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11.
Geographical distance constitutes friction in searching for research collaborators. Taking advantage of a quasinatural experiment featured by High-Speed Railway (HSR) lines in China, this paper employs the difference-in-differences model to identify the causal impact of a substantial improvement in the intercity transportation infrastructure on collaborative innovation across cities. The data pertain to a universe of patent applications filed by Chinese universities and their citations. We find that HSR contributes to a substantial increase in the innovation quantity and quality of collaborative patenting innovation between universities and corporates. It contributes to industry collaboration by utilizing university academic disciplines in the related technology fields. Lastly, HSR facilitates universities to search for new research partners with better quality beyond the geographical boundary. 相似文献
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Gravity models with fixed coefficients have been used to explain the trade flows between countries different in income levels and separated by long distances. It is unrealistic to assume that these models can hold with the same parameters across very heterogeneous countries. This paper proposes and estimates an international trade model with variable coefficients constructed by combining Pöy-hönen's and Linnemann's gravity-based trade models via the expansion method. 相似文献
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This paper examines interprovincial migration in the People's Republic of China (PRC) during 1982–87 when China was going through economic restructuring. Chinese migration patterns bear some resemblances as well as dissimilarities with those generally observed in Western societies. In China, the age-specific migration rate does not vary much until the preretirement stage. Return to places of origin is obviously the most plausible explanation of Chinese migration patterns. In addition, a clear-cut gender gap exists, higher than that imagined in Western societies. Chinese women appear far behind Chinese men in their propensity to migrate, and the determinants of migration are quite different for Chinese women and Chinese men. 相似文献
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多年来,国内旅游业服务质量低,设施条件差,潜在市场不能及时转化为现实市场。本文分析了制约国内旅游业发展的因素和国内旅游市场的潜力,提出国内旅游业的发展构想。 相似文献
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We develop a new conceptual approach to locating inspection stations for hazardous vehicles, prevention, and compare it to the previous, punitive, philosophy of the flow-capturing location model. We implement this preventive protection philosophy with a new mixed integer program that maximizes hazard avoidance by locating a number of inspection stations to detect and remove hazardous vehicles as early in their trips as possible. We test the model's performance and analyze the spatial characteristics of solutions simulating several potential applications. Our computations demonstrate that a relaxed integer-linear program is overly demanding computationally and that a simple greedy heuristic lacks robustness. We suggest further approaches to developing more powerful and efficient solution methods. 相似文献
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ABSTRACTThe emerging problem of left-behind children has attracted mounting academic and policy attention. Prior studies primarily cast light on left-behind children’s education, health, and behavior, while their subjective well-being is much less understood yet. Based on a nationally representative sample of rural children aged 10–15 in 2014, we examine the impacts of different types of parental migration on children’s subjective well-being and how these affects vary between boys and girls. The results show that parental migration is a double-edged sword: children from both-parent migrant families report compromised life satisfaction and relationship quality compared with those in integral families, and mother-only migration significantly lowers children’s subjective health. On the flip side, father-only migration enhances children’s aspiration for attaining college, an encouraging effect that is even stronger than that of parental education and family income. These effects are heterogeneous by children’s gender: boys seem to be more susceptible to the disruptive effects of both-parent migration; mother-only migration effectively promotes girls’ educational aspiration while father-only migration promotes boys’. This study portrays a comprehensive image of left-behind children. Relaxation of hukou restriction, equal access to education, and revitalization of rural economies are imperative to improve the well-being of left-behind children.Abbreviations: LBC: Left-behing children; SWB: subjective well-being 相似文献
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参与性收藏是近些年来西方一些博物馆基于"记录今天"理念而新兴的收藏。从收藏的角度,参与性收藏是博物馆通过主题策划与活动设计,组织社会公众携相关物件加入博物馆收藏,并成为馆藏的一部分,以参与的方式将公众与博物馆物品、内容、语境联系起来,其主题多与当下社会发展、生产生活方式变迁等相关,方式上突破传统收藏相对单一、封闭的模式,具有流动、共享、多元、充满活力的特点。从藏品内涵上,具有"记录今天""关注日常""突出藏品与人的关联"等特点,丰富了博物馆藏品的内涵与外延,这是对传统收藏的丰富与推进。在参与性收藏的视野下,航海类博物馆收藏具有更深广的创新空间。 相似文献
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正It is just the dawn,but the sheepfolds have already begun to move restlessly.Sunlight makes its way in.Tashi Tsedan and Redan open the sheepfolds one after another.Flocks of sheep suddenly gush out like an influx of water from an opened gate.These two herdsmen from Jirong Village in Drik Town of Gampa County are fulfilling their duty grazing these flocks of Gampa sheep,a well-known breed of Tibetan sheep. 相似文献