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均陶堆花工艺装饰的创作,要虚与实、巧与拙、刚与柔、粗与细、方与圆、曲与直、生与熟、苍与秀相结合,才能创作出好作品。 相似文献
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以纯角蛋白为原料,采用静电纺丝技术制备的角蛋白纳米纤维膜脆性大、力学性能差,添加化学助剂能够明显改善角蛋白溶液的可纺性,提高角蛋白纳米纤维膜的综合性能。本文主要介绍了在静电纺丝过程中优化和改善角蛋白纳米纤维膜性能的三类化学助剂,包括改善纺丝液可纺性的助纺剂、增强纳米纤维膜综合性能的交联剂以及增加纳米纤维膜特殊功能的抗菌剂。阐述了以上三类化学助剂在静电纺角蛋白纳米纤维膜材料中的相关作用机理,对比了添加化学助剂前后角蛋白纳米纤维膜的结构和性能的变化情况,展望了化学助剂在静电纺角蛋白纳米纤维材料中潜在的应用价值和广阔的应用前景,提出了今后化学助剂在优化静电纺角蛋白纳米纤维综合性能方面的研究方向。 相似文献
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研究了丁腈橡胶(NBR)、氟橡胶(FKM)及氢化丁腈橡胶(HNBR)等三种典型橡胶在不同比例甲醇汽油中的理化性能与机械性能变化,并与乙醇汽油体系的溶胀进行了对比研究。实验结果表明:NBR在不同甲醇比例的浸泡体系中,尺寸、质量及体积变化率均小于6%,且尺寸变化率最小,基本维持在3%以下;溶胀后NBR的机械性能下降显著。FKM各项理化性能及机械性能在汽油中的变化均最小,在M30甲醇汽油体系中最大,且随着时间延长,其理化性能变化逐渐增大,而机械性能则无明显变化;在相同条件下,FKM的理化性能及机械性能变化均大于NBR与HNBR,而NBR与HNBR的变化趋势基本一致;NBR在甲醇汽油中的溶胀程度与其在乙醇汽油中基本相当。 相似文献
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The chemical and rheological properties of two asphalts selected from different sources (Urals, Russia; Cold Lake, Canada) were investigated. Analyses of chemical (elemental composition, fractional composition, molecular weights) and physical properties (complex viscosity, loss tangent, shear compliance) were performed on all original and aged (rolling thin film oven test, RTFOT; pressurized aging vessel, PAV) samples. The analyses of the chemical properties of both asphalts revealed higher asphaltene content, higher heteroatom content, and lower aging susceptibility of the Cold Lake asphalt (less significant changes in group composition). Based on its chemical composition, the Cold Lake asphalt was expected to perform better in the rheological tests than the Urals asphalt. The rheological tests confirmed this hypothesis and revealed better low- and high-temperature properties of the Cold Lake asphalt and a slower deterioration of its physical properties upon oxidative aging. 相似文献
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硫代烃基三甲基硅烷(RSSiMe3)是一种化学性质活泼,应用前景十分广阔的有机硅硫试剂。本文介绍近20年来它们的一些重要化学性质及其在有机合成中的应用。 相似文献
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目前流体在纳微尺度下的化学非均一表面上表现出的优异性能已引起普遍关注,但是如何使其在化工中得以应用成为化学工程师们面临的难题之一。本文在分析了化学非均一表面在化工应用中已表现出优异性能的基础上,从化学非均一表面的润湿行为和受限空间下化学非均一对分子传递的影响两方面综述了其研究进展。认为化学非均一表面的表面性质受到诸多因素影响非常复杂,但利用现代表面技术和分子模拟的手段,可从微观、分子层面研究流体在化学非均一表面的作用机理,进而可改善和提高诸多化工过程,是推动现代化工发展的重要途径之一。 相似文献
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Mohamed Mahmoud Nasef Hamdani Saidi Hussin Mohd Nor Ooi Mun Foo 《Polymer International》2000,49(12):1572-1579
The physical and chemical properties of polystyrene grafted and sulfonated polytetrafluoroethylene (PTFE‐graft‐PSSA) membranes prepared by radiation‐induced grafting of styrene onto commercial PTFE films using simultaneous irradiation technique followed by a sulfonation reaction are evaluated. The investigated properties include water uptake, ion exchange capacity, hydration number and ionic conductivity. All properties are correlated with the amount of grafted polystyrene (degree of grafting). The thermal stability of the membrane evaluated by thermal gravimetric analysis (TGA) is compared with that of original and grafted PTFE films. The membrane surface structural properties are analysed by electron spectroscopy for chemical analysis (ESCA). Membranes having degrees of grafting of 18 % and above show a good combination of physical and chemical properties that allow them to be proposed for use as proton conducting membranes, provided that they have sufficient chemical and mechanical stability. © 2000 Society of Chemical Industry 相似文献
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The technical production of elastomers based on epichlorhydrine enables the industrial application of products with a very interesting combination of mechanical and chemical properties. In the present paper the influence of the chemical structure on the mechanical and chemical properties is studied. The compooundation and the industrial manufacture are not discussed. 相似文献