Cross-region innovation is widely recognized as an important source of the long-term regional innovation capacity.In the recent past,a growing number of studies has investigated the network structure and mechanisms of...Cross-region innovation is widely recognized as an important source of the long-term regional innovation capacity.In the recent past,a growing number of studies has investigated the network structure and mechanisms of cross-region innovation collaboration in various contexts.However,existing research mainly focuses on physical effects,such as geographical distance and high-speed railway connections.These studies ignore the intangible drivers in a changing environment,the more digitalized economy and the increasingly solidified innovation network structure.Thus,the focus of this study is on estimating determinants of innovation networks,especially on intangible drivers,which have been largely neglected so far.Using city-level data of Chinese patents(excluding Hong Kong,Macao,and Taiwan Province of China),we trace innovation networks across Chinese cities over a long period of time.By integrating a measure on Information and Communications Technology(ICT)development gap and network structural effects into the general proximity framework,this paper explores the changing mechanisms of Chinese innovation networks from a new perspective.The results show that the structure of cross-region innovation networks has changed in China.As mechanisms behind this development,the results confirm the increasingly important role of intangible drivers in Chinese inter-city innovation collaboration when controlling for effects of physical proximity,such as geographical distance.Since digitalization and coordinated development are the mainstream trends in China and other developing countries,these countries'inter-city innovation collaboration patterns will witness dramatic changes under the influence of intangible drivers.展开更多
It has been suggested that the importance of network architecture to species diversity and stability should be based on preference networks(comprised of niche differentiations),rather than observational networks,becau...It has been suggested that the importance of network architecture to species diversity and stability should be based on preference networks(comprised of niche differentiations),rather than observational networks,because species abundance may significantly affect interaction frequencies.Considering that resource abundance is usually greater for herbivores than parasites,we hypothesize that the abundance effect is stronger for parasitic than herbivory interactions.To test this hypothesis,we collected 80 quantitative observational networks including 34 herbivorous and 46 parasitic networks from the published literature,and derived preference networks by removing the effects of species abundance.We then determined the network nestedness using both weighted NODF and spectral radius.We also determined species degree distribution,interaction evenness,weighted connectance and robustness for both observational and preference networks.The observational networks(including both herbivory and parasitic networks)were more nested judged by weighted NODF than spectral radius.Preference networks were less nested for parasitic than herbivory networks in terms of both weighted NODF and spectral radius,possibly because removing the abundance effect increased interaction evenness.These trends indicate that the abundance effect on network nestedness is stronger for parasitic than herbivory networks.Weighted connectance and robustness were greater in most preference networks than observational networks,indicating that preference networks may have high network stability and community persistence compared with observational ones.The data indicate that future network analyses should not only address the structural difference between mutualistic and antagonistic interactions,but also between herbivory and parasitic interactions.展开更多
基金Under the auspices of China Scholarship Council。
文摘Cross-region innovation is widely recognized as an important source of the long-term regional innovation capacity.In the recent past,a growing number of studies has investigated the network structure and mechanisms of cross-region innovation collaboration in various contexts.However,existing research mainly focuses on physical effects,such as geographical distance and high-speed railway connections.These studies ignore the intangible drivers in a changing environment,the more digitalized economy and the increasingly solidified innovation network structure.Thus,the focus of this study is on estimating determinants of innovation networks,especially on intangible drivers,which have been largely neglected so far.Using city-level data of Chinese patents(excluding Hong Kong,Macao,and Taiwan Province of China),we trace innovation networks across Chinese cities over a long period of time.By integrating a measure on Information and Communications Technology(ICT)development gap and network structural effects into the general proximity framework,this paper explores the changing mechanisms of Chinese innovation networks from a new perspective.The results show that the structure of cross-region innovation networks has changed in China.As mechanisms behind this development,the results confirm the increasingly important role of intangible drivers in Chinese inter-city innovation collaboration when controlling for effects of physical proximity,such as geographical distance.Since digitalization and coordinated development are the mainstream trends in China and other developing countries,these countries'inter-city innovation collaboration patterns will witness dramatic changes under the influence of intangible drivers.
基金This study was financially supported by National Natural Science Foundation of China(grant nos.32071605,31530007 and 31870417).
文摘It has been suggested that the importance of network architecture to species diversity and stability should be based on preference networks(comprised of niche differentiations),rather than observational networks,because species abundance may significantly affect interaction frequencies.Considering that resource abundance is usually greater for herbivores than parasites,we hypothesize that the abundance effect is stronger for parasitic than herbivory interactions.To test this hypothesis,we collected 80 quantitative observational networks including 34 herbivorous and 46 parasitic networks from the published literature,and derived preference networks by removing the effects of species abundance.We then determined the network nestedness using both weighted NODF and spectral radius.We also determined species degree distribution,interaction evenness,weighted connectance and robustness for both observational and preference networks.The observational networks(including both herbivory and parasitic networks)were more nested judged by weighted NODF than spectral radius.Preference networks were less nested for parasitic than herbivory networks in terms of both weighted NODF and spectral radius,possibly because removing the abundance effect increased interaction evenness.These trends indicate that the abundance effect on network nestedness is stronger for parasitic than herbivory networks.Weighted connectance and robustness were greater in most preference networks than observational networks,indicating that preference networks may have high network stability and community persistence compared with observational ones.The data indicate that future network analyses should not only address the structural difference between mutualistic and antagonistic interactions,but also between herbivory and parasitic interactions.
