β晶相聚丙烯成纤性能的研究

作者研究了β晶相聚丙烯的成纤性能。研究表明,在一定的温度范围内,熔体温度对聚丙烯初生纤维的β晶含量影响甚微,而纺丝的冷却速率和冷却介质对其有较显著的影响。含β晶相聚丙烯初生纤维经拉伸后,在纤维的表面呈现许多微孔及裂缝。与普通聚丙烯纤维比较,制得的纤维有较小的表观密度,其吸湿性有明显的提高。     

高吸水涤纶的催化碱处理

本文讨论了改性涤纶在催化剂存在下的碱处理反应机理,以及碱处理条件如温度、碱浓、催化剂浓度和碱处理时间与纤维减量率的关系。导出了减量率与时间、温度的关系式。并用扫描电镜观察了纤维的表面形态结构。实验结果表明,改性高吸水涤纶的碱减量不仅与纤维组成,纤维结构,还和处理条件有关。催化剂的引入可大大减少处理时间,降低处理温度。因此可节省能源,降低单耗和改善工作条件。     

聚偏二氟乙烯(PVF_2)纤维结构性能的研究

本文对不同分子量的 PVF_2熔纺纤维,用广、小角 X 衍射,DSC,双折射和力学性能测定法进行了研究,对其α晶体取向、β晶体的产生和样品力学性能随纺丝张力变化的规律作了研究.结果表明,α和β晶体共存于高分子量样品中,产生β晶体的临界张力约为3×10~6Pa,β晶体含量随纺丝张力而增加,结晶取向和力学性能与纺丝张力有关而在一定范围内与分子量大小无关.     

PP纤维水泥复合材料的界面行为--单纤维拉出试验初探

通过普通圆截面PP、改性圆截面PP和三叶PP短纤维水泥基复合材料的拉出试验,获得了最大载荷-纤维埋入长度曲线和载荷—拉出长度曲线,并据此讨论了这类复合材料的界面行为。     

Observation and Study of Fracture Behaviour for Fiber Reinforced Cement

Polypropylene, carbon, aramid and polyethylene fibers reinforced cement composites were fabricated respectively. Their fracture behaviors were observed using scanning electron microscopy and the bonding between fiber and matrix was observed in detail.     

INTERFACIAL MICROSTRUCTURE OF SILICON CARBIDE FIBER REINFORCED COMPOSITES

Electron microscopy, including bright field imaging, dark field imaging, high resolution imaging, (SAD) and (EDX), was employed to investigate the interfacial microstructure of silicon carbide fiber reinforced composites. It is found that SiC / SiC has well-defined interface layer between fibers and matrix, consisting primary of graphite crystallites. The interface of SiC / Pyrex displays a very poor bonding. For SiC / JG6 it is difficult to distinguish the interface region from fiber and matrix in TEM image.     

Preparation and Morphological Study of Coal-tar-based Carbon Foam

A novel process for fabricating coal-tar pitch derived carbon foam was introduced. The coal-tar based mesophase pitch was characterized by Infrared Spectrum and Wide Angle X-ray Diffraction. Scanning Electron Microscope was used for the morphological study of carbon foam. The results showed that the pitch foam with pores of 300 -500 μm and low density of 0.2-0.5 g/cm^-3 could be successfully fabricated and further carbonized and graphtized to obtain a novel carbon foam     

Study on Abrasion Resistance of Modified Polypropylene Fiber Reinforced Cement

Modified polypropylene fiber reinforced cement compos-ites were investigated in their abrasion resistance andsurface morphology. The test results showed the addingof fiber could noticeably improve the abrasion resistanceof composite. The bonding and friction of fibers/cementwere the main contribution to abrasion resistance im-provement, which resulted from the surface morphologyobservation.     

各类谱图叠加峰分解的一种方法(简报)

本文阐述了用一简单的无约束最优化方法来分解谱分析实验曲线的叠加峰。给出了框图和讨论了目标函数的归结。此法是对现有一些阻尼最小二乘法的改进。它对 ATA 矩阵作了三角分解,以改进的 Fletcher 方法和二次插值得到择优阻尼因子和下降步长,从而大大节约了每次迭代选择优良阻尼因子的时间和稳定了下降的趋势。本法备有网格搜索,以免在驻点搜索失败。由于采用了一系列比较完整的算法,它还能用来测定拟合曲线的数目和确定分解曲线的函数式等。本法经过较全面的数学模拟调试。于 Z-80微处理机上使用,实践证明,它的精度较高,收敛速度较快,对初始假设值设置的宽容度较大,并且提供了与测试仪器直接连用的条件。     

高速涤纶长丝的成形特征——第一部分:纺丝线上涤纶POY织态的形成

提出了一个涤纶高速预取向丝凝固过程的模型.用宽角X-射线分析、光学方法,红外光谱和热机械分析进行研究,所得超分子结构参数,均与这一模型相符.在比上油点稍高处控制温度,对纺丝线上纤维的结晶行为有重要影响.