The air passenger transport network system is an important agent of social and economic connections between cities. Studying on the airline network structure and providing optimization strategies can improve the airline industry sustainability evolution. As basic building blocks of broad networks, the concept of network motifs is cited in this paper to apply to the structural characteristic analysis of the passenger airline network. The ENUMERATE SUBGRAPHS (G, k) algorithm is used to identify the motifs and anti-motifs of the passenger airline network in China. A total of 37 airline companies are subjected to motif identification and exploring the structural and functional characteristics of the airline networks corresponding to different motifs. These 37 airline companies are classified according to the motif concentration curves into three development stages, which include mono-centric divergence companies at the low-level development stage, transitional companies at the intermediate development stage, and multi-centric and hierarchical companies at the advanced development stage. Finally, we found that adjusting the number of proper network motifs is useful to optimize the overall structure of airline networks, which is profitable for air transport sustainable development.
Although industrial agglomeration and specialization have been studied for more than 100 years, it is still a controversial field. In the era of big data, it is of great significance to study industrial agglomeration and regional specialization by using firm-level data. Based on 3,053,024 pieces of firm-level big data, the spatial evolution and spatial patterns of industrial agglomeration and specialization of 9 major industries in the Yangtze River Delta, China were revealed. Results show that: (1) the degree of industrial agglomeration is highly related to industrial attributes; industries which are directly related to production tend to be geographically concentrated, while industries that serve for production tend to be spatially dispersed; (2) the evolution characteristics and trajectories of industrial agglomeration vary by industries: wholesale and retail trade and real estate are becoming more spatially dispersed; information industries, leasing and commercial services, scientific research and polytechnic services, as well as finance are experiencing continuous spatial agglomeration; construction and manufacturing show a tendency of transfer from spatial agglomeration to spatial dispersion; (3) since 1990, most industries in the Yangtze River Delta have formed distinct spatial patterns of industrial specialization. Most core cities have experienced obvious deindustrialization processes; and high-end industries are clustering to the three biggest core cities of Shanghai, Nanjing, and Hangzhou.
For knowing the present status and development trends of unmanned aerial vehicle (UAV) in China, the paper uses patent analysis method to carry out quantitative and qualitative research based on technology life cycle theory. The research concludes that China's UAV technology has been in the period of growth stage with large development potential and an increasingly number of technology fields are springing up. But some problems, such as low percentage of invention patent, single type of innovation subject, weakness of innovation ability and imbalance in development of different region, still exist. In order to promote the equalization, standardization and internationalization of UAV industry, the paper puts forward some recommendations.
The 28 cities in the upper, middle and lower reaches of the Yangtze River can be regarded as an epitome of the cities in eastern, central and western China. Therefore, the low-carbon development level of the cities along the Yangtze River objectively reflects the overall development degree and regional difference of Chinese low-carbon cities. On the basis of analyzing and understanding the connotation of low-carbon cities, this thesis sets up the appraisal index system of low-carbon cities, puts forward the concept of low-carbon index, and conducts a cluster analysis and appraisal to the low-carbon indexes of 28 cities along the Yangtze River through a spatio-temporal path.
According to the current situation of agricultural and the theory of industrial design, the views using the method of industrial design concept, technology, to promote the development of agricultural machinery product innovation, transformation were proposed. The agricultural machinery product development strategy and the effective ways based on industrial design innovation technology were studied. It has a guiding role in development of agricultural products with innovative and development of agricultural machinery manufacturing.
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