28,142 research outputs found

    Young measures in a nonlocal phase transition problem

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    A nonlocal variational problem modelling phase transitions is studied in the framework of Young measures. The existence of global minimisers among functions with internal layers on an infinite tube is proved by combining a weak convergence result for Young measures and the principle of concentration-compactness. The regularity of such global minimisers is discussed, and the nonlocal variational problem is also considered on asymptotic tubes

    Solving Dirac equations on a 3D lattice with inverse Hamiltonian and spectral methods

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    A new method to solve the Dirac equation on a 3D lattice is proposed, in which the variational collapse problem is avoided by the inverse Hamiltonian method and the fermion doubling problem is avoided by performing spatial derivatives in momentum space with the help of the discrete Fourier transform, i.e., the spectral method. This method is demonstrated in solving the Dirac equation for a given spherical potential in 3D lattice space. In comparison with the results obtained by the shooting method, the differences in single particle energy are smaller than 10410^{-4}~MeV, and the densities are almost identical, which demonstrates the high accuracy of the present method. The results obtained by applying this method without any modification to solve the Dirac equations for an axial deformed, non-axial deformed, and octupole deformed potential are provided and discussed.Comment: 18 pages, 6 figure

    Adaptive Neural Network Feedforward Control for Dynamically Substructured Systems

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    (c) 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works

    Socially engaged architecture in a Chinese rural village: Xihe Village Community Centre, 2014

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    This paper attempts to explore the social production of architecture in contemporary Chinese rural villages through a case study on the Community Centre in Xihe Village. This community project, designed and built in 2014, exemplifies a lesser-known type of Chinese architectural practice engaging in a local and specific context, which suddenly gave participation a dramatic image in current breakneck Chinese rural-urban transition of large scale and rapid speed. By looking at this highly specific case through a detailed description and critical evaluation, this paper takes this participatory architectural project as the very first critical example of the socially-engaged architecture in China; as presenting an alternative architecture of resistance in response to the top-down guiding principle ‘Construction of A New Socialist Countryside’ launched by the government in 2005. Source material was collected through fieldwork in the village, including observational study, photographic documentation, and intensive formal and informal interviews with practitioners, authorities, and villagers. The analysis emphasizes the social process and consequences of different stages of this building, in order to explore hidden potentials and methodologies tailoring the architectural design and construction to the site-specificity. The social consequence of the building process is much more important than the object produced. By investigating the architectural version within a broader framework combining anthropology and activism, the paper attempts to introduce a more socially resilient way of making architecture in the current Chinese rural-urban transition. On the one hand it addresses the contingencies in working with underprivileged village communities in inner rural China, which have scarce resources and fragile identities; on the other hand it cuts through the surface of rural vernacular China to expose the undercurrent of silent issues in architecture that constitute the indigenous, the everyday, resistance, transition, and resilience

    A rapid staining-assisted wood sampling method for PCR-based detection of pine wood nematode Bursaphelenchus xylophilus in Pinus massoniana wood tissue

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    For reasons of unequal distribution of more than one nematode species in wood, and limited availability of wood samples required for the PCR-based method for detecting pinewood nematodes in wood tissue of Pinus massoniana, a rapid staining-assisted wood sampling method aiding PCR-based detection of the pine wood nematode Bursaphelenchus xylophilus (Bx) in small wood samples of P. massoniana was developed in this study. This comprised a series of new techniques: sampling, mass estimations of nematodes using staining techniques, and lowest limit Bx nematode mass determination for PCR detection. The procedure was undertaken on three adjoining 5-mg wood cross-sections, of 0.5 · 0.5 · 0.015 cm dimension, that were cut from a wood sample of 0.5 · 0.5 · 0.5 cm initially, then the larger wood sample was stained by acid fuchsin, from which two 5-mg wood cross-sections (that adjoined the three 5-mg wood cross-sections, mentioned above) were cut. Nematode-staining-spots (NSSs) in each of the two stained sections were counted under a microscope at 100· magnification. If there were eight or more NSSs present, the adjoining three sections were used for PCR assays. The B. xylophilus – specific amplicon of 403 bp (DQ855275) was generated by PCR assay from 100.00% of 5-mg wood cross-sections that contained more than eight Bx NSSs by the PCR assay. The entire sampling procedure took only 10 min indicating that it is suitable for the fast estimation of nematode numbers in the wood of P. massonina as the prelimary sample selections for other more expensive Bx-detection methods such as PCR assay