Synthesis of double silylene-bridged binuclear titanium complexes and their use as catalysts for ethylene polymerization

Five new double silylene-bridged binuclear titanium complexes were synthesized by the reaction of RCpTiCl₃ and Li₂[μ,μ-(SiMe₂)₂ (C₅H₃)₂] in toluene. They were all well characterized. These complexes activated with methylaluminoxane (MAO) are highly active catalysts (2.33 × 10⁵ g PE/mol Cat h) for the polymerization of ethylene even at low Al/Ti (Al/Ti = 300). The molecular weight distribution of the polymer indicates broad or bimodal (MWD = 26.76) distribution.     

Investigation on the barrier height and inhomogeneity of nickel silicide Schottky

The apparent Schottky barrier height (SBH) of the nickel silicide Schottky contacts annealed at different temperatures was investigated based on temperature dependence of I-V characteristic. Thermionic emission-diffusion (TED) theory, single Gaussian and double Gaussian models were employed to fit I-V experimental data. It is found the single Gaussian and double Gaussian SB distribution model can give a very good fit to the I-V characteristic of apparent SBH for different annealing temperatures. Also, the apparent SBH and the leakage current increase with annealing temperatures under reverse voltage. In addition, the homogeneity of interfaces for the samples annealed at temperatures of 500 and 600 °C is much better than that of the samples annealed at temperatures of 400, 700, and 800 °C. This may result from the phase transformation of nickel silicide due to the different annealing temperatures and from the low Schottky barrier (SB) patches.     

Corrigendum to the paper ``Adjoining an Order Unit to a Matrix Ordered Space'

An error has been detected (and also corrected) in Theorem 2.8 of the paper entitled “Adjoining an Order Unit to a Matrix Ordered Space” (Positivity, (2005)9: 207–223; DOI ). Accordingly, some of the results of the paper have been modified. Also, a notion of C*-matricially, Riesz normed spaces has been introduced.     

Enhanced transmission of electromagnetic waves through metamaterials

This paper reviews our recent experimental and simulation results regarding the electromagnetic wave transmission through three configurations of sandwiching structures of metamaterials: a metallic mesh sandwiched between two identical layers composed of split rings, metallic fractals, and fractal slits, respectively. We observed the enhanced transmission of the waves through these three types of sandwiching composites with respect to the opaque metallic mesh. The locations of the transmission peaks in the spectrum are associated closely with the band characteristics of the sandwiching layer by appearing either on the left- or the right-hand side of its band. PACS 41.20.Jb; 42.70.Qs; 78.20.-e; 42.25.Bs; 47.53.+n     

醌蛋白——猪肾二胺氧化酶的提取和性质

新鲜猪肾匀浆后，经热处理、盐析、羟基磷灰石和ＤＥＡＥ－纤维素柱层析等纯化步骤，二胺氧化酶的收得率为２３．９％，纯化倍数为４２５．该酶进行凝胶电泳后，经氨基黑、酶活性和ＮＢＴ溶液染色分别得到相对应的蛋白质、酶活性及醌辅基谱带．该酶可与腐胺、尸胺、己二胺、组胺等底物作用，释放出Ｈ２Ｏ２，当底物为腐胺时，最适浓度为５ｍｍｏｌＬ－１，Ｋｍ值为０．５ｍｍｏｌＬ－１，最适ｐＨ为７．０，最适温度为４０°Ｃ．在非酶系统中，该酶可与ＮＢＴ溶液反应，呈现紫色，并随时间延长而加深．经ＳＤＳ板状不连续聚丙烯酰胺凝胶电泳，得该酶亚基分子量为８．３×１０４．     

Chemoselective Catalytic Hydrogenation of α,β-Unsaturated Ketones and α,β-Unsaturated Carboxylic Esters

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The Micro-Theory of Ultra-Short Pulse Propagating in Nonlinear Fiber

The modified quantum nonlinear Schrodinger equation of ultra-short pulse propagating in fiber is derived using dispersion relation and the Hamiltonian of the transmission system. The derived equation is solved with linearization approximation, and modulation instability is analyzed. The equation is also solved with Hartree approximation. The results indicate that pulse power, loss and self-steeping effect change the critical frequency, the maximum gain and the gain spectrum range, but the third order dispersion has no effect on modulation instability. The expectation value of optical field is average of a set of modified classical solitons, and higher order terms change the amplitude, pulse position and phase of soliton.     

LB膜中螺吡喃材料的光学性质研究

利用ＬＢ技术制备螺吡喃有序分子膜，研究了气液界面上螺吡喃材料在不同成份和不同ｐＨ值亚相时的成膜行为，着重研究了螺吡喃在ＬＢ膜这个特殊介质环境中不同于溶液的光致变色机理和光学性质