高分子金属配合物用于合成碳酸二甲酯的催化性能

研究了以二氧化硅负载聚丙烯腈-丙烯酰胺-金属(PAN-AM-M)配合物为催化剂，在环氧氯丙烷存在下，由甲醇和二氧化碳直接合成碳酸二甲酯的反应活性。考察了反应条件的影响。结果表明，PAN-AM-Zn表现出较高活性，合成碳酸二甲酯的最佳反应条件为：甲醇与环氧氯丙烷的原料配比为4：1，反应温度130℃，催化剂用量2％(反应物料质量百分数)。     

C2C型拍卖网站模式及发展策略

从C 2C型拍卖网站角度出发,对其进行了介绍,并结合了我国目前C 2C拍卖网站的概况进行了分析;最后指出了拍卖网站应以用户为核心,提出了虚拟社群的经营发展策略。     

角毛壳菌产纤维素酶条件的研究

对角毛壳菌（Chaetomium cupreum）产纤维素酶的发酵条件进行了研究．结果表明：Mendels培养基适于角毛壳菌产纤维素酶，CMC酶活可达到15．7U，β-葡萄糖苷酶活达到了15．8U，滤纸酶活达到12、1U．最佳产酶碳源是微结晶纤维素．发酵156h是角毛壳菌产滤纸酶活的最佳时间，达到了14．4U，发酵180h是角毛壳菌产CMC酶活和β-葡萄捷节酶活的最佳时间，酶活可分别达到37．6U和38、4U．     

Natural frequencies of functionally graded plates by a meshless method

We use the global collocation method, the first and the third-order shear deformation plate theories, the Mori–Tanaka technique to homogenize material properties, and approximate the trial solution with multiquadric radial basis functions to analyze free vibrations of functionally graded plates. Frequencies computed by the present method are found to agree well with those from the analytical solution of Vel and Batra, and the numerical solution of Qian et al. based on the meshless local Petrov–Galerkin formulation.     

Fabrication of nanoscaled silica layer on the surfaces of submicron SiO2-Ag core-shell spheres

A two-step silica deposition process, including prefunctionalization with poly(vinylpyrrolidone) and the following silica deposition, has been used to fabricate silica layer on the surface of nanoscaled silver shell. The influencing parameters of silica coating process were optimized to prevent the precoated silver nanoparticles from desquamating from silica spheres, finally to obtain mono-dispersed silica spheres with silver and silica multilayer films. The resulted silica layer was dense and uniform, its thickness was controllable in the range of 20–50 nm. Such coated silica layer can provide improved thermal stability of the SiO₂-Ag core-shell structural spheres.     

Effect of annealing on the characteristics of Au layers grown on the high-temperature deposited Ni50Fe50 layers

80 nm-thick Ni₅₀Fe₅₀ layers were sputter-deposited on glass substrates at 400 °C and then Au layers were sputter-deposited on the Ni₅₀Fe₅₀ layers. The Au/Ni₅₀Fe₅₀ bilayer films were annealed in a vacuum of 5×10⁻⁴ Pa from 250 to 450 °C for 30 min or 90 min. The characteristics of the Au layers were studied by Auger electron spectroscopy, field emission scanning electron microscopy, X-ray diffraction and a four-point probe technique. When the annealing temperature reaches 450 °C, Fe and Ni atoms diffuse markedly into the Au layer and the Fe content is more than the Ni content. When the annealing temperature is lower than 450 °C, the grain size of the Au layers does not change markedly with annealing temperature. However, as the annealing temperature reaches 450 °C, the annealing promotes the grain growth of the Au layer. As the annealing temperature exceeds 300 °C, the resistivity of the bilayer films increases with increasing annealing temperature. The diffusion of Fe and Ni atoms into the Au layer results in an increase in the resistivity of the annealed bilayer film. Large numbers of Fe and Ni atoms diffusing into the Au layer of the annealed Au/Ni₅₀Fe₅₀ bilayer film lead to a significant decrease in the lattice constant of the Au layer.     

钛、镍材在氯碱工业中的应用

介绍了用离子膜电解槽生产烧碱具有产品质量高、烧碱含盐量低、原料及能耗少、环境污染小等特点.我国目前在建的烧碱厂和各大烧碱厂扩建的新产能用离子膜法生产烧碱的有近60家.钛、镍设备在离子膜烧碱生产装置中的主要应用部位有阳极系的阳极液槽、氯气洗涤塔,淡盐水系统的脱氯塔淡盐水分配器、仪表、冷却器,次氯酸钠系统的冷却器、吸收塔、分离器,氯气系统的湿氯冷却器,盐水系统的液面计,除害系统的换热器、除害风机,以及加料泵、浓碱泵和蒸发器等.预计从2005年至2010年每年新增离子膜生产装置约106t(烧碱产量),需要钛板2 350 t、钛网400t、镍板和镍网300～400 t;每年需修复的金属隔膜槽4×105t(烧碱产量),需要钛板225 t、钛网1 105 t、钛-铜复合棒3 310t.     

可逆式双机架冷轧轧机系统中卷径的测量及计算

本文介绍了轧钢厂砹机架可逆冷轧轧机控制系统对卷径的测量和计算方法，该方法控制精度比较高，较好的满足系统控制的要求。     

新型软开关电力高频开关整流电源

本文讨论了一种电力操作电源用高频开关充电电源模块的设计。该模块采用了一种简单的零电压零电流开关(ZVZCS)的全桥PWM变换电路拓扑。与其他ZVZCS全桥PWM变换电路相比,这种变换器的电路拓扑结构很简单,通过适当的控制方式及合适的参数选择,这种变换器可以在很宽的负载变化范围内以软开关方式高效率地工作。文中对这种变换器的工作原理、工作过程进行了较详细的理论分析,并根据分析过程中的数学描述对电路的有关参数设计给予了说明。最后通过仿真并用-6kW样机实验验证了所讨论的变换器工作原理的正确性及实用上的可行性。     

独立调压调频单相正弦波变频电源的一种新型控制策略的研究

重复控制方法具有良好的稳态输出特性和鲁棒性能,尤其是在非线性负载系统中,它能在很大程度上消除输出波形的谐波成分,因而重复控制方法在逆变电源中的应用备受关注。但重复控制方法也有动态响应速度较慢的问题,根据本设计的具体要求,本文提出了一种基于重复控制和数字PID控制的新型控制策略,并在Matlab/Simulink软件环境下建立了独立调压、调频的单相正弦波变频电源的闭环控制系统的仿真模型。实验结果表明,该控制方法是可行、有效的。