Morphology of polyethylene ski base materials     

Jörg Fischer  Gernot M. Wallner  Alois Pieber 《Journal of sports sciences》2013,31(5):555-562

Abstract

We used high-resolution Raman spectroscopy and differential scanning calorimetry for a comprehensive analysis of carbon black-filled polyethylene ski base grades at processing stages from the raw material to the structured ski base. Based on Raman mapping, we assessed the applicability of an advanced evaluation procedure for amorphous, disordered, and crystalline phase fractions of polyethylene for polyethylene extrusion and sinter grades. For sinter grades, a sufficient segregation between carbon black and polyethylene was confirmed, allowing for a comprehensive Raman spectroscopic morphological analysis. Significant morphological changes in polyethylene due to processing from the raw material to the semi-finished film and to the structured ski base were identified. Throughout the processing chain, we observed a decrease in crystallinity and an increase in the amorphous phase fraction. Although the raw material and the sintered semi-finished film exhibited a different but uniform polyethylene morphology, the morphological changes due to structuring of the ski base are limited to the top surface layer. The highest amorphous phase fractions were detected in the surface of the structured ski bases.  相似文献   

Study of Fe(II) sulphides in waterlogged archaeological wood     

《文物保护研究》2013,58(4):297-307

Abstract

Wet organic archaeological materials extracted from seawater may suffer damage as a result of degradation influenced by micro-organisms. One of the most common phenomena is indirectly induced by sulphate-reducing bacteria (SRB). Due to their metabolic activity in anoxic conditions, SRB generate hydrogen sulphide from sulphate ions present in seawater. When steel items are in contact with organic matter in presence of sulphides, corrosion of the metal leads to the precipitation of Fe(II) sulphides. These phases are responsible for dramatic post-excavation damage: their oxidation during storage or exhibition in museums leads to the formation of voluminous crystals, which may cause cracking and crumbling, and lead to the production of sulphuric acid. In order to characterize Fe(II) sulphides and their by-products, 13 waterlogged samples were analysed by environmental scanning electron microscopy, micro-Raman spectroscopy, and X-ray diffraction. Experiments were performed on untreated wood fragments, on a fragment of rope, and on mineral concretions scratched from the surface of wood remains, all extracted from different shipwrecks. Mackinawite was detected inside the fragments and between the fibres of the rope. Greigite was detected in scattered locations. Pyrite and sulphated phases, like gypsum and iron sulphates, were identified at the surface of the wood fragments and in the mineral concretions.  相似文献   

烟酸分子的简正振动与拉曼光谱     

韩礼刚 《洛阳师范学院学报》2009,28(2):44-46

利用量子化学软件计算得出了烟酸分子的平衡构形,基于这个构形,理论上计算出了烟酸分子的简正振动光谱,并与实验测得的结果进行了比较,最后对其简正振动模式进行了全面归属.  相似文献   

基于密度泛函理论的ANB分子简正振动分析     

陶亚萍  梁会琴 《洛阳师范学院学报》2009,28(5):38-40,182

采用密度泛函方法B3LYP/6-311G(d,p)计算了5-氨基-2-硝基苯甲酸分子(ANB)的平衡构型以及振动频率,在定义内坐标、对称坐标的基础上计算了振动频率在各力常数上的势能分布百分比,从而完成分子简正频率的归属指认.  相似文献   

NiSi／Si（001）声子模式对称性分析     

唐波  万里  程新红  张学飞  任一民  徐大鹏  罗海军  黄运米 《温州大学学报(社会科学版)》2009,(4):55-60

通过极化拉曼对以Si（001）为衬底、生长方向为NiSi[200]//Si[001]NiSi薄膜材料的拉曼峰进行了声子模式的分组,确定实验得到的NiSi薄膜的六个拉曼峰分别属于三类声子模式．其中213cm^-1、295cm^-1和367cm^-1处拉曼峰属于Ag对称性;196cm^-1和254cm^-1处拉曼峰属于B3g对称性;401cm^-1。处拉曼峰属于B1g或B2g对称性．  相似文献   

SRS导致光纤DWDM系统串扰的探讨     

梅孝安  袁帅  陶家友  罗子波 《湖南科技学院学报》2007,28(4):22-24

文章推导出光纤密集波分复用系统中SRS串扰的计算公式,通过数值计算,分析了不同参数下的SRS串扰变化情况。  相似文献   

对暗孤子传输系统的影响因素的探讨     

王亚丽  陈天江 《绵阳师范学院学报》2004,23(2):48-51

对影响暗孤子传输系统的一些主要因素 ,如初相位的影响、随机色散的影响、增益随机变化的影响、内脉冲拉曼散射效应的影响进行了总结性的探讨 ,并发现在许多情况下 ,引入非线性增益能够有效地抑制暗孤子的时间抖动。因此 ,对暗孤子传输系统中非线性增益的有效运用能改善系统的误码率并降低时间抖动 ,在今后的暗孤子传输系统的设计中有着广泛的应用前景。  相似文献   

光纤中Raman效应对暗孤子传输特性的影响     

谢应茂  赖昭胜  冯郁 《赣南师范学院学报》1992,(Z2)

本文采用修正守恒律方法,研究了单模光纤中Raman效应对暗孤子传输特性的影响,导出了暗孤子参数的演化规律,理论与最近的实验结果[Opt.Lett.14,868(1989)]一致。  相似文献   

紫外分光光度法测定蔬菜中硝酸盐含量   总被引：2，自引：0，他引：2  

曹书杰 《南阳师范学院学报》2008,7(3):53-55

基于硝酸盐在207．38nm处有强烈吸收,且干扰少,在pH=7中性条件下,建立了用紫外分光光度法测定蔬菜中的硝酸盐含量的方法。此法测定的结果表明回收率在95．1％～100．9％之间,相对标准偏差为1．55％～4．14％。操作方法简便．适用于蔬菜中的硝酸盐含量的测定。  相似文献   

CaAl2O4:Eu2+,Nd3+荧光粉燃烧合成工艺的研究     

李文植  杨坤涛 《鄂州大学学报》2006,13(3):58-61

应用燃烧法在较低温度（600℃）下成功合成了CaAl2O4：Eu^2＋,Nd^3＋荧光粉，并研究了稀土离子Eu^2＋和Nd^3＋含量及点火温度对荧光粉发光性能的影响，确定了合成余辉亮度大、持续发光时间长的荧光粉时．稀土离子的最佳掺量和最佳合成温度。在此基础上研究了燃烧反应前驱体溶液中物质的结合情况。  相似文献