The statistical definition of migration in China is attached with its unique household registration (hukou) system, the migrants so defined are also called the floating population. A new analytical paradigm is needed to deal with the complexity of sub-flows in the floating population. The paper classifies five types of the floating population in census context by referring the UN migration criteria, and constructs a new paradigm for analyzing the floating population in China. As a particular provincial-level region (hereafter province) is concerned, the inflow and outflow people belong to different hukou groups balanced by their own counter-flow, namely, inflow vs back-inflow (both have no hukou of the province), outflow vs back-outflow (both have hukou of the province). With the clue of inter-census migration cohort, a sub-flows model is constructed to identify the inter-provincial migration based on the retention rate. The annual retention rate of the inter-provincial migration cohort from 2010 to 2020 is 88.7%. Based on the provincial retention rates, an all-increment table of population change by province in China is made by modelling simulation. The paper surfaces new characteristics of population growth and inter-provincial migration: (1) Provincial population changes are divided into five types, among which the inflow-leading increase type is mainly found in municipalities and the eastern coastal areas, while the fertility-leading increase type and the fertility-overriding increase type are mainly in the western provinces and the agricultural provinces in the middle, and the outflow-overriding decrease type and the outflow-leading decrease type in Shanxi, Inner Mongolia, Gansu and the northeastern provinces. (2) The mechanical growth of population can be divided into four types: rapid increase, equilibrium, outflow-overriding decrease and dual decrease (both hukou and non-hukou migration are negative). A "W"-shaped mechanical growth rate profile from northwest to southeast is found with the equilibrium belt standing in its middle. (3) Population floating is divided into three types. The counter-flows are highly-correlated: inflow rate and outflow rate are negatively correlated while the inflow-back-inflow and outflow-back-outflow are significant positively correlated. The analytical paradigm and model of floating population in China can be further extended to the study of "citizenship seeking migration" including international migration, and even further to identity migration including migrations with status changing such as enrollment, employment and marriage.

Understanding the spatial segregation and social integration of immigrants and local residents is highly significant in summarizing the historical experience of Chinese modernization. Additionally, it serves as a crucial foundation for promoting a people-centered new urbanization, fostering spatial fairness and justice, and achieving common prosperity. However, current research on residential spatial differentiation primarily focuses on analyzing the spatial distribution characteristics, differentiation patterns, and indicator calculations of various groups, and has limited investigation into social integration issues. This paper explores this social and spatial differentiation phenomenon in Hangzhou, usingthe initial residence registration information and mobile phone signalling data to analyze the characteristics and mechanisms of living space differentiation. Additionally, this article combines a small sample of questionnaires with a bottom-up exploration of social integration under spatial differentiation. From the research, four key findings emerge: (1) The majority of residents in the city are migrants. There is a clear difference in the distribution of living spaces between immigrants and local residents, with local residents mainly concentrated in the old city area, while the distribution of immigrants is more scattered. Compared to the typical "immigrant city" in the United States, Hangzhou has less spatial differentiation between immigrants and local residents. (2) The residential space differentiation between immigrants and local residents in the city presents a combination pattern of " multi-nuclei, sectoral, concentric zone". However, unlike the centrifugal diffusion trend of the local people in the United States, the local residents in Hangzhou tends to gather towards the center, while immigrants choose centrifugal diffusion and peripheral aggregation. (3) The spatial differentiation of living spaces is mainly caused by the competition for spatial resources between immigrants and local residents under urban expansion. However, behind the phenomenon of "local residents live in the old city", immigrants are no longer a disadvantaged group. Some intelligent new immigrants actively choose to live in high-quality peripheral areas. (4) The integration between immigrants and local residents is satisfactory, but it is more cautious about the issue of intermarriage. Additionally, residential spatial segregation has not had a negative impact on social integration. There are four main reasons for this. To begin with, the majority of the population consists of immigrants, and urban residents no longer pay attention to identity labels in their daily interactions. Besides, there is relatively little cultural difference within ethnic groups, and the assimilation between immigrants and local residents is increasing. And then, interactions between individuals in workplace and third place can alleviate the negative impacts caused by residential spatial segregation. Finally, China's coordinated development and people-oriented social system can also create favorable conditions for social integration.

In the wake of unprecedented global urbanization, an alarming trend of shrinking cities has emerged worldwide, presenting a profound challenge to conventional urban-regional planning approaches, primarily centered on growth scenarios. This trend has also bestowed upon Chinese geographers and urban and rural planning practitioners a new mandate in this evolving era. One region that exemplifies this predicament is Northeast China, experiencing the most severe population decline and the highest concentration of shrinking cities in the country. How to rationally recognize and properly deal with this phenomenon (or problem) of regional urban shrinkage has become the core scientific issue to be focused on in the comprehensive implementation of regional coordinated high-quality development, Chinese-style modernization of common prosperity for all and all-round revitalization of Northeast China in the new era. This paper delves into a logical speculation and practical discussion to understand the underlying causes and implications of regional urban shrinkage in Northeast China: Initially, it examines the original concept of regional shrinking cities within the context of urbanization, critically evaluating the rationality of such shrinkage in light of the broader national strategic objectives. Subsequently, the generation logic of regional urban shrinkage in Northeast China is explored through three key factors: the "pull" effect of regional spatial correlation, the "extrusion" effect of urban shrinkage at a regional level, and the "catalyst" effect of transportation and communication technology development in reducing the cost of factor flow. Moreover, this study draws on the market-led shrewd contraction theory and the government-led vitality regeneration governance logic. It takes into account the governance objectives of achieving "regional coordinated high-quality development, people-oriented new urbanization, efficiency and fairness, and comprehensive security concept". With a systematic perspective that considers scale heterogeneity, development context relevance, factor differentiation, and multidisciplinary integration, the paper outlines a governance model and strategy for addressing regional urban shrinkage in Northeast China. By emphasizing the alignment of governance approaches with national development goals, this research underscores that regional urban shrinkage goes beyond a mere outcome of market-driven population migration. The presence of underlying "market failures" severely impacts the vision of the five major securities (national defense, food, ecology, energy, industry) advocated by Chinese President Xi Jinping for the Northeast China region. The findings of this study offer valuable insights to guide Northeast China's pursuit of high-quality development and contribute to the region's revitalization efforts.

Fostering coordination among the economy, society, resources and environment is a crucial requirement for high-quality urbanization. This work developed an indicator system for the degree of coordination involving urbanization-economy, urbanization-society, urbanization-resources and urbanization-environment based on the dynamic evolution of urbanization and time series analysis. Using counties as the statistical unit, the study investigated the spatiotemporal evolution process and impact mechanism of the multidimensional coordinated urbanization from 2000 to 2020 on the Qinghai-Tibet Plateau. Urbanization-resource coordination was found to be the highest overall. The levels of coordination between urbanization-economy and urbanization-society were relatively low, whereas the coordination degree for urbanization-environment was moderate and essentially consistent. The measurements described above showed a convergent tendency between 2000 and 2020. The levels of coordination between Qinghai and southern Gansu generally decreased, and the rate of urbanization outpaced that of economic growth, placing significant strain on the environment and resources. The overall degree of coordination improved in Xizang, western Sichuan, and Yunnan, despite the fact that their individual coordination levels were on the decline. The regression findings showed that the industrial development, which is primarily influenced by the industrial structure, is a crucial element in enhancing the degree of urbanization-economy coordination. The financial capacity of the government has a significant impact on the degree to which urbanization and society are coordinated. As the scale of fiscal spending expands, it correspondingly rises the degree of coordination. Furthermore, economic development and government fiscal spending have a negative effect on the coordination degree of urbanization-resources and urbanization-environment. When industrial proportion and government fiscal spending capacity increase, the coordination degree of urbanization-resources and urbanization-environment declines, indicating the plateau's dilemma between economic development and environmental protection. However, if the industrial enterprises are primarily larger than the designated size and the scale of the center town agglomeration is enormous, it is conducive to strengthen the coordination degree of urbanization-resources and urbanization-environment.

Urban housing prices are influenced by various factors, encompassing macroeconomic conditions, urban planning strategies, and the specific characteristics of housing. These elements play a crucial role in shaping urban planning and development. Nonetheless, the regression analysis depicting the interplay between urban housing prices and their influencing factors reveals significant spatial non-stationarity and intricate nonlinear characteristics. Addressing the limitations of Euclidean distance in delineating spatial proximity for housing price modeling and the challenges encountered by the geographically weighted regression model (GWR) in capturing complex nonlinear features, this study introduces travel duration (TD) as a spatial distance metric and integrates it with a spatially weighted neural network to establish a geographically neural network weighted regression model with travel duration (TD-GNNWR) to estimate housing prices. In an empirical experiment using 2019 second-hand house data in Wuhan, the TD-GNNWR model demonstrates a 16% enhancement in fitting accuracy compared to the GWR model. The TD-GNNWR model notably enhances accuracy within sparsely sampled regions and better mimics their spatial distribution. Moreover, it adeptly captures spatial non-stationarity, offering a more precise elucidation of factors influencing housing prices in Wuhan and the resultant spatial discrepancies stemming from urban zoning. Our findings underscore the comprehensive impact of various factors on housing prices in Wuhan, such as building characteristics, neighborhood attributes, and transportation accessibility. Factors like greening rates, property fees, proximity to primary schools, universities, and public transportation exert substantial influence on housing prices in Wuhan, with varying directions and strengths across different areas, signifying clear spatial differentiation. The TD-GNNWR model clearly elucidates the mechanisms underlying housing price determinants while illustrating the inherent spatial non-stationarity, which is beneficial for urban planning departments and real estate managers in policy formulation, macro-control, urban planning, and investment decision-making. This work can also serve as a valuable reference for tackling challenges in urban analysis and modeling, thereby enriching methodologies within real estate research.

With the acceleration of urbanization, traditional large-scale remote sensing image and economic statistical methods cannot accurately depict the dynamics of urban economic development from a fine scale. Streetscape images can reflect the material spatial features of the urban built environment. And based on this, economic development indicator (EDI) can be predicted at a finer scale. The study proposes an improved Deeplabv3_MEP semantic segmentation model for streetscape images to extract the percentage of streetscape elements. Then, graph neural network (GCN) and convolutional neural network (CNN) are used separately with streetscape factor index and streetscape images as inputs to predict EDI. And the XGBoost model is used to analyze the driving factors of EDI. The carbon sinks are calculated and a Lasso regression model is constructed to evaluate the effectiveness of green economic development in administrative regions. The results show that: (1) At the city-level division scale, the economic indicator of Jinan city shows a trend of high concentration towards the city center and a gradual decrease towards the outskirts. (2) At the district-level division scale, Lixia district has the highest level of economic development. And the development level in sporadic areas in the east is very high, while that in other areas is lower. (3) At the street-level division scale, the closer the street is to the district or county center, the higher the average income level of residents, and the closer the street is to the city center, the higher the average income level of residents. (4) Driving factors such as wall, sky, road, and car, contribute more to EDI, while factors such as pole and motorcycle contribute less, with bus being the lowest. (5) There is a phenomenon of mismatch between the green economic development index and the level of economic development.

Population equilibrium development is the valuable guide and ideal pursuit of China's population policy and has significant implications for regional equilibrium development. However, there are still misunderstandings about interpreting population spatial equilibrium, and its scientific connotation requires further explanation and promotion. Population spatial equilibrium gives the meaning of space based on population equilibrium, which can be understood as the spatial equilibrium of population distribution. When other factors remain unchanged, the net migration between regions is zero; that is, the total number of immigrants of each region are equal to its total number of emigrants to achieve the dynamic equilibrium of population distribution among regions. A migration stream will exist between regions in an equilibrium state. Migration and equilibrium can coexist, but the population distribution between regions remains dynamic and stable, and the population spatial distribution structure will not change. Specific conditions cause the inherent stipulation of population spatial equilibrium. The equilibrium point will also change with economic, social, resource, and environmental changes. Equilibrium is a relative concept derived from the instantaneous concept; instantaneous equilibrium is an ideal state in the long term. The population spatial distribution is constantly changing from disequilibrium to equilibrium and from equilibrium to disequilibrium. This paper describes a theoretical model of multi-regional population spatial equilibrium based on the regional wage rate, human climate suitability index, urban crowding degree, and distance. Using the Yangtze River Delta as an example, the study analyzes the equilibrium population spatial distribution under current economic, social, environmental, and population conditions. The study found that the population of the study area is concentrated along the river and the coast, mainly in the south of Jiangsu, along the coast of Hangzhou Bay, and the canal from Nanjing to the north of Jiangsu. By comparing the equilibrium population with the current distribution, the Yangtze River Delta can be divided into quasi-equilibrium, attractive, and repulsive areas. The attractive areas, such as Shanghai, Nanjing, and Hangzhou, have large population agglomeration potential. In contrast, the repulsive areas are mainly located in northern and western Anhui, northern Zhejiang, and other areas close to the quasi-equilibrium area. This suggests that under free migration, the population will further concentrate in the areas of Shanghai, Nanjing, Hangzhou, and southern Jiangsu.

The city government relocation in China will stimulate the spatial reallocation of resources, thus affecting regional economic development. In previous studies, only impacts of city government relocation in single move-in or move-out districts are evaluated. More, the results are usually relied on individual city case studies. Therefore, large sample empirical studies from a multi-regional perspective are urgently needed. This paper expands the theoretical framework of the relocation impact of city government, a regional factor in political geography, on economic development, and constructs panel data from 2000 to 2017 to examine the economic performance of government relocation policy of prefecture-level cities on the move-in districts, move-out districts, and other areas and its impact path through the difference-in-difference method. It is found that the government relocation could significantly promote the economic development of the move-in districts and drive the economic development of other districts and counties in the city through spillover effect, while the move-out districts are not significantly improved or damaged. Further mechanism testing show that the government relocation policy promotes local economic development through the effect of enterprise agglomeration and industrial upgrading in the move-in districts. Therefore, a reasonable relocation of city government can be an effective policy tool to promote the economic development of different regions within a city, but strict demonstration and approval are important prerequisites.

Residential differentiation is an essential component of socio-spatial differentiation, but only part of it, since there might be considerable differences in urban social space structure at different times and in a different context because of the high mobility of urban population. However, integrated and comparative research of urban social space that integrates multiple temporal and spatial scales as well as multi-domain dimensions at home and abroad is still in its infancy. Based on mobile terminal user portrait data supported by big data environment and AI simulation technology, this paper explores the spatial differentiation pattern of daytime activities (10:00-17:00) and night residence (21:00-06:00) of social groups in Nanjing inner city, and conducts a comparative study of multi-dimensional and multi-scale spatial differentiation indexes. The research finds that: (1) Both similarity and difference exist in the spatial distribution of day / night social groups. There is a large proportion of middle-aged rich groups along Beijing West Road and Beijing East Road, and a high density of local elderly residents in the north and south of the city. In the city center, there are a large number of white-collar employees during the day and a mix of different social groups at night. (2) Different from the existing research findings in European and American countries, the daily mobility of urban population does not mitigate the socio-spatial differentiation. The spatial differentiation degree of most social attribute indicators, such as gender, occupation and consuming capacity on the street, community and grid scales, shows that daytime activities are higher than nighttime residence. (3) The scale effect of socio-spatial differentiation is significant, more specifically, not only the spatial differentiation index of smaller scale units is higher, but subtler even different socio-spatial differentiation can be revealed from smaller scale units, and this differentiation can be evidently presented by cross-scale comparison. As an exploratory attempt to the problem of "multi-contextual segregation" in social space, it is conducive to construct the research framework of urban social space integrating multi-space, multi-dimension and cross-domain, and further expanding the theory and practice of urban socio-spatial differentiation in China.

Nowadays, the disordered expansion of urban land has become an important problem on China's urbanization. Urban population growth is widely recognized as a crucial driver of urban spatial expansion. Therefore, it is necessary to clarify the spatiotemporal differentiation characteristics of urban expansion and understand the relationship between urban population size and urban expansion. Based on Landsat TM/OLI remote sensing images and socioeconomic statistics data, this paper identified the urban land in the Yangtze River Economic Belt (YREB), China, between 1990 to 2020. This was achieved by combining object-oriented automatic extraction and human-computer interaction visual interpretation. The study then examined the spatiotemporal differentiation characteristics of urban expansion at difference scales using expansion speed, expansion difference index, kernel density analysis and spatial autocorrelation. Finally, the relationship between urban population size and urban expansion in different regions was investigated using the Two-way Fixed Effects Model. The main results are as follows: (1) After 2015, urban expansion speed decreased significantly in different parts of the YREB. Moreover, the time series characteristics of urban expansion in the cities of the upper and middle reaches were found to be different from those in the lower reaches. The upper reaches had higher expansion speed than the middle reaches after 2010. Spatially, the urban expansion in the YREB shows significant spatial heterogeneity. High-speed expansion areas have shifted from east to west, and the differences in urban land scale between the upper-middle and the lower reaches tend to converge. Urban expansion in the lower reaches exhibits strong spatial dependency, while in the middle-upper reaches, there is no significant spatial autocorrelation. (2) The relationship between urban population size and urban expansion differs significantly among different regions. The upper reaches show a negative correlation, while the middle-lower reaches exhibit a "U-shaped" relationship. This indicates that there is no obvious over-expansion of population size in the upper reaches, whereas there is in the middle-lower reaches. Residents in the middle reaches have demonstrated a higher sensitivity to urban comfort and quality of life. Finally, the study provides regional policy recommendations, aiming to offer scientific references for targeted urban policies and promote high-quality urban development.

As the frontier of China's land and sea economic development, the coastal zone of the East China Sea (ECS) has witnessed a significant escalation of urban risks against a backdrop of high-intensity utilization. Research on urban resilience provides a basis for mitigating the impact of human activities and natural disasters, holding crucial significance for the sustainable socioeconomic development of coastal cities. Taking into account both resilience capabilities and resource environmental costs, we established a "background-operation-efficiency" evaluation system to analyze the spatiotemporal evolution characteristics of urban resilience at the county scale in the ECS coastal zone. Additionally, geographic detectors and GTWR models were employed to investigate the influencing factors of resilience operation capacity. The results show that: (1) The resilience background capacity of county-level cities in the study area continues to increase, and the spatial pattern is relatively stable. It exhibits a distribution trend with a higher level in Shanghai, a higher level in northern Zhejiang but a lower level in southern Zhejiang, a higher level in the middle of Fujian while a lower level in the north and south of Fujian. Generally, cities tend to cluster homogeneously, mainly forming low-low agglomerations. (2) The resilience operation capacity of county-level cities has steadily improved, showing a positional pattern of Shanghai > Zhejiang > Fujian. High value areas are concentrated in urban areas, presenting a spatial evolution pattern of resilience operation in two stages of polarization and diffusion. Cities in the ECS coastal zone generally exhibit low-low agglomerations. (3) The resilience efficiency of county-level cities initially decreases, then slowly increases before rapidly increasing. High value areas are mostly distributed in urban areas and island cities. The most common city type is "low background-low operation-medium efficiency", and there are many cities of the "low background-low operation-low efficiency" and "medium background-medium operation-low efficiency" types; (4) The level of economic development is the primary factor influencing the resilience operation capabilities of county-level cities in the ECS coastal zone, but its impact tends to weaken. The influence of urban openness and infrastructure level is increasing, while that of urbanization level and urban agglomeration level is gradually diminishing.

As a key node of inter-regional input and output, the participation of dual circulations of cities is of great significance to the construction of a new development paradigm. Based on the value-added decomposition framework of WWZ, using the latest Chinese inter-city input-output tables in 2012, 2015 and 2017, this paper constructs participation indicators of "dual circulations" at the city-industry level, and focuses on the analysis of the influencing factors of participation of domestic circulation at the city level. The study found that: (1) In 2012, 2015 and 2017, the overall domestic circulation participation in China was 71.62%, 72.42% and 74.08%, and the international circulation participation was 28.38%, 27.58% and 25.92%, respectively, which shows that the dominant position of China's domestic circulation is gradually strengthening. (2) At the industry level, the domestic circulation participation of manufacturing industry is low, which is closely related to its deep embeddedness in global value chains characterised by trade in intermediate goods. In contrast, the service industry has higher participation, which is in line with its poor tradable characteristics. (3) At the city level, the participation of international circulation in eastern cities is high, with an average of 30.74%. The participation of domestic circulation in central and western cities is relatively high, with an average of nearly 90%. China is gradually forming a spatial distribution in which the central and western cities are dominated by domestic circulation and the eastern coastal cities are dominated by international circulation. (4) Foreign direct investment is not conducive to the improvement of domestic circulation participation in urban China. while the level of transportation infrastructure and government intervention will help further strengthen the dominant position of domestic circulation in urban China. At the same time, the domestic circulation participation of the four major sectors shows different influencing factors.

The study of the new economic geography has paid attention to the polarization and balanced development of urban systems. In reality, however, transport accessibility is subject to great uncertainty in explaining the polarization and balance of the urban system. In fact, the polarization or equilibrium of the regional urban system is not only unique in China, but also a general phenomenon in countries with different development outcomes, political systems and degrees of marketization. From the perspective of industrial heterogeneity, this study empirically analyzes the process and mechanism of the industrial structure of regional central cities on the population growth of neighboring cities in China from 1980 to 2020, and examines the influence of industrial structure on the polarization and equilibrium development of the regional urban system. The results show that, firstly, the manufacturing sector strengthens the spillover effect from the core city and promotes the population growth in neighboring cities, while the service sector weakens the spillover effect and hinders the growth in neighboring cities. Secondly, the manufacturing-oriented cities have relatively small city scale, while the service-oriented cities are relatively large. Therefore, the driving effect of manufacturing-oriented central cities on the neighboring cities is larger, which tends to produce a relatively balanced regional city system. Correspondently, the spillover effect of service-oriented central cities on the neighboring cities is smaller, which tends to form a relatively polarized regional city system. Finally, as the share of services in the industrial structure of central cities continues to rise, China's urban system may become more polarized rather than balanced. Certainly, the higher the proportion of manufacturing in the central city, the more balanced the regional urban system is. In fact, the empirical results show that the industrial structure and the spillover effect of the core city have an inverted U-shaped relationship, i.e. a high proportion of manufacturing or services weakens the driving effect of the core city on surrounding cities. The reasons for this vary. The high proportion of manufacturing and the small size of the central city have a limited spillover effect on the neighboring cities and therefore can hardly drive their growth; while the high proportion of service industry and the negative effect of the service industry on the spillover effect lead to the slow development of the neighboring small-and-medium-sized cities. It is worth noting that because of the significant spatial impact of industry on the urban system, the future regional urbanization strategy should be coordinated with the industrial strategy. More importantly, with the gradual liberalization of the household registration system, industry selection can become an effective policy option for macro-control of the regional urban system.

As a product of certain type of social interaction, urban scaling laws assume that urban attributes such as urban economic outputs are largely determined by urban population size (internal interactions), implying the assumption of agglomeration economies. Urban population agglomeration represents a local network effect, while the global network effect on a larger spatial scale between cities should also be considered in terms of the improvement of social productivity. Taking 275 Chinese cities at prefecture level and above as the research object, we constructed an urban human mobility network by Baidu migration data and portraied the degree of external interaction by human mobility between cities. We comparatively analysed the non-linear relationship between population size within cities and external interaction and urban economic outputs under the urban scaling framework. Results show that there is a significant super-linear scaling relationship between urban economic output and external interaction, revealing the higher multiplier effect of external interaction on urban economic outputs. The role of network spatial interaction cannot be ignored and it has become an important complement to agglomeration economies. Further, indicators such as urban population density, agglomeration and network externalities are introduced to quantitatively and comprehensively measure the effects of urban population agglomeration and interurban population mobility and their synergistic effects on urban economic outputs. The agglomeration effect brought about by urban population size remains the main driver of regional economic development, and the ability of cities to benefit from exchange and cooperation on a larger spatial scale has yet to be enhanced. This study contributes to fully understanding the origins of urban scaling laws from taking both internal and external interaction into consideration, deepening the recognization of the agglomeration effect and network effect of regional economic growth. This paper is supposed to support for promoting high-quality integrated urban development and deepening the practice of coordinated regional development.

Based on the multi-directional flow matrix and the social network analysis, the paper proposes a system extending and optimizing the connotation and measurement of urban niche, constructs a research framework of urban niche in urban agglomerations from the perspective of space of flows, and takes the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) as a case to dissect the "ecostate-ecorole" characteristics of cities, revealing niche and competition and cooperation relationships of cities. The study shows that: (1) In terms of the overall ecorole, the rank-size distribution of inter-city factor flows in the GBA is the primacy ratio distribution at the level of employment service flow, economic service flow, knowledge flow and ecological service flow, while it is the centralized one at the level of information flow, and the balanced one at the level of comprehensive flow and cooperation flow, with a log-normal distribution pattern. (2) In terms of local ecorole, the city group varies depending on factor flows and is interweaved with each other to form a multi-dimensional flow intensity structure of "core-regional core-margin", of which, Hong Kong and Shenzhen, Guangzhou and Foshan, Zhuhai and Macao, share the closest inter-city cooperation. Meanwhile, three inland city groups show signs, namely, "Guangzhou-Foshan- Zhaoqing", "Shenzhen-Dongguan-Huizhou" and "Zhuhai-Zhongshan-Jiangmen". (3) In terms of macro ecostate, cities play different roles in different factor flows of urban agglomerations, which can be summarized into five types: diffused, benefited, balanced, isolated and intermediary. Also, the participation modes of cities in clusters can be grouped as participation in full and in part, according to the analysis of intercity dominant flow in each factor matrix. (4) In terms of micro ecostate, cities share complex partnership and competitive relationship. There are 11 pairs of reciprocal partners, 7 pairs of complementary partners, 42 pairs of fierce competitors and 31 pairs of mild competitors. Based on the flow data, the paper broadens the perspective of study on urban niche of urban agglomerations, and puts forward a new idea of improving the spatial structure of urban agglomerations and regional competition and cooperation relationships, so as to provide a valuable decision-making basis for building the GBA into the world-class city cluster.

Building a market-oriented green technology innovation system to accelerate the diffusion of green technology between regions, cities, and institutions has become a national strategy. Using green patent transfer to characterize the diffusion of green technology, this paper analyzed the temporal development dynamics and spatial distribution pattern of green technology diffusion in China from 2001 to 2020, and also discussed the main factors driving the diffusion of green technologies in Chinese cities. The study found that from 2001 to 2020, the popular technologies in China's green technology market rapidly changed from environmental governance technology to green building technology and clean energy technology, while enterprises were always the main actors of green technology diffusion. Secondly, from 2001 to 2020, with the cross-city flow of green technology becoming the new normal, a unified national green technology trading market was gradually taking shape. Thirdly, green technology diffusion activities were highly concentrated in the "T" region composed of the eastern coastal areas and the Yangtze River Economic Belt, in which the inter-city green technology diffusion formed a diamond network with the Beijing-Tianjin, Yangtze River Delta, Pearl River Delta and Chengdu-Chongqing regions as the hubs. Fourthly, following the principle of preference connection and the law of assortativity, new cities in the intercity green technology diffusion network tended to obtain green technology from hub cities, but the flow of green technology between hub cities was more frequent. Fifthly, the regression results of the model under the multi-dimensional proximity analysis framework also verified the above laws, and revealed the differences in the formation mechanism of intercity green technology diffusion caused by technology gap, geographical proximity, economic proximity and cognitive proximity among cities.

There are important changes in urban-rural structure of population mobility at the late-intermediate stage of urbanization in China, which will have a significant impact on population redistribution, urbanization and regional development. This paper divides the interprovincial urban and rural floating population into four mobility types by using the 2010 and 2020 censuses data, and on the basis of identifying the mainstream types, their spatial patterns evolution and the relationship with regional economic development are investigated through the mobility ratio indexes and regression models. The study results can be summarized as follows. (1) The urban and rural floating population is large and grows rapidly. Meanwhile, rural-urban mobility keeps the dominant position, and urban-urban mobility rises rapidly, these two population mobility types have become the mainstream ones of interprovincial urban and rural floating population in China. (2) In terms of the net mobility pattern of urban-urban floating population, the net-inflow areas are further concentrated in the three major coastal centers of Beijing, Shanghai and Guangdong, and Liaoning, Xinjiang and Yunnan are also maintained at a certain net-inflow rate, but most of the provincial-level regions are in the net-outflow areas. The major changes of the net mobility pattern of urban-urban floating population have shaped a spatial connection network. The main features of this network can be described as three cross-regional flow circles of Beijing-Tianjin-Hebei, Yangtze River Delta, and Pearl River Delta in coastal China. At the same time, the space connections within the regions are strengthening in northeast China, northwest China and southwest China. (3) The net mobility pattern of rural-urban floating population shows that in coastal areas, the net-inflow rate rises or decreases during the study period, while in inland areas, the increase in the net-inflow rate of Liaoning and Xinjiang leads to the decline in the net-outflow rate of their neighboring provinces. The changes of the net mobility pattern of rural-urban floating population depict the dual characteristics of continuous formation and different changes of the coastal flow circle, and the development of the inland flow circle in Xinjiang and Liaoning. (4) There is a mutual relationship between urban-urban and rural-urban population mobility and regional economic development. For regional economic development of both population mobility types, the impact is significantly positive and has been increasing. When we add the floating stock into the models, the positive effect of this variable has decreased in urban-urban mobility's model, while it still plays the first-place positive effect in rural-urban mobility's model. The two population mobility types have a positive effect on the national economic development and the inflow areas' economic development.

Patent agency service is an important support to promote the creation, application and protection of intellectual property in the context of high-quality development. In this study, the network characteristics and influence mechanism of patent agency services were explored using the social network analysis method, spatial analysis method and econometric model. The patent service network in China shows a trend of expansion in scale and complexity in structure. From a single core in Beijing, the innovation service network gradually transforms into a multi-core topology. The innovation service network space has changed from the single two-tier pattern of "Beijing-Guangzhou" and "Beijing-Shanghai" to the complex structure of "Beijing as the core, with the coexistence of multi-nodes". The diffusion of innovative service flows is reflected in the form of hierarchical and contagious diffusion. The market-oriented changes in the patent management system and the spatial expansion of the demand for patent services have jointly shaped the pattern and evolution of the patent service network. The econometrical results show that the administrative hierarchy level, economic and population size, innovation capacity, and multidimensional proximity of the service city and the served city can significantly enhance the innovation service linkage between cities. This study, for the first time, explores the characteristics and evolutionary mechanisms of urban networks from the perspective of IP services. It emphasizes that administrative hierarchy, market size, and relational proximity jointly contribute to the system and evolution of urban networks, and enriches the study of innovation geography from the perspective of service linkages.

Multidimensional proximity is a major driving force for promoting knowledge flows and forming innovation networks, but from the perspective of proximity, the micro-mechanisms through which inter-individual social relations influence the formation of multi-scale innovation networks remains unclear. Taking the Yangtze River Delta megalopolis as the research region, and conducting questionnaire surveys of 926 corresponding authors who have published papers in Web of Science Core Collection, this paper identifies social relations of paper co-authors and builds a multi-scale urban innovation network to explore the influence of multidimensional proximity between individuals on the formation of multi-scale urban innovation networks. The study finds that: (1) The social relations of paper co-authors can be divided into three types: geography, learning, and business ties. They promote knowledge flow at different scales through geographic, cognitive, and social proximity, which can explain the micro-mechanisms of the formation of multi-scale urban innovation networks in the study region. (2) In general, the influence of geography ties on knowledge flow at different scales is indirect, the influence of learning ties is reflected at the megalopolitan, national, and global scales, and the influence of business ties is mainly reflected at the national scale. In addition, cities with stronger external innovation connections tend to have more diverse manifestations of the geography, learning, and business ties. (3) Compared with business ties, learning ties exert a stronger overall impact on urban innovation network at each scale, indicating that cognitive proximity at the individual level is more conducive to promoting knowledge flows than social proximity. (4) Both the supervisor-student relationship based on learning ties and project-based relationship based on business ties play significant roles in the formation of urban innovation networks at different scales. The former is mainly presented due to the transfer and sharing of tacit knowledge during the flows of talents, the latter is mainly manifested by a relatively solidified cooperative matching mode formed between cities with stronger innovation capabilities.

Beijing has transitioned from the growth stage to the spatial renewal and improvement stage. Specifically, the evolution of urban functional space is an important symbol and spatial carrier in the process of development and transformation. This paper analyses structural modes and aggregation laws of spatial evolution based on long-term functional datasets, aiming to provide decision-making support and criteria for scientific reconstruction and refined governance of urban functional spaces. It is found in this study that: (1) the main centre of urban functional evolution of Beijing is located in the core area and migrates eastwards; the sub-centres and outer suburban centres are further formed, showing an evolutionary trend that polarisation goes before stabilisation; (2) the differentiation characteristics of the functional spatial pattern are significant; (3) the evolution of functional space presents a structural mode of polarisation of service function centres, sequential spillover of industrial function, and differentiation of residential function circles; (4) the aggregation laws of functional evolution include the separation of work and residence as a spatial response to the capital's service-oriented single-centre structure, the equalisation of public services as an important support for upgrading the quality of urban residential space, and the industrial agglomeration and transition as a key path for iteration.

In view of the inherent differences in the willingness of long-term residence, permanent settlement, and hukou conversion, as well as the identification and classification of related indicators, this paper examines the occurrence sequence and urban differences of the migrant population's willingness of long-term residence, permanent settlement and hukou conversion in the residence process based on the questionnaire of the migrant population in 25 cities in China. Through multi-level logit regressions, this paper compares the differences and similarities of the influence mechanisms of different willingness, and the determinants of the willingness to stay. The study finds that: (1) From the perspective of the process, the willingness to stay of the migrant population is sequential and progressive. Generally speaking, the willingness of permanent settlement is generated based on the willingness of long-term residence, and the willingness of hukou conversion occurs based on the willingness of permanent settlement. However, the willingness of hukou conversion in first-tier cities is higher than that of permanent settlement, and the relationship is more complicated. (2) From the perspective of the influence mechanisms, in addition to human capital, the generation of the willingness of long-term residence is mainly affected by social relations and social integration; the willingness of permanent settlement is significantly affected by economic income and family migration, and certain level of economic income and family migration can greatly improve the willingness to settle down permanently; the willingness of hukou conversion is mainly affected by identity and urban factors, and the higher degree of identity in the inflow area, the higher willingness of hukou conversion. (3) From the perspective of urban hierarchy, the willingness of permanent settlement shows an inverted "U"-shaped trend, with the highest willingness to settle down in provincial capital cities and the lowest in first-tier cities such as Beijing; the willingness of hukou conversion increases with the increase in urban hierarchy, and the migrants have higher willingness of hukou conversion in upper-level cities. The former is driven by economic factors, and is the result of the trade-off between the city's attractiveness and the cost of living, while the latter is driven by the degree of recognition, which is higher in upper-level cities. In the process of citizenization, the formation of the willingness to settle down is a key part. It is necessary to implement policies based on characteristics of the city to help improve the economic strength of the migrant population, promote family migration, and weaken the indicative significance of hukou conversion.

China has entered the stage of transformation from a "demographic dividend" to a "talent dividend", and talent has increasingly become the key driver of national and regional development in the era of a knowledge economy. As the reserve of talents, university graduates are the main target of the "war for talent" among Chinses cities. Based on the 2019 Graduate Employment Quality Reports of China's "double first-class" universities, adopting the Gini coefficient, spatial autocorrelation, and spatial econometric interaction model, this paper demonstrates the migration pattern of "double first-class" university graduates upon their graduation and investigates its underlying influencing factors. The results reveal that the destination areas of university graduates from "first-class universities" and "first-class disciplines" are highly concentrated in eastern China, with the former showing a higher concentration level. While economic factors still play a vital role in determining the migration of university graduates, the influence of quality of place is also significant, especially for graduates from "first-class universities". In addition, the policy factors also significantly influence the migration pattern of graduates from both types of universities. There are significant network autocorrelation effects among graduates' employment migration flows. The network autocorrelation effects based on places of study and places of employment are significantly positive. These network autocorrection effects reinforce the uneven distribution pattern of university graduates' migration. This study highlights the importance of employing a regional coordination perspective rather than a single-region perspective in terms of the formation and further optimization of regional talent policies.

Selecting 887 inter-provincial border counties in China as a research area, this paper constructs an evaluation index system incorporating five dimensions to measure the degree of urbanization that each county experienced from 2000 to 2019, describes characteristics of the evolution of urbanized spatial patterns combined with spatial autocorrelation analysis, uses geodetectors to identify the main factors influencing urbanization and interactive relationships, divides driving areas into types on the above basis, and proposes targeted suggestions. The results show that: (1) From 2000 to 2019, the urbanization level of China's inter-provincial border areas continued to increase, but the overall level remained low, and displayed a spatial distribution pattern of stepwise decline from east to central to west. (2) The urbanization level of counties on the inter-provincial border showed a significant positive spatial correlation. In terms of spatial distribution, HH-clustering counties formed a "T" pattern, and LL-clustering counties concentrated in the inter-provincial border areas of the northwest, northeast, and southwest. (3) Economic development and traffic level are the leading factors affecting the spatial pattern of urbanization in the inter-provincial border areas. (4) The spatial pattern of urbanization in the inter-provincial border areas results from the main factors directly driving economic development and determining transportation levels. In addition, medical care, social investment, and natural conditions also directly impact the spatial pattern of urbanization. Government behavior and educational services exert indirect effects. (5) Inter-provincial border areas are divided into six types with distinct patterns of leading driving factors: terrain element restriction, location traffic leading, economic development driving, social investment driving, public service lagging, and government leading. (6) Urbanization of inter-provincial border areas exerts a spatial nearest neighbor effect, and the urbanization level of counties close to urban agglomerations of developed regions is high. The marginality of urbanization space of counties in the inter-provincial border areas is prominent. In areas with more county borders in the inter-provincial areas, urbanization levels tend to be lower.

Based on the quasi-natural experiment, this paper uses the method of time double difference (DID) to empirically test the differential impact and mechanism of the opening of China Railway Express on the export trade of cities along the rail line by using the panel data of 279 prefecture-level cities in China from 2004 to 2019. The results show that: (1) The opening of China Railway Express has significantly promoted the export trade growth of cities along the rail line in China. The better the local transportation infrastructure conditions, the stronger the driving effect on the growth of local export trade. Exports are also positively regulated by the number of countries passing through and the logistics transportation capacity of the destination country. (2) Heterogeneity analysis found that the opening of the train has a significant positive impact on the export trade of the node cities of the supply hub, but it has no significant impact on the railway hub cities, and has a certain inhibitory effect on the export of the port cities. From the perspective of city size, the positive promotion effect of trade mainly occurs in small and medium-sized cities. Based on the analysis of different geographical location train channels, it is found that the promotion effect on the export trade growth of cities along the western channel is obvious. (3) The organization and operation of China Railway Express follow the "axle-spoke" mode, and their radiating space to the surrounding areas is roughly within 150 kilometers. The intermediary mechanism test shows that the opening of China Railway Express can promote the growth of export trade by improving the regional marketization level, and the positive intermediary effect of marketization level is more significant for cities in peripheral regions. The intermediary effect of transportation time cost saving is not significant, and the saving of time required by traditional shipping is not the main reason to promote the growth of export trade.

The construction of high-speed railway hub is one of the important elements to guide the spatial expansion of the city. Taking 37 cities with high-speed railway hubs in Yangtze River Economic Belt as examples, this paper constructs a model of high-speed railway hub-driven the city's center of gravity transit index, analyzes the spatial expansion effect of cities driven by high-speed railway hubs, and uses Geodetector to reveal the mechanism of urban spatial expansion driven by high-speed railway hubs. The results of this study showed that: (1) The spatial expansion effect of cities in the Yangtze River Economic Belt driven by high-speed railway hubs is divided into three levels: firstly, the cities' center of gravity is driven to expand significantly to high-speed railway hubs, showing a "targeted" state of expansion; secondly, the cities' center of gravity is driven to expand moderately to high-speed railway hubs, showing a "budding" state of expansion; thirdly, the cities' center of gravity is driven to expand inconspicuously to high-speed railway hubs, showing "no obvious adhesion" state of expansion. (2) The role mechanism of urban spatial expansion driven by high-speed railway hubs is mainly manifested in 4 dimensions and 11 factors, such as city level, the degree of development of high-speed railway hubs, and station-city relationship. Among them, city level plays the role of "driving force", and the factors of "city level" and "rate of change in external accessibility of cities" play a significant role; the degree of development of high-speed railway hub plays the role of "traction", and the factor of "high-speed rail hub grade" plays a significant role; the relationship between station and city plays the role of "catalyst", and the factor of "accessibility of hub" plays a significant role; the degree of government policy plays the role of "guidance".

As people's needs shift from the material level to the spiritual level, the safety perception of city is increasingly important to the sound development of society. In the meanwhile, there are group differences in the spatial distribution of safety perception, and understanding these differences and their environmental influences can help to respect and meet diverse needs during the process of urban planning and management. Previous research mainly focused on safety perception of residents in their home area, while few studies have investigated the safety perception of different groups outside their residential area. Besides, how environmental factors affect the group differences of their safety perception maps is unclear. Based on current deficiencies, a survey including 1149 participants was carried out in central area of Guangzhou to collect different safety perception maps of three income groups. Negative binomial regression models were used to test the environmental impact on the spatial distribution of safety perception of different income groups, with the environmental factors selected from three aspects: built environment, socioeconomic environment and environmental disorganization. The results show that: (1) long-distance transport facilities such as railway station and coach station, the junction area of Guangzhou-Foshan, and business districts in old city are all marked as high-risk perception area among three income groups. (2) There are certain differences in the spatial distribution of safety perception of the three income groups, among which the safety perception map of the low-income group is significantly different compared to two other groups. (3) Environmental factors such as the distribution of important transport facilities, blue space, land use diversity and intersection density have significant influence on the safety perception map of all income groups. (4) Density factors such as density of entertainment facilities and commercial buildings have a greater impact on the sense of safety of low- and medium-income groups. Design factors like sky openness and green space proportion have more impact on the median- and high-income groups. The impact of socioeconomic level and environmental disorganization factors (e.g., density of police station and instability of passenger flow) present great differences among three income groups. The study can provide theoretical reference for the construction of urban safety environment, establishment of safety image, as well as for humanistic and detailed urban planning and management in the future.

The planning and construction of urban 15-minute life circle is a key tool for equally allocating urban public resources and promoting sustainable development. However, it is challenging to design the public service systems toward urban living circle: how many service facilities are required, where to locate the facilities, and how to promote service equality for urban residents. A new facility location problem was proposed for public facility planning toward urban living circle. The new problem, μ CFLP, is a variant of classical capacitated facility location problem (CFLP) with constraints of maximum service radius and partial demand covering. A mixed integer linear programming model was formulated for the μCFLP and a matheustic algorithm was designed for solving this model. The model and the solution method were tested on 6 study areas. According to the Chinese city scale classification standard, 6 typical urban regions in China were selected. Then, the community health service center was taken as a service example to conduct the service facility layout planning experiment. The results show that: (1) the new model can balance the service quality, efficiency and fairness, and thus can be applied to the layout planning of public service facilities toward urban living circle. (2) In cities with low population density, the model is sensitive to the two planning parameters: service radius and coverage; and thus it is necessary to balance service quality and efficiency. While in the metropolis with high population density, it is relatively easy to meet the construction standard of 15-minute life circle. The experimental results show that the model proposed in this study has obvious advantages for the planning of urban service facilities toward the 15-minute life circle goal. First, the number of facilities need not be determined in advance. Second, the optimal layout of facilities can be explored according to the combination of coverage radius and coverage parameters.

Based on data from the 1% National Population Sample Survey 2015 and the 2014 China Migrant Population Dynamic Survey (CMDS), the paper selects four indicators to measure housing quality of the migrant population including floor area, housing facilities, construction period and living communities (urban or rural) and discusses the phenomenon about spatial differentiation of migrant populations' housing quality in 310 prefecture- and provincial-level cities in China, using GIS spatial analysis methods such as Moran's I coefficient and Getis-Ord G_i^*. Besides, we investigate the influencing factors of migrant populations' housing quality. Some conclusions can be drawn as follows: (1) Compared with the local residents, the housing quality of the migrants is not that worse. (2) The spatial distribution of housing quality of migrant population presents marked spatial differentiation on cities of different levels and scales, population sizes and geographical divisions. (3) The results of spatial autocorrelation analysis demonstrate that there is a significant positive spatial correlation in the indicators of the migrant population's housing quality on a national scale, and identify the phenomenon of their spatial clustering and the centers of such spatial clustering. (4) The housing quality is influenced by both internal factors of migrant population and external factors of in-flow cities. (5) Population, economic development and the housing market play different roles in the housing quality of migrant population.

Population migration process has an innate uncertainty with the increasing complexity of regional socioeconomic development. Bayesian model averaging (BMA) provides a feasible solution to the uncertainty of linear regression models. However, model uncertainties are seldom considered in spatial modeling. To reduce the uncertainties in migration modeling, this paper incorporates BMA approaches with spatial origin-destination (OD) models to quantify the spillover mechanism of interprovincial migration in China, 2010-2015. Specifically, we specified network dependence for migration flows and selected origin/destination's population size, gross domestic product (GDP), real wage, urbanization rate, the number of beds in health facilities per 1000 persons, the number of people over college level per 100000 persons in 2010 and migration stocks between 2005 and 2010 as well as railway travel time between provincial capitals in 2010 as explanatory variables. Among 2615 unique models based on 300000 samples using Markov chain Monte Carlo model combination (MC³), 58 models with posterior probability greater than 0.1% were chosen to estimate explanatory variables' origin effects, destination effects, and network effects. Some findings are as follows: (1) BMA model estimates are more robust and reliable. Compared with results from the single spatial origin-destination (OD) model, the widths of 90% credible interval of different explanatory variables are markedly reduced, indicating the degree of model uncertainty has been greatly decreased. (2) Regional population size, quality, and migration stocks have a significant influence on interprovincial migration processes. After model sampling, the inclusion probabilities of population size and GDP at origins, education level and migration stocks at destinations as well as distance variable are beyond 90%. (3) Network effects of most variables are statistically significant, accounting for more than 40% of their corresponding total effects. Moreover, the spillover effects of real wage, education level, and migration stocks are even greater than their corresponding origin and destination effects. (4) The impacts of most explanatory variables on interprovincial migration would be overestimated without considering uncertainties in modeling migration processes.

Using data from the national migration survey of 2018, the intentions of migrants with respect to duration of residence have been categorized into three types, namely, short-term residence, long-term residence, and permanent residence. On this basis, GIS spatial analysis and hierarchical linear modelling (HLM) have been used to examine the determinants and the spatial variation of various categories of residence intentions in 290 prefecture- and provincial-level cities of China. The results show that those with short-term and long-term residence intentions account for 60% of the total number of migrants, suggesting that bi- and multi-locational livelihood strategies are still dominant among migrants in China. It was found that there is a strong contrast between the spatial patterns for short-term residence intentions and that of permanent residence intentions. Furthermore, the short-term residence intentions are relatively high in the eastern region of the country and relatively low in the northeastern region; in contrast, the permanent residence intentions exhibit a spatial pattern completely different from that of the short-term residence intentions, and the long-term residence intentions are the highest in the central and western regions. The HLM results show that the characteristics of both the destination and the migrants at the individual level affect different categories of residence intentions. It is found that the short-term and long-term residence intentions are relatively high, and the permanent residence intentions are relatively low in the eastern and central regions, and in areas with more developed economies and high average wage levels. Moreover, for male, inter-provincial migrating, agricultural hukou status, lower educational attainments, shorter migration duration, and lower average monthly household income, are the factors conducive to short-term and long-term residence intentions; for female, intra-provincial migrating, non-agricultural hukou status, higher educational attainments, longer migration duration, and higher average monthly household income, tend to promote permanent residence intentions.