绢云母紫外线屏蔽剂在聚丙烯中的应用

研究了绢云母基质紫外线屏蔽剂对GC-1的老化性能和力学性能的影响。氙灯模拟太阳强制光老化研究表明，添加了GC-1可明显改善PP的耐老化性能，机械强度保留率明显提高。其中，拉伸强度保留率由不足50％提高到70％，弯曲强度保留率由79％提高到90％，冲击强度保留率提高一倍。同时GC-1还可以改善PP的机械性能，增韧能力超过常规填料。GC-1在PP中的添加量以20％为最佳。     

基于深度自编码的局部增强属性网络表示学习

基于深度自编码器的网络表示,可以捕获高度非线性的网络结构,但当链接稀疏时学到的表示不够准确。针对这一问题,提出一种基于深度自编码的局部增强属性网络表示学习模型,以提高表示学习的准确度。该模型首先利用链接与属性特征,采用多个深度自编码器,学习保持网络拓扑结构及属性特征的低维网络表示。之后,基于节点间近邻结构及属性相似性,对学出的低维网络表示进行节点约束,实现网络局部结构增强,达到最大程度保持原始结构信息及属性特征的目的。在五个真实属性网络上的实验结果表明,提出的模型在聚类与分类任务中,效果均优于目前流行的表示学习方法。     

ATR‐UV monitoring of methyl methacrylate miniemulsion polymerization for determination of monomer conversion

Attenuated Total Reflection (ATR) UV spectroscopy has been used to monitor monomer conversion in methyl methacrylate miniemulsion polymerization. It was found that the vinylic groups of methyl methacrylate strongly absorb the UV light with a maximum absorption at 225 nm. This absorption peak decreases as monomer is converted to polymer. The polymer has a strong absorption at a lower UV region. The results from this feasibility study indicate that ATR‐UV sensor technique has a great potential to be used for on‐line or in‐line process monitoring in emulsion and miniemulsion polymerization. With a partial least square (PLS) calibration model, very good prediction the monomer conversion was obtained. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1471–1475, 2006     

脂环族阴离子水性聚氨酯分散体的结构及表征

以异佛二酮二异氰酸酯（IPDI）为原料，采用内乳化法合成了不同羧基含量的阴离子水性聚氨酯分散液，利用FT-IR、DSC、TEM、TGA、XRD对其结构进行了表征。结果表明，所合成的水性聚氨酯中氢键主要存在于硬段的亚氨基与硬段的氨酯羰基和脲羰基之间。在-100～220℃的温度范围内出现了2个玻璃化转变，其热分解主要经历了两个阶段。随着羧基质量分数增加，水性聚氨酯硬段与硬段间的氢键增加，软段的玻璃化温度向低温方向移动，硬段的玻璃化温度向高温方向移动，其胶束粒子的平均粒径变小。     

Durability testing for the recovery of sodium hydroxide from alkaline waste solutions

Testing successfully demonstrated the operation of an electrochemical flow cell for more than 1000h to recover 13–14wt% sodium hydroxide from an alkaline waste solution. The nickel cathode, platinized-titanium anode and cationic membrane exhibited no visible signs of attack upon inspection after testing. The membrane experienced a slow, but steady decline in current efficiency, from a high of greater than 95% down to approximately 90% after 1079h. We attribute the loss in current efficiency to the accumulation of silicon and aluminium within the membrane structure.     

聚乙烯废弃物复合材料的化学改性研究

采用从造纸废渣中分离出的二次纤维和废塑料制得二次纤维/聚乙烯废弃物复合材料。研究了NaOH预处理、二次纤维的用量以及苯甲酸改性对复合材料力学性能的影响。结果表明:NaOH的质量分数为2%,处理时间为20 min,用量约质量比20%,苯甲酸的用量为质量比4%时,所得复合材料的综合性能最佳。     

造纸废渣填料增强废弃聚乙烯基复合材料研究

采用从造纸废渣中分离出的填料和废旧农用聚乙烯(PE)地膜制备造纸废渣填料增强废弃PE基复合材料,研究了填料粒径和用量对复合材料力学性能的影响。采用硅烷偶联剂KH-550作为填料的表面改性剂,马来酸酐接枝PE(PE-g-MAH)作为体系的增容剂来改善复合材料的综合性能。结果表明,这两种途径均可不同程度地提高复合材料的力学性能,PE-g-MAH的加入可有效改善基体与填料之间的相互作用。     

Synthesis, formation and characterization of ZnTiO3 ceramics

Zinc titanate (ZnTiO₃) powders of perovskite structure were synthesized by conventional solid state reaction using metal oxides. Powders of ZnO and TiO₂ in a molar ratio of 1:1 were mixed in a ball mill and then heated at temperatures from 700 to 1000 °C for various time periods in air. The crystallization temperature of ZnTiO₃ powder was 820 °C, activation energy for crystallization was 327.14 kJ/mol and for grain growth was 48.84 kJ/mol. A transition point was observed when the electrical resistivity was measured versus temperature. Like some ferroelectric materials, a PTCR behavior above the transition temperature was observed with Curie temperature of 5 °C.     

Particle morphology and NMR structure of polymethylmethacrylate/polystyrene emulsifier‐free core–shell cationic latices in the presence of DBMEA

In the absence of emulsifier, we prepared stable emulsifier‐free polymethylmethacrylate/polystyrene (PMMA/PSt) copolymer latex by batch method with comonomer N,N‐dimethyl, N‐butyl, N‐methacryloloxylethyl ammonium bromide (DBMEA) by using A1BN as initiator. The size distribution of the latex particles was very narrow and the copolymer particles were spherical and very uniform. Under the same recipe and polymerization conditions, PMMA/PSt and PSt/PMMA composite polymer particle latices were prepared by a semicontinuous emulsifier‐free seeded emulsion polymerization method. The sizes and size distributions of composite latex particles were determined both by quasi‐elastic light scattering and transmission electron microscopy (TEM). The effects of feeding manner and staining agents on the morphologies of the composite particles were studied. The results were as follows: the latex particles were dyed with pH 2.0 phosphotungestic acid solution and with uranyl acetate solution, respectively, revealing that the morphologies of the composite latex particles were obviously core–shell structures. The core–shell polymer structure of PMMA/PSt was also studied by ¹H, ¹³C, 2D NMR, and distortionless enhancement by polarization transfer, or DEPT, spectroscopy. Results showed that PMMA/PSt polymers are composed of PSt homopolymer, PMMA homopolymer, and PMMA‐g‐PSt graft copolymers; results by NMR are consistent with TEM results. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1681–1687, 2005     

基于4A信息安全管理系统的设计与实现

针对目前多个子系统和安全设备由于没有独立认证、权限、审计和帐号而导致系统无法有效整合提出了解决方案.利用当前成熟的Portal技术和加密算法,实现了多个系统和4A管理平台的信息有机关联和功能交互两者的一致性及多个系统间的安全有效访问控制,为客户提供了功能完善的、高安全级别的4A管理.