Over the last decades, Chinese enterprises have emerged as the most active builders and investors in worldwide hydropower development. These international economic activities result from China's progressive reforms in both economic and political arenas. Chinese construction of overseas hydropower stations includes foreign aid, foreign trade and foreign investments. This article analyzes the spatial-temporal evolution pattern and mechanism of Chinese-constructed hydropower stations abroad, and reveals the major influencing factors since the year 2000. The major research findings are presented as follows. Firstly, at the global scale, the numbers, ways of construction, and spatial patterns of Chinese-constructed hydropower stations are varied at different stages. Secondly, the state has played a leading role in the construction of Chinese overseas hydropower stations in carrying out its strategy in the past four stages: (a) China directly designated the departments to aiding between 1955 and 1981. (b) The state controlled foreign-aid capital outflows, and encouraged state-owned enterprises to sign contracts with foreign companies, while the projects were supported financially by Western banks from 1982 to 2000. (c) The state has decentralized its power to transgovernmental policy networks and stimulated state-owned enterprises to compete in investment and contracting projects, while the enterprises sought financial support from Chinese banks, such as the Export-Import Bank of China between 2001 and 2009. (d) Based on national initiatives such as the Belt and Road, the state designed a Chinese solution to pursue common prosperity and development and integrated state-owned enterprises to adopt the strategy of associated competition, while the projects began to be supported financially by multilateral institutions promoted by China after 2010. And thirdly, the impact factors on the Chinese-constructed overseas hydropower stations since 2000 are the relations of political and economic diplomacy between China and the host countries, the proportion of the population below the poverty line, the condition of electricity supply, the amount of received aid, the level of industrial growth and market base of the host country.

Pollution-intensive industries can promote regional economic growth. They also pose a great threat to regional environmental system. Polluting industries may be protected by regional policies due to their contribution to economic growth, but the local governments may also impose some restrictions and controls on them by means of the environmental regulations. From 1980 to 2014, the development period of pollution-intensive industries in China can be divided into three stages: slow growth, rapid expansion, and structural transition. The spatial distribution of pollution industries changed from dispersal to concentration and then to decentralization. The central provinces such as Henan, Hubei, Hunan and Jiangxi have become the major areas of pollution-intensive industries transfer. By establishing the regional attribute model and the regional-industrial interaction model, this paper quantitatively analyzes the influence of environmental regulation and local protection on the spatial distribution of the pollution-intensive industries in China during 2001-2014, and tests whether there exist the pollution haven hypothesis and the Porter hypothesis. Environmental regulation and local protection are important factors that influence the spatial distribution of polluting industries, but there exists obvious industrial and regional heterogeneity. Industries with a high degree of pollution are more likely to be affected by environmental regulations, and industries with high share of state ownership are more likely to be protected by local governments. Environmental regulation and local protection are two opposite forces, which have the effect of mutual inhibition and weakening. The roles of environmental regulation and local protection in coastal and inland areas have significant differences. The effect of environmental regulation is more prominent in eastern China, while that of local protection in central and western China is more significant. In order to prevent the central and western regions from being the "pollution haven" and to realize the win-win between economic growth and environmental protection, a differentiated policy should be formulated according to local conditions and the development stage.

As one of the significant economic development tools, the transport investment's comprehensive economic effects considering spatiotemporal heterogeneity have attracted attention from different levels of government and private development sectors. Much of current literature, however, lacks a perspective of spatial differences and spatial linkages, and the relevant economic influential paths still need to be further examined. To fill this understanding gap, the paper attempts to understand the economic growth and spatial aggregation effects of transport investment and the potential influential paths based on a joint estimation by the spatial panel and structural equation modeling, respectively. The results of the study indicate that: (1) The significant economic growth, as well as economic impacts of spatial aggregation of transport investment are observed, but in general the effects would decrease after controlling the spatial autocorrelation issue; (2) The economic effects of the investment in transport sectors have considerable spatial and temporal differences. For areas with high level of urbanization and economic performance, the economic effect of transport investment is much higher and more significant. To some extent, transport investment in these areas exerts a more significant impact of spatial aggregation. The temporal effects show that from 1997 to 2015 the transport investment can reinforce the economic performance and the level of spatial aggregation. Also, the transport investments at the previous stage, in general, have a greater effect on economic growth, and would lead to a spatial decentralization trend of economic activities; (3) Transport investment can promote economic growth by direct and a variety of indirect pathways. The indirect pathways can affect the investments on the related industries, labor growth, and urbanization. These findings would provide some policy implications for the decision-making of transport investment in urban China.

Spatio-temporal differentiation of regional economic growth viewed from inner functional structure in a typical area is a hot research topic in economic geography in recent years. Based on the core-peripheral theory and the creative methodology framework, we identified the Beijing-Tianjin-Hebei (BTH) region into the first central group, the secondary central group and peripheral group, and then displayed the evolution of spatio-temporal differentiation of regional economic growth and disparities in the region from 1994 to 2014 using some indexes which can represent regional economic growth and economic level respectively supported by some statistical indictors and geostatistical analysis methods. The results indicated that there was a positive correlation between accelerating economic growth and widening economic disparities, and the inter-group differences become the main portion of the widening disparities after 2001 in the BTH region. The evolution of spatial differentiation can be divided into four stages according to the characteristics of overall regional economic growth and spatial distribution. In the first stage, economic growth dispersed from the core to peripheral areas. The differences include the intra-group differences, the inter-group differences, and the differences decreased. During the second stage, the economic growth slowed down and clustered in core areas, which resulted in an increase in economic disparities. In the third stage, the overall economic growth rate of the BTH region rose but fluctuated, and the high-speed economic growing regions were mainly distributed surrounding the core. In the last stage, the average economic growth rate declined and the high-speed economic growing regions returned to the core. In summary, the peripheral areas have not yet received the steady and robust driving force emitted from the core. After that, some factors influencing economic growth of three types of groups were estimated in a constructive multiple linear regression model. The coefficient estimates of variables indicated a significant gradient which reflected the gradient of economic structure and economic level among the three groups.