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Comprehensive evaluation and spatial-temporal evolution characteristics of urban resilience in Chengdu-Chongqing Economic Circle
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作者 Xin Li Shuyi Zhang +1 位作者 Rongxi Ren Yafei Wang 《Chinese Journal of Population,Resources and Environment》 2024年第1期58-67,共10页
To clarify the connotations and extensions of urban resilience,this study focuses on the Chengdu-Chongqing Economic Circle with 16 cities as research subjects.A comprehensive evaluation index system was constructed to... To clarify the connotations and extensions of urban resilience,this study focuses on the Chengdu-Chongqing Economic Circle with 16 cities as research subjects.A comprehensive evaluation index system was constructed to measure the resilience of each city from 2003 to 2020.The spatial-temporal evolution characteristics were analyzed using Kernel density estimation,standard deviation ellipse,and spatial Markov chain analysis,and the spatial Tobit model was introduced to discover the influencing factors.The results indicate the following:①Urban resilience in the Chengdu-Chongqing Economic Circle displays an upward trend,with the center of gravity moving to the southwest,and the polarization phenomenon intensifying.②The urban resilience level in a region has certain spatial and geographical dependence,while the probability of urban resilience transfer differs in adjacent cities with different resilience levels.③Urban centrality,economic scale,openness level,and financial development promote urban resilience,whereas government scale significantly inhibits it.Finally,this paper proposes countermeasures and suggestions to improve the urban resilience of the Chengdu-Chongqing Economic Circle. 展开更多
关键词 Chengdu-chongqing Economic Circle Urban resilience spatial-temporal evolution Driving factor
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Temporal and spatial evolution of global major grain trade patterns
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作者 Ziqi Yin Jiaxuan Hu +3 位作者 Jing Zhang Xiangyang Zhou Lingling Li Jianzhai Wu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第3期1075-1086,共12页
The complex and volatile international landscape has significantly impacted global grain supply security. This study uses a complex network analysis model to examine the evolution and trends of the global major grain ... The complex and volatile international landscape has significantly impacted global grain supply security. This study uses a complex network analysis model to examine the evolution and trends of the global major grain trade from 1990 to 2020, focusing on network topology, centrality ranking, and community structure. There are three major findings. First, the global major grain trade network has expanded in scale, with a growing emphasis on diversification and balance. During the study period, the United States, Canada, China, and Brazil were the core nodes of the network. Grain-exporting countries were mainly situated in Asia, the Americas, and Europe, and importing countries in Asia, Africa, and Europe. Second, a significant increase in the number of high centrality countries with high export capacity occurred, benefiting from natural advantages such as fertile land and favorable climates. Third, the main global grain trade network is divided into four communities, with the Americas-Europe community being the largest and most widespread. The formation of the community pattern was influenced by geographic proximity, driven by the core exporting countries. Therefore, the world needs to enhance the existing trade model, promote the multi-polarization of the grain trade network, and establish a global vision for the future community. Countries and regions should participate actively in global grain trade security governance and institutional reform, expand trade links with other countries, and optimize import and export policies to reduce trade risks. 展开更多
关键词 grain trade pattern evolution complex network
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Prediction and Output Estimation of Pattern Moving in Non-Newtonian Mechanical Systems Based on Probability Density Evolution
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作者 Cheng Han Zhengguang Xu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期515-536,共22页
A prediction framework based on the evolution of pattern motion probability density is proposed for the output prediction and estimation problem of non-Newtonian mechanical systems,assuming that the system satisfies t... A prediction framework based on the evolution of pattern motion probability density is proposed for the output prediction and estimation problem of non-Newtonian mechanical systems,assuming that the system satisfies the generalized Lipschitz condition.As a complex nonlinear system primarily governed by statistical laws rather than Newtonian mechanics,the output of non-Newtonian mechanics systems is difficult to describe through deterministic variables such as state variables,which poses difficulties in predicting and estimating the system’s output.In this article,the temporal variation of the system is described by constructing pattern category variables,which are non-deterministic variables.Since pattern category variables have statistical attributes but not operational attributes,operational attributes are assigned to them by posterior probability density,and a method for analyzing their motion laws using probability density evolution is proposed.Furthermore,a data-driven form of pattern motion probabilistic density evolution prediction method is designed by combining pseudo partial derivative(PPD),achieving prediction of the probability density satisfying the system’s output uncertainty.Based on this,the final prediction estimation of the system’s output value is realized by minimum variance unbiased estimation.Finally,a corresponding PPD estimation algorithm is designed using an extended state observer(ESO)to estimate the parameters to be estimated in the proposed prediction method.The effectiveness of the parameter estimation algorithm and prediction method is demonstrated through theoretical analysis,and the accuracy of the algorithm is verified by two numerical simulation examples. 展开更多
关键词 Non-newtonian mechanical systems prediction and estimation pattern moving probability density evolution pseudo partial derivative
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Spatial-temporal Patterns and Evolution History of Rural Settlements from the Perspective of Inheritance——A Case Study of Lianzhou City,Guangdong Province 被引量:3
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作者 CAO Xiaoshu REN Huizi +1 位作者 HUANG Xiaoyan LIU Jieyu 《Journal of Landscape Research》 2013年第6期39-42,45,共5页
Formation and evolution of rural settlement patterns in Lianzhou City,Guangdong Province were analyzed from the perspective of space and time,on the basis of its gazetteer and relevant historical data.The results show... Formation and evolution of rural settlement patterns in Lianzhou City,Guangdong Province were analyzed from the perspective of space and time,on the basis of its gazetteer and relevant historical data.The results show that Lianzhou was first founded in the sixth year of Yuanding Period of the Western Han Dynasty,and its development could be roughly classified into 6 stages according to the construction of south–north traffic lines and regional development progress,and it witnessed the fastest development in the Ming and Qing Dynasty.In terms of spatial distribution,rural settlements in the local area show spatial continuity,Lianzhou Town is the core of rural settlement growth in the city,and towns with the most concentrated rural settlements in all stages are located in central-west and northeast parts of the city,and those with lower density of rural settlements are mostly located in minority regions in the north and mountainous areas in the east.On the basis of the above facts,the paper studies the influence of natural geological conditions,immigrant,traffic,economic development and ethnic composition on the establishment and development of rural settlements in Lianzhou City. 展开更多
关键词 RURAL SETTLEMENT SETTLEMENT DENSITY spatial-temporal evolution CONTINUITY Lianzhou
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Transforming Digital Experiences: The Evolution of Digital Experience Platforms (DXPs) from Monoliths to Microservices: A Practical Guide
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作者 Sourabh Sethi Sarah Panda 《Journal of Computer and Communications》 2024年第2期142-155,共14页
The research aims to explore the transition from monolithic Digital Experience Platforms (DXPs) to Microservices-based DXPs, addressing scalability challenges. The study systematically decomposes monolithic structures... The research aims to explore the transition from monolithic Digital Experience Platforms (DXPs) to Microservices-based DXPs, addressing scalability challenges. The study systematically decomposes monolithic structures into Microservices, emphasizing business capability and subdomain decomposition. Concrete insights, challenges, and solutions encountered during this transformation process are presented. The research contributes valuable insights into the challenges and benefits of adopting Microservices in DXPs. Results highlight the importance of architectural patterns and strategic scaling dimensions for improved performance and scalability. The case study on Backbase’s Engagement Banking Platform showcases successful implementation, providing flexibility, integration, and efficient development in the evolving DXP landscape. 展开更多
关键词 Digital Experience Platforms (DXPs) Microservices Software evolution Distributed Systems Architectural patterns
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Spatial-temporal evolution of gas migration pathways in coal during shear loading 被引量:2
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作者 Peng Shoujian Xu Jiang +2 位作者 Yin Guangzhi Liu Dong Wang Weizhong 《International Journal of Mining Science and Technology》 SCIE EI 2012年第6期769-773,共5页
Custom designed and built meso shear test equipment was used to examine the shear crack propagation in gassy coal under different gas pressures.The spatial-temporal evolution of gas migration pathways in the coal duri... Custom designed and built meso shear test equipment was used to examine the shear crack propagation in gassy coal under different gas pressures.The spatial-temporal evolution of gas migration pathways in the coal during shear loading was also researched.The results show that gas pressure can hasten crack growth at the shear fracture surface,can reduce the shear strength of gassy coal,and can accelerate the shear failure process.Shear failure in gassy coal exhibits five stages:the pre-crack stage;the stable crack growth stage;the unsteady crack growth stage;the fracture stage;and,finally,the friction crack stage.The shear breaking creates two kinds of crack,shear cracks and tensile cracks.Cracks first appear in the shear plane at both ends and then extend toward the center until a shear fracture surface forms.The direction of shear crack propagation diverges from the predetermined shear plane by an angle of about 5°-10°. 展开更多
关键词 COAL Gas MIGRATION PATHWAY SHEAR loading spatial-temporal evolution
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Spatial-temporal Evolution of the Urban-rural Coordination Relationship in Northeast China in 1990-2018 被引量:4
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作者 WANG Ying CHEN Xiaohong +2 位作者 SUN Pingjun LIU Hang HE Jiaxin 《Chinese Geographical Science》 SCIE CSCD 2021年第3期429-443,共15页
To comprehensively understand the law of urban-rural relationship and propose scientific measures of urban-rural coordinated development in Northeast China,this study uses the coupling coordination degree model and ge... To comprehensively understand the law of urban-rural relationship and propose scientific measures of urban-rural coordinated development in Northeast China,this study uses the coupling coordination degree model and geographically and temporally weighted regression(GTWR)model to analyze the spatial-temporal patterns and the corresponding driving mechanisms of its urban-rural coordination since 1990.The results are as follows.First,the urban-rural coupling coordination degree in Northeast China was very low and improved slowly,but its stages of evolution is a good interpretation of the strategic arrangements of China's urbanization.Second,the urban-rural coupling coordination degree in Northeast China had spatial differences and was characterized by central polarization,converging on urban agglomeration,which was high in the south and low in the north.Moreover,the gap between the north and south weakened.Third,the spatial-temporal evolution of the urban-rural coordination relationship in Northeast China was influenced by pulling from the central cities,pushing from rural transformation,and government regulations.The influence intensity of the three mechanisms was weak,but the pulling from the central cities was stronger than that of the other two mechanisms.Furthermore,the spatial difference between the three mechanisms determines the spatial pattern and its evolution of the urban-rural coordination relationship in Northeast China.Fourth,to promote the development of urban-rural coordination in Northeast China,it is essential to advance urban-rural economic correlation,enhance the government^role in regulating and guiding,and adopt different policies for each region in Northeast China. 展开更多
关键词 urban-rural coordination relationship spatial-temporal evolution coupling coordination degree model geographically and temporally weighted regression(GTWR) Northeast China
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Spatial-temporal evolution of vegetation evapotranspiration in Hebei Province,China 被引量:4
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作者 WANG Qian-feng TANG Jia +6 位作者 ZENG Jing-yu QU Yan-ping ZHANG Qing SHUI Wei WANG Wu-lin YI Lin LENG Song 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2018年第9期2107-2117,共11页
Evapotranspiration(ET)is the sum of soil or water body evaporation and plant transpiration from the earth surface and ocean to the atmosphere,and thus plays a significant role in regulating carbon and water resource c... Evapotranspiration(ET)is the sum of soil or water body evaporation and plant transpiration from the earth surface and ocean to the atmosphere,and thus plays a significant role in regulating carbon and water resource cycles.The time-series data set from the remote sensing MOIDS product(MOD16)was used to study the spatial-temporal evolution of vegetation evapotranspiration in salinized areas during 2000–2014 by analyzing the variability,spatial patterns and Mann-Kendall(MK)nonparametric trends for the time series.The results indicate that inter-annual and intra-annual variations of ET across various vegetated areas show seasonal changes,with the abnormal months identified.The cultivated land displays a greater degree of spatial heterogeneity and the spatial pattern of ET in the area covered by broadleaved deciduous forests corresponds to a higher ET rate and increased water consumption.A widespread decline of ET is observed only in cultivated areas.However,agricultural cultivation doesn’t worsen water shortage and soil salinization problems in the region,and water shortage problems are worsening for other vegetated areas.This research provides a basis of reference for the reasonable allocation of water resources and restructuring of vegetation patterns in salinized areas. 展开更多
关键词 土壤水分蒸发蒸腾损失总量 空间时间 区域植被 进化 中国 空间模式 生长区域 栽培区域
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Spatial-temporal Evolution Analysis on Land Use Multifunctionality in the China-Vietnam Border Area
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作者 HUANG Tianneng WANG Nian 《Chinese Geographical Science》 SCIE CSCD 2022年第6期995-1012,共18页
Exploring the spatial and temporal evolution characteristics of the border land use multifunctionality(LUMF)provides insights for taking advantage of border land use and optimizing border land use policies.Based on th... Exploring the spatial and temporal evolution characteristics of the border land use multifunctionality(LUMF)provides insights for taking advantage of border land use and optimizing border land use policies.Based on the improved Technique for Order Preference by Similarity to an Ideal Solution(TOPSIS)mode,this study identifies and evaluates the LUMFs in the China-Vietnam border area between 2000 and 2018 from the perspectives of agricultural production,social security,ecological service,landscape recreation,and national security.The results show that:1)The comprehensive land use functions in most counties and cities continued to be improved.2)The comprehensive land use function exhibits remarkable spatial divergence and aggregation characteristics.The high-value area of the agricultural production function and social security function evolves from the east to the west.In addition,the spatial evolution of ecological service function is complicated,without an obvious spatial divergence and aggregation pattern.The landscape recreation function shows different spatial differentiation characteristics in the early and middle stage,and forms a large cluster in the later stage.Finally,the spatial evolution pattern of the national security function is significant.3)Designing differentiated border land policies,improving border land use security,and establishing a long-term mechanism for ecological protection and ecological compensation can aid in optimizing the LUMF level in the border area. 展开更多
关键词 land use multifunctionality spatial-temporal evolution characteristics improved Technique for Order Preference by Similarity to an Ideal Solution(TOPSIS) spatial analysis China-Vietnam border area
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The Analysis of Spatial-Temporal Evolution of City Accessibility Based on Highway Network in Henan Province in China
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作者 Mingting Ba Hongling Meng +1 位作者 Kaiguang Zhang Yanmin Sun 《Journal of Transportation Technologies》 2021年第2期296-310,共15页
Accessibility is an important tool</span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;&qu... Accessibility is an important tool</span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">to evaluate the maturity of a regional traffic network structure</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> which </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">describes the traffic convenience in the traffic</span><span style="font-family:Verdana;"> network. </span><span style="font-family:Verdana;">The paper defines a new accessibility index by using the resident pop</span><span style="font-family:Verdana;">ulation weighted average value of the sum of inverse of the traveling time </span><span style="font-family:Verdana;">distance and time threshold coming from ordinary traffic network, and then uses this accessibility index to analyze the spatial-temporal characteristics of Henan highway network, as well as its evolution patterns from 2005 to 2020. The results show that with the expansion and improvement of Henan highway network, city accessibility level has been significantly improved, spatial convergence is obvious, the cities in the north central are always High-High aggregation area, the cities in the south are always Low-Low aggregation area, gradually forming the characteristics of Northwest high and Southeast low, relative balance between East and West. There is some non-conforming phenomenon in highway mileage growth and improvement of the city accessibility levels, but this situation is being weakened, the highway network layout is gradually rationalized, the spatial distribution of city accessibility and that of population are beginning to converge. 展开更多
关键词 Highway Network ACCESSIBILITY Inverse of Time Distance Spatial Distribution spatial-temporal evolution Spatial Aggregation Henan Province
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Spatiotemporal evolution of ecosystem service value and topographic gradient effect in the Da-Xiao Liangshan Mountains in Sichuan Province,China 被引量:1
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作者 JIN Tao CHEN Yang +2 位作者 SHU Bo GAO Min QIU Jian 《Journal of Mountain Science》 SCIE CSCD 2023年第8期2344-2357,共14页
The Da-Xiao Liangshan mountains are critical ecological function areas and essential ecological barriers in the upper reaches of the Yangtze River in China.This study selected a total of six periods of land use land c... The Da-Xiao Liangshan mountains are critical ecological function areas and essential ecological barriers in the upper reaches of the Yangtze River in China.This study selected a total of six periods of land use land cover(LULC)data from 1995 to 2020,to estimate the ecosystem service value(ESV)and analyzed its spatiotemporal evolution and topographic gradient divergence.The results showed that:(1)The ESV increased by 1.1 billion yuan,with an increase rate of 1.47%from 1995 to 2020.Two time periods,2005–2010 and 2015–2020,showed more significant increases than other periods.(2)The elevation and slope of mountainous areas determine the type of land use and further influence the spatial pattern of ESV.(3)Although woodland and grassland are the main land use types of the study area(more than 90%),the hydrological regulation function of the water area partially compensated for the impact of the encroachment of the built-up area on the ESV of grassland.(4)The spatial distribution of ESVs showed an inverted V-shaped characteristic as the topographic gradient increased,with the dominant position being the 5th topographic gradient zone.Finally,this study provided relevant recommendations for ecosystem protection and optimization.The findings of this study clarified the influence of topographical factors on the spatial differentiation of ESV and provided novel insights into ecosystem protection. 展开更多
关键词 Ecosystem service value(ESV) Dynamic evolution Terrain gradient effect Spatial pattern Liangshan Yi region
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Evolution and Spatial Patterns of Spheres of Urban Influence in China 被引量:5
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作者 WANG Kaiyong DENG Yu +1 位作者 SUN Daowei SONG Tao 《Chinese Geographical Science》 SCIE CSCD 2014年第1期126-136,共11页
This article presents the findings of a study of the spheres of urban influence with regard to all cities in China(not including Hong Kong,Macao and Taiwan Province of China)in the years 1990,2000 and 2009.An optimize... This article presents the findings of a study of the spheres of urban influence with regard to all cities in China(not including Hong Kong,Macao and Taiwan Province of China)in the years 1990,2000 and 2009.An optimized gravity model with comprehensive time distance was used to carry out a detailed analysis of the spatial patterns of Chinese spheres of urban influence and the spatial characteristics of urban agglomerations.Such urban agglomerations are characterized by high density population and a developed economy,which are also considered as the national competition unit.This paper initially identifies four spatial patterns of urban agglomerations based on the spatial layout of city groups during their evolution.Some basic characteristics of urban agglomerations are outlined,including the number of cities,the size of cities and the functions of urban centers.These characteristics are examined by using statistical methods and Geographic Information System(GIS).The main findings from this research are that the development stages and structures of urban agglomerations in China vary significantly.It is also clear that the stages and evolution of spatial patterns are strongly affected and dominated by both policy and location factors. 展开更多
关键词 SPHERES of URBAN INFLUENCE types of spatial pattern dynamic evolution URBAN AGGLOMERATION
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Dynamic evolution patterns of the degree of ground resistivity anisotropy and the sets mogenic process 被引量:1
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作者 毛桐恩 胥广银 +2 位作者 范思源 赵明 孙景芳 《Acta Seismologica Sinica(English Edition)》 CSCD 1999年第2期200-205,共8页
Following a new train of thinking, this paper has explored first the potential information in the ground resistivitydata observed by the existing geoelectric observation system, investigated and proposed a new dimensi... Following a new train of thinking, this paper has explored first the potential information in the ground resistivitydata observed by the existing geoelectric observation system, investigated and proposed a new dimensionlessgeoelectric precursor factor, the degree of ground resistivity anisotropy, S, and studied the characteristics of dynamic evolution pattern of S during the seismogenic process. The results show that, during the seismogenic process, the degree of ground resistivity anisotropy (S) displays h process of "normal" → "abnormal strengthening(amplitude, range)" → "abnormal weakening"→ "earthquake occurrence"→ "normal". The earthquake wouldoccur at the time when the S value has entered the late stage of strengthening and turns to weaken and in the gradient belt on the margin ofS anomaly region. The dynamic evolution pattern ofS reflects the changes of the tectonicstress field during the seismogenic process. Therefore, it would be possible to trace the process of earthquake generation and occurrence from the dynamic evolution pattern ofS so as to service eaJ’thquake prediction. 展开更多
关键词 DEGREE of GROUND RESISTIVITY ANISOTROPY dynamic evolution pattern SEISMOGENIC PROCESS
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Genome-Wide Identification, Evolution and Expression Analyses of GA2ox Gene Family in Brassica napus L.
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作者 Yanhua Li Hualei Huang +8 位作者 Youming Shi Shuqin Huang Tao Liu Changming Xiao Xiaoqing Tian Ping Zhao Xiaoyan Dai Taocui Huang Yan Zhou 《Phyton-International Journal of Experimental Botany》 SCIE 2023年第3期815-835,共21页
Gibberellin 2-oxidases(GA2ox)are important enzymes that maintain the balance of bioactive GAs in plants.GA2ox genes have been identified and characterized in many plants,but these genes were not investigated in Brassi... Gibberellin 2-oxidases(GA2ox)are important enzymes that maintain the balance of bioactive GAs in plants.GA2ox genes have been identified and characterized in many plants,but these genes were not investigated in Brassica napus.Here,we identified 31 GA2ox genes in B.napus and 15 of these BnaGA2ox genes were distributed in the A and C subgenomes.Subcellular localization predictions suggested that all BnaGA2ox proteins were localized in the cytoplasm,and gene structure analysis showed that the BnaGA2ox genes contained 2–4 exons.Phylogenetic analysis indicated that BnGA2ox family proteins in monocotyledons and dicotyledons can be divided into four groups,including two C_(19)-GA2ox and two C_(20)-GA2ox clades.Group 4 is a C_(20)-GA2ox Class discovered recently.Most BnaGA2ox genes had a syntenic relationship with AtGA2ox genes.BnaGA2ox genes in the C subgenome had experienced stronger selection pressure than genes in the A subgenome.BnaGA2ox genes were highly expressed in specific tissues such as those involved in growth and development,and most of them were mainly involved in abiotic responses,regulation of phytohormones and growth and development.Our study provided a valuable evolutionary analysis of GA2ox genes in monocotyledons and dicotyledons,as well as an insight into the biological functions of GA2ox family genes in B.napus. 展开更多
关键词 Brassica napus GA2ox gene family evolution expression patterns
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Spatial Pattern Evolution and Influencing Factors of Cold Storage in China 被引量:4
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作者 LI Jinfeng XU Haicheng +2 位作者 LIU Wanwan WANG Dongfang ZHOU Shuang 《Chinese Geographical Science》 SCIE CSCD 2020年第3期505-515,共11页
Cold storage is the vital infrastructure of cold chain logistics. In this study, we analyzed the spatial pattern evolution characteristics, spatial autocorrelation and influencing factors of cold storage in China by u... Cold storage is the vital infrastructure of cold chain logistics. In this study, we analyzed the spatial pattern evolution characteristics, spatial autocorrelation and influencing factors of cold storage in China by using kernel density estimation(KDE), spatial autocorrelation analysis(SAA), and spatial error model(SEM). Results showed that: 1) the spatial distribution of cold storage in China is unbalanced, and has evolved from ‘one core’ to ‘one core and many spots’, that is, ‘one core’ refers to the Bohai Rim region mainly including Beijing, Tianjin, Hebei, Shandong and Liaoning regions, and ‘many spots’ mainly include the high-density areas such as Shanghai, Fuzhou, Guangzhou, Zhengzhou, Hefei, Wuhan, ürümqi. 2) The distribution of cold storage has significant global spatial autocorrelation and local spatial autocorrelation, and the ‘High-High’ cluster area is the most stable, mainly concentrated in the Bohai Rim;the ‘Low-Low’ cluster area is grouped in the southern China. 3) Economic development level, population density, traffic accessibility, temperature and land price, all affect the location choice of cold storage in varying degrees, while the impact of market demand on it is not explicit. 展开更多
关键词 cold storage spatial pattern evolution kernel density estimation(KDE) spatial autocorrelation analysis(SAA) spatial error model(SEM) China
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Spatial-temporal pattern and formation mechanism of county urbanization on the Chinese Loess Plateau 被引量:1
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作者 SONG Yong-yong MA Bei-bei +3 位作者 DAI Lan-hai XUE Dong-Qian XIA Si-you WANG Peng-tao 《Journal of Mountain Science》 SCIE CSCD 2021年第4期1093-1111,共19页
Urbanization is a comprehensive and complex socioeconomic phenomenon that plays an influential role in promoting global socioeconomic development.The Loess Plateau region is an important part of the China’s ecologica... Urbanization is a comprehensive and complex socioeconomic phenomenon that plays an influential role in promoting global socioeconomic development.The Loess Plateau region is an important part of the China’s ecological security pattern,and occupies an important position in the implementation of China’s new-type urbanization strategy and the realization of the urban dream.The characteristics of the staged changes and regional differentiation of urbanization in the area from 1990 to 2018 were studied with focus on regions and subregions by selecting 341 county-level administrative units on the Chinese Loess Plateau as the research area,and employing partition analysis and geographic detector methods.This revealed the formation mechanism of the spatial differentiation pattern of urbanization on the Loess Plateau.We found that the urbanization of the Loess Plateau,previously in a slow growth phase,entered the accelerated development phase,presenting a macro pattern of high rates of urbanization in central and eastern areas and low rates in western areas.The formation of the regional differentiation patterns of urbanization on the Loess Plateau were the combined results of natural geographical and socioeconomic factors.Among these factors,the interaction of any two factors had a stronger impact on regional urbanization patterns than a single factor,which was specifically manifested as nonlinear or bi-factor enhancement effects.The findings of this paper may provide a theoretical reference and scientific basis for the scientific promotion of healthy urbanization on the Chinese Loess Plateau and the ecologically fragile areas of developing countries around the world. 展开更多
关键词 URBANIZATION spatial-temporal pattern Influencing factors Driving mechanism Geographical detector Chinese Loess Plateau
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The Spatial-Temporal Distribution Patterns of Dyke Swarms in Central Asia and their Tectonic Significance: Case Studies in Eastern Tianshan and Western Junggar 被引量:1
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作者 FENG Qianwen LI Jinyi LIU Jianfeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期152-153,共2页
Dykes are a special kind of intrusive rocks which were formed by deep magma intruded into the existing brittle fractures in the crust.Dykes swarms in different tectonic environments are very significant to re-construct
关键词 deep Asia Case Studies in Eastern Tianshan and Western Junggar The spatial-temporal Distribution patterns of Dyke Swarms in Central Asia and their Tectonic Significance
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Research on Evolution of Goal-Driven Service Composition Patterns
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作者 李征 李昭 +2 位作者 何克清 王健 冯在文 《Journal of Donghua University(English Edition)》 EI CAS 2012年第1期14-18,共5页
With the development of Web service technology, using composite services to satisfy users' requirements has become an inevitable tendency. Goal changes caused by changing requirements of users may directly drive t... With the development of Web service technology, using composite services to satisfy users' requirements has become an inevitable tendency. Goal changes caused by changing requirements of users may directly drive the corresponding evolution of service composition. However, most researches focus on how to compose services, and little efforts have been placed on how to evolve the composite services with changing requirements. In this paper, the service composition patterns are defined based on workflow patterns, and the changes of service composition patterns are analyzed according to changing goals. Finally, a case study is given to demonstrate the feasibility of the proposed approach. 展开更多
关键词 workflow pattern service composition pattern goal evolution
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Spatial-temporal analysis of wetland landscape pattern under the influence of artificial dykes in the Yellow River delta
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作者 Xin Fu Gaohuan Liu +2 位作者 Siyue Chai Chong Huang Fadong Li 《Chinese Journal of Population,Resources and Environment》 2013年第2期109-117,共9页
The influence of anthropogenic activities,especially artificial dykes,on the coastal wetland landscape is now considered as a serious problem to the coastal ecosystem.It is important and necessary to analyze changes o... The influence of anthropogenic activities,especially artificial dykes,on the coastal wetland landscape is now considered as a serious problem to the coastal ecosystem.It is important and necessary to analyze changes of coastal landscape pattern under the influence of artificial dykes for the protection and management of coastal wetland.Our study aimed to reveal the quantitative characteristics of the coastal wetland landscape and its spatial-temporal dynamics under the influence of artificial dykes in the Yellow River delta(YRD).It was analyzed by the methods of the statistical analysis of landscape structure,five selected landscape indices and the changes of spatial centroids of three typical wetland types,including reed marshes,tidal fiats and aquaculture-salt fields.The results showed that:(1)Reduction of wetland area,especially the degradation of natural wetlands,had been the principal problem since the dykes were constructed in the YRD.The dykes created conditions for the development of artificial wetlands.However,the new born artificial wetlands were still less than the vanished natural wetlands.(2)Compared with the open area,the building of artificial dykes significantly speeded up the changes of landscape patterns and the aggravation of the landscape fragmentation in the closed area.(3)The changes of area-weighted centroids of three typical wetland landscapes were greatly affected by dykes,and the movement of the centroid of the aquaculture-salt field was very sensitive to the dykes constructed in the corresponding period. 展开更多
关键词 artificial DYKES COASTAL WETLAND COASTAL zone of the YELLOW River DELTA LANDSCAPE pattern spatial-temporal analysis
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Preliminary analysis of the mitochondrial genome evolutionary pattern in primates
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作者 Liang ZHAO Xingtao ZHANG +2 位作者 Xingkui TAO Weiwei WANG Ming LI 《Zoological Research》 SCIE CAS CSCD 北大核心 2012年第S02期47-56,共10页
Since the birth of molecular evolutionary analysis,primates have been a central focus of study and mitochondrial DNA is well suited to these endeavors because of its unique features.Surprisingly,to date no comprehensi... Since the birth of molecular evolutionary analysis,primates have been a central focus of study and mitochondrial DNA is well suited to these endeavors because of its unique features.Surprisingly,to date no comprehensive evaluation of the nucleotide substitution patterns has been conducted on the mitochondrial genome of primates.Here,we analyzed the evolutionary patterns and evaluated selection and recombination in the mitochondrial genomes of 44 Primates species downloaded from GenBank.The results revealed that a strong rate heterogeneity occurred among sites and genes in all comparisons.Likewise,an obvious decline in primate nucleotide diversity was noted in the subunit rRNAs and tRNAs as compared to the protein-coding genes.Within 13 protein-coding genes,the pattern of nonsynonymous divergence was similar to that of overall nucleotide divergence,while synonymous changes differed only for individual genes,indicating that the rate heterogeneity may result from the rate of change at nonsynonymous sites.Codon usage analysis revealed that there was intermediate codon usage bias in primate protein-coding genes,and supported the idea that GC mutation pressure might determine codon usage and that positive selection is not the driving force for the codon usage bias.Neutrality tests using site-specific positive selection from a Bayesian framework indicated no sites were under positive selection for any gene,consistent with near neutrality.Recombination tests based on the pairwise homoplasy test statistic supported complete linkage even for much older divergent primate species.Thus,with the exception of rate heterogeneity among mitochondrial genes,evaluating the validity assumed complete linkage and selective neutrality in primates prior to phylogenetic or phylogeographic analysis seems unnecessary. 展开更多
关键词 Mitochondrial genome evolutionary pattern Codon usage bias Complete linkage evolution neutrality PRIMATES
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