3,255 research outputs found
Effects of spatial noncommutativity on energy spectrum of a trapped Bose-Einstein condensate
In noncommutative space, we examine the problem of a noninteracting and
harmonically trapped Bose-Einstein condensate, and derive a simple analytic
expression for the effect of spatial noncommutativity on energy spectrum of the
condensate. It indicates that the ground-state energy incorporating the spatial
noncommutativity is reduced to a lower level, which depends upon the
noncommutativity parameter . The appeared gap between the
noncommutative space and commutative one for the ground-state level of the
condensate should be a signal of spatial noncommutativity.Comment: 7 pages; revtex
Discussion on Effective Approaches of Universities Fixed Assets Management
The universities fixed asset is one of important constituents of the state asset and is the material base for the universities to develop the education and enhance education quality and the scientific research level as well. Strengthening the universities fixed asset management is not only the universitie’s own development request, is also the need of organizational reform of universities education. This article embarks from the analysis of existence problems in currentuniversities fixed asset management, researches and explores the effective approaches to strengthen the universities fixed assets management. Key words: Universities, fixed assets, management, effective approaches Résumé: Les biens immobilisés des universités sont une des composants de l’actif national et la base matérielle pour les universités de développer l’éducation et élever la qualité éducative ainsi que le niveau de recherche scientifique. Le renforcement du management des biens immobilisés des universités est non seulement l’exigence du développement de l’université, mais également la demande de la réforme organisationnelle de l’éducation universitaire. L’article présent, commençant par l’analyse des problèmes existants dans la management actuel des biens immobilisés universitaires, étudie les méthodes effectives de renforcer le management dans ce domaine. Mots-Clés: universités, biens immobilisés, management, méthodes effective
Stochastic modelling of hygrothermal performance of highly insulated wood framed walls
Recent years, the majority of building codes in North America require an energy efficient envelope to improve the building energy efficiency. There are different design strategies to achieve a higher insulation level of the wood framed building envelope, such as increasing the depth of stud cavity to accommodate thicker insulation or adding an exterior insulation while keeping the depth of stud cavity unchanged. However, the highly insulated walls may lead to a higher risk of moisture problems. The deep cavity walls will reduce the temperature of the wood sheathing, which may increase the potential for condensation and mold growth. The exterior insulated walls may result in a low drying capacity of the wood sheathing if the exterior insulation has a low vapour permeance. Although hygrothermal simulations have been widely used to investigate the moisture performance of wood framed walls, the uncertainty of the input parameters may lead to discrepancies between simulation results and real performance of the walls. This paper investigates the hygrothermal performance of highly insulated wood framed walls- deep cavity wall and exterior insulated wall using a stochastic simulation approach. The uncertainties of the input parameters including the material properties, air leakage and rain leakage rates are taken into account in stochastic modelling. The mold growth risks of the walls are evaluated based on the stochastic simulation results
Metal adsorption by quasi cellulose xanthogenates derived from aquatic and terrestrial plant materials
The FTIR spectra, SEM-EDXA and copper adsorption capacities of the raw plant materials, alkali treated straws and cellulose xanthogenate derivatives of Eichhornia crassipes shoot, rape straw and corn stalk were investigated. FTIR spectra indicated that of the three plant materials, the aquatic biomass of Eichhornia crassipes shoot contained more O-H and C=O groups which accounted for the higher Cu²⁺ adsorption capacities of the raw and alkali treated plant material. SEM-EDXA indicated the incorporation of sulphur and magnesium in the cellulose xanthogenate. The Cu²⁺ adsorption capacities of the xanthogenates increased with their magnesium and sulphur contents. However more copper was adsorbed than that can be explained by exchange of copper with magnesium. Precipitation may contribute to the enhanced uptake of copper by the cellulose xanthogenate
Existence of solutions for fractional differential equations with three-point boundary conditions at resonance in
In this paper, by applying the coincidence degree theory which was first introduced by Mawhin, we obtain an existence result for the fractional three-point boundary value problems in , where the dimension of the kernel of fractional differential operator with the boundary conditions can take any value in . This is our novelty. Several examples are presented to illustrate the result
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