连续照明时成像对比度与气象条件的关系

 通过同轴激光连续照明成像模型分析了大气后向散射对成像对比度的影响，得出了考虑散射因素时成像对比度的计算公式。基于不同气象条件下大气粒子散射特点，讨论了霾和雾两种不同天气时成像对比度随照明距离的变化规律，并与实验结果进行了对比，计算结果与实验吻合较好。     

PURIFICATION OF L-METHIONINE AND N-ACETYL-D-METHIONINE FROM THE MIXTURE OF ENZYMATICALLY DEACYLATED N-ACETYL-DL-METHIONINE

1. INTRODUCTION Methionine, namely 2-amido-4-thiomethyl butyric acid with a structure of CH3SCH2CH2CHCOOH, is one of the essential amino acids and has two natural enantionmers, D and L-methionine. The mixture of L- and D-isomers can be used as analeptics or nutritive additives to maintain the equilibrium of amino acids of feed [1,2]. L-methionine can release active methyl and accelerate the synthesis of choline, which further speeds up the conversion of the lipid accumulated in liv…     

Microwave Synthesis, Characterization and DNA-binding Properties of a New Cobalt（ Ⅱ ） Complex with 2,6-Bis（benzimidazol-2-yl）pyridine

A new cobalt(Ⅱ) complex with tridentate ligand 2, 6-bis (benzimidazol-2-yl)pyridine has been synthesized by microwave irradiation method and characterized by elemental analysis,electrochemical and spectral methods. The binding of the complex with calf thymus DNA has also been investigated by absorption and fluorescence spectra.     

Isolation of 2-Chloro-5-methylpyridine from its Isomer 2-Chloro-3-methylpyridine by Formation of its Copper(II) Complex

2-Chloro-5-methylpyridine is an important intermediate for the preparation of biological active compounds, especially insecticides1, e.g. imidacloprid2, and is usually manufac- tured from 3-methylpyridine N-oxide. However, the manufacturing process also forms the by-products: 3-methylpyridine and its isomer 2-chloro-3-methylpyridine3. The pro- perties of the isomers are similar, it is difficult to separate by ordinary methods, such as distillation. Scheme 1 79.4%13.6%5.2%NClCH3NCH3ClNC…     

Baker＇s Yeast Mediated Reduction of Optically Active Diketone

Baker‘s yeast mediated reduction of optically active diketone is described. The two keto groups are efficiently differentiated and the ee value of the recovered material is considerably raised. It affords highly optically active key intermediates efficiently for the synthesis of natural polyhydroxylated agarofuran products.     

高速色散补偿系统中喇曼放大器性能研究

利用喇曼放大器的非线性偏微分耦合方程组,对带喇曼放大器的色散补偿系统进行了仿真,并与传统的仿真方法进行了比较.结果表明:在色散完全补偿系统中,当传输速率较高时,忽略色散后的传统仿真方法的结果,与采用色散补偿技术后使整个系统色散为零的仿真结果有一定偏差,此时不能忽略色散的作用.还对前补偿系统和后补偿系统进行了研究,利用Q值性能判别法,分别得到了信号光脉冲的最佳占空比和最佳脉冲阶数.     

Thermal Oxidation of Polyethylene Films Containing Dispersed Copper and Amine Antioxidant

Thermal oxidation of polyethylene filled with dispersed copper and containing an amine antioxidant was studied. The concentration ranges in which the catalytic effect of the metal on the polymer oxidation or the stabilizing effect of the antioxidant prevails were determined. Under certain conditions, dispersed copper enhances the stabilizing effect of the antioxidant.     

EXTENSION OF MULTIPLIERS AND INJECTIVE HILBERT MODULES

The author studies the problem whether a multiplier of a hereditary C^*-subalgebra B of a C^*-algebra A can be extended to a multiplier of A. One related problem is the Hahn-Banach extension theorem for Hilbert modules over C^*-algebras. It is shown that every self-dual Hilbert module over W^*-algebra or an injective C^*-algebra is injective.     

花丝内插物强化竖直管内凝结换热的实验研究

1前言大空隙率多孔体管内插物-绕花丝内插物，被认为是强化管内凝结换热的最有效途径之一[1]．但以往的研究，由于实验雷诺数范围较小，蒸汽速度较低，要正确全面评价其性能尚显不够。本文在原有工作的基础上，进一步完善了实验系统，改进了测试手段，扩大了实验雷诺数范围，并测试了其阻力性能，对花丝内插物强化管内凝结换热进行了较深入全面的实验研究，以全面评价花丝内插物对管内凝结换热的强化效果。2实验系统本文实验系统如图1所示。实验段是一个竖直套管冷凝器，如图2所示．本试验研究蒸汽完全凝结时的传热。凝结水流量采用容积法计…     

关于三商映射

三商映射是完备映射和开映射的共同推广。本文综述三商映射的理论，论术这三商映射，开映射，紧覆盖映射，诱导完备映之间的一些转换关系，提出了几个供进一步研究的问题。