With economic development and urbanization in China,the rural settlements have experienced great change.To explore the evolution process of rural settlements in terms of land,population and industry can reveal the dev...With economic development and urbanization in China,the rural settlements have experienced great change.To explore the evolution process of rural settlements in terms of land,population and industry can reveal the development law of rural spatial distribution,population structure and industrial economy in different stages and regions.Studying the development status and evolution characteristics of villages in the upper Tuojiang River basin in Southwest China in the past 20 years are of significant value.The upper Tuojiang River basin includes the main types of terrain found in the Southwest region:mountainous,plains,and hills,exhibiting a certain typicality of geographical characteristics.This study took towns and townships at the town-level scale as the basic unit of research,and constructed an evaluation system for village evolution based on'land,population,and industry'.It employed Criteria Importance Through Inter-Criteria Correlation(CRITIC)analysis to examine the characteristics of village evolution in the area from 2000 to 2020,and used geographic detector analysis to identify the leading factors affecting village evolution.The results show that:(1)From 2000 to 2010,villages in the upper Tuojiang River basin experienced significant changes,and the pace of these transformations slowed from 2010 to 2020.(2)From a comprehensive perspective,from 2000 to 2020,villages in hilly areas show a decline,while villages in plain areas near the city center show a positive urbanization development.(3)Road accessibility and distance from the city center are the main factors that explain the spatial differentiation of village evolution degree in the study area.This study elucidates the spatiotemporal evolution characteristics of villages in the upper Tuojiang River basin and identifies the primary factors contributing to their changes,which will provide a reference for investigating the development of rural areas in different terrains of Southwest China.展开更多
This study utilized census data from Henan Province for the years 2000,2010,and 2020 to investigate the spatiotemporal evolution of population aging,defined by the proportion of the population aged 65 and above.Employ...This study utilized census data from Henan Province for the years 2000,2010,and 2020 to investigate the spatiotemporal evolution of population aging,defined by the proportion of the population aged 65 and above.Employing spatial analysis techniques such as spatial autocorrelation and the standard deviation ellipse,the research mapped out the progression and distribution of aging demographics.Furthermore,the study delved into the influencing factors of aging using an optimal parameters-based geographical detector.Results indicate a deepening degree of population aging in Henan Province,transitioning from an adult type to an old type structure.There is a marked positive spatial correlation among counties,with high-value aging areas initially decreasing,then increasing,and notably spreading from the central to the central and southern regions of the province.The center of gravity for population aging,specifically around Changge City and Xuchang City,exhibits a trajectory moving southeast before shifting northwest.Factor detection reveals that in 2000,2010,and 2020,the elderly dependency ratio predominantly influences the aging trend,with explanatory powers of 88.4%,87.9%,and 90.9%,respectively.Interaction analysis indicates that the interaction between the old-child ratio and the elderly dependency ratio has a strong explanatory power for the aging patterns in Henan Province,reaching 97.3%,97.0%,and 97.4%,respectively.展开更多
The population spatial distribution pattern and its evolving pattern play an important role in regional allocation of social resources and production factors, formulation of regional development plans, construction of...The population spatial distribution pattern and its evolving pattern play an important role in regional allocation of social resources and production factors, formulation of regional development plans, construction of a better life society, and promotion of regional economic development. Based on the resident population statistics data of Henan province from 2006 to 2021, with county as the basic study unit, the paper studies the spatial morphology characteristics and its evolution patterns of resident population distribution, by using spatial analysis methods such as population distribution center, standard deviation ellipse, and spatial auto correlation analysis. The results show that: the resident population spatial distribution shows unbalanced state, the population agglomeration areas mainly distribute in the northeast part and north part, where the resident population growth rate is significantly higher than other regions, over time, this trend is gradually becoming significant. The resident population distribution has a trend of centripetal concentration, with the degree and trend of centripetal gradually strengthening. The resident population distribution has obvious directional characteristics, but the significance is not high, the weighted resident population average center is approximately located at (4.13740˚N, 113.8935˚E), and the azimuth of the distribution axis is approximately 11.19˚. The population distribution has obvious agglomeration characteristics, with the built-up areas of Zhengzhou and Luoyang as their centers, where have a significant siphon effect on the surrounding population. The southern and southwestern regions in the province form a relatively stable belt area of Low-Low agglomeration areas.展开更多
Upon the analogy of definition of heterosis and inbreeding depresstion in terms of population genetics, the heterosis is thought to be evaluated overall with fitness. By establishing a mathematical model, the equilibr...Upon the analogy of definition of heterosis and inbreeding depresstion in terms of population genetics, the heterosis is thought to be evaluated overall with fitness. By establishing a mathematical model, the equilibrium status of three genotypes of random mating population (i. e. RR, Rr and rr) under different fitness, which exposes that heterosis is the precondition for multiallele to exist in the population. The heterosis protects the genetic diversity and makes the population owning a stronger self-control and evolution potential by improving the hetemzygote's fithess so as not to wash out different types of genes. It deepens Darwin's thoughts of individual section by making the individual fitness consonant with population fitness.展开更多
Persistent uplift means the Qinghai-Tibet Plateau(QTP)is an ideal natural laboratory to investigate genome evolution and adaptation within highland environments.However,how paleogeographic and paleoclimatic events inf...Persistent uplift means the Qinghai-Tibet Plateau(QTP)is an ideal natural laboratory to investigate genome evolution and adaptation within highland environments.However,how paleogeographic and paleoclimatic events influence the genome and population of endemic fish species remains unclear.Glyptosternon maculatum is an ancient endemic fish found on the QTP and the only critically endangered species in the Sisoridae family.Here,we found that major transposons in the G.maculatum genome showed episodic bursts,consistent with contemporaneous geological and climatic events during the QTP formation.Notably,histone genes showed significant expansion in the G.maculatum genome,which may be mediated by long interspersed nuclear elements(LINE)repetitive element duplications.Population analysis showed that ancestral G.maculatum populations experienced two significant depressions 2.6 million years ago(Mya)and 10000 years ago,exhibiting excellent synchronization with Quaternary glaciation and the Younger Dryas,respectively.Thus,we propose that paleogeography and paleoclimate were dominating driving forces for population dynamics in endemic fish on the QTP.Tectonic movements and temperature fluctuation likely destroyed the habitat and disrupted the drainage connectivity among populations.These factors may have caused severe bottlenecks and limited migration among ancestral G.maculatum populations,resulting in the low genetic diversity and endangered status of the species today.展开更多
This paper examines the temporal change and spatial variation of population pressure on the ecological environment in China.We have collected sufficient data from the statistical yearbooks of 31 provincial administrat...This paper examines the temporal change and spatial variation of population pressure on the ecological environment in China.We have collected sufficient data from the statistical yearbooks of 31 provincial administrative areas in 1990,1995,2000,2005,and 2010.Using a geographic information system(GIS) and relevant models,we analyzed the trend of the population pressure on ecological environment and the change of the gravity center of ecological environment quality.We conclude that:(1) generally,population pressure on the ecological environment in China was becoming higher during1990-2010,especially in some areas where the population and environment were in serious imbalance and the ecological environment experienced severe pollution;(2) during a certain period,population pressure on the ecological environment was becoming lower in some areas,but the ecological environment was getting worse;(3) the areas with super-high population pressure on the ecological environment were Beijing,Tianjin,and Shanghai;(4) the gravity center of population pressure on the ecological environment and the center of ecological environment quality move differently during the study time period,but the general trend was similar- both of them were moving from west to east.Based on the analysis,this paper also provides some policy suggestions on the control of ecological environment quality.展开更多
Aimed at improving the insufficient search ability of constraint differential evolution with single constraint handling technique when solving complex optimization problem, this paper proposes a constraint differentia...Aimed at improving the insufficient search ability of constraint differential evolution with single constraint handling technique when solving complex optimization problem, this paper proposes a constraint differential evolution algorithm?based on ensemble of constraint handling techniques and multi-population?framework, called ECMPDE. First, handling three improved variants of differential evolution algorithms are dynamically matched with two constraint handling techniques through the constraint allocation mechanism. Each combination includes three variants with corresponding constraint handling technique?and these combinations are in the set. Second, the population is divided into three smaller subpopulations and one larger reward subpopulation. Then a combination with three constraint algorithms is randomly selected from the set, and the three constraint algorithms are run in three sub-populations respectively. According to the improvement of fitness value, the optimal constraint?algorithm is selected to run on the reward sub-population, which can share?information and close cooperation among populations. In order to verify the effectiveness of the proposed algorithm, 12 standard constraint optimization problems?and 10 engineering constraint optimization problems are tested. The experimental results show that ECMPDE is an effective algorithm for solving constraint optimization problems.展开更多
In recent years, the population size and scale of the Shiyang River Basin unceasingly expanding lead to a series of ecological environment: surface water reducing, land desertification and Ground water levels fall, et...In recent years, the population size and scale of the Shiyang River Basin unceasingly expanding lead to a series of ecological environment: surface water reducing, land desertification and Ground water levels fall, etc. Research evolution characteristics of population distribution and migration growth of Shiyang River Basin contribute to river water resources and the industrial development of the comprehensive management. The article using the distribution of population structure index, population distribution center of gravity model and the population migration growth analysis model analyzes the distribution of the population evolution characteristics and population migration growth characteristics of Shiyang River Basin in 2000 to 2010. The results show that: 1) Considering Shiyang River Basin, population density is generally low, population distribution difference is bigger and concentration distribution in the middle corridor plain and three big population distribution center of Minqin oasis area, presenting a “point-areas-ribbon” structure characteristics. 2) The population distribution trend of Shiyang River Basin is constantly concentration, but the change is slow;the population distribution of Minqin is in the highest concentration degree, but the trend has been declining. 3) The focus of population density in river basin locates in Liangzhou district of Daliu country;in ten years, it migrates about 1209 m to southwest Wuwei City direction, but migration along the direction things is bigger than the north and south direction. The focus of population density and the basin geometry center is far away. 4) For ten years, at the township for basic statistics unit, each level population migration change within the overall is not significant: township level > prefecture-level cities level > counties level. 5) For ten years, there are significant changes in population migration between watershed township units, Wuwei City and Gulang Town are the two main concentrations of population centers.展开更多
This paper presents an application of a metapopulation model structured in classes for the study of population evolution of a network of schools.The global dynamics are considered in two parts,the local,where the evol...This paper presents an application of a metapopulation model structured in classes for the study of population evolution of a network of schools.The global dynamics are considered in two parts,the local,where the evolution for each grade in a cycle is accounted,and the metapopulation or the movement of students between schools.Simulation of the model is presented.展开更多
Under the background of new infrastructure,the Yellow River Basin’s superior growth cannot be separated originating with the synergistic effect of scientific and technological inventiveness and ecological civilizatio...Under the background of new infrastructure,the Yellow River Basin’s superior growth cannot be separated originating with the synergistic effect of scientific and technological inventiveness and ecological civilization construction.In light of the coupling coordination analysis of the coordination effect of provincial high-tech industry agglomeration and resource carrying capacity in the Yellow River Basin from 2009 to 2021,The evolution of the geographical and temporal pattern of development was investigated using the Moran index and kernel density estimation.The results show that the agglomeration of high-tech industries in the Yellow River Basin presents a development trend of seek improvement in stability,and there is a good coupling and coordination throughout the progression of scientific and technological innovation and the loading capacity of the resource,from the viewpoint of a time series.From the perspective of spatial pattern distribution,the whole basin aims at the lower reaches,accelerates the optimization of digital industry and promotes Yellow River Basin development of superior quality through innovation support and increase of input,and based on policy guidance.展开更多
Ecological land(Eco-land) is a basic resource for human beings to survive, and eco-land use is a strategy, a way to manage the land resource. So, ecologically-sustainable land use is essential for human beings to surv...Ecological land(Eco-land) is a basic resource for human beings to survive, and eco-land use is a strategy, a way to manage the land resource. So, ecologically-sustainable land use is essential for human beings to survive. This paper investigates the spatiotemporal characteristics and mechanisms of urban-rural eco-land using a new and innovative integration way based on eco-land change data in China's Loess Plateau(LP) prefecture level cities and explores factors of eco-land change. The spatial difference characteristic of eco-land among different level cities in the LP is that: small cities > big cities > middle cities. From 2009 to 2016, the eco-land in the LP from the perspective of urban-rural areas has changed significantly. Significant differences of urban-rural eco-land were identified among various urban growth types, and all the cities in the LP were further classified into four types based on eco-land change trend, with type A and B cities identified as the vital zone and major zone. Taking the eco-fragile region Loess Plateau(LP) as an example, our results demonstrated that the migrants to cities in LP could relieve ecological pressures and promote restoration of ecological vegetation. We have demonstrated that urbanization and the influence of government policy can be discerned through the quantification of the spatial-temporal change of eco-land and suggest that combining both urban and rural eco-land can support more effective land use decisions and provide theoretical basis for the practical application of urban planning, policy-making and sustainable development. What's more, governments should strive to population mobility and restore vegetation to sustain this fragile ecological environment.展开更多
Rank Histograms are suitable tools to assess the quality of ensembles within an ensemble prediction system or framework. By counting the rank of a given variable in the ensemble, we are basically making a sample analy...Rank Histograms are suitable tools to assess the quality of ensembles within an ensemble prediction system or framework. By counting the rank of a given variable in the ensemble, we are basically making a sample analysis, which does not allow us to distinguish if the origin of its variability is external noise or comes from chaotic sources. The recently introduced Mean to Variance Logarithmic (MVL) Diagram accounts for the spatial variability, being very sensitive to the spatial localization produced by infinitesimal perturbations of spatiotemporal chaotic systems. By using as a benchmark a simple model subject to noise, we show the distinct information given by Rank Histograms and MVL Diagrams. Hence, the main effects of the external noise can be visualized in a graphic. From the MVL diagram we clearly observe a reduction of the amplitude growth rate and of the spatial localization (chaos suppression), while from the Rank Histogram we observe changes in the reliability of the ensemble. We conclude that in a complex framework including spatiotemporal chaos and noise, both provide a more complete forecasting picture.展开更多
In order to improve the distribution and convergence of constrained optimization algorithms,this paper proposes a constrained optimization algorithm based on double populations. Firstly the feasible solutions and infe...In order to improve the distribution and convergence of constrained optimization algorithms,this paper proposes a constrained optimization algorithm based on double populations. Firstly the feasible solutions and infeasible solutions are stored separately through two populations,which can avoid direct comparison between them. The usage of efficient information carried by the infeasible solutions will enlarge exploitation scope and strength diversity of populations. At the same time,adopting the presented concept of constraints domination to update the infeasible set may keep good variety of population and give consideration to convergence. Also the improved mutation operation is employed to further raise the diversity and convergence.The suggested algorithm is compared with 3 state- of- the- art constrained optimization algorithms on standard test problems g01- g13. Simulation results show that the presented algorithm has certain advantages than other algorithms because it can ensure good convergence accuracy while it has good robustness.展开更多
The evolutionary and functional features of RNA editing are well studied in mammals,cephalopods,and insects,but not in birds.Here,we integrated transcriptomic and whole-genomic analyses to exhaustively characterize th...The evolutionary and functional features of RNA editing are well studied in mammals,cephalopods,and insects,but not in birds.Here,we integrated transcriptomic and whole-genomic analyses to exhaustively characterize the expansive repertoire of adenosine-to-inosine(A-to-I)RNA editing sites(RESs)in the chicken.In addition,we investigated the evolutionary status of the chicken editome as a potential mechanism of domestication.We detected the lowest editing level in the liver of chickens,compared to muscles in humans,and found higher editing activity and specificity in the brain than in non-neural tissues,consistent with the brain’s functional complexity.To a certain extent,specific editing activity may account for the specific functions of tissues.Our results also revealed that sequences critical to RES secondary structures remained conserved within avian evolution.Furthermore,the RNA editome was shaped by purifying selection during chicken domestication and most RESs may have served as a selection pool for a few functional RESs involved in chicken domestication,including evolution of nervous and immune systems.Regulation of RNA editing in chickens by adenosine deaminase acting on RNA(ADAR)enzymes may be affected by non-ADAR factors whose expression levels changed widely after ADAR knockdown.Collectively,we provide comprehensive lists of candidate RESs and non-ADAR-editing regulators in the chicken,thus contributing to our current understanding of the functions and evolution of RNA editing in animals.展开更多
A novel theoretical model is presented maintaining that consciousness evolved on the basis of time distinctions. Various models of time pertain to the existence of future, present and past. It is proposed that the fut...A novel theoretical model is presented maintaining that consciousness evolved on the basis of time distinctions. Various models of time pertain to the existence of future, present and past. It is proposed that the future represents potentialities, the present the actualization of certain potentialities, and the past a record of actualized potentialities. Actualization of potentialities derives from micro quantum wave function collapses with specific constellations corresponding to macro level form. Consciousness provides for an awareness of potentialities being actualized in the present, the time frame of consciousness closely aligning with the time frame of potentialities being actualized in the moment. Evolution of such awareness is highly probable, given the ensuing motivation enabling behavior to be altered in the moment to minimize the actualization of maladaptive potentialities, and maximize the actualization of adaptive potentialities. The model also provides a logical proof for the occurrence of time distinctions.展开更多
Among the bio-inspired techniques,PSO-based clustering algorithms have received special attention. An improved method named Particle Swarm Optimization (PSO) clustering algorithm based on cooperative evolution with mu...Among the bio-inspired techniques,PSO-based clustering algorithms have received special attention. An improved method named Particle Swarm Optimization (PSO) clustering algorithm based on cooperative evolution with multi-populations was presented. It adopts cooperative evolutionary strategy with multi-populations to change the mode of traditional searching optimum solutions. It searches the local optimum and updates the whole best position (gBest) and local best position (pBest) ceaselessly. The gBest will be passed in all sub-populations. When the gBest meets the precision,the evolution will terminate. The whole clustering process is divided into two stages. The first stage uses the cooperative evolutionary PSO algorithm to search the initial clustering centers. The second stage uses the K-means algorithm. The experiment results demonstrate that this method can extract the correct number of clusters with good clustering quality compared with the results obtained from other clustering algorithms.展开更多
This paper uses data for the period 1950-2050 compiled by the United Nations Population Division together with methods including spatial autocorrelation analysis, hie- rarchical cluster analysis and the standard devia...This paper uses data for the period 1950-2050 compiled by the United Nations Population Division together with methods including spatial autocorrelation analysis, hie- rarchical cluster analysis and the standard deviational ellipse, to analyze the spatio-temporal evolution of population and urbanization in the 75 countries located along the routes of the Silk Road Economic Belt and the 21st-century Maritime Silk Road, to identify future popula- tion growth and urbanization hotspots. The results reveal the following: First, in 2015, the majority of Belt and Road countries in Europe, South Asia and Southeast Asia had high population densities, whereas most countries in Central Asia, North Africa and West Asia, as well as Russia and Mongolia, had low population densities; the majority of countries in South Asia, Southeast Asia, Central Asia, West Asia and North Africa had rapid population growth, whereas many countries in Europe had negative population growth; and five Belt and Road countries are in the initial stage of urbanization, 44 countries are in the acceleration stage of urbanization, and 26 are in the terminal stage of urbanization. Second, in the century from 1950 to 2050, the mean center of the study area's population is consistently located in the border region between India and China. Prior to 2000, the trajectory of the mean center was from northwest to southeast, but from 2000 it is on a southward trajectory, as the population of the study area becomes more concentrated. Future population growth hotspots are predicted to be in South Asia, West Asia and Southeast Asia, and hotspot countries for the period 2015-2030 include India, China, Pakistan and Indonesia, though China will move into nega- tive population growth after 2030. Third, the overall urban population of Belt and Road coun- tries increased from 22% in 1950 to 49% in 2015, and it is expected to gradually catch up with the world average, reaching 64% in 2050. The different levels of urbanization in different countries display significant spatial dependency, and in the hundred-year period under con-sideration, this dependency increases before eventually weakening. Fourth, between 2015 and 2030, urban population hotspots will include Thailand, China, Laos and Albania, while Kuwait, Cyprus, Qatar and Estonia will be urban "coldspots." Fifth, there were 293 cities with populations over 1 million located along the Belt and Road in 2015, but that number Js ex- pected to increase to 377 by 2030. Of those, 43 will be in China, with many of the others located in India, Indonesia and the eastern Mediterranean.展开更多
Influenced by globalization,rural transition in developed Western countries has experienced processes of productivism,post-productivism,and multifunctional development.By contrast,rural transition in most developing c...Influenced by globalization,rural transition in developed Western countries has experienced processes of productivism,post-productivism,and multifunctional development.By contrast,rural transition in most developing countries has been accompanied by rapid urbanization,which has become a core topic in geography research.As the world’s largest developing country,China has undergone profound development since the reform and opening-up.Moreover,rural spaces in some eastern coastal areas have entered the stage of reconstruction after decades of industrialization and urbanization.This paper takes Suzhou as the case area and measures the process of rural transition from 1990 to 2015 by constructing an index system.It then analyzes the characteristics of space-time evolution using exploratory spatial data analysis(ESDA)methods to reveal the influence of economic and social development on rural transition.The results show that rural transition,which generally entails the weakening of rurality and enhancing of urbanity on a macro scale,tends to be heterogeneous across different regions on a micro scale.This paper argues that multifunctionality will be the main future trend of rural transition in rapidly urbanizing areas.The experience in Suzhou could provide an example for establishing policies on sustainable development in rural spaces and achieving urban-rural co-governance.展开更多
This paper selects Beijing, Shanghai, Guangzhou, and Wuhan as examples and builds a database based on the statistics of the ? fth and sixth national population censuses and the latest statistics of aging population co...This paper selects Beijing, Shanghai, Guangzhou, and Wuhan as examples and builds a database based on the statistics of the ? fth and sixth national population censuses and the latest statistics of aging population collected by ministries and commissions of the Central Government and local departments, as well as by our research team from 2000 to 2010. With its data unit accurate to Jiedao~① level, it is the ? rst time to analyze the micro-level spatial distribution characteristics of the aging population in China's mega cities in comparison with research accomplishments in geography, which lays a foundation for further relevant studies and strategy formulation. The paper draws spatial distribution maps of the aging population in Beijing, Shanghai, Guangzhou, and Wuhan by Geograpic Information System(GIS), and uses Aging Degree Index and Population Gravitational Center respectively to analyze the spatial distribution characteristics and spatial evolution trends of aging population in these mega cities. The research indicates that, on the one hand, the spatial distribution of the aging population shows similar characteristics with that of developed countries when they were at the same urbanization level, especially with Japan which shares a cultural homology with China; on the other hand, it is greatly in? uenced by the distribution of af? liated residential space of large industrial sectors, enterprises, and research institutes under the early planned economic system. There are two trends: one is centrifugal spread, namely, the elderly are moving from the city center to the outside; the other is centripetal concentration, namely, the elderly who lived in the outer suburbs are moving towards the city center. These phenomena, such as centripetal concentration, suburban spread, exurban concentration, and socio-spatial differentiation of urban aging population, are driven by selective development in the city center, city function upgrading, re-hollowing of villages, and occupation and income differentiation of the elderly before retirement.展开更多
基金The authors thank the project of Remote Sensing Data and Related Parameters Processing in Southwest China(Project No.612106241)the project of Urban Remote Sensing Data Processing and Multi-Source Integration in Central China(Project No.111/611508101).
文摘With economic development and urbanization in China,the rural settlements have experienced great change.To explore the evolution process of rural settlements in terms of land,population and industry can reveal the development law of rural spatial distribution,population structure and industrial economy in different stages and regions.Studying the development status and evolution characteristics of villages in the upper Tuojiang River basin in Southwest China in the past 20 years are of significant value.The upper Tuojiang River basin includes the main types of terrain found in the Southwest region:mountainous,plains,and hills,exhibiting a certain typicality of geographical characteristics.This study took towns and townships at the town-level scale as the basic unit of research,and constructed an evaluation system for village evolution based on'land,population,and industry'.It employed Criteria Importance Through Inter-Criteria Correlation(CRITIC)analysis to examine the characteristics of village evolution in the area from 2000 to 2020,and used geographic detector analysis to identify the leading factors affecting village evolution.The results show that:(1)From 2000 to 2010,villages in the upper Tuojiang River basin experienced significant changes,and the pace of these transformations slowed from 2010 to 2020.(2)From a comprehensive perspective,from 2000 to 2020,villages in hilly areas show a decline,while villages in plain areas near the city center show a positive urbanization development.(3)Road accessibility and distance from the city center are the main factors that explain the spatial differentiation of village evolution degree in the study area.This study elucidates the spatiotemporal evolution characteristics of villages in the upper Tuojiang River basin and identifies the primary factors contributing to their changes,which will provide a reference for investigating the development of rural areas in different terrains of Southwest China.
基金Humanities and Social Science Project of the Ministry of Education(NO.17YJCZH041)。
文摘This study utilized census data from Henan Province for the years 2000,2010,and 2020 to investigate the spatiotemporal evolution of population aging,defined by the proportion of the population aged 65 and above.Employing spatial analysis techniques such as spatial autocorrelation and the standard deviation ellipse,the research mapped out the progression and distribution of aging demographics.Furthermore,the study delved into the influencing factors of aging using an optimal parameters-based geographical detector.Results indicate a deepening degree of population aging in Henan Province,transitioning from an adult type to an old type structure.There is a marked positive spatial correlation among counties,with high-value aging areas initially decreasing,then increasing,and notably spreading from the central to the central and southern regions of the province.The center of gravity for population aging,specifically around Changge City and Xuchang City,exhibits a trajectory moving southeast before shifting northwest.Factor detection reveals that in 2000,2010,and 2020,the elderly dependency ratio predominantly influences the aging trend,with explanatory powers of 88.4%,87.9%,and 90.9%,respectively.Interaction analysis indicates that the interaction between the old-child ratio and the elderly dependency ratio has a strong explanatory power for the aging patterns in Henan Province,reaching 97.3%,97.0%,and 97.4%,respectively.
文摘The population spatial distribution pattern and its evolving pattern play an important role in regional allocation of social resources and production factors, formulation of regional development plans, construction of a better life society, and promotion of regional economic development. Based on the resident population statistics data of Henan province from 2006 to 2021, with county as the basic study unit, the paper studies the spatial morphology characteristics and its evolution patterns of resident population distribution, by using spatial analysis methods such as population distribution center, standard deviation ellipse, and spatial auto correlation analysis. The results show that: the resident population spatial distribution shows unbalanced state, the population agglomeration areas mainly distribute in the northeast part and north part, where the resident population growth rate is significantly higher than other regions, over time, this trend is gradually becoming significant. The resident population distribution has a trend of centripetal concentration, with the degree and trend of centripetal gradually strengthening. The resident population distribution has obvious directional characteristics, but the significance is not high, the weighted resident population average center is approximately located at (4.13740˚N, 113.8935˚E), and the azimuth of the distribution axis is approximately 11.19˚. The population distribution has obvious agglomeration characteristics, with the built-up areas of Zhengzhou and Luoyang as their centers, where have a significant siphon effect on the surrounding population. The southern and southwestern regions in the province form a relatively stable belt area of Low-Low agglomeration areas.
文摘Upon the analogy of definition of heterosis and inbreeding depresstion in terms of population genetics, the heterosis is thought to be evaluated overall with fitness. By establishing a mathematical model, the equilibrium status of three genotypes of random mating population (i. e. RR, Rr and rr) under different fitness, which exposes that heterosis is the precondition for multiallele to exist in the population. The heterosis protects the genetic diversity and makes the population owning a stronger self-control and evolution potential by improving the hetemzygote's fithess so as not to wash out different types of genes. It deepens Darwin's thoughts of individual section by making the individual fitness consonant with population fitness.
基金supported by the Key Research and Development Projects in Tibet:Preservation of Characteristic Biological Germplasm Resources and Utilization of Gene Technology in Tibet(XZ202001ZY0016N)National Natural Science Foundation of China(32072980)Special Finance of Tibet Autonomous Region(XZNKY-2019-C-053)。
文摘Persistent uplift means the Qinghai-Tibet Plateau(QTP)is an ideal natural laboratory to investigate genome evolution and adaptation within highland environments.However,how paleogeographic and paleoclimatic events influence the genome and population of endemic fish species remains unclear.Glyptosternon maculatum is an ancient endemic fish found on the QTP and the only critically endangered species in the Sisoridae family.Here,we found that major transposons in the G.maculatum genome showed episodic bursts,consistent with contemporaneous geological and climatic events during the QTP formation.Notably,histone genes showed significant expansion in the G.maculatum genome,which may be mediated by long interspersed nuclear elements(LINE)repetitive element duplications.Population analysis showed that ancestral G.maculatum populations experienced two significant depressions 2.6 million years ago(Mya)and 10000 years ago,exhibiting excellent synchronization with Quaternary glaciation and the Younger Dryas,respectively.Thus,we propose that paleogeography and paleoclimate were dominating driving forces for population dynamics in endemic fish on the QTP.Tectonic movements and temperature fluctuation likely destroyed the habitat and disrupted the drainage connectivity among populations.These factors may have caused severe bottlenecks and limited migration among ancestral G.maculatum populations,resulting in the low genetic diversity and endangered status of the species today.
基金supported by National Natural Science Foundation of China[Grant No.41171134]Peking University-Lincoln Institute Center for Urban Development and land Policy2013 Jiangsu Province Graduate Student Research Innovation project[Grant No.CXLX13_034]
文摘This paper examines the temporal change and spatial variation of population pressure on the ecological environment in China.We have collected sufficient data from the statistical yearbooks of 31 provincial administrative areas in 1990,1995,2000,2005,and 2010.Using a geographic information system(GIS) and relevant models,we analyzed the trend of the population pressure on ecological environment and the change of the gravity center of ecological environment quality.We conclude that:(1) generally,population pressure on the ecological environment in China was becoming higher during1990-2010,especially in some areas where the population and environment were in serious imbalance and the ecological environment experienced severe pollution;(2) during a certain period,population pressure on the ecological environment was becoming lower in some areas,but the ecological environment was getting worse;(3) the areas with super-high population pressure on the ecological environment were Beijing,Tianjin,and Shanghai;(4) the gravity center of population pressure on the ecological environment and the center of ecological environment quality move differently during the study time period,but the general trend was similar- both of them were moving from west to east.Based on the analysis,this paper also provides some policy suggestions on the control of ecological environment quality.
文摘Aimed at improving the insufficient search ability of constraint differential evolution with single constraint handling technique when solving complex optimization problem, this paper proposes a constraint differential evolution algorithm?based on ensemble of constraint handling techniques and multi-population?framework, called ECMPDE. First, handling three improved variants of differential evolution algorithms are dynamically matched with two constraint handling techniques through the constraint allocation mechanism. Each combination includes three variants with corresponding constraint handling technique?and these combinations are in the set. Second, the population is divided into three smaller subpopulations and one larger reward subpopulation. Then a combination with three constraint algorithms is randomly selected from the set, and the three constraint algorithms are run in three sub-populations respectively. According to the improvement of fitness value, the optimal constraint?algorithm is selected to run on the reward sub-population, which can share?information and close cooperation among populations. In order to verify the effectiveness of the proposed algorithm, 12 standard constraint optimization problems?and 10 engineering constraint optimization problems are tested. The experimental results show that ECMPDE is an effective algorithm for solving constraint optimization problems.
文摘In recent years, the population size and scale of the Shiyang River Basin unceasingly expanding lead to a series of ecological environment: surface water reducing, land desertification and Ground water levels fall, etc. Research evolution characteristics of population distribution and migration growth of Shiyang River Basin contribute to river water resources and the industrial development of the comprehensive management. The article using the distribution of population structure index, population distribution center of gravity model and the population migration growth analysis model analyzes the distribution of the population evolution characteristics and population migration growth characteristics of Shiyang River Basin in 2000 to 2010. The results show that: 1) Considering Shiyang River Basin, population density is generally low, population distribution difference is bigger and concentration distribution in the middle corridor plain and three big population distribution center of Minqin oasis area, presenting a “point-areas-ribbon” structure characteristics. 2) The population distribution trend of Shiyang River Basin is constantly concentration, but the change is slow;the population distribution of Minqin is in the highest concentration degree, but the trend has been declining. 3) The focus of population density in river basin locates in Liangzhou district of Daliu country;in ten years, it migrates about 1209 m to southwest Wuwei City direction, but migration along the direction things is bigger than the north and south direction. The focus of population density and the basin geometry center is far away. 4) For ten years, at the township for basic statistics unit, each level population migration change within the overall is not significant: township level > prefecture-level cities level > counties level. 5) For ten years, there are significant changes in population migration between watershed township units, Wuwei City and Gulang Town are the two main concentrations of population centers.
文摘This paper presents an application of a metapopulation model structured in classes for the study of population evolution of a network of schools.The global dynamics are considered in two parts,the local,where the evolution for each grade in a cycle is accounted,and the metapopulation or the movement of students between schools.Simulation of the model is presented.
基金supported by the 2021 Research and Practice Project of Higher Education Teaching Reform in Henan Province(Grant No.2021SJGLX072Y).
文摘Under the background of new infrastructure,the Yellow River Basin’s superior growth cannot be separated originating with the synergistic effect of scientific and technological inventiveness and ecological civilization construction.In light of the coupling coordination analysis of the coordination effect of provincial high-tech industry agglomeration and resource carrying capacity in the Yellow River Basin from 2009 to 2021,The evolution of the geographical and temporal pattern of development was investigated using the Moran index and kernel density estimation.The results show that the agglomeration of high-tech industries in the Yellow River Basin presents a development trend of seek improvement in stability,and there is a good coupling and coordination throughout the progression of scientific and technological innovation and the loading capacity of the resource,from the viewpoint of a time series.From the perspective of spatial pattern distribution,the whole basin aims at the lower reaches,accelerates the optimization of digital industry and promotes Yellow River Basin development of superior quality through innovation support and increase of input,and based on policy guidance.
基金funded by the National Key Research and Development Program of China (Grant No.2017YFC0504701)National Natural Science Foundation of China (Grant Nos.41130748 and 41471143)the National Social Science Foundation of China (Grant No 15ZDA021)
文摘Ecological land(Eco-land) is a basic resource for human beings to survive, and eco-land use is a strategy, a way to manage the land resource. So, ecologically-sustainable land use is essential for human beings to survive. This paper investigates the spatiotemporal characteristics and mechanisms of urban-rural eco-land using a new and innovative integration way based on eco-land change data in China's Loess Plateau(LP) prefecture level cities and explores factors of eco-land change. The spatial difference characteristic of eco-land among different level cities in the LP is that: small cities > big cities > middle cities. From 2009 to 2016, the eco-land in the LP from the perspective of urban-rural areas has changed significantly. Significant differences of urban-rural eco-land were identified among various urban growth types, and all the cities in the LP were further classified into four types based on eco-land change trend, with type A and B cities identified as the vital zone and major zone. Taking the eco-fragile region Loess Plateau(LP) as an example, our results demonstrated that the migrants to cities in LP could relieve ecological pressures and promote restoration of ecological vegetation. We have demonstrated that urbanization and the influence of government policy can be discerned through the quantification of the spatial-temporal change of eco-land and suggest that combining both urban and rural eco-land can support more effective land use decisions and provide theoretical basis for the practical application of urban planning, policy-making and sustainable development. What's more, governments should strive to population mobility and restore vegetation to sustain this fragile ecological environment.
基金support from MEC,Spain,through Grant No.CGL2007-64387/CLIthe AECID,Spain,for support through projects A/013666/07 and A/018685/08
文摘Rank Histograms are suitable tools to assess the quality of ensembles within an ensemble prediction system or framework. By counting the rank of a given variable in the ensemble, we are basically making a sample analysis, which does not allow us to distinguish if the origin of its variability is external noise or comes from chaotic sources. The recently introduced Mean to Variance Logarithmic (MVL) Diagram accounts for the spatial variability, being very sensitive to the spatial localization produced by infinitesimal perturbations of spatiotemporal chaotic systems. By using as a benchmark a simple model subject to noise, we show the distinct information given by Rank Histograms and MVL Diagrams. Hence, the main effects of the external noise can be visualized in a graphic. From the MVL diagram we clearly observe a reduction of the amplitude growth rate and of the spatial localization (chaos suppression), while from the Rank Histogram we observe changes in the reliability of the ensemble. We conclude that in a complex framework including spatiotemporal chaos and noise, both provide a more complete forecasting picture.
文摘In order to improve the distribution and convergence of constrained optimization algorithms,this paper proposes a constrained optimization algorithm based on double populations. Firstly the feasible solutions and infeasible solutions are stored separately through two populations,which can avoid direct comparison between them. The usage of efficient information carried by the infeasible solutions will enlarge exploitation scope and strength diversity of populations. At the same time,adopting the presented concept of constraints domination to update the infeasible set may keep good variety of population and give consideration to convergence. Also the improved mutation operation is employed to further raise the diversity and convergence.The suggested algorithm is compared with 3 state- of- the- art constrained optimization algorithms on standard test problems g01- g13. Simulation results show that the presented algorithm has certain advantages than other algorithms because it can ensure good convergence accuracy while it has good robustness.
基金supported by the National Natural Science Foundation of China(32100342,U1902204,31771415,31801054)Bureau of Science and Technology of Yunnan Province(2015FA026)+1 种基金Youth Innovation Promotion AssociationWest Light Foundation of CAS(Y902401081)。
文摘The evolutionary and functional features of RNA editing are well studied in mammals,cephalopods,and insects,but not in birds.Here,we integrated transcriptomic and whole-genomic analyses to exhaustively characterize the expansive repertoire of adenosine-to-inosine(A-to-I)RNA editing sites(RESs)in the chicken.In addition,we investigated the evolutionary status of the chicken editome as a potential mechanism of domestication.We detected the lowest editing level in the liver of chickens,compared to muscles in humans,and found higher editing activity and specificity in the brain than in non-neural tissues,consistent with the brain’s functional complexity.To a certain extent,specific editing activity may account for the specific functions of tissues.Our results also revealed that sequences critical to RES secondary structures remained conserved within avian evolution.Furthermore,the RNA editome was shaped by purifying selection during chicken domestication and most RESs may have served as a selection pool for a few functional RESs involved in chicken domestication,including evolution of nervous and immune systems.Regulation of RNA editing in chickens by adenosine deaminase acting on RNA(ADAR)enzymes may be affected by non-ADAR factors whose expression levels changed widely after ADAR knockdown.Collectively,we provide comprehensive lists of candidate RESs and non-ADAR-editing regulators in the chicken,thus contributing to our current understanding of the functions and evolution of RNA editing in animals.
文摘A novel theoretical model is presented maintaining that consciousness evolved on the basis of time distinctions. Various models of time pertain to the existence of future, present and past. It is proposed that the future represents potentialities, the present the actualization of certain potentialities, and the past a record of actualized potentialities. Actualization of potentialities derives from micro quantum wave function collapses with specific constellations corresponding to macro level form. Consciousness provides for an awareness of potentialities being actualized in the present, the time frame of consciousness closely aligning with the time frame of potentialities being actualized in the moment. Evolution of such awareness is highly probable, given the ensuing motivation enabling behavior to be altered in the moment to minimize the actualization of maladaptive potentialities, and maximize the actualization of adaptive potentialities. The model also provides a logical proof for the occurrence of time distinctions.
基金National Natural Science Foundation of China ( No.60873058)Science and Technology Project of Shandong Province of China (No.2009GG10001008)Soft Science Research Project, China (No.2009RKA285)
文摘Among the bio-inspired techniques,PSO-based clustering algorithms have received special attention. An improved method named Particle Swarm Optimization (PSO) clustering algorithm based on cooperative evolution with multi-populations was presented. It adopts cooperative evolutionary strategy with multi-populations to change the mode of traditional searching optimum solutions. It searches the local optimum and updates the whole best position (gBest) and local best position (pBest) ceaselessly. The gBest will be passed in all sub-populations. When the gBest meets the precision,the evolution will terminate. The whole clustering process is divided into two stages. The first stage uses the cooperative evolutionary PSO algorithm to search the initial clustering centers. The second stage uses the K-means algorithm. The experiment results demonstrate that this method can extract the correct number of clusters with good clustering quality compared with the results obtained from other clustering algorithms.
基金The Strategic Priority Research Program of the CAS,Pan-Third Pole Environment Study for a Green Silk Road(Pan-TPE),No.XDA20040400Key Deployment Project of the CAS,No.ZDRW-ZS-2016-6-2
文摘This paper uses data for the period 1950-2050 compiled by the United Nations Population Division together with methods including spatial autocorrelation analysis, hie- rarchical cluster analysis and the standard deviational ellipse, to analyze the spatio-temporal evolution of population and urbanization in the 75 countries located along the routes of the Silk Road Economic Belt and the 21st-century Maritime Silk Road, to identify future popula- tion growth and urbanization hotspots. The results reveal the following: First, in 2015, the majority of Belt and Road countries in Europe, South Asia and Southeast Asia had high population densities, whereas most countries in Central Asia, North Africa and West Asia, as well as Russia and Mongolia, had low population densities; the majority of countries in South Asia, Southeast Asia, Central Asia, West Asia and North Africa had rapid population growth, whereas many countries in Europe had negative population growth; and five Belt and Road countries are in the initial stage of urbanization, 44 countries are in the acceleration stage of urbanization, and 26 are in the terminal stage of urbanization. Second, in the century from 1950 to 2050, the mean center of the study area's population is consistently located in the border region between India and China. Prior to 2000, the trajectory of the mean center was from northwest to southeast, but from 2000 it is on a southward trajectory, as the population of the study area becomes more concentrated. Future population growth hotspots are predicted to be in South Asia, West Asia and Southeast Asia, and hotspot countries for the period 2015-2030 include India, China, Pakistan and Indonesia, though China will move into nega- tive population growth after 2030. Third, the overall urban population of Belt and Road coun- tries increased from 22% in 1950 to 49% in 2015, and it is expected to gradually catch up with the world average, reaching 64% in 2050. The different levels of urbanization in different countries display significant spatial dependency, and in the hundred-year period under con-sideration, this dependency increases before eventually weakening. Fourth, between 2015 and 2030, urban population hotspots will include Thailand, China, Laos and Albania, while Kuwait, Cyprus, Qatar and Estonia will be urban "coldspots." Fifth, there were 293 cities with populations over 1 million located along the Belt and Road in 2015, but that number Js ex- pected to increase to 377 by 2030. Of those, 43 will be in China, with many of the others located in India, Indonesia and the eastern Mediterranean.
基金National Social Science Foundation of China,No.21FSHB014National Natural Science Foundation of China,No.42001196。
文摘Influenced by globalization,rural transition in developed Western countries has experienced processes of productivism,post-productivism,and multifunctional development.By contrast,rural transition in most developing countries has been accompanied by rapid urbanization,which has become a core topic in geography research.As the world’s largest developing country,China has undergone profound development since the reform and opening-up.Moreover,rural spaces in some eastern coastal areas have entered the stage of reconstruction after decades of industrialization and urbanization.This paper takes Suzhou as the case area and measures the process of rural transition from 1990 to 2015 by constructing an index system.It then analyzes the characteristics of space-time evolution using exploratory spatial data analysis(ESDA)methods to reveal the influence of economic and social development on rural transition.The results show that rural transition,which generally entails the weakening of rurality and enhancing of urbanity on a macro scale,tends to be heterogeneous across different regions on a micro scale.This paper argues that multifunctionality will be the main future trend of rural transition in rapidly urbanizing areas.The experience in Suzhou could provide an example for establishing policies on sustainable development in rural spaces and achieving urban-rural co-governance.
基金sponsored by Natural Science Foundation of China(No.51178357,51308423)and adapted based on the keynote speech in the Annual National Planning Conference 2013
文摘This paper selects Beijing, Shanghai, Guangzhou, and Wuhan as examples and builds a database based on the statistics of the ? fth and sixth national population censuses and the latest statistics of aging population collected by ministries and commissions of the Central Government and local departments, as well as by our research team from 2000 to 2010. With its data unit accurate to Jiedao~① level, it is the ? rst time to analyze the micro-level spatial distribution characteristics of the aging population in China's mega cities in comparison with research accomplishments in geography, which lays a foundation for further relevant studies and strategy formulation. The paper draws spatial distribution maps of the aging population in Beijing, Shanghai, Guangzhou, and Wuhan by Geograpic Information System(GIS), and uses Aging Degree Index and Population Gravitational Center respectively to analyze the spatial distribution characteristics and spatial evolution trends of aging population in these mega cities. The research indicates that, on the one hand, the spatial distribution of the aging population shows similar characteristics with that of developed countries when they were at the same urbanization level, especially with Japan which shares a cultural homology with China; on the other hand, it is greatly in? uenced by the distribution of af? liated residential space of large industrial sectors, enterprises, and research institutes under the early planned economic system. There are two trends: one is centrifugal spread, namely, the elderly are moving from the city center to the outside; the other is centripetal concentration, namely, the elderly who lived in the outer suburbs are moving towards the city center. These phenomena, such as centripetal concentration, suburban spread, exurban concentration, and socio-spatial differentiation of urban aging population, are driven by selective development in the city center, city function upgrading, re-hollowing of villages, and occupation and income differentiation of the elderly before retirement.