglomeration trends of the population and economic factors were consistent.The agglomeration was mainly located in the suburban areas of the municipal area,and the agglomeration degree was significantly higher in these areas than in other areas.In terms of the spatial distribution,the economic development level of the rural areas in the northeastern part of the Qinling-Daba Mountains was generally higher than that in the central and western parts,and the unbalanced trends of the population and economic spatial differentiation in the eastern and western regions were significant.The spatial coupling relationship between the population and economy changed from coordinated development to economic advancement.This was mainly due to the mutual restriction and joint actions of the industrial structure,capital situation,natural environment,policies,and institutional regulations,among which the industrial structure and capital status had significant effects.
基金the Second Tibetan Plateau Scientific Expedition and Research(2019QZKK0404)the Chinese Academy of Sci-ences Strategy Priority Research Program(Category A)(XDA20020300)National Natural Science Foundation of China key projects(41630644)。
文摘The development of Qingzang national park cluster is part of China’s efforts to establish a major ecological civi-lization project in the Qingzang Plateau,in line with global sustainable development goals.Based on preliminary scientific investigation and research in the Qingzang Plateau,the construction of the park cluster will include 21 national parks.To mitigate the conflict between conservation of the national park cluster and the develop-ment of local communities,this study proposes an analysis framework to identify the spatial coupling features between the national park cluster and sustainable development of communities.Four elements were selected to construct the analysis framework,including natural conditions,geographic location,cultural background,and national policies.This framework was applied to the 457 township communities within the 21 national parks.Results show the weak influence of the construction of the national park cluster for approximately 304 township communities,without significant spatial coupling traits,while the remaining 153 communities demonstrated significant spatial coupling features.These latter townships had developed four types of spatial coupling with na-tional parks,including eco-migrants,transportation hubs,characteristic cultures,and border development,which account for 17.4%,35.3%,19.8%,and 27.5%of the 153 townships respectively.A composite type with more than one spatial coupling feature was also found for 14 communities within the 153 townships.This provides a reference for policy making towards four major types of interactive modes between townships and the national park construction for the sustainable development of Qingzang Plateau.
基金Humanities and Social Sciences Fund of Ministry of Education of China,No.24YJA630097National Natural Science Foundation of China,No.42471304。
文摘The uneven distribution of medical resources has led to increasingly frequent patient mobility;however, the interaction between this phenomenon and the healthcare supply-demand relationship remains underexplored. The present study constructed the 2023Cross-City Patient Mobility Network in China using one million patient mobility data records obtained from online healthcare platforms. We applied urban network analysis to uncover mobility patterns and used the coupling coordination degree model to assess healthcare supply-demand relationships before and after patient mobility. Explainable machine learning further revealed the impact of supply-demand coupling on patient mobility. The results indicated the following: Patient mobility followed administrative boundaries, although megacities serve areas beyond provincial borders;The scale of healthcare supply and demand displayed a multi-centric spatial pattern with a general decline from east to west, and these characteristics of demand distribution were further solidified by patient mobility;Cities with low supply-demand coupling and undersupply experienced patient outflows, while cities with high coupling and oversupply attracted them. In turn, patient mobility helped balance healthcare supply and demand, optimising the coupling relationship across cities. Thus, this research not only provides a methodological reference for understanding the interaction between patient mobility and healthcare systems but also offers empirical insights for public health policy.
基金supported by Re-search Project No.200420140001 of China Geological Survey
文摘At present, gas hydrates are known to occur in continental high latitude permafrost regions and deep sea sediments. For middle latitude permafrost regions of the Tibetan Plateau, further research is required to ascertain its potential development of gas hydrates. This paper reviewed pertinent literature on gas hydrates in the Tibetan Plateau. Both geological and ge- ographical data are synthesized to reveal the relationship between gas hydrate formation and petroleum geological evo- lution, Plateau uplift, formation of permafrost, and glacial processes. Previous studies indicate that numerous residual basins in the Plateau have been formed by original sedimentary basins accompanied by rapid uplift of the Plateau. Ex- tensive marine Mesozoic hydrocarbon source rocks in these basins could provide rich sources of materials forming gas hydrates in permafrost. Primary hydrocarbon-generating period in the Plateau is from late Jurassic to early Cretaceous, while secondary hydrocarbon generation, regionally or locally, occurs mainly in the Paleogene. Before rapid uplift of the Plateau, oil-gas reservoirs were continuously destroyed and assembled to form new reservoirs due to structural and thermal dynamics, forcing hydrocarbon migration. Since 3.4 Ma B.P., the Plateau has undergone strong uplift and extensive gla- ciation, periglacier processes prevailed, hydrocarbon gas again migrated, and free gas beneath ice sheets within sedi- mentary materials interacted with water, generating gas hydrates which were finally preserved under a cap formed by frozen layers through rapid cooling in the Plateau. Taken as a whole, it can be safely concluded that there is great temporal and spatial coupling relationships between evolution of the Tibetan Plateau and generation of gas hydrates.
基金supported by the National Natural Science Foundation of China(12172281,11972284 and 11872303)Fund for Distinguished Young Scholars of Shaanxi Province(2019JC-29)+1 种基金Foundation Strengthening Programme Technical Area Fund(2021-JCJQ-JJ-0565)Fund of the Youth Innovation Team of Shaanxi Universities and the Open Foundation of State Key Laboratory of Structural Analysis of Industrial Equipment(GZ19103).
文摘Although the complex structure-preserving method presented in our previous studies can be used to investigate the orbit–attitude–vibration coupled dynamic behaviors of the spatial flexible damping beam,the simulation speed still needs to be improved.In this paper,the infinite-dimensional dynamic model describing the orbit–attitude–vibration coupled dynamic problem of the spatial flexible damping beam is pretreated by the method of separation of variables,and the second-level fourth-order symplectic Runge–Kutta scheme is constructed to investigate the coupling dynamic behaviors of the spatial flexible damping beam quickly.Compared with the simulation speed of the complex structure-preserving method,the simulation speed of the symplectic Runge–Kutta method is faster,which benefits from the pretreatment step.The effect of the initial radial velocity on the transverse vibration as well as on the attitude evolution of the spatial flexible damping beam is presented in the numerical examples.From the numerical results about the effect of the initial radial velocity,it can be found that the appearance of the initial radial velocity can decrease the vibration frequency of the spatial beam and shorten the evolution interval for the attitude angle to tend towards a stable value significantly.In addition,the validity of the numerical results reported in this paper is verified by comparing with some numerical results presented in our previous studies.
基金National Key Research and Development Program of China,No.2019YFD1101304National Natural Science Foundation of China,No.52278059+1 种基金Natural Science Foundation of Hunan Province of China,No.2024JJ8316Hunan Provincial Innovation Foundation For Postgraduate,No.CX20250634。
文摘Urban spatial morphology(USM)optimization is critical to balancing biodiversity conservation and sustainable urbanization.However,previous studies predominantly focused on the socio-economic efficiency and static ecological metrics and rarely addressed the dynamic USM optimization across spatial scales.Here,we developed a multi-level ecological network(MEN)framework to resolve the tension between urban expansion and ecological integrity.By integrating the cost-weighted distance analysis with a hierarchical network transmission mechanism,we established a cross-scale spatial optimization system,which coordinated the regional ecological corridors and local habitat patches.Comparative experiments with conventional single-scale approaches and scenario simulations using the PLUS model show that the MEN framework had superior performance in three dimensions:(1)spatial governance:the primary-level network(peri-urban natural reserves)effectively contained urban sprawl,and the secondary-level network(intra-urban green corridors)mitigated habitat fragmentation and improved the built-environment;(2)scenario robustness:the model maintained an optimal compactness-loose balance in multiple development pathways;(3)landscape metrics:patch fragmentation decreased by 18.25%,and the internal landscape richness improved by 10.66%compared to the scenario without USM optimization.The findings provide new insight to establish a hierarchical ecological optimization framework as a nature-based spatial protocol to reconcile metropolitan growth with landscape sustainability.
基金Supported by Open Fund of Key Laboratory of Plant Nutrition and Fertilizer,Ministry of Agriculture(2013-1)Guangxi Natural Science Foundation for Youths(2011GXNSFB018026)+2 种基金Guangxi Scientific Research and Technological Development Program(14125008-2-15)Scientific and Technological Development Fund for Youths of Guangxi Academy of Agricultural Sciences(2013YQ18,2013YF06)the State Key Program of National Natural Science of China(U1033004-06)~~
文摘The coupling of water and fertilizer is the only way for high yield, efficiency, sugar on sugarcane. On sugarcane production, the spatial and temporal controlling technology of fertigation is an important direction of the sustainable and healthy development of ecological agriculture in cane area of China. This paper reviews main achievements and advances on the coupling effect of water and fertilizer on sugarcane from time and space at home or abroad in recent years, analyzes the application prospects of the temporal and spatial coupling effect of water and fertilizer on sugarcane and puts forward some problems which need further research in future.
基金National Natural Science Foundation of China,No.42001187,No.41701629。
文摘The spatial relationships between traffic accessibility and supply and demand(S&D)of ecosystem services(ESs)are essential for the formulation of ecological compensation policies and ESs regulation.In this study,an ESs matrix and coupling analysis method were used to assess ESs S&D based on land-use data for 2000,2010,and 2020,and spatial regression models were used to analyze the correlated impacts of traffic accessibility.The results showed that the ESs supply and balance index in the middle reaches of the Yangtze River urban agglomeration(MRYRUA)continuously decreased,while the demand index increased from 2000 to 2020.The Gini coefficients of these indices continued to increase but did not exceed the warning value(0.4).The coupling degree of ESs S&D continued to increase,and its spatial distribution patterns were similar to that of the ESs demand index,with significantly higher values in the plains than in the montane areas,contrasting with those of the ESs supply index.The results of global bivariate Moran’s I analysis showed a significant spatial dependence between traffic accessibility and the degree of coupling between ESs S&D;the spatial regression results showed that an increase in traffic accessibility promoted the coupling degree.The present results provide a new perspective on the relationship between traffic accessibility and the coupling degree of ESs S&D,representing a case study for similar future research in other regions,and a reference for policy creation based on the matching between ESs S&D in the MRYRUA.
文摘The electrical performance of radomes on high-speed aircraft can be influenced by the thermal and mechanical loads produced during high-speed flight,which can affect the detection dis-tance and accuracy of the guidance system.This paper presents a new method that uses the Finite Difference Time Domain(FDTD)method to calculate the electrical performance of radomes under Thermo-Mechanical-Electrical(TME)coupling.This method can accurately characterize the effects of material dielectric temperature drift and structural deformation on the electrical performance of the radome under flight conditions,enabling high-precision full-wave calculations of the broadband electrical performance of the radome.The method initiates by utilizing a Finite Element Grid Model(FE-GM)of the radome to sequentially acquire the radome's response temperature field and structural deformation field through thermal and mechanical simulations.Subsequently,spatial mapping techniques are developed to accurately incorporate the dielectric temperature drift and structural deformation of the radome into its Yee grid Electromagnetic(EM)simulation model.A verification case was designed to test the proposed method,and the results confirmed its high computational accuracy.Additionally,the effectiveness and necessity of the method were further demonstrated by analyzing the electrical performance of a fused silica ceramic radome used on a high-speed aircraft.
基金National Social Science Foundation of China(Grant No.19XMZ095)Chongqing Social Science Planning Major Project(Grant No.2020WT22)
文摘The construction of a new type of urbanization is a necessary path for the development of modern cities,and a powerful support for coordinating the balanced development of urban and rural areas and promoting high-quality agricultural development.Based on the panel data of 30 provinces in China from 2004 to 2018,the article constructs a new urbanization and agricultural high-quality development evaluation system;then using the coupling coordination degree model and the spatial correlation analysis method,the paper empirically tests the coupling coordination of the two systems degree and its spatial relevance.The results of the study show that the average level of coupling and coordination between new urbanization and high-quality agricultural development in the period under study is at a barely coordinated level,with the highest level being moderately coordinated.There are significant inter-regional differences,with a higher level of coupling and coordination in the eastern regions and more room for improvement in the central and western regions.At this stage,the trend of"club convergence"is remarkable,with highhigh agglomeration and low-low agglomeration coexisting,and the polarization is serious.Therefore,comprehensively promoting the rural revitalization strategy,adhering to the integrated development of urban and rural areas,and enhancing inter-regional collaborative governance are powerful measures to promote the joint progress of new urbanization and high-quality agricultural development.
文摘Based on combing the existing research on the production-living-ecological space,the paper quantitatively analyzes the evaluation system-development level-temporal and spatial evolution,future trend-influencing factors of the production-living-ecological functions coupling and coordination in the Yellow River Basin from 2009 to 2018.Through multi-scale analysis and comparison,the paper tries to identify problem areas and put forward corresponding measures.The research results show that:(1)The coupling and coordination degree of the production-living-ecological functions in the Yellow River Basin both show an upward trend,and its future growth trend is relatively slow.(2)The spatial-temporal differential characteristics of the coordinated development level of the production-living-ecological functions are obvious,and gradually develop towards the direction of benign resonance in time,showing a spatial distribution pattern of“high in the northeast and low in the southwest”.(3)There is a big difference in the level of coordinated development of the production-living-ecological functions,and the coordination degree of the“production-living”function is the lowest.(4)Scientific and technological investment,economic development level,government capacity,and urbanization level have a significant positive impact on the spatial effect of the coordinated development of the production-living-ecological functions of the Yellow River Basin,and the same factor has different effects on different regions.
基金supported by the Program for New Century Excellent Talents in University(NCET),China(Grant No.NCET-05-0784)
文摘Three coupling coefficients are defined to describe spatiotemporal coupling in ultrashort pulses. With these coupling coefficients, the first-order spatiotemporal couplings of Gaussian pulse and beam are described analytically. Also, the first-order and the second-order spatiotemporal couplings caused by angular dispersion elements are studied using these coupling coefficients. It can be shown that these coupling coefficients are dimensionless and normalized, and readily indicate the severity of spatiotemporal coupling.
基金Project supported by the National Natural Science Youth Foundation of China(Grant No.60906042)the National Natural Science Foundation of China(Grant Nos.10974058 and 61178003)
文摘Based on the microscopic nonlocal optical response theory, the intersubband optical absorption properties in AlGa As/Ga As couple quantum wells（CQWs） are investigated for p-polarized states. The numerical results show that spatial nonlocality of optical responses can induce a radiation shift on optical absorption spectra due to nonlocal effects. The dependence of the radiation shift on the CQW structure and the applied electric field is clarified. It is also demonstrated that the maximal radiation shift and the least optical absorbance can be obtained by adopting an appropriate CQW structure and a suitable applied electric field. This work may provide some methods of designing the nanomaterials with controllable nonlocality and observing the spatial nonlocal effects in experiment.
基金Supported by the National Natural Science Foundation of China(No.61801371,61801372,61701291,61771417)Natural Science Basic Research Plan in Shaanxi Province of China(No.2018JM5052)+1 种基金National Key Research and Development Program of China(No.2018YFC0808301)Talent Foundation of Xi’an University of Science and Technology(No.2018QDJ028)
文摘A rate-compatible spatially coupled repeat-accumulate (RC-SC-RA) code is proposed. Its protograph is obtained by extending a given (J, K, L) SC-RA coupled chain (denoted as the mother chain) with extra check nodes and parity bit nodes T times. At each time, the extension is realized via coupling the message bits in the same way as that in the mother chain. Rate-compatibility is achieved by adjusting the extension parameters and applying random puncturing technique. Density evolution analysis shows that the iterative decoding thresholds of all the member codes in the proposed RC-SC-RA code family are very close to Shannon limits over the binary erasure channel. Finite length simulation results are consistent with the thresholds well. Moreover, the proposed RC-SC-RA codes perform better than spatially coupled low density parity check (SC-LDPC) codes in decoding performance especially in lower-rate region.
基金Under the auspices of Natural Science Foundation of Heilongjiang Province(No.LH2019D008)Youth Fund for Humanities and Social Sciences of the Ministry of Education(No.19YJC630177)+1 种基金Innovative Youth Talent Cultivation Plan of Heilongjiang Provincial Universities(No.UNPYSCT-2018194)Human Civilization and Social Science Supportive Program for Excellent Young Scholars of Harbin Normal University(No.SYQ2014-06)。
文摘The construction of a livable environment for the elderly is an important measure to address the challenges of aging and improve their livelihood and well-being.Based on China’s national conditions and combined with the actual development needs of the cities,it is of great significance to explore the coupling and coordination characteristics and influencing factors within the livable environment system for the elderly for the coordination and stable development.This article was based on the three subsystems of’living service environment,socioeconomic environment and ecological livable environment’,following the research framework of’process-pattern-trend-impact’,constructs an evaluation index system for the livable environment for the elderly.Entropy weight-TOPSIS evaluation model,coupling coordination degree model,center of gravity and standard deviation ellipse model and the geographic detector model were used starting from the evolution of coupling coordination types to study the spatial and temporal pattern and dynamic trend characteristics and influencing factors of internal coupling coordination types in the livable environment system for the elderly from2010 to 2019.The results showed that:1)The coordinated development of life service environment system and ecological livable environment system(LE)and socioeconomic environment system and ecological livable environment system(SE)in the livable environment for the elderly decreased from the intermediate coordination level coordination areas to the low-level quality improvement and optimization areas:coordinated transition type.The overall development level of life service environment system and socioeconomic environment system(LS)was low,and it was always at a low level.2)The coupling degree of livable environment system for the elderly was high,the coupling coordination type shown a gradually decreasing layer structure with Zhejiang,Beijing and Guangdong high-level leading demonstration areas as the axis belt.3)The coupling coordination center of the elderly livable environment system was located in Henan,and the standard deviation ellipse was distributed in the northeast-southwest direction.The development center and the ellipse of the high-level leading demonstration areas and the intermediate coordination level areas were concentrated in the central and eastern regions,while the low-level coordination areas for improving quality and efficiency are mainly located in the western region.4)Urban development,green facilities,infrastructure,government macroscopic regulation and control,economic stimulus,and housing construction were all important factors affecting the coordinated development of the livable environment system for the elderly,exerting a varying degree of effect on the level of coordinated development of various types of systems.
文摘This paper reports on investigations into capacity of ad hoc network whose nodes are equipped with multiple element antennas (MEAs). The investigation of this multi-user Multiple Input Multiple Output (MIMO) system takes into account mutual coupling (MC) in addition to spatial correlation that is present in array antennas. A closed-form expression for an upper bound of mutual information (capacity) of MIMO ad hoc network is derived. An optimal signal transmission scheme is proposed to maximize the MIMO ad hoc network capacity. Simulation results for capacity of non-optimized and optimized cases of signal transmission are presented.
