80 research outputs found

    Roots of Unity: Representations of Quantum Groups

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    Representations of Quantum Groups U_q (g_n), g_n any semi simple Lie algebra of rank n, are constructed from arbitrary representations of rank n-1 quantum groups for q a root of unity. Representations which have the maximal dimension and number of free parameters for irreducible representations arise as special cases.Comment: 23 page

    Status of the Superconducting Magnets for FAIR

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    Silicon microdosimetry measurements in Fast Neutron Therapy were simulated using the GEANT4 Monte Carlo toolkit. The possibility of using silicon microdosimeters for verification of Monte Carlo based treatment planning systems in hadron therapy is suggested

    Selective Oxidation of 1,2-propane Glycol to Methylglyoxal: the Preparation of Ag/ZrO2 Catalysts by Biosynthesis Methods

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    丙酮醛(MGX)是一种重要的有机合成中间体,主要用作药物中间体,也广泛用于制备农药、食品添加剂等。丙酮醛通过与甲醛、氨等反应可以制得医药中间体4-甲基咪唑,还可以通过歧化反应制得用途广泛的乳酸。近年来随着咪唑以及呋喃酮等香料需求的增加,丙酮醛的需求量也日益增加,但它的天然存在量很少,而国内丙酮醛的生产起步晚,且规模较小。另外,丙酮醛的传统制备方法中所采用的催化剂多为电解银催化剂,电解银催化剂在反应温度低于500℃时活性不够,产物中有较多副产物羟基丙酮,而在高于500℃时,银微晶在高温条件下容易快速团聚导致催化活性下降。因此探索和深入研究在低温条件下具有高催化性能的催化剂,是丙酮醛实现经济、“绿...As an important organic intermediate, methylglyoxal(MGX) is mainly used as drug intermediates, and also has important applications in agricultural pesticide, food additives and so on. MGX can react with formaldehyde and ammonia to produce imidazole, which is a kind of drug intermediates. In addition, lactic acid can be produced by disproportionation reaction of MGX. Recently, the demand for MGX in...学位:工学硕士院系专业:化学化工学院化学工程与生物工程系_工业催化学号:2062007115090

    Warm and Cold Magnetic and Mechanical Alignment Tests of LHC Short Straight Sections

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    This paper contains a summary of the results of the magnetic and mechanical alignment tests performed at CERN on the first 111 arc Short Straight Sections. These include the mechanical axis of the Cold Bore Tube at room temperature, the magnetic axis of main quadrupoles and correctors at both room and cryogenic temperature, and the field direction of the main quadrupoles. The measurements show that the quality of the assemblies is generally within the requirements for the machine

    Generalization of the Darboux transformation and generalized harmonic oscillators

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    The Darbroux transformation is generalized for time-dependent Hamiltonian systems which include a term linear in momentum and a time-dependent mass. The formalism for the NN-fold application of the transformation is also established, and these formalisms are applied for a general quadratic system (a generalized harmonic oscillator) and a quadratic system with an inverse-square interaction up to N=2. Among the new features found, it is shown, for the general quadratic system, that the shape of potential difference between the original system and the transformed system could oscillate according to a classical solution, which is related to the existence of coherent states in the system

    Representations of U_q(sl(N)) at Roots of Unity

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    The Gelfand--Zetlin basis for representations of Uq(sl(N))U_q(sl(N)) is improved to fit better the case when qq is a root of unity. The usual qq-deformed representations, as well as the nilpotent, periodic (cyclic), semi-periodic (semi-cyclic) and also some atypical representations are now described with the same formalism.Comment: 18 pages, Plain TeX, Macros harvmac.tex and epsf needed 3 figures in a uuencoded tar separate file. Some references are added. Also available at http://lapphp0.in2p3.fr/preplapp/psth/uqsln.ps.g
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