46,911 research outputs found

    The Architecture of a Novel Weighted Network: Knowledge Network

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    Networked structure emerged from a wide range of fields such as biological systems, World Wide Web and technological infrastructure. A deeply insight into the topological complexity of these networks has been gained. Some works start to pay attention to the weighted network, like the world-wide airport network and the collaboration network, where links are not binary, but have intensities. Here, we construct a novel knowledge network, through which we take the first step to uncover the topological structure of the knowledge system. Furthermore, the network is extended to the weighted one by assigning weights to the edges. Thus, we also investigate the relationship between the intensity of edges and the topological structure. These results provide a novel description to understand the hierarchies and organizational principles in knowledge system, and the interaction between the intensity of edges and topological structure. This system also provides a good paradigm to study weighted networks.Comment: 5 figures 11 page

    Adoption of e-commerce by the agri-food sector in China: the case of Minyu e-commerce company

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    In recent years, increasing numbers of smallholders in developing countries such as China have begun to sell agricultural products directly to consumers via online shops using a third-party trade platform. It is increasingly clear that e-commerce has become a new and effective way to help smallholders gain access to the market. The investigation of agricultural e-commerce practices has a significant role in helping to understand the development of the agri-food sector in China. This teaching case provides an example of adopting e-commerce in the interaction and trading activities between participants in the food sector through a typical agricultural products e-commerce company in China, Minyu E-commerce. Particularly, the case analyzes the business model evolution through the ecosystem life cycle at the company. This case can be used to teach graduate/postgraduate students in agricultural business, MBA and executive programmes about the agri-food e-commerce business model

    A model of orthotopic murine bladder (MBT-2) tumor implants

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    We produced a model of orthotopic transplantation in C3H/He mice by transplanting MBT-2 cells. A single-cell suspension of 1.0 × 105 MBT-2 cells/0.02 ml was successfully injected into the submucosal layer of the bladder, with an incidence of 100% after four experimental weeks. Inoculated tumor grew expansively into the bladder cavity from the bladder submucosa and invaded the serosa and the surrounding tissue. This model more closely resembled the characteristics of human bladder tumor when compared to other bladder cancer models. The results of the histological observation, electron microscopic examination and DNA content analysis by flow cytometry showed that the transplanted carcinoma maintained the biologic characteristics of the primary tumo

    First-principles study of phenyl ethylene oligomers as current-switch

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    We use a self-consistent method to study the distinct current-switch of 2′2^{'}-amino-4-ethynylphenyl-4'-ethynylphenyl-5'-nitro-1-benzenethiol, from the first-principles calculations. The numerical results are in accord with the early experiment [Reed et al., Sci. Am. \textbf{282}, 86 (2000)]. To further investigate the transport mechanism, we calculate the switching behavior of p-terphenyl with the rotations of the middle ring as well. We also study the effect of hydrogen atom substituting one ending sulfur atom on the transport and find that the asymmetry of I-V curves appears and the switch effect still lies in both the positive and negative bias range.Comment: 6 pages, 6 figure
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