Exploring the spatial evolution patterns of land use in creative urban tourism complexes provides theoretical and decision-making support to foster creative tourism projects.This study focuses on the Hangzhou Leisure ...Exploring the spatial evolution patterns of land use in creative urban tourism complexes provides theoretical and decision-making support to foster creative tourism projects.This study focuses on the Hangzhou Leisure Expo Garden as a case study,utilizing a land use change index model to analyze the spatial evolution characteristics and dynamic processes of creative urban tourism complexes,as well as to explore their spatial differentiation mechanisms.The analysis indicates that Hangzhou Leisure Expo Garden,initially a derelict industrial area dominated by production and residential land use,has evolved into a creative urban tourism complex with tourism comprehensive service land at its core,going through the pattern evolution processes of“constrained sprawl,”“intensive expansion,”and“random integration.”From the perspective of tourism human-land relationships,the formation of land use evolution patterns in creative urban tourism complexes results from various stakeholders(government,tourism enterprises,residents,tourists,etc.),as humanistic factors,continuously adapting to specific urban spaces,which are considered as geographical elements and have locational advantages and are oriented towards economic and social values.Based on the acquisition of stakeholder interests,the transformation of resource-disadvantaged areas into tourism advantage areas is facilitated,thereby achieving the re-creation of tourism creative space and promoting intensive spatial growth.展开更多
Rural industrial development and ecological civilization transformation are crucial to China's comprehensive advancement of rural revitalization. However, many regions still face the issue of a conflict between ec...Rural industrial development and ecological civilization transformation are crucial to China's comprehensive advancement of rural revitalization. However, many regions still face the issue of a conflict between economic development and ecological protection. Symbiosis theory provides a new perspective for understanding the interactive relationship of rural industry and ecology(RIE). Jiangxi Province, one of China's first national pilot zones for ecological conservation, exemplifies rural areas' typical challenges in balancing industrial development and ecological protection, and has been selected as the study area. By integrating the characteristics of RIE with symbiosis theory, a comprehensive RIE assessment framework was constructed. The comprehensive model, spatial autocorrelation method, and symbiosis theory model were employed to address the spatio-temporal evolution characteristics of RIE, reveal the symbiotic relationship(SR) and the symbiosis types of RIE, and explore the path of symbiotic development between RIE. Results indicated that:(1) Since 2015, RIE has shown an upward trend, with regional differences in ecological development levels gradually shrinking. Significant spatial correlation and agglomeration characteristics exist, but a coordinated regional development pattern has not yet emerged.(2) Overall, the symbiosis degree(SD) between RIE showed a positive trend with narrowing gaps, the symbiosis coefficient(SC) of industry to ecology converged to 0.5 under a positive asymmetric mutualism(PAM) mode, suggesting that their relationship tended to be coordinated. Specifically, rural ecology grew increasingly influential on industry in most counties.(3) Rural areas were classified into different types led by industry-dominated PAM, and various optimization paths were proposed. Future efforts should promote the equalization of the interaction forces between RIE according to local conditions.展开更多
Urban air quality degradation from rising CO_(2) is acute in rapidly developing tropical cities such as Makassar,Indonesia.We deploy a drone-based Internet of Things(IoT)platform for real-time CO_(2) monitoring,integr...Urban air quality degradation from rising CO_(2) is acute in rapidly developing tropical cities such as Makassar,Indonesia.We deploy a drone-based Internet of Things(IoT)platform for real-time CO_(2) monitoring,integrating low-cost sensors(NDIR,MQ135,MG811)on a DJI Phantom 4 with cloud streaming to Firebase.Measurements were collected at five sites,namely Jl.AP.Pettarani,Jl.Ahmad Yani,Jl.Sultan Hasanuddin,Jl.Nusantara,and KIMA at 08:00,12:00,and 16:00 in September 2024 while vertically profiling 1-20 m with three repeat flights per site and time.Descriptive statistics and one-way ANOVA with Tukey HSD assessed spatio-temporal differences;Pearson correlation quantified cross-sensor agreement.Results show marked spatial and diurnal variability:Jl.AP.Pettarani exhibits the highest mean concentration(442.5 ppm),likely due to flyover-induced trapping,whereas Jl.Ahmad Yani records the lowest(390.0 ppm).Vertical profiles reveal mid-altitude peaks in street-canyon and industrial settings,and dilution with height in greener areas,indicating ventilation contrasts.Preprocessing removed outliers and applied temperature-humidity corrections to low-cost sensors.Differences across locations and times are statistically significant(p<0.05),and cross-sensor correlations are strong(r≈0.88-0.96)after correction.Compared with fixed ground stations,the system provides fine-scale three-dimensional coverage and real-time visualization useful for field decisions.Limitations include payload-constrained endurance and intermittent data loss in obstructed areas.Findings support targeted interventions,improving canyon ventilation around flyovers and expanding urban greenery relevant to Makassar and similar tropical cities.展开更多
Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects ...Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects such as cracks and pores.In this study,3DP gypsum samples with different printing directions were subjected to a series of uniaxial compression tests with in situ micro-computed tomography(micro-CT)scanning to quantitatively investigate their mechanical anisotropic properties and damage evolution characteristics.Based on the two-dimensional(2D)CT images obtained at different scanning steps,a novel void ratio variable was derived using the mean value and variance of CT intensity.Additionally,a constitutive model was formulated incorporating the proposed damage variable,utilizing the void ratio variable.The crack evolution and crack morphology of 3DP gypsum samples were obtained and analyzed using the 3D models reconstructed from the CT images.The results indicate that 3DP gypsum samples exhibit mechanical anisotropic characteristics similar to those found in naturally sedimentary rocks.The mechanical anisotropy is attributed to the bedding planes formed between adjacent layers and pillar-like structures along the printing direction formed by CaSO_(4)·2H_(2)O crystals of needle-like morphology.The mean gray intensity of the voids has a positive linear relationship with the threshold value,while the CT variance and void ratio have concave and convex relationships,respectively.The constitutive model can effectively match the stress–strain curves obtained from uniaxial compression experiments.This study provides comprehensive explanations of the failure modes and anisotropic mechanisms of 3DP gypsum samples,which is important for characterizing and understanding the failure mechanism and microstructural evolution of 3DP rocks when modeling natural rock behavior.展开更多
[Objective] The aim of this study was to perform genome-wide analysis of glucose-6-phosphate dehydrogenase（G6PDH） and reveal its evolution in Eucalyptus grandsis.[Method] The gene character,protein sequence and phyl...[Objective] The aim of this study was to perform genome-wide analysis of glucose-6-phosphate dehydrogenase（G6PDH） and reveal its evolution in Eucalyptus grandsis.[Method] The gene character,protein sequence and phylogenetic tree of G6PDH gene were analyzed by BLAST and other bioinformatics software within Eucalyptus grandsis whole genome database.[Result] Six G6PDH genes,including one cytomic type and five plastids,were detected in the E.grandsis genome.All the G6PDHs have conserved motifs of motif 1,motif 2,motif 3,motif 7,motif 9 and motif 11.Furthermore,promoter sequences of all E.grandsis G6PDH contain TATA box,enhancer,light-responsive,hormone-responsive and stress-responsive regulatory elements.[Conclusion] This study provided reference for the further revealing molecular function of E.grandsis G6PDH gene family展开更多
In order to provide reference for the breeding of new peanut varieties and introduction of peanut cultivars in Fujian Province, the pedigree and trait evolution of 33 peanut varieties registered （certified, identifie...In order to provide reference for the breeding of new peanut varieties and introduction of peanut cultivars in Fujian Province, the pedigree and trait evolution of 33 peanut varieties registered （certified, identified） during 1949-2011 in Fujian Province were analyzed. Results showed that, 45 parents were used as parents for peanut breeding, and 22 parents were originated from Fujian Province, 24 parents were registered varieties; Shitouqi, Yueyou 92, Shanyou 523, Quanhua No.10 and Quanhua 327 were milestone parents of peanut varieties in Fujian Province, and the phylogenetic relationship of varieties mainly came from Guangdong. Systematic se- lection was the main breeding method during 1951-1980 in Fujian Province, while crossbreeding became the main method of peanut breeding since 1991. With the variety update of peanuts, the yield levels were constantly increasing. The gradual increase of 100-pod weight and 100-kernel weight played an important role in the improvement of peanut yield. Fat content increased slightly with time, while protein content changed in contrast. Plant height was gradually decreased, and anti-lodging and fertilizer-tolerance capacity was improved, which were suitable for close planting. The total number of branches was decreased slightly, while the number of bearing branches barely changed.展开更多
To study the mechanism of rockburst and its spatio-temporal evolution criterion,a rockburst simulation experiment was performed on granite specimens,each with a prefabricated circular hole,under different lateral load...To study the mechanism of rockburst and its spatio-temporal evolution criterion,a rockburst simulation experiment was performed on granite specimens,each with a prefabricated circular hole,under different lateral loads.Using micro camera,acoustic emission(AE)system,and infrared thermal imager,the AE characteristics and thermal radiation temperature migration were studied during the rockburst process.Then,the failure mode and damage evolution of the surrounding rock were analyzed.The results demonstrate that increasing the lateral load can first increase and then reduce the bearing capacity of the hole.In this experiment,the hole failure process could be divided into four periods:quiet,particle ejection,stability failure and collapse.Correspondingly,the AE signals evolved from a calm stage,to have intermittent appearance;then,they were continuous with a sudden increase,and finally increased dramatically.The failure of the surrounding rock was mainly tensile failure,while shear failure tended to first increase and then decrease.Meanwhile,damage to the hole increased gradually during the particle ejection period,whereas damage to the rockburst mainly occurred in the stability failure period.The thermal radiation temperature migration exhibited warming in shallow parts,inward expansion,cooling in the shallow parts with free surface heating,inward expansion,a sudden rise in temperature of the rockburst pits,and finally specimen failure.The initial reinforcement support should fully contribute to surface support.Furthermore,an appropriate tensile capacity and good energy absorption capacity should be established in support systems for high-stress roadways.展开更多
High concentrations of PM_(2.5) are universally considered as a main cause for haze formation. Therefore, it is important to identify the spatial heterogeneity and influencing factors of PM_(2.5) concentrations for re...High concentrations of PM_(2.5) are universally considered as a main cause for haze formation. Therefore, it is important to identify the spatial heterogeneity and influencing factors of PM_(2.5) concentrations for regional air quality control and management. In this study, PM_(2.5) data from 2000 to 2015 was determined from an inversion of NASA atmospheric remote sensing images. Using geo-statistics, geographic detectors, and geo-spatial analysis methods, the spatio-temporal evolution patterns and driving factors of PM_(2.5) concentration in China were evaluated. The main results are as follows.(1) In general, the average concentration of PM_(2.5) in China increased quickly and reached its peak value in 2006; subsequently, concentrations remained between 21.84 and 35.08 μg/m3.(2) PM_(2.5) is strikingly heterogeneous in China, with higher concentrations in the north and east than in the south and west. In particular, areas with relatively high PM_(2.5) concentrations are primarily in four regions, the Huang-Huai-Hai Plain, Lower Yangtze River Delta Plain, Sichuan Basin, and Taklimakan Desert. Among them, Beijing-Tianjin-Hebei Region has the highest concentration of PM_(2.5).(3) The center of gravity of PM_(2.5) has generally moved northeastward, which indicates an increasingly serious haze in eastern China. High-value PM_(2.5) concentrations have moved eastward, while low-value PM_(2.5) has moved westward.(4) Spatial autocorrelation analysis indicates a significantly positive spatial correlation. The "High-High" PM_(2.5) agglomeration areas are distributed in the Huang-Huai-Hai Plain, Fenhe-Weihe River Basin, Sichuan Basin, and Jianghan Plain regions. The "Low-Low" PM_(2.5) agglomeration areas include Inner Mongolia and Heilongjiang, north of the Great Wall, Qinghai-Tibet Plateau, and Taiwan, Hainan, and Fujian and other southeast coastal cities and islands.(5) Geographic detection analysis indicates that both natural and anthropogenic factors account for spatial variations in PM_(2.5) concentration. Geographical location, population density, automobile quantity, industrial discharge, and straw burning are the main driving forces of PM_(2.5) concentration in China.展开更多
As important mechanisms of regional strategy and policy, prefecture-level regions have played an increasingly significant role in the development of China＇s economy. However, little research has grasped the essence o...As important mechanisms of regional strategy and policy, prefecture-level regions have played an increasingly significant role in the development of China＇s economy. However, little research has grasped the essence of the economic development stage and the spatio-temporal evolution process at the prefecture level; this may lead to biased policies and their ineffective implementations. Based on Chenery＇s economic development theory, this paper identifies China＇s economic development stages at both national and prefectural levels. Both the Global Moran I index and the Getis-Ord Gi＊ index are employed to investigate the spatio-temporal evolution of China＇s economic development from 1990 to 2010. Major conclusions can be drawn as follows. （1） China＇s economic development is generally in the state of agglomeration. It entered the Primary Production Stage in 1990, and the Middle Industrialized Stage in 2010, with a ＇balanced-unbalanced-gradually rebalanced＇ pattern in the process. （2） China＇s rapid economic growth experienced a spatial shift from the coastal areas to the the inland areas. Most advanced cities in mid-western China can be roughly categorized into regional hub cities and resource-dependent cities. （3） Hot spots in China＇s economy moved northward and westward. The interactions between cities and prefectures became weaker in Eastern China, while cities and prefectures in Central and Western China were still at the stage of individual development, with limited effect on the surrounding cities. （4） While the overall growth rate of China＇s economy has gradually slowed down during the past two decades, the growth rate of cities and prefectures in Central and Western China was much faster than those in coastal areas. （5） Areas rich in resources, such as Xinjiang and Inner Mongolia, have become the new hot spots of economic growth in recent years. For these regions, however, more attention needs to be paid to their unbalanced industrial structures and the lagging social development against the backdrop of the rapid economic growth, driven predominantly by the exploitation of resources.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
This paper analysed the evolution of landslide research and research foci in different countries. The data comprise 3105 landslide SCI articles published between January 1977 and June 2015 from the Web of Science. The...This paper analysed the evolution of landslide research and research foci in different countries. The data comprise 3105 landslide SCI articles published between January 1977 and June 2015 from the Web of Science. The data are extracted under interaction constraints of the journal title, category, and keywords. The complex network method is used for the analysis. First, from the perspective of topics and methods, the evolution is systematically assessed by generating a co-citation network of the articles and a semantic cluster analysis. Second, from the perspective of topics and landsliderelated disasters, the focus in different countries is discussed by generating co-occurrence networks. These networks are the co-occurrence of the countries and keywords, and the co-occurrence of countries and landslide-related disaster phrases. The main conclusions are as follows:(1) landslide susceptibility analysis and methods of machine learning are popular research topics and methods, respectively. The topics change through time, and the article output is influenced by increasing landslide-related disasters, increasing economic losses and casualties, a desire for a more complete and accurate landslide inventory, and the use of effective methods, such as geographical information Science(GIS) and machine learning.(2) The research focus in each country is related with the country-specific disasters or economic costs caused by landslides to some degree. In addition to Italy and the USA, China is the country most commonly affected by landslides, and it should develop its own landslide database and complete in-depth studies of disaster mitigation.展开更多
Prognostics and health management （PHM） significantly improves system availability and reliability, and reduces the cost of system operations. Design for testability （DFT） developed concurrently with system design...Prognostics and health management （PHM） significantly improves system availability and reliability, and reduces the cost of system operations. Design for testability （DFT） developed concurrently with system design is an important way to improve PHM capability. Testability modeling and analysis are the foundation of DFT. This paper proposes a novel approach of testability modeling and analysis based on failure evolution mechanisms. At the component level, the fault progression-related information of each unit under test （UUT） in a system is obtained by means of failure modes, evolution mechanisms, effects and criticality analysis （FMEMECA）, and then the failure-symptom dependency can be generated. At the system level, the dynamic attributes of UUTs are assigned by using the bond graph methodology, and then the symptom-test dependency can be obtained by means of the functional flow method. Based on the failure-symptom and symptom-test dependencies, testability analysis for PHM systems can be realized. A shunt motor is used to verify the application of the approach proposed in this paper. Experimental results show that this approach is able to be applied to testability modeling and analysis for PHM systems very well, and the analysis results can provide a guide for engineers to design for testability in order to improve PHM performance.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
In today's world, the innovation of science and technology has become the key support for improving comprehensive national strength and changing the mode of social production and lifestyle. The country that posses...In today's world, the innovation of science and technology has become the key support for improving comprehensive national strength and changing the mode of social production and lifestyle. The country that possesses world-class scientific and technological innovation cities maximizes the attraction of global innovation factors and wins a strategic initiative in international competition. Based on the urban zip code geodatabase, an evaluation system of urban innovation with the perspective of innovation outputs, and the spatial evolutionary mode, concerning the structure of innovation space of Shanghai and Beijing from 1991 to 2014, was developed. The results of the research indicated that the zip code geodatabase provided a new perspective for studying the evolving spatial structure of urban innovation. The resulting evaluation of the spatial structure of urban innovation using the urban zip code geodatabase established by connecting random edge points, was relatively effective. The study illustrates the value of this methodology. During the study period, the spatial structure of innovation of Shanghai and Beijing demonstrated many common features: with the increase in urban space units participating in innovation year by year, the overall gap of regional innovation outputs has narrowed, and the trend towards spatial agglomeration has strengthened. The evolving spatial structure of innovation of Shanghai and Beijing demonstrated differences between the common features during the 25 years as well: in the trend towards the suburbanization of innovation resources, the spatial structure of innovation of Shanghai evolved from a single-core to a multi-core structure. A radiation effect related to traffic arteries as spatial diffusion corridors was prominent. Accordingly, a spatial correlation effect of its innovation outputs also indicated a hollowness in the city center; the spatial structure of innovation of Beijing had a single-core oriented structure all the way. Together with the tendency for innovation resources to be agglomerated in the city center, the spatial correlation effect of innovation outputs reflected the characteristics of the evolutionary feature where "rural area encircles cities". The innovation spatial structure of Shanghai and Beijing have intrinsic consistency with the spatial structure of their respective regions(Yangtze River Delta urban agglomeration and Beijing-Tianjin-Hebei metropolitan region), which suggested that the principle of proportional and disproportional distribution of a city-scale pattern of technological and innovational activities is closely related to its regional innovation pattern.展开更多
The building of the ocean power strategy and the implementation of the blue agriculture plan urgently need to strengthen the sustainable development of marine fishery.Taking vulnerability as the starting point, this p...The building of the ocean power strategy and the implementation of the blue agriculture plan urgently need to strengthen the sustainable development of marine fishery.Taking vulnerability as the starting point, this paper constructs the vulnerability index system of marine fishery industry ecosystem from the aspects of sensitivity and response capacity, and combines the entropy method with the Topsis to comprehensively analyze the spatio-temporal evolution characteristics of vulnerability of marine fishery industry ecosystem in the Bohai Rim Region from 2001 to 2015.The results show that: 1) In the time dimension, from 2001 to 2015, the vulnerability of the marine fishery industry ecosystem in the Bohai Rim Region shows a fluctuant and degressive trend;2) In the spatial dimension, the spatial distribution of the marine fishery industry ecosystem vulnerability in the Bohai Rim Region presents the gradient characteristics which shows high vulnerability in the east and low vulnerability in the west.According to the evolution track of the system’s vulnerability level, the vulnerability of the marine fishery industry ecosystem is divided into ‘declining’ and ‘stable’ types of evolutionary structures;3) The development of marine fishery in the Bohai Rim Region needs to be derived from the marine fishery’s ecological environment and the industrial development mode and structure, which can improve the marine environment remediation efforts, optimize the marine fishery industry structure, vigorously focus on pelagic fishery, and enhance the introduction of marine fishery’s science and technology talents, etc.Then, the marine fishery’s development in the Bohai Rim Region will be moving in the green, circular and sustainable direction.展开更多
It is urgent and important to explore the dynamic evolution in comprehensive transportation green efficiency(CTGE)in the context of green development.We constructed a social development index that reflects the social ...It is urgent and important to explore the dynamic evolution in comprehensive transportation green efficiency(CTGE)in the context of green development.We constructed a social development index that reflects the social benefits of transportation services,and incorporated it into the comprehensive transportation efficiency evaluation framework as an expected output.Based on the panel data of 30 regions in China from 2003-2018,the CTGE in China was measured using the slacks-based measure-data envelopment analysis(SBM-DEA)model.Further,the dynamic evolution trends of CTGE were determined using the spatial Markov model and exploratory spatio-temporal data analysis(ESTDA)technique from a spatio-temporal perspective.The results showed that the CTGE shows a U-shaped change trend but with an overall low level and significant regional differences.The state transition of CTGE has a strong spatial dependence,and there exists the phenomenon of“club convergence”.Neighbourhood background has a significant impact on the CTGE transition types,and the spatial spillover effect is pronounced.The CTGE has an obvious positive correlation and spatial agglomeration characteristics.The geometric characteristics of the LISA time path show that the evolution process of local spatial structure and local spatial dependence of China’s CTGE is stable,but the integration of spatial evolution is weak.The spatio-temporal transition results of LISA indicate that the CTGE has obvious transfer inertness and has certain path-dependence and spatial locking characteristics,which will become the major difficulty in improving the CTGE.展开更多
Accelerating the promotion of high-quality development of tourism(HQDT) is of great significance to the sustainable development of tourism. This paper defined the concept of HQDT, and then built an evaluation system f...Accelerating the promotion of high-quality development of tourism(HQDT) is of great significance to the sustainable development of tourism. This paper defined the concept of HQDT, and then built an evaluation system for HQDT measurement to analyze the spatio-temporal evolution characteristics of China’s HQDT based on provincial panel data from 2010 to 2019, using Geodetector to explore the similarities and differences between driving factors of HQDT and tourism development scale(TDS). The results show that:1) Taking the development concepts of innovation, coordination, green, openness and sharing as the guidance, and considering the organic unity of quantity and quality, the evaluation index system of the HQDT consists of six dimensions of economic stability, innovation driving, coordination and linkage, green and sustainability, openness and cooperation, and sharing and harmony, which respectively represent the basis, momentum, means, orientation, direction and purpose of the HQDT;2) The level of China’s HQDT shows an upward trend, presenting the characteristics of eastern region > central region > western region > northeastern region in 2019. The regional differences in China’s HQDT show a downward trend, and the intra-regional differences have replaced the inter-regional differences as the main source of regional differences;3) China’s HQDT shows the characteristics of higher in the east and lower in the west along the Hu line, while the improvement speed of HQDT shows the characteristics of faster in the west and slower in the east, making the decline of east-west differentiation of China’s HQDT and the movement of the gravity center towards southwest;4) Both HQDT and TDS are obviously driven by tourism capital investment and regional consumption. In terms of differences, the HQDT is more driven by government guidance, innovation driving force, and opening up, while the main driving factors of TDS are more biased toward capital elements and hardware facilities, including informatization, tourism resource, traffic, and eco-environment.展开更多
In this paper, we make use of the functional spectral analysis to infer the periodicity of paleoclimate in the Hongzuisi section since about 15 ka. Through combined analysis of organic carbon isotope and CaCO\-3 conte...In this paper, we make use of the functional spectral analysis to infer the periodicity of paleoclimate in the Hongzuisi section since about 15 ka. Through combined analysis of organic carbon isotope and CaCO\-3 content, the law of paleoclimatic evolution of the Hongzuisi section is obtained. There were climatic changes from 10 ka to about 0.1 ka over the last 15 ka. Among these cycles, the cycle of several ka is most remarkable. The result indicates that functional spectral analysis is helpful for paleoclimatic study, which can provide useful information about paleoclimatic reconstruction and future forecast.展开更多
Global production networks have become the most important organizational platforms for coordinating international production activities,and their evolution patterns profoundly affect value distribution across the worl...Global production networks have become the most important organizational platforms for coordinating international production activities,and their evolution patterns profoundly affect value distribution across the world.In this study,we shall firstly carry out an in-depth quantitative research to analyze the patterns and evolution of global production networks,using a long time-sequenced multi-region input-output table and the network analysis approach.Then based on the method of value-added decomposition,we will develop an index system to measure the degree of participation of regions in global production networks.Finally,we will try to identify the factors affecting the degree of participation of countries in global production networks by constructing a regression model.The results show that from 1995 to 2015,the evolution of global production networks measured by input-output linkages experienced four stages:expansion,contraction,re-expansion,and re-contraction.In addition,the core communities of global production networks evolved from two major production communities(Europe and the Americas)to three pillars(Europe,Americas,and Asia)while more segmented communities are mainly affected by geographical proximity.The latter consists of European,North American,South American,African and Asian communities.The evolution of the global production network pattern primarily manifests as a process of cooperation strengthening or weakening among communities,based on changes in the external environment and the need for individual development strategies.Meanwhile,the United States,Germany,and the United Kingdom have consistently ranked among the top entities in global production networks,whereas China,Russia,and Southeast Asia have the fastest rises in ranking.In addition,government efficiency,resources endowment,infrastructure conditions and technology levels play important roles in the participation in global production networks.展开更多
MicroRNA（miRNA） is a class of important regulating non-coding small molecular RNA. The gma-MIR166 gene family consists of 21 members and their expression patterns diversify widely. It is important to analyze the evo...MicroRNA（miRNA） is a class of important regulating non-coding small molecular RNA. The gma-MIR166 gene family consists of 21 members and their expression patterns diversify widely. It is important to analyze the evolution of gma-MIR166 gene family in order to understand the evolutionary mechanisms of miRNAs in soybean. In this study, we implemented soybean wide genome block analysis, the molecular phylogeny of gma-MIR166 and block analysis of gma-MIR166 family. The results showed that both chromosome big segmental duplications and tandem duplications were main reasons contributed to the expanding of gmaMIR166 gene family. These findings suggested that gma-MIR166 gene family might originate from one or two ancient miRNA genes. The results of research provided a support for evolutionary study of miRNAs in soybean and related species in Fabaceae.展开更多
文摘Exploring the spatial evolution patterns of land use in creative urban tourism complexes provides theoretical and decision-making support to foster creative tourism projects.This study focuses on the Hangzhou Leisure Expo Garden as a case study,utilizing a land use change index model to analyze the spatial evolution characteristics and dynamic processes of creative urban tourism complexes,as well as to explore their spatial differentiation mechanisms.The analysis indicates that Hangzhou Leisure Expo Garden,initially a derelict industrial area dominated by production and residential land use,has evolved into a creative urban tourism complex with tourism comprehensive service land at its core,going through the pattern evolution processes of“constrained sprawl,”“intensive expansion,”and“random integration.”From the perspective of tourism human-land relationships,the formation of land use evolution patterns in creative urban tourism complexes results from various stakeholders(government,tourism enterprises,residents,tourists,etc.),as humanistic factors,continuously adapting to specific urban spaces,which are considered as geographical elements and have locational advantages and are oriented towards economic and social values.Based on the acquisition of stakeholder interests,the transformation of resource-disadvantaged areas into tourism advantage areas is facilitated,thereby achieving the re-creation of tourism creative space and promoting intensive spatial growth.
基金supported by the National Natural Science Foundation of China (No.42361050,42201232)Humanities and Social Sciences Research Project of Jiangxi Colleges and Universities (No.JC24211)+1 种基金Science and Technology Research Project of Jiangxi Provincial Department of Education (No.GJJ2200553)Jiangxi provincial Social Science Foundation of China (No.23JL11)。
文摘Rural industrial development and ecological civilization transformation are crucial to China's comprehensive advancement of rural revitalization. However, many regions still face the issue of a conflict between economic development and ecological protection. Symbiosis theory provides a new perspective for understanding the interactive relationship of rural industry and ecology(RIE). Jiangxi Province, one of China's first national pilot zones for ecological conservation, exemplifies rural areas' typical challenges in balancing industrial development and ecological protection, and has been selected as the study area. By integrating the characteristics of RIE with symbiosis theory, a comprehensive RIE assessment framework was constructed. The comprehensive model, spatial autocorrelation method, and symbiosis theory model were employed to address the spatio-temporal evolution characteristics of RIE, reveal the symbiotic relationship(SR) and the symbiosis types of RIE, and explore the path of symbiotic development between RIE. Results indicated that:(1) Since 2015, RIE has shown an upward trend, with regional differences in ecological development levels gradually shrinking. Significant spatial correlation and agglomeration characteristics exist, but a coordinated regional development pattern has not yet emerged.(2) Overall, the symbiosis degree(SD) between RIE showed a positive trend with narrowing gaps, the symbiosis coefficient(SC) of industry to ecology converged to 0.5 under a positive asymmetric mutualism(PAM) mode, suggesting that their relationship tended to be coordinated. Specifically, rural ecology grew increasingly influential on industry in most counties.(3) Rural areas were classified into different types led by industry-dominated PAM, and various optimization paths were proposed. Future efforts should promote the equalization of the interaction forces between RIE according to local conditions.
基金supported by the Directorate of Research,Technology,and Community Service(DRTPM),Ministry of Education,Culture,Research,and Technology,grant number 2817/UN36.11/LP2M/2024.
文摘Urban air quality degradation from rising CO_(2) is acute in rapidly developing tropical cities such as Makassar,Indonesia.We deploy a drone-based Internet of Things(IoT)platform for real-time CO_(2) monitoring,integrating low-cost sensors(NDIR,MQ135,MG811)on a DJI Phantom 4 with cloud streaming to Firebase.Measurements were collected at five sites,namely Jl.AP.Pettarani,Jl.Ahmad Yani,Jl.Sultan Hasanuddin,Jl.Nusantara,and KIMA at 08:00,12:00,and 16:00 in September 2024 while vertically profiling 1-20 m with three repeat flights per site and time.Descriptive statistics and one-way ANOVA with Tukey HSD assessed spatio-temporal differences;Pearson correlation quantified cross-sensor agreement.Results show marked spatial and diurnal variability:Jl.AP.Pettarani exhibits the highest mean concentration(442.5 ppm),likely due to flyover-induced trapping,whereas Jl.Ahmad Yani records the lowest(390.0 ppm).Vertical profiles reveal mid-altitude peaks in street-canyon and industrial settings,and dilution with height in greener areas,indicating ventilation contrasts.Preprocessing removed outliers and applied temperature-humidity corrections to low-cost sensors.Differences across locations and times are statistically significant(p<0.05),and cross-sensor correlations are strong(r≈0.88-0.96)after correction.Compared with fixed ground stations,the system provides fine-scale three-dimensional coverage and real-time visualization useful for field decisions.Limitations include payload-constrained endurance and intermittent data loss in obstructed areas.Findings support targeted interventions,improving canyon ventilation around flyovers and expanding urban greenery relevant to Makassar and similar tropical cities.
基金supported by grants from the Human Resources Development program(Grant No.20204010600250)the Training Program of CCUS for the Green Growth(Grant No.20214000000500)by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)funded by the Ministry of Trade,Industry,and Energy of the Korean Government(MOTIE).
文摘Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects such as cracks and pores.In this study,3DP gypsum samples with different printing directions were subjected to a series of uniaxial compression tests with in situ micro-computed tomography(micro-CT)scanning to quantitatively investigate their mechanical anisotropic properties and damage evolution characteristics.Based on the two-dimensional(2D)CT images obtained at different scanning steps,a novel void ratio variable was derived using the mean value and variance of CT intensity.Additionally,a constitutive model was formulated incorporating the proposed damage variable,utilizing the void ratio variable.The crack evolution and crack morphology of 3DP gypsum samples were obtained and analyzed using the 3D models reconstructed from the CT images.The results indicate that 3DP gypsum samples exhibit mechanical anisotropic characteristics similar to those found in naturally sedimentary rocks.The mechanical anisotropy is attributed to the bedding planes formed between adjacent layers and pillar-like structures along the printing direction formed by CaSO_(4)·2H_(2)O crystals of needle-like morphology.The mean gray intensity of the voids has a positive linear relationship with the threshold value,while the CT variance and void ratio have concave and convex relationships,respectively.The constitutive model can effectively match the stress–strain curves obtained from uniaxial compression experiments.This study provides comprehensive explanations of the failure modes and anisotropic mechanisms of 3DP gypsum samples,which is important for characterizing and understanding the failure mechanism and microstructural evolution of 3DP rocks when modeling natural rock behavior.
基金Supported by Seeding Raising Project from Guangdong Provincial Department(LYM10040)Open Research Project of Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants,MOE,Beijing Forestry University(FOP2010-4)~~
文摘[Objective] The aim of this study was to perform genome-wide analysis of glucose-6-phosphate dehydrogenase（G6PDH） and reveal its evolution in Eucalyptus grandsis.[Method] The gene character,protein sequence and phylogenetic tree of G6PDH gene were analyzed by BLAST and other bioinformatics software within Eucalyptus grandsis whole genome database.[Result] Six G6PDH genes,including one cytomic type and five plastids,were detected in the E.grandsis genome.All the G6PDHs have conserved motifs of motif 1,motif 2,motif 3,motif 7,motif 9 and motif 11.Furthermore,promoter sequences of all E.grandsis G6PDH contain TATA box,enhancer,light-responsive,hormone-responsive and stress-responsive regulatory elements.[Conclusion] This study provided reference for the further revealing molecular function of E.grandsis G6PDH gene family
基金Supported by Science and Technology Spark Program of Fujian Province(2010S0018)Putian Science and Technology Project of Fujian Province(2012N05)~~
文摘In order to provide reference for the breeding of new peanut varieties and introduction of peanut cultivars in Fujian Province, the pedigree and trait evolution of 33 peanut varieties registered （certified, identified） during 1949-2011 in Fujian Province were analyzed. Results showed that, 45 parents were used as parents for peanut breeding, and 22 parents were originated from Fujian Province, 24 parents were registered varieties; Shitouqi, Yueyou 92, Shanyou 523, Quanhua No.10 and Quanhua 327 were milestone parents of peanut varieties in Fujian Province, and the phylogenetic relationship of varieties mainly came from Guangdong. Systematic se- lection was the main breeding method during 1951-1980 in Fujian Province, while crossbreeding became the main method of peanut breeding since 1991. With the variety update of peanuts, the yield levels were constantly increasing. The gradual increase of 100-pod weight and 100-kernel weight played an important role in the improvement of peanut yield. Fat content increased slightly with time, while protein content changed in contrast. Plant height was gradually decreased, and anti-lodging and fertilizer-tolerance capacity was improved, which were suitable for close planting. The total number of branches was decreased slightly, while the number of bearing branches barely changed.
基金Project(2017YFC0603003)supported by the National Key Research and Development Project of ChinaProjects(51974009,51674008)supported by the National Natural Science Foundation of China+3 种基金Project(201904a07020010)supported by the Key Research and Development Program of Anhui Province,ChinaProject(2018D187)supported by the Leading Talent Project of Anhui“Special Support Program”,Anhui Provincial Academic and Technology Leaders Research Activities Funding,ChinaProject(gxbjZD2016051)supported by the Excellence Talent Training Program of High School,ChinaProject(2019CX2008)supported by the Graduate Innovation Fund of Anhui University of Science and Technology,China。
文摘To study the mechanism of rockburst and its spatio-temporal evolution criterion,a rockburst simulation experiment was performed on granite specimens,each with a prefabricated circular hole,under different lateral loads.Using micro camera,acoustic emission(AE)system,and infrared thermal imager,the AE characteristics and thermal radiation temperature migration were studied during the rockburst process.Then,the failure mode and damage evolution of the surrounding rock were analyzed.The results demonstrate that increasing the lateral load can first increase and then reduce the bearing capacity of the hole.In this experiment,the hole failure process could be divided into four periods:quiet,particle ejection,stability failure and collapse.Correspondingly,the AE signals evolved from a calm stage,to have intermittent appearance;then,they were continuous with a sudden increase,and finally increased dramatically.The failure of the surrounding rock was mainly tensile failure,while shear failure tended to first increase and then decrease.Meanwhile,damage to the hole increased gradually during the particle ejection period,whereas damage to the rockburst mainly occurred in the stability failure period.The thermal radiation temperature migration exhibited warming in shallow parts,inward expansion,cooling in the shallow parts with free surface heating,inward expansion,a sudden rise in temperature of the rockburst pits,and finally specimen failure.The initial reinforcement support should fully contribute to surface support.Furthermore,an appropriate tensile capacity and good energy absorption capacity should be established in support systems for high-stress roadways.
基金The Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDA19040401China Postdoctoral Science Foundation,No.2016M600121+1 种基金National Natural Science Foundation of China,No.41701173,No.41501137The State Key Laboratory of Resources and Environmental Information System
文摘High concentrations of PM_(2.5) are universally considered as a main cause for haze formation. Therefore, it is important to identify the spatial heterogeneity and influencing factors of PM_(2.5) concentrations for regional air quality control and management. In this study, PM_(2.5) data from 2000 to 2015 was determined from an inversion of NASA atmospheric remote sensing images. Using geo-statistics, geographic detectors, and geo-spatial analysis methods, the spatio-temporal evolution patterns and driving factors of PM_(2.5) concentration in China were evaluated. The main results are as follows.(1) In general, the average concentration of PM_(2.5) in China increased quickly and reached its peak value in 2006; subsequently, concentrations remained between 21.84 and 35.08 μg/m3.(2) PM_(2.5) is strikingly heterogeneous in China, with higher concentrations in the north and east than in the south and west. In particular, areas with relatively high PM_(2.5) concentrations are primarily in four regions, the Huang-Huai-Hai Plain, Lower Yangtze River Delta Plain, Sichuan Basin, and Taklimakan Desert. Among them, Beijing-Tianjin-Hebei Region has the highest concentration of PM_(2.5).(3) The center of gravity of PM_(2.5) has generally moved northeastward, which indicates an increasingly serious haze in eastern China. High-value PM_(2.5) concentrations have moved eastward, while low-value PM_(2.5) has moved westward.(4) Spatial autocorrelation analysis indicates a significantly positive spatial correlation. The "High-High" PM_(2.5) agglomeration areas are distributed in the Huang-Huai-Hai Plain, Fenhe-Weihe River Basin, Sichuan Basin, and Jianghan Plain regions. The "Low-Low" PM_(2.5) agglomeration areas include Inner Mongolia and Heilongjiang, north of the Great Wall, Qinghai-Tibet Plateau, and Taiwan, Hainan, and Fujian and other southeast coastal cities and islands.(5) Geographic detection analysis indicates that both natural and anthropogenic factors account for spatial variations in PM_(2.5) concentration. Geographical location, population density, automobile quantity, industrial discharge, and straw burning are the main driving forces of PM_(2.5) concentration in China.
基金National Natural Science Foundation of China, No.41171107
文摘As important mechanisms of regional strategy and policy, prefecture-level regions have played an increasingly significant role in the development of China＇s economy. However, little research has grasped the essence of the economic development stage and the spatio-temporal evolution process at the prefecture level; this may lead to biased policies and their ineffective implementations. Based on Chenery＇s economic development theory, this paper identifies China＇s economic development stages at both national and prefectural levels. Both the Global Moran I index and the Getis-Ord Gi＊ index are employed to investigate the spatio-temporal evolution of China＇s economic development from 1990 to 2010. Major conclusions can be drawn as follows. （1） China＇s economic development is generally in the state of agglomeration. It entered the Primary Production Stage in 1990, and the Middle Industrialized Stage in 2010, with a ＇balanced-unbalanced-gradually rebalanced＇ pattern in the process. （2） China＇s rapid economic growth experienced a spatial shift from the coastal areas to the the inland areas. Most advanced cities in mid-western China can be roughly categorized into regional hub cities and resource-dependent cities. （3） Hot spots in China＇s economy moved northward and westward. The interactions between cities and prefectures became weaker in Eastern China, while cities and prefectures in Central and Western China were still at the stage of individual development, with limited effect on the surrounding cities. （4） While the overall growth rate of China＇s economy has gradually slowed down during the past two decades, the growth rate of cities and prefectures in Central and Western China was much faster than those in coastal areas. （5） Areas rich in resources, such as Xinjiang and Inner Mongolia, have become the new hot spots of economic growth in recent years. For these regions, however, more attention needs to be paid to their unbalanced industrial structures and the lagging social development against the backdrop of the rapid economic growth, driven predominantly by the exploitation of resources.
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under the auspices of National Key Research and Development Plan of China (Grant No. 2017YFB0504102)the Fundamental Research Funds for the Central Universities
文摘This paper analysed the evolution of landslide research and research foci in different countries. The data comprise 3105 landslide SCI articles published between January 1977 and June 2015 from the Web of Science. The data are extracted under interaction constraints of the journal title, category, and keywords. The complex network method is used for the analysis. First, from the perspective of topics and methods, the evolution is systematically assessed by generating a co-citation network of the articles and a semantic cluster analysis. Second, from the perspective of topics and landsliderelated disasters, the focus in different countries is discussed by generating co-occurrence networks. These networks are the co-occurrence of the countries and keywords, and the co-occurrence of countries and landslide-related disaster phrases. The main conclusions are as follows:(1) landslide susceptibility analysis and methods of machine learning are popular research topics and methods, respectively. The topics change through time, and the article output is influenced by increasing landslide-related disasters, increasing economic losses and casualties, a desire for a more complete and accurate landslide inventory, and the use of effective methods, such as geographical information Science(GIS) and machine learning.(2) The research focus in each country is related with the country-specific disasters or economic costs caused by landslides to some degree. In addition to Italy and the USA, China is the country most commonly affected by landslides, and it should develop its own landslide database and complete in-depth studies of disaster mitigation.
基金the National Natural Science Foundation of China(No.51175502)
文摘Prognostics and health management （PHM） significantly improves system availability and reliability, and reduces the cost of system operations. Design for testability （DFT） developed concurrently with system design is an important way to improve PHM capability. Testability modeling and analysis are the foundation of DFT. This paper proposes a novel approach of testability modeling and analysis based on failure evolution mechanisms. At the component level, the fault progression-related information of each unit under test （UUT） in a system is obtained by means of failure modes, evolution mechanisms, effects and criticality analysis （FMEMECA）, and then the failure-symptom dependency can be generated. At the system level, the dynamic attributes of UUTs are assigned by using the bond graph methodology, and then the symptom-test dependency can be obtained by means of the functional flow method. Based on the failure-symptom and symptom-test dependencies, testability analysis for PHM systems can be realized. A shunt motor is used to verify the application of the approach proposed in this paper. Experimental results show that this approach is able to be applied to testability modeling and analysis for PHM systems very well, and the analysis results can provide a guide for engineers to design for testability in order to improve PHM performance.
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National Natural Science Foundation of China,No.41471108,No.41501141
文摘In today's world, the innovation of science and technology has become the key support for improving comprehensive national strength and changing the mode of social production and lifestyle. The country that possesses world-class scientific and technological innovation cities maximizes the attraction of global innovation factors and wins a strategic initiative in international competition. Based on the urban zip code geodatabase, an evaluation system of urban innovation with the perspective of innovation outputs, and the spatial evolutionary mode, concerning the structure of innovation space of Shanghai and Beijing from 1991 to 2014, was developed. The results of the research indicated that the zip code geodatabase provided a new perspective for studying the evolving spatial structure of urban innovation. The resulting evaluation of the spatial structure of urban innovation using the urban zip code geodatabase established by connecting random edge points, was relatively effective. The study illustrates the value of this methodology. During the study period, the spatial structure of innovation of Shanghai and Beijing demonstrated many common features: with the increase in urban space units participating in innovation year by year, the overall gap of regional innovation outputs has narrowed, and the trend towards spatial agglomeration has strengthened. The evolving spatial structure of innovation of Shanghai and Beijing demonstrated differences between the common features during the 25 years as well: in the trend towards the suburbanization of innovation resources, the spatial structure of innovation of Shanghai evolved from a single-core to a multi-core structure. A radiation effect related to traffic arteries as spatial diffusion corridors was prominent. Accordingly, a spatial correlation effect of its innovation outputs also indicated a hollowness in the city center; the spatial structure of innovation of Beijing had a single-core oriented structure all the way. Together with the tendency for innovation resources to be agglomerated in the city center, the spatial correlation effect of innovation outputs reflected the characteristics of the evolutionary feature where "rural area encircles cities". The innovation spatial structure of Shanghai and Beijing have intrinsic consistency with the spatial structure of their respective regions(Yangtze River Delta urban agglomeration and Beijing-Tianjin-Hebei metropolitan region), which suggested that the principle of proportional and disproportional distribution of a city-scale pattern of technological and innovational activities is closely related to its regional innovation pattern.
基金Under the auspices of the National Natural Science Foundation of China(No.41201114,41976207)Finance Department of Liaoning Province(No.18C021)
文摘The building of the ocean power strategy and the implementation of the blue agriculture plan urgently need to strengthen the sustainable development of marine fishery.Taking vulnerability as the starting point, this paper constructs the vulnerability index system of marine fishery industry ecosystem from the aspects of sensitivity and response capacity, and combines the entropy method with the Topsis to comprehensively analyze the spatio-temporal evolution characteristics of vulnerability of marine fishery industry ecosystem in the Bohai Rim Region from 2001 to 2015.The results show that: 1) In the time dimension, from 2001 to 2015, the vulnerability of the marine fishery industry ecosystem in the Bohai Rim Region shows a fluctuant and degressive trend;2) In the spatial dimension, the spatial distribution of the marine fishery industry ecosystem vulnerability in the Bohai Rim Region presents the gradient characteristics which shows high vulnerability in the east and low vulnerability in the west.According to the evolution track of the system’s vulnerability level, the vulnerability of the marine fishery industry ecosystem is divided into ‘declining’ and ‘stable’ types of evolutionary structures;3) The development of marine fishery in the Bohai Rim Region needs to be derived from the marine fishery’s ecological environment and the industrial development mode and structure, which can improve the marine environment remediation efforts, optimize the marine fishery industry structure, vigorously focus on pelagic fishery, and enhance the introduction of marine fishery’s science and technology talents, etc.Then, the marine fishery’s development in the Bohai Rim Region will be moving in the green, circular and sustainable direction.
基金National Key Research and Development Program of China(2019YFB1600400)National Natural Science Foundation of China(72174035)+2 种基金National Natural Science Foundation of China(71774018)Liaoning Revitalization Talents Program(XLYC2008030)Liaoning Provincial Natural Science Foundation Shipping Joint Foundation Program(2020-HYLH-20)。
文摘It is urgent and important to explore the dynamic evolution in comprehensive transportation green efficiency(CTGE)in the context of green development.We constructed a social development index that reflects the social benefits of transportation services,and incorporated it into the comprehensive transportation efficiency evaluation framework as an expected output.Based on the panel data of 30 regions in China from 2003-2018,the CTGE in China was measured using the slacks-based measure-data envelopment analysis(SBM-DEA)model.Further,the dynamic evolution trends of CTGE were determined using the spatial Markov model and exploratory spatio-temporal data analysis(ESTDA)technique from a spatio-temporal perspective.The results showed that the CTGE shows a U-shaped change trend but with an overall low level and significant regional differences.The state transition of CTGE has a strong spatial dependence,and there exists the phenomenon of“club convergence”.Neighbourhood background has a significant impact on the CTGE transition types,and the spatial spillover effect is pronounced.The CTGE has an obvious positive correlation and spatial agglomeration characteristics.The geometric characteristics of the LISA time path show that the evolution process of local spatial structure and local spatial dependence of China’s CTGE is stable,but the integration of spatial evolution is weak.The spatio-temporal transition results of LISA indicate that the CTGE has obvious transfer inertness and has certain path-dependence and spatial locking characteristics,which will become the major difficulty in improving the CTGE.
基金Under the auspices of National Social Science Foundation of China (No. 21BJY202)the 2019 Cultural and Tourism Research Project of Ministry of Culture and Tourism of the People’s Republic of China (No. 19DY13)Social Science Planning Project Research of Shandong Province (No. 19CQXJ13)。
文摘Accelerating the promotion of high-quality development of tourism(HQDT) is of great significance to the sustainable development of tourism. This paper defined the concept of HQDT, and then built an evaluation system for HQDT measurement to analyze the spatio-temporal evolution characteristics of China’s HQDT based on provincial panel data from 2010 to 2019, using Geodetector to explore the similarities and differences between driving factors of HQDT and tourism development scale(TDS). The results show that:1) Taking the development concepts of innovation, coordination, green, openness and sharing as the guidance, and considering the organic unity of quantity and quality, the evaluation index system of the HQDT consists of six dimensions of economic stability, innovation driving, coordination and linkage, green and sustainability, openness and cooperation, and sharing and harmony, which respectively represent the basis, momentum, means, orientation, direction and purpose of the HQDT;2) The level of China’s HQDT shows an upward trend, presenting the characteristics of eastern region > central region > western region > northeastern region in 2019. The regional differences in China’s HQDT show a downward trend, and the intra-regional differences have replaced the inter-regional differences as the main source of regional differences;3) China’s HQDT shows the characteristics of higher in the east and lower in the west along the Hu line, while the improvement speed of HQDT shows the characteristics of faster in the west and slower in the east, making the decline of east-west differentiation of China’s HQDT and the movement of the gravity center towards southwest;4) Both HQDT and TDS are obviously driven by tourism capital investment and regional consumption. In terms of differences, the HQDT is more driven by government guidance, innovation driving force, and opening up, while the main driving factors of TDS are more biased toward capital elements and hardware facilities, including informatization, tourism resource, traffic, and eco-environment.
基金GrantedbytheNationalNaturalScienceFoundationofChina (No .4 9972 0 5 7)
文摘In this paper, we make use of the functional spectral analysis to infer the periodicity of paleoclimate in the Hongzuisi section since about 15 ka. Through combined analysis of organic carbon isotope and CaCO\-3 content, the law of paleoclimatic evolution of the Hongzuisi section is obtained. There were climatic changes from 10 ka to about 0.1 ka over the last 15 ka. Among these cycles, the cycle of several ka is most remarkable. The result indicates that functional spectral analysis is helpful for paleoclimatic study, which can provide useful information about paleoclimatic reconstruction and future forecast.
基金Strategic Priority Research Program of Chinese Academy of Sciences,No.XDA20080000National Natural Science Foundation of China,No.41901154。
文摘Global production networks have become the most important organizational platforms for coordinating international production activities,and their evolution patterns profoundly affect value distribution across the world.In this study,we shall firstly carry out an in-depth quantitative research to analyze the patterns and evolution of global production networks,using a long time-sequenced multi-region input-output table and the network analysis approach.Then based on the method of value-added decomposition,we will develop an index system to measure the degree of participation of regions in global production networks.Finally,we will try to identify the factors affecting the degree of participation of countries in global production networks by constructing a regression model.The results show that from 1995 to 2015,the evolution of global production networks measured by input-output linkages experienced four stages:expansion,contraction,re-expansion,and re-contraction.In addition,the core communities of global production networks evolved from two major production communities(Europe and the Americas)to three pillars(Europe,Americas,and Asia)while more segmented communities are mainly affected by geographical proximity.The latter consists of European,North American,South American,African and Asian communities.The evolution of the global production network pattern primarily manifests as a process of cooperation strengthening or weakening among communities,based on changes in the external environment and the need for individual development strategies.Meanwhile,the United States,Germany,and the United Kingdom have consistently ranked among the top entities in global production networks,whereas China,Russia,and Southeast Asia have the fastest rises in ranking.In addition,government efficiency,resources endowment,infrastructure conditions and technology levels play important roles in the participation in global production networks.
基金Supported by Heilongjiang Postdoctoral Fund(LBH-Z12045)Northeast Agricultural University Innovation Foundation For Postgraduate(yjscx14053)
文摘MicroRNA（miRNA） is a class of important regulating non-coding small molecular RNA. The gma-MIR166 gene family consists of 21 members and their expression patterns diversify widely. It is important to analyze the evolution of gma-MIR166 gene family in order to understand the evolutionary mechanisms of miRNAs in soybean. In this study, we implemented soybean wide genome block analysis, the molecular phylogeny of gma-MIR166 and block analysis of gma-MIR166 family. The results showed that both chromosome big segmental duplications and tandem duplications were main reasons contributed to the expanding of gmaMIR166 gene family. These findings suggested that gma-MIR166 gene family might originate from one or two ancient miRNA genes. The results of research provided a support for evolutionary study of miRNAs in soybean and related species in Fabaceae.
