均分散TiO2纳米晶的制备及应用研究进展

介绍了不同晶形TiO2纳米晶的制备、应用;对TiO2纳米晶的合成方法以及相关材料的应用进展,尤其是均分散TiO2纳米晶的制备技术进行了综述。     

Pb2+ binding by polyaspartyl polymers and their application to Pb2+ removal from glycyrrhizin

Polyaspartate is an excellent Pb²⁺‐binding agent in comparison with some polyaspartamide derivatives with different side chains, in that it possesses a higher Pb²⁺ uptake and a lower Pb²⁺ equilibrium concentration. Equilibrium sorption data for Pb²⁺ on polyaspartate can be well fitted with the Freundlich and Langmuir models. Experimental results show that a crosslinked polyaspartate hydrogel is superior to poly(acrylic acid)‐based resins and polystyrene‐based chelating resins. IR spectra and X‐ray photoelectron spectra reveal that the polyaspartate hydrogel binds Pb²⁺ by both an ion‐exchange mechanism and a chelating mechanism. The polyaspartate hydrogel is also an effective agent for the removal of Pb²⁺ from glycyrrhizin. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2215–2220, 2005     

提高硫酸生产用钒催化剂性能的技术措施与效果

针对国产的硫酸生产用钒催化剂普遍存在的反应活性欠稳定、颗粒强度偏低、催化剂床层阻力偏大等问题，采取了对载体硅藻土进行共再浆水选处理、煅烧处理、热浓硫酸处理;晨添加剂中加入稀有元素，提高钾钒比，优化中和条件；采用专利技术成型，成品采用立式煅烧等技术措施，提高了钒催化剂的性能。改进后的钒催化剂不易粉化，低温型钒催化剂的活性明显提高，起燃温度可降至350℃，390℃以下的活性明显优于宽温型的，宽温型钒催化剂在390－450℃的活性更为优异。     

优化技术在原油管输调度中的应用

以甬沪宁原油管网为例,说明调度优化系统将数学规划模型和仿真模型2种调度方法完美结合,首先采用数学规划模型计算出最优解或可行的满意解,然后将结果导入仿真模型进行模拟,修正数学模型近似或忽略的因素.主要描述混合整数线性规划技术以及仿真技术在原油管输调度中的应用及应用的初步效果.     

Poly(3‐chlorothiophene) films prepared by the direct electrochemical oxidation of 3‐chlorothiophene in mixed electrolytes of boron trifluoride diethyl etherate and sulfuric acid

3‐Chlorothiophene (CT) was electrochemically polymerized in mixed electrolytes of a boron trifluoride diethyl etherate solution containing 0–20% (by volume) sulfuric acid. The oxidation potentials of the monomer in these media were measured to be only 1.06–1.31 V (vs Ag/AgCl). These values were much lower than that of CT in acetonitrile and 0.1 mol/L (Bu)₄NBF₄ (1.92 V vs Ag/AgCl). Poly(3‐chlorothiophene) (PCT) films with conductivities of 0.1–2 S cm^?1 were obtained. The structure, morphology, and electrochemical behavior of the PCT films also were investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 502–509, 2003     

橡胶注射过程中压力变化的研究

对橡胶注射过程中的压力变化进行了理论与实验研究。充模流动模型的压力、能量控制方程分别为：选用高斯方法求解总体有限元方程。实验与计算分析对比证明．本文选用的数学模型和计算方法所得结果与实测结果基本吻合、该模型可用以代替大量的实验，对橡胶充模过程进行模拟，并用Ｇｒａｐｈｅｒ软件对数值结果进行处理，以图表直观地表达出各种因素对充模过程的影响。     

Surface morphology control of immiscible polymer-blend thin films

The effects of the molecular weights (molecular weight of polystyrene, M_w,PS, varying from 2.9 to 129 k) on the surface morphologies of spin-coated and annealed polystyrene/poly (methyl methacrylate) (PS/PMMA=50/50, w/w) blend films were investigated by atomic force microscopy and X-ray photoelectron spectroscopy. For the spin-coated films, when the M_w,PS varied from 2.9 to 129 k, three different kinds of surface morphologies (a nanophase-separated morphology, a PMMA cellular or network-like morphology whose meshes filled with PS, a sea-island like morphology) were observed and their formation mechanisms are discussed, respectively. Upon annealing, two different morphology-evolution processes were observed. It is found that a upper PS-rich phase layer is formed when M_w,PS<4 k, and this behavior is mainly attributed to the low interfacial tension between PS and PMMA component. When M_w,PS>4 k, the PS-rich phase forms droplets on top of the PMMA-rich phase layer which wets the SiO_x substrate. These results indicate that the surface morphology of the polymer blend films can be controlled by the polymer molecular weight and annealing conditions.     

基于环境选择和配对选择的多目标粒子群算法

为了使多目标粒子群算法中种群粒子能够快速地收敛于怕累托最优边界,针对标准多目标粒子群算法中缺乏粒子评价标准以及种群个体历史最优值位置和全局最优值位置选择问题,提出了一种基于环境选择和配对选择策略的多目标粒子群算法.该算法在每次迭代时,采用SPEA2中的环境选择和配对选择策略及适应度值计算方法,以此来提高种群粒子之间的信息交换力度,减少标准多目标粒子群算法中大量的随机性,使种群粒子能够更快速地收敛于怕累托最优边界.经典测试函数的仿真实验结果表明,在标准多目标粒子群算法中运用SPEA2的环境选择、配对选择策略和适应度值计算方法,能够使种群粒子更快速地收敛于帕累托最优边界,验证了算法改进的可行性和有效性.     

Water‐absorptive blend fibers of copoly(acrylic acid–acrylamide) and poly(vinyl alcohol)

Through the addition of N‐hydroxymethyl acrylamide as a potential crosslinker, water‐absorptive blend fibers of copoly(acrylic acid–acrylamide) and poly(vinyl alcohol) with three‐dimensional network structures were prepared with heat‐crosslinking technology after fiber formation. Fourier transform infrared, scanning electron microscopy, dynamic mechanical analysis, and thermogravimetry were used to analyze the structures and properties of the fibers. The tensile behavior and absorbent capacities of the fibers were also studied. The results showed that there were lots of chemical crosslinking points in the fibers, the compatibility of copoly(acrylic acid–acrylamide) and poly(vinyl alcohol) was perfect, and the tensile properties of the fibers could be improved effectively through stretching in a vapor bath. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3353–3357, 2006     

Nonisothermal crystallization behavior of glass‐bead‐filled polypropylene

The effects of the glass‐bead content and size on the nonisothermal crystallization behavior of polypropylene (PP)/glass‐bead blends were studied with differential scanning calorimetry. The degree of crystallinity decreased with the addition of glass bead, and the crystallization temperature of the blends was marginally higher than that of pure PP at various cooling rates. Furthermore, the half‐time for crystallization decreased with an increase in the glass‐bead content or particle size, implying the nucleating role of the glass beads. The nonisothermal crystallization data were analyzed with the methods of Avrami, Ozawa, and Mo. The validity of various kinetic models for the nonisothermal crystallization process of PP/glass‐bead blends was examined. The approach developed by Mo successfully described the nonisothermal crystallization behavior of PP and PP/glass‐bead blends. Finally, the activation energy for the nonisothermal crystallization of pure PP and PP/glass‐bead blends based on the Kissinger method was evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2026–2033, 2006