高性能纤维的弯曲疲劳断裂研究

在自制弯曲疲劳装置上 ,对 3种高强对位芳纶及超高相对分子质量聚乙烯纤维 (Dyneema SK65 )进行双面弯曲疲劳试验。结果表明 ,Twaron 2 0 0 0弯曲疲劳寿命的自然对数与预加应力、弯曲角度呈线性关系 ,Dyneema SK65弯曲疲劳寿命明显长于对位芳纶 ,Twaron 2 0 0 0 ,Kevlar 12 9相近 ,都比Kevlar 2 9略长 ;高强型对位芳纶的弯曲疲劳断裂断口芯层呈现出“毛笔头”或“拔丝形”原纤化分裂形态 ,超高相对分子质量聚乙烯纤维弯曲疲劳断裂断口有明显的脆性折断形态 ,无原纤出现。     

纳米技术在涂料中的产业化应用

介绍了国内外纳米涂料的现状及其产业化进展。     

The kinetics of desorption in the presence of a gas phase of the desorbing molecule: CO/Re(001)

TPD/Exchange from CO/Re(001) in a gas ambience showed that the absolute rate of desorption depends on the gas pressure and has a first plus second order rate law. It is proposed that desorption is a two step process from the adsorbed state to a stable intermediate which is itself weakly adsorbed.     

凉型风味料介绍

本文分析了主要凉味剂的立体构型 ,简单介绍了以L -薄荷脑 (又称L -薄荷醇 )和L -薄荷脑为基本骨架的酯类、醚类和缩酮类化合物的结构和味觉特征 ,它们的安全性以及在食品、口腔卫生用品、化妆品和肤用药中的应用。     

Orthogonal and fine lithographic structures attained from the next generation proton beam writing facility

A second generation proton beam writing (PBW) system has been built at the Centre for Ion Beam Applications at the National University of Singapore for fabrication of high aspect ratio 3D nano lithographic structures. System improvements and a few lithographic structures obtained with this facility are presented in this paper. Through accurate alignment of the magnetic quadrupole lenses and the electrostatic scanning system, orthogonal beam scanning has been achieved. The earlier constrain of limited beam scan area has been overcome by adopting a combination of beam and stage scanning as well as stitching. With these improvements smallest ever Ni structure of 65 nm in width has been fabricated using nickel electroplating on a proton beam written PMMA sample in the second generation PBW facility. Using this improved PBW facility, we have also demonstrated the fabrication of fine lithographic patterns with 19 nm line width and 60 nm spacing in 100 nm thick negative high resolution hydrogen silsesquioxane resist. Future possible system improvements leading to finer resolution will be discussed briefly.     

硼酚醛树脂在涂料中的应用

通过将硼酚醛树脂和环氧树脂进行混用,利用硼酚醛树脂优异的耐酸、碱腐蚀性能以及耐高温性能和环氧树脂可以常温固化成膜的特点,制备常温固化的耐高温防腐蚀涂料。     

镧和钴掺杂纳米TiO2的溶胶-凝胶法制备及其光催化性能

采用溶胶-凝胶法，制备了TiO2、Co^2＋／TiO2、La^3＋／TiO2＋,Co^2＋,La^3＋／TiO2光催化剂。通过考察掺杂离子的种类和用量对所得催化剂用于紫外光催化降解亚甲基蓝性能的影响，得出La^3＋／TiO2中La^3＋的适宜掺杂量为1.0％，Co^2＋，La^3＋／TiO2中，当La^3＋的掺杂量为1.0％时，Co^2＋的适宜掺杂量为0.2％，相应的脱色效率为99.83％、98.79％。当掺杂量适当时，四种催化剂用于紫外光催化降解亚甲基蓝的活性次序为：La^3＋／TiO2〉Co^2＋，La^3＋／TiO2〉TiO2〉Co^2＋／Ti02o XRD分析结果表明，所得光催化剂均为纳米粒子。     

ZnO微／纳米纤维的静电纺丝及其表征

以聚乙烯吡咯烷酮(PVP)为络合剂与醋酸锌[Zn(CH3COO)2]反应制得前驱体溶液,用静电纺丝法制备了PVP／Zn(CH3COO)2纤维,经煅烧得到具有微孔结构的氧化锌(ZnO)微／纳米纤维。对所制备纤维分别采用差热-热重分析、红外光谱分析、X射线衍射分析、扫描电镜等手段进行了表征。结果表明: PVP/Zn(CH3COO)纤维表面光滑,直径约300-700 nm,经700℃煅烧后,可得到ZnO微／纳米纤维。     

Reconstruction of multi-view compressed imaging using weighted total variation

This paper concentrates on the problem of image reconstruction from compressed sensing (CS) measurements in multi-view compressed imaging systems, where each view is acquired independently by CS technique. In order to take advantage of both the inter-view correlation and the spatial prior information in multi-view image sets, a weighted total variation (TV) regularized model, which combines the TV norm of a target view and the TV norm of the corresponding residual, is proposed. To efficiently solve the weighted TV regularization constrained problem, novel algorithms are presented for both the anisotropy TV and the isotropy TV cases. Given the multi-view CS measurements, a sliding window-based recovery framework is also developed to work with the weighted TV-based reconstruction algorithms and produce high-quality results. We show by experiments that the proposed methods greatly outperform the straight forward reconstruction which applies view by view image reconstruction independently, and also have significant advantages over other benchmark methods.     

Evaluation of some of the properties of plasma treated wool fabric

Low temperature plasma (LTP) treatment was applied to wool fabric with the use of a nonpolymerizing gas, namely oxygen. Properties of the LTP‐treated samples including low stress mechanical behavior, air permeability, and thermal characteristics were evaluated in this study. Kawabata evaluation system fabric (KES‐F) was employed to determine the tensile, shearing, bending, and compression strength properties and surface roughness of the specimens. The changes in these properties are believed to be closely related to the interfiber and interyarn frictional force induced by the LTP. The decrease in the air permeability of the LTP‐treated wool fabric was found to be probably because of the plasma action effect on increasing the fabric thickness and a change in fabric surface morphology, which was confirmed by scanning electron microscopy micrographs. The change in the thermal properties of the LTP‐treated wool fabric was in good agreement with the earlier findings and can be attributed to the amount of air trapped between the yarns and fibers. This study suggested that the LTP treatment can influence the final properties of the wool fabric, and also provide information for developing LTP‐treated wool fabric for industrial use. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5958–5964, 2006