Paper-like Microfibrous Nickel Catalyst for Hydrogen Production via NH3 Decomposition in Fuel Cell Applications

Recently, miniature H2 generator to power fuel cells for portable/micro electronic devices and passenger propulsion has been the focus of intense research activities1-3. One of the strategies is to find simple CO-free H2 production with novel microreactor…     

A fibrous hypercrosslinked sorbent prepared on PP-ST-DVB matrix via post-crosslinking reaction

A fibrous sorbent possessing abundant micropore structure was firstly prepared via post-crosslinking reaction on the PP-ST-DVB original fiber. Its micromorphology and sorptive properties were investigated, and the results demonstrated that the novel fibrous hypererosslinked sorbent has narrow pore-size distribution, small average porous radius （1.90 nm）, high specific surface area （362.31 m^2/g）, and fine sorptive properties for small organic molecules.     

漆酶催化不同小分子物质改善纤维性能

以紫丁香醇和L–苯丙氨酸作为酚类物质和氨基酸的代表物质,比较了漆酶/酚类物质和漆酶/氨基酸对OCC(废瓦楞箱板纸)纸浆纤维表面性能的改善效果.使用红外光谱分析、扫描电镜、纤维形态分析对纤维表面形貌进行观察.并对漆酶和小分子物质共同处理后的OCC纸浆进行物理性能检测.纤维形态分析和表面电镜的测定证明了酚类物质和氨基酸可以接枝到纤维表面,表现为纤维粗度增加,纤维表面出现沉积物及纤维间连接膜生成,从而提高成纸强度,特别是湿环压强度提高更为明显.     

Adhesion of PBO Fiber in Epoxy Composites

The high mechanical and thermal performance of poly p-phenylene- 2, 6-benzobisoxazole ( PBO ) fiber provides great potential applications as reinforcement fibers for composites. A composite of PBO fiber and epoxy resin has excellent electrical insulation properties, therefore, it is considered to be the best choice for the reinforcement in high magnetic field coils for pulsed magnetic fields up to 100 T.However, poor adhesion between PBO fiber and matrix is found because of the chemically inactive and/or relatively smooth surface of the reinforcement fiber preventing efficient chemical bonding in the interface, which is a challenging issue to improve mechanical properties. Here, we report the surface modification of PBO fibers by ultraviolet (UV)irradiation, O2 and NH3 plasma, as well as acidic treatments. The interfacial adhesion strength values of all the treatments show the similar level as determined for aramid fibers by pull-out tests, a significant impact on fibermatrix-adhesion was not achieved. The surface free energy and roughness are increased for both sized and extracted fibers after plasma treatments together with maleic anhydride grafting. The sized fiber shows marginal improvement in adhesion strength and no change in fiber tensile strength because of the barrier effect of the finish.For the extracted fiber, different surface treatments either show no apparent effect or cause reduction in adhesion strength. Atomic force microscopy (AFM) topography analysis of the fracture surfaces proved adhesive failure at the fiber surface. The fiber surface roughness is increased and more surface flaws are induced, which could result in coarse interface structures when the treated fiber surface has no adequate wetting and functional groups. The adhesion failure is further confirmed by similar adhesion strength and compression shear strength values when the fiber was embedded in various epoxy resins with different temperature behavior. The tensile strength of fiber is sensitive to surface treatment conditions as revealed by a bimodal Weibull statistical distribution analysis. Considerable strength reduction occurred, particularly for cases of acidic and plasma treatments, while UV irradiation shows the better ability to retain fiber strength.     

碱性果胶酶处理对亚麻落麻纤维性能的影响

选用碱性果胶酶对亚麻落麻纤维进行精细化处理,探讨了酶法精细化处理的3个因素:酶质量分数、酶处理时间和处理液pH值,对亚麻落麻纤维线密度、长度、断裂强度、断裂伸长率的影响.研究结果表明,碱性果胶酶在pH值为8.0时活性最好；随着酶质量分数的增加,纤维的线密度和长度呈减小趋势,但在酶质量分数＞2％时略有增加,纤维断裂强度和断裂伸长率呈上升趋势；随着处理时间的增加,纤维线密度和长度先迅速下降后趋于平缓,并略有上升的趋势,纤维断裂强度和断裂伸长率先增加后略有减小.     

兔毛加工理化性能的研究

本文讨论了兔毛在加工过程中存在的有关问题。首先探讨了兔毛的基本特性,进一步探讨了免毛加工工艺特性及兔毛加工技术等,并提出了作者的初浅看法。     

过氧乙酸在苎麻脱胶预处理工艺中的应用

分析了过氧乙酸在苎麻预处理工艺中的应用,探讨了过氧乙酸用量,温度,时间和pH值4个因素对过氧乙酸预处理效果的影响。根据苎麻精干麻的断裂强度、断裂伸长率、断裂比功、SEM和XRD等物理机械性能和表面形态的测试,对比分析了过氧乙酸-氢氧化钠脱胶工艺和传统化学脱胶工艺的精干麻性能。实验表明,当过氧乙酸浓度为2.5%,温度为50℃,pH值为8.0,时间为2 h,苎麻精干麻的断裂强度可以达到最佳。     

纤维性日粮对猪后肠策生物区系和生产性能的影响

就纤维性日粮对猪后脾性现生物区系和生产性能的影响进行了综述。结果表明,猪大肠微生物区系中存在高活性的瘤胃纤维分解菌和半纤维分解菌。此外,从猪大肠中还新分离出一株高活性的纤维分解菌。饲喂高水平纤维性日粮可诱导大肠纤维分解菌数量增高,且成年猪的纤维分解菌的数量是生长猪的６～７倍,表明成年猪有利用纤维性饲料的潜力。高纤维日粮对成年猪尤其是母猪的生产性能没有负影响。     

浅谈剩余电流动作保护器

剩余电流动作保护器(RCD)在我国是从80年代新兴发展的一种保护电器。随着我国引进IEC标准后开始采用TN-S、TN-C-S、TT系统和IT系统,这些系统都具有单独的PE线,并且该保护开关体积小、造价低、便于维护和安装,能有效地保护人身及设备的安全等特点,引起了广大电力同行和用户的关注和青睐,掀起了一场低压配电网络安全保护的技术革命,RCD也随之大量装用。本文试图通过我国对漏电保护开关的原理及应用分析,探讨漏电保护开关的正确设置安装、维护和使用方法,以供同行及用户参考。     

琼胶纤维的制备与性能研究

用湿法纺丝制备琼胶纤维,扫描电镜(SEM)观察纤维的表面形态,并且测试了纤维的拉伸性能和吸水性能。结果表明用二甲基亚砜(DMSO)做溶剂,50%无水乙醇做凝固浴,纺丝原液的溶度为12%,可制得纤维性能良好的琼胶纤维,而且纤维的拉伸强度达到了5.52 cN/tex,在蒸馏水中的膨胀度为114%,在0.9%的盐溶液中为111%。