21,857 research outputs found
Adoption of e-commerce by the agri-food sector in China: the case of Minyu e-commerce company
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
Fully gapped superconducting state in Au2Pb: a natural candidate for topological superconductor
We measured the ultra-low-temperature specific heat and thermal conductivity
of AuPb single crystal, a possible three-dimensional Dirac semimetal with a
superconducting transition temperature 1.05 K. The electronic
specific heat can be fitted by a two-band s-wave model, which gives the gap
amplitudes (0)/ = 1.38 and (0)/ = 5.25.
From the thermal conductivity measurements, a negligible residual linear term
in zero field and a slow field dependence of at low
field are obtained. These results suggest that AuPb has a fully gapped
superconducting state in the bulk, which is a necessary condition for
topological superconductor if AuPb is indeed one.Comment: 6 pages, 4 figure
A link prediction-based method for identifying potential cooperation partners: A case study on four journals of informetrics
© 2018 Portland International Conference on Management of Engineering and Technology, Inc. (PICMET). Global academic exchange and cooperation have become an increasing trend in both academia and industry, but how to quickly and effectively identify potential partners is becoming an urgent problem. This paper proposes a link prediction-based model to help researchers identify partners from a large collection of academic articles in a given technological area. We initially construct a co-authorship network, and take a series of indices based on network and similarity of researchers into consideration. A fitting model of link prediction is then established, in which logistic regression analysis is involved. An empirical study on four journals of informetrics is conducted to demonstrate the reliability of the proposed method
Vortices, circumfluence, symmetry groups and Darboux transformations of the (2+1)-dimensional Euler equation
The Euler equation (EE) is one of the basic equations in many physical fields
such as fluids, plasmas, condensed matter, astrophysics, oceanic and
atmospheric dynamics. A symmetry group theorem of the (2+1)-dimensional EE is
obtained via a simple direct method which is thus utilized to find \em exact
analytical \rm vortex and circumfluence solutions. A weak Darboux
transformation theorem of the (2+1)-dimensional EE can be obtained for \em
arbitrary spectral parameter \rm from the general symmetry group theorem. \rm
Possible applications of the vortex and circumfluence solutions to tropical
cyclones, especially Hurricane Katrina 2005, are demonstrated.Comment: 25 pages, 9 figure
Two-dimensional Superconductivity from Dimerization of Atomically Ordered AuTe2Se4/3 Cubes
The emergent phenomena such as superconductivity and topological phase
transitions can be observed in strict two-dimensional crystalline matters.
Artificial interfaces and one atomic thickness layers are typical 2D materials
of this kind. Although having 2D characters, most bulky layered compounds,
however, do not possess these striking properties. Here, we report the 2D
superconductivity in bulky AuTe2Se4/3,where the reduction in dimensionality is
achieved through inducing the elongated covalent Te-Te bonds. The
atomic-resolution images reveal that the Au, Te and Se are atomically ordered
in a cube, among which are Te-Te bonds of 3.18 A and 3.28 A. The
superconductivity at 2.85 K is discovered, which is unraveled to be the
quasi-2D nature owing to the BKT topological transition. The nesting of nearly
parallel Fermi sheets could give rise to strong electron-phonon coupling. It is
proposed to further depleting the thickness could result in more
topologically-related phenomena.Comment: 16 pages, 5 figures,To be published in Nature Communication
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