Transnational technology transfer network in China:Spatial dynamics and its determinants

Patent transfer has been regarded as an important channel for the nations and regions to acquire external technology,and also a direct research object to depict the relationship between supply and demand of technology flow.Therefore,based on traceable patent transfer data,this article has established a dual-pipeline theoretical framework of transnational-domestic technology transfer from the interaction of the global and local(glocal)perspective,and combines social networks,GIS spatial analysis as well as spatial econometric model to discover the spatial evolution of China’s transnational technology channels and its determinant factors.It is found that:(1)The spatial heterogeneity of the overall network is significant while gradually weakened over time.(2)The eastward shift of the core cities involved in transnational technology channels is accelerating,from the hubs in North America(New York Bay Area,Silicon Valley,Caribbean offshore financial center,etc.)and West Europe(London offshore financial center etc.)to East Asia(Tokyo and Seoul)and Southeast Asia(Singapore),which illustrates China has decreased reliance on the technology from the USA and West Europe.(3)The four major innovation clusters:Beijing-Tianjin-Hebei region(Beijing as the hub),Yangtze River Delta(Shanghai as the hub),The Greater Bay Area(Shenzhen and Hong Kong as the hubs)and north Taiwan(Taipei and Hsinchu as the hubs),are regarded as global technology innovation hubs and China’s distribution centers in transnational technology flow.Among those,Chinese Hong Kong’s betweenness role of technology is strengthened due to linkage of transnational corporations and their branches,and low tax coverage of offshore finance,thus becoming the top city for technology transfer.Meanwhile,Chinese Taiwan’s core position is diminishing.(4)The breadth,intensity,and closeness of domestic technology transfer are conducive to the expansion of transnational technology import channels.Additionally,local economic level has positive effect on transnational technology transfer channels while technology strength and external economic linkage have multifaceted influences.

Risk field assessment of longwall working face by the double-sided roof cutting along the gob

In order to study the mechanism of the dual side roof cutting technology on the composite disaster of gas and coal spontaneous combustion in goaf,a model for the evolution of porosity and permeability in the dual side roof cutting working face was constructed.The location of the occurrence of the compound disaster of gas explosion and coal spontaneous combustion under the double-sided roof cutting mode was studied,and the sensitivity of the evolution pattern of the compound disaster area to the amount of air supply and gas gush was summarized.The results indicate that the top cutting pressure relief technology significantly reduces the permeability of porous media,and the sensitivity of the goaf on the intake side to airflow disturbances is significantly reduced.As the volume of air supply increases,the distance between the gas explosion risk area and the coal spontaneous combustion risk area gradually decreases,and the probability of composite disaster areas is 0.The increase of air supply and gas emission makes the gas concentration in the middle and deep goaf increase in an exponential function,and the width of the gas explosion risk area increases gradually.When the outflow reaches 40 m^(3)/min,there is no composite disaster zone,indicating that the rapid increase in outflow inhibits the occurrence of composite disasters.