This study employs panel data from 284 Chinese cities(2011-2023)to investigate the impact of digital-real economy integration on urban green and low-carbon transformation.The empirical analysis reveals a distinct east...This study employs panel data from 284 Chinese cities(2011-2023)to investigate the impact of digital-real economy integration on urban green and low-carbon transformation.The empirical analysis reveals a distinct east-west gradient in both integration and transformation levels,with eastern cities leading the trend,alongside a consistent nationwide increase.We find that digital-real economy integration significantly advances urban green and low-carbon development and generates positive spatial spillover effects.Mechanism analyses show that integration facilitates this transformation by enhancing factor allocation efficiency,improving energy utilization efficiency,and upgrading the industrial structure.The effects are more pronounced in eastern cities,non-old industrial bases,and resource-dependent cities.Policy implications include formulating digital strategies to spur industrial upgrading,investing in technology and talent,promoting clean energy,and supporting green industries to foster high-quality,low-carbon urban development.展开更多
This study makes a comparison between China and foreign countries about the ＂supportive shipping policies＂ in the period of late Qing Dynasty, from 1840 to 1911. After the first opium war, China was forced to open t...This study makes a comparison between China and foreign countries about the ＂supportive shipping policies＂ in the period of late Qing Dynasty, from 1840 to 1911. After the first opium war, China was forced to open the gate of the old oriental country to the world. As more treaty ports opened, the import and export of goods increased the growing trade that brought about the increased demands of shipping transportation. In the same period, British, France, America, Germany and Japan governing bodies instated various kinds of laws, regulations and other policies encouraging their national shipping companies to grab shipping market share. As a result, foreign steamship companies monopolized Chinese shipping market quickly. Faced with this situation, in 1872, the China Merchants＇ Steam Navigation Company was the fisst steamship company of China to be formed. It was a government-supervised and merchant-managed company, and the Qing Dynasty government took a series of measures to support it under the fierce competition, these measures were different from foreign countries＇.展开更多
Composite scarf repair is applied in airplane load-bearing structures. But the repairs would have different boundary supports in real situation, such as simply support, clamped support and flexible support. With diffe...Composite scarf repair is applied in airplane load-bearing structures. But the repairs would have different boundary supports in real situation, such as simply support, clamped support and flexible support. With different boundary supports, the bonded scarf repair of composite structures could have diverse damage mechanisms and responses. This work intends to study the impact performance of different boundaries. For this purpose, experimental tests were carried out on the specimens with two sides support and four sides support. The impact load and deflection was monitored during the tests. After impact being finished, the meso-mechanism was studied by means of micro-cracks of the side section for two sides support condition and cross section for the four sides support condition. It was possible to conclude that the four sides boundary possess higher impact resistance maximum loads, lower displacements and lower extent load dropping. In terms of damage modes, as the impact energy relative low 12 J and 16 J, the central position of scarf bonding zone for two sides support appears adhesive cohesive failure and adhesive-composite interface failure. When the energy increases to 20 J, the dominated damage of two sides support moves down to the feathered tip. For four sides support, the critical energy level is 25 J, under which the scarf adhesive begins to be damaged.展开更多
基金funded by the China Agricultural University 2115 Talent Project.
文摘This study employs panel data from 284 Chinese cities(2011-2023)to investigate the impact of digital-real economy integration on urban green and low-carbon transformation.The empirical analysis reveals a distinct east-west gradient in both integration and transformation levels,with eastern cities leading the trend,alongside a consistent nationwide increase.We find that digital-real economy integration significantly advances urban green and low-carbon development and generates positive spatial spillover effects.Mechanism analyses show that integration facilitates this transformation by enhancing factor allocation efficiency,improving energy utilization efficiency,and upgrading the industrial structure.The effects are more pronounced in eastern cities,non-old industrial bases,and resource-dependent cities.Policy implications include formulating digital strategies to spur industrial upgrading,investing in technology and talent,promoting clean energy,and supporting green industries to foster high-quality,low-carbon urban development.
文摘This study makes a comparison between China and foreign countries about the ＂supportive shipping policies＂ in the period of late Qing Dynasty, from 1840 to 1911. After the first opium war, China was forced to open the gate of the old oriental country to the world. As more treaty ports opened, the import and export of goods increased the growing trade that brought about the increased demands of shipping transportation. In the same period, British, France, America, Germany and Japan governing bodies instated various kinds of laws, regulations and other policies encouraging their national shipping companies to grab shipping market share. As a result, foreign steamship companies monopolized Chinese shipping market quickly. Faced with this situation, in 1872, the China Merchants＇ Steam Navigation Company was the fisst steamship company of China to be formed. It was a government-supervised and merchant-managed company, and the Qing Dynasty government took a series of measures to support it under the fierce competition, these measures were different from foreign countries＇.
文摘Composite scarf repair is applied in airplane load-bearing structures. But the repairs would have different boundary supports in real situation, such as simply support, clamped support and flexible support. With different boundary supports, the bonded scarf repair of composite structures could have diverse damage mechanisms and responses. This work intends to study the impact performance of different boundaries. For this purpose, experimental tests were carried out on the specimens with two sides support and four sides support. The impact load and deflection was monitored during the tests. After impact being finished, the meso-mechanism was studied by means of micro-cracks of the side section for two sides support condition and cross section for the four sides support condition. It was possible to conclude that the four sides boundary possess higher impact resistance maximum loads, lower displacements and lower extent load dropping. In terms of damage modes, as the impact energy relative low 12 J and 16 J, the central position of scarf bonding zone for two sides support appears adhesive cohesive failure and adhesive-composite interface failure. When the energy increases to 20 J, the dominated damage of two sides support moves down to the feathered tip. For four sides support, the critical energy level is 25 J, under which the scarf adhesive begins to be damaged.
