过氧化物交联聚乙烯的力学性能研究

采用过氧化物交联方法研究了交联聚乙烯的工艺、配方和性能，探讨了过氧化物用量对材料力学性能及凝胶含量的影响，以及炭黑、氧化锌、抗氧剂对材料性能的影响。结果表明，过氧化物交联聚乙烯的力学性能有一定的提高，随着DCP含量的增加，交联PE的凝胶含量提高，而随着凝胶含量的提高，交联PE的拉伸强度提高，断裂伸长率下降；炭黑对材料有一定的补强作用，氧化锌的加入有助于交联反应和拉伸强度的提高。     

Synthesis of exfoliated PP/LDH nanocomposites via melt‐intercalation: Structure,thermal properties,and photo‐oxidative behavior in comparison with PP/MMT nanocomposites

Exfoliated polypropylene (PP)/layered double hydroxide (LDH) nanocomposites have been successfully synthesized via melt‐intercalation. Their structure, thermal properties, and photo‐oxidative behavior have been characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMA), X‐ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectrum. TGA and DMA data show that the PP/LDH nanocomposites have enhanced thermal stability compared with virgin PP and corresponding PP/montmorillonites (MMT) nanocomposites, especially in high temperature range during the thermal decomposition of the samples. XPS and FTIR results give positive evidence that the photo‐oxidation mechanism of PP in the PP/LDH materials is not modified compared with that of virgin PP. However, photo‐oxidation rate of PP/LDH materials is much lower than that of PP and PP/MMT samples, indicating that the PP/LDH nanocomposites have better UV‐stability. POLYM. ENG. SCI. 46:1153–1159, 2006. © 2006 Society of Plastics Engineers     

低温快烧无铅精陶釉的研制

采用高温熔融法制备了适用精陶的低温无铅熔块，并应用热膨胀分析仪、SEM等方法研究了精陶釉的光泽度、热稳定性、热膨胀系数等性能。结果表明：采用Li2O，SrO，B2O3等复合熔剂，可以制备出光泽度高，热稳定好，坯釉膨胀系数匹配，结合良好，适于低温快烧工艺的无铅精陶釉。     

Building Technical Trading System with Genetic Programming: A New Method to Test the Efficiency of Chinese Stock Markets

Testing whether technical trading rules can beat buy-and-hold strategy is a common approach to study the efficiency of stock markets. Noticing that the common approach of evaluating popular technical trading rules’ profitability would result in the biases of data snooping and incomplete test, we build a technical trading system with genetic programming to test the efficiency of Chinese stock markets. This system takes historical prices and volumes as inputs, randomly generates treelike structured technical trading rules composed of basic functions, and optimizes the rules using genetic programming according to the inputs. Using daily prices and volumes of Shenzhen Stock Exchange 100 index from January 2, 2004 to March 12, 2010, we find out that the optimal technical trading rules generated by our technical trading system have statistically significant out-of-sample excess returns compared with buy-and-hold strategy considering realistic transaction costs. Therefore, we conclude that Chinese stock markets have not achieved weak-form efficiency.     

Phtocrosslinking of polyethylene for production of thin wall insulated wire

A photocrosslinking precess for polyethylene and its industrial irradiation apparatus has recently been developed and used successfully in the manufactre of thin wall crosslinked polyethylene-insulated wires. Polyethylene (PE) resin with the desired amounts of additives, such as photoinitiator, multifunctional crosslinker, and antioxidant is mixe homogeneously. The amixture of PE is granulated, and then extruded on a conductor wire. The coated PE layer in the melt is subsequently irradiated in a specially designed UV irradiation apparatus for 5 to 10 s. The studies show that the photocrosslinked PE-insulation high voltage television wires produced by this new technique possess excellent electrical and mchanical properties and much lower operating cost compared with wires produced by the electron beam crosslinking technique.     

复杂制品注塑成型模拟分析

应用CAE软件MoldflowPlasticsInsight4.1的充模、保压、冷却、翘曲等分析模块,对汽车尾门饰件注塑成型过程进行CAE分析,研究了浇口位置、工艺参数等对制品性能的影响。最后,基于模拟结果分析了制品翘曲的主要原因,为模具设计及注塑工艺的确定提供参考。     

我国氢能产业发展和氢资源探讨

分析了我国氢能产业近期发展情况,我国氢能产业正步入快速发展机遇期。指出氢能是21世纪最具发展潜力的一种清洁二次能源,具有"清洁、高效、安全、可持续"四大特点,被誉为未来世界能源架构的核心。重点讨论了我国氢资源和绿色氢气制备问题,指出目前实际使用的氢气包括"灰氢""蓝氢"和"绿氢"三大类,显然"灰氢"不可取,"蓝氢"可以用,"废氢"可回收,"绿氢"是方向。讨论了加快氢能系统建设,建立发展氢气存储和运输系统及加氢站基础设施建设等问题。未来,我国氢能产业发展潜力巨大,但是在下决心大力发展氢能产业时,需要高度注意目前存在的实际情况和困难,要防范一系列的产业风险,做到有序发展,稳中有进,才能实施氢能产业的可持续发展。     

纳米二氧化钛的杀菌性能测试

采用新工艺制备出具有光催化性的纳米二氧化钛。为了验证其杀菌性，以工业循环冷却水中的异养菌为实验对象进行杀菌实验，结果表明：自制纳米二氧化钛具有良好的杀菌性，杀菌率可达99．2％，而且可以回收，循环使用，产品有广阔的应用前景。     

分光光度法测定工业碳酸锶中氯化物

采用目视比浊法测定工业碳酸锶中的氯化物，若溶液有色，准确定量非常困难。在溶样时加入氧化剂，利用分光光度计进行比浊。研究了在氧化剂存在下，样品的溶解、过滤对结果的影响，添加氧化剂对体系稳定性的影响，建立了用分光光度计进行比浊测定氯化物的方法，方法具有良好的线性关系，回收率在101％-106％，相对标准偏差在1．15％-3．65％，结果准确、快速，满足了生产对氯化物含量定量的要求。     

Preparation,characterization, and adsorption properties for metal ions of a novel chelating resin containing sulfoxide and diethylene glycol

A novel chelating resin containing sulfoxide and diethylene glycol, poly{4‐vinylbenzyl‐[2‐2‐(hydroxyethyl)ethoxyl]sulfoxide} (PVESO) was synthesized using chloromethylated polystyrene (PS‐Cl) as material. Its structure was characterized by elemental analysis, infrared spectra, and scanning electron microscopy (SEM). The adsorption capacities of the resin for Hg²⁺, Ag⁺, Cu²⁺, Zn²⁺, and Pb²⁺ at various pH values were determined. The maximum adsorption capacities for Hg²⁺ and Ag⁺ were 1.56 and 0.75 mmol g^?1 respectively. The resin had high selectivity for Hg²⁺ and Ag⁺ over the pH range 1.0–7.0. The adsorption capacities for Hg²⁺ and Ag⁺ under competitive condition were also determined by batch experiment method. In addition, the adsorption kinetics of the resin towards Hg²⁺ at different temperatures was also investigated. The results showed that the adsorption rate was governed by film diffusion at 20°C and 25°C, by particle diffusion at 30°C and 35°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6054–6059, 2006