532 research outputs found

    From colonial port to socialist metropolis : imperialist legacies and the making of 'New Dalian'

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    This article explores the transformation of the city of Dalian from a colonial export port to an industrialized core city of the Japanese wartime empire and finally a model production city of the People's Republic of China. These shifts in the economic and political function of the city also resulted in complex identity issues for Dalian's urban residents. Dalian's rise reminds that there were trajectories of urban development and modernity in China which were different from that of Shanghai. Dalian provides an important, local view of the transition from empire to nation in this strategically important part of Manchuria

    Gateway to Manchuria:: The Port City of Dalian under Japanese, Russian and Chinese Control, 1898–1950

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    Dieser Aufsatz untersucht die Transformation der Stadt Dalian (Russ. Dal’nii, Jap. Dairen) von einem Exporthafen der von kolonialen EinflĂŒssen geprĂ€gten Mandschurei zu einer Industriemetropole des japanischen Imperiums wĂ€hrend der Kriegszeit und schließlich zu einer Modellstadt fĂŒr industrielle Produktion der Volksrepublik China. Dalian ist ein besonders eindrĂŒckliches lokales Beispiel fĂŒr den Übergang vom Imperium zur Nation in dem strategisch wichtigen Gebiet der Mandschurei. Der Beitrag analysiert, wie die aufeinander folgenden Regime die Stadt definierten und sich die Stadt in wechselnden geographischen und ökonomischen Kontexten verĂ€nderte, von einem weit entfernten russischen Handelsposten ĂŒber ein Zentrum des Exports wĂ€hrend der japanischen Kolonialzeit und einer japanischen ProduktionsstĂ€tte wĂ€hrend des Krieges zu einer sowjetisch besetzten Zone und bis zu einem integralen Teil der Volksrepublik China. Diese fortwĂ€hrenden Verschiebungen ĂŒbten einen großen Einfluss auf die lokale Gesellschaft aus, insbesondere auf die chinesische Bevölkerungsmehrheit der Stadt. Der Wandel der wirtschaftlichen und politischen Funktionen der Stadt verĂ€nderte nicht nur ihre physische Gestalt, sondern auch die komplexe, im steten Wechsel begriffene IdentitĂ€t ihrer Bewohner. Als eine instant city oder „neue Stadt“ an den Grenzen des Imperiums, des militĂ€rischen Schutzgebiets und der Nation war die urbane IdentitĂ€t Dalians dynamischer als in anderen StĂ€dten Nordostasiens. Die Geschichte dieser Stadt rĂŒckt bislang von der historischen Forschung vernachlĂ€ssigte Aspekte der großen Narrative von Entkolonialisierung, Revolution und Nationalstaatsbildung, die gemeinhin mit der Region in Verbindung gebracht werden, ins Zentrum der Analyse

    Half-Metallic Ferromagnetism in the Heusler Compound Co2_2FeSi revealed by Resistivity, Magnetoresistance, and Anomalous Hall Effect measurements

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    We present electrical transport data for single-crystalline Co2_2FeSi which provide clear-cut evidence that this Heusler compound is truly a half-metallic ferromagnet, i.e. it possesses perfect spin-polarization. More specifically, the temperature dependence of ρ\rho is governed by electron scattering off magnons which are thermally excited over a sizeable gap Δ≈100K\Delta\approx 100 K (∌9meV\sim 9 meV) separating the electronic majority states at the Fermi level from the unoccupied minority states. As a consequence, electron-magnon scattering is only relevant at T≳ΔT\gtrsim\Delta but freezes out at lower temperatures, i.e., the spin-polarization of the electrons at the Fermi level remains practically perfect for Tâ‰ČΔT\lesssim\Delta. The gapped magnon population has a decisive influence on the magnetoresistance and the anomalous Hall effect (AHE): i) The magnetoresistance changes its sign at T∌100KT\sim 100 K, ii) the anomalous Hall coefficient is strongly temperature dependent at T≳100KT\gtrsim 100 K and compatible with Berry phase related and/or side-jump electronic deflection, whereas it is practically temperature-independent at lower temperatures

    Molecular double core-hole electron spectroscopy for chemical analysis

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    We explore the potential of double core hole electron spectroscopy for chemical analysis in terms of x-ray two-photon photoelectron spectroscopy (XTPPS). The creation of deep single and double core vacancies induces significant reorganization of valence electrons. The corresponding relaxation energies and the interatomic relaxation energies are evaluated by CASSCF calculations. We propose a method how to experimentally extract these quantities by the measurement of single and double core-hole ionization potentials (IPs and DIPs). The influence of the chemical environment on these DIPs is also discussed for states with two holes at the same atomic site and states with two holes at two different atomic sites. Electron density difference between the ground and double core-hole states clearly shows the relaxations accompanying the double core-hole ionization. The effect is also compared with the sensitivity of single core hole ionization potentials (IPs) arising in single core hole electron spectroscopy. We have demonstrated the method for a representative set of small molecules LiF, BeO, BF, CO, N2, C2H2, C2H4, C2H6, CO2 and N2O. The scalar relativistic effect on IPs and on DIPs are briefly addressed.Comment: 35 pages, 6 figures. To appear in J. Chem. Phys

    MATILDA.FT, a Mesoscale Simulation Package for Inhomogeneous Soft Matter

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    In this paper we announce the public release of a massively-parallel, GPU-accelerated software, which is the first to combine both coarse-grained molecular dynamics and field-theoretical simulations in one simulation package. MATILDA.FT (Mesoscale, Accelerated, Theoretically-Informed, Langevin, Dissipative particle dynamics, and Field Theory) was designed from the ground-up to run on CUDA-enabled GPUs, with the Thrust library acceleration, enabling it to harness the possibility of massive parallelism to efficiently simulate systems on a mesoscopic scale. MATILDA.FT is a versatile software, enabling the users to use either Langevin dynamics or Field Theory to model their systems - all within the same software. It has been used to model a variety of systems, from polymer solutions, and nanoparticle-polymer interfaces, to coarse-grained peptide models, and liquid crystals. MATILDA.FT is written in CUDA/C++ and is object oriented, making its source-code easy to understand and extend. The software comes with dedicated post-processing and analysis tools, as well as the detailed documentation and relevant examples. Below, we present an overview of currently available features. We explain in detail the logic of parallel algorithms and methods. We provide necessary theoretical background, and present examples of recent research projects which utilized MATILDA.FT as the simulation engine. We also demonstrate how the code can be easily extended, and present the plan for the future development. The source code, along with the documentation, additional tools and examples can be found on GitHub repository.Comment: 18 pages, 9 figure

    Boltzmann equation and hydrodynamic fluctuations

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    We apply the method of invariant manifolds to derive equations of generalized hydrodynamics from the linearized Boltzmann equation and determine exact transport coefficients, obeying Green-Kubo formulas. Numerical calculations are performed in the special case of Maxwell molecules. We investigate, through the comparison with experimental data and former approaches, the spectrum of density fluctuations and address the regime of finite Knudsen numbers and finite frequencies hydrodynamics.Comment: This is a more detailed version of a related paper: I.V. Karlin, M. Colangeli, M. Kroger, PRL 100 (2008) 214503, arXiv:0801.2932. It contains comparison between predictions and experiment, in particular. 11 pages, 6 figures, 2 table

    Structural characterization of vanadium oxide catalysts supported on nanostructured silica SBA-15 using X-ray absorption spectroscopy

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    The local structure of vanadium oxide supported on nanostructured SiO2 (VxOy/SBA-15) was investigated by in situ X-ray absorption spectroscopy (XAS). Because the number of potential parameters in XAS data analysis often exceeds the number of "independent" parameters, evaluating the reliability and significance of a particular fitting procedure is mandatory. The number of independent parameters (Nyquist) may not be sufficient. Hence, in addition to the number of independent parameters, a novel approach to evaluate the significance of structural fitting parameters in XAS data analysis is introduced. Three samples with different V loadings (i.e. 2.7 wt %, 5.4 wt %, and 10.8 wt %) were employed. Thermal treatment in air at 623 K resulted in characteristic structural changes of the V oxide species. Independent of the V loading, the local structure around V centers in dehydrated VxOy/SBA-15 corresponded to an ordered arrangement of adjacent V2O7 units. Moreover, the V2O7 units were found to persist under selective oxidation reaction conditions

    Opposing function of MYBBP1A in proliferation and migration of head and neck squamous cell carcinoma cells

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    BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is one of the most prevalent and lethal cancers worldwide and mortality mostly results from loco-regional recurrence and metastasis. Despite its significance, our knowledge on molecular, cellular and environmental mechanisms that drive disease pathogenesis remains largely elusive, and there are limited therapeutic options, with only negligible clinical benefit. METHODS: We applied global gene expression profiling with samples derived from a recently established mouse model for oral cancer recurrence and identified a list of genes with differential expression between primary and recurrent tumors. RESULTS: One differentially expressed gene codes for Myb-binding protein 1a (MYBBP1A), which is known as a transcriptional co-regulator that physically interacts with nuclear transcription factors, such as NFÎșB and p53. We confirmed significantly reduced MYBBP1A protein levels on tissue sections of recurrent mouse tumors compared to primary tumors by immunohistochemistry, and found aberrant MYBBP1A protein levels also in tumor samples of HNSCC patients. Interestingly, silencing of MYBBP1A expression in murine SCC7 and in human HNSCC cell lines elicited increased migration but decreased cell growth. CONCLUSION: We provide experimental evidence that MYBBP1A is an important molecular switch in the regulation of tumor cell proliferation versus migration in HNSCC and it will be a major challenge for the future to proof the concept whether regulation MYBBP1A expression and/or function could serve as a novel option for anti-cancer therapy
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