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现代化水泥生产工艺中,水泥与混凝土外加剂之间的适应性问题得到广泛关注,随着企业生产规模的扩大,水泥工艺外加剂种类繁多,其相关技术日渐成熟。基于此,本文以外加剂技术作为研究对象,分析水泥工艺与外加剂之间的适应性,并从水泥生料制备系统与水泥制备系统中阐述外加剂技术与水泥工艺的融合应用。 相似文献
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水泥生产中的外加剂技术在国外已有60多年的历史。但较长一段时间内,我国的水泥外加剂技术进展缓慢。近年来,随着各个领域的科技日新月异的发展,我国的水泥外加剂技术也取得了突飞猛进的成就。它以能降低成本和绿化环境的显著效益对水泥工业发展做出的突出贡献,越来越得到了人们的重视和认可。对于外加剂技术的作用 相似文献
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通过调查研究,综合国内外已有的研究成果,对外加剂与水泥适应性问题进行了研究。研究表明,由于外加剂与水泥相互作用的复杂性,对于不同水泥,外加剂所表现的性能不尽相同。根据国产水泥的性能特点及其与外加剂之间的物理、化学作用,提出减水剂掺量应略高于其饱和点,并根据水泥中C3A含量及含碱量加以适当调整;在适当条件下掺保水剂以减少泌水.改善混凝土工作性能等措施。 相似文献
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D.F. Bahr D.V. Bucci L.S. Schadler J.A. Last J. Heberlein E. Pfender W.W. Gerberich 《Diamond and Related Materials》1996,5(12):1462-1472
Diamond films grown using a thermal plasma technique are characterized using a variety of techniques. The relationships between the chemistry, morphology, and mechanical properties are explored using microscopy, Raman spectroscopy, Auger electron spectroscopy, and X-ray photoelectron spectroscopy. The characteristics of films grown using two different nucleation enhancement techniques are shown. Films grown using high methane concentrations at the beginning of growth produce large grained columnar films, whereas films grown on substrates which have been treated with a diamond polishing step show nanocrystalline structures. Variations in sp3 and sp2 bonding and peak shifts are tracked through the thickness of the film, corresponding to variations in the methane concentration during growth. Stresses are measured using peak shifts and beam bending techniques. Adhesion is tested using indentations, and is shown to increase both as growth temperatures and surface roughness increase. 相似文献
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为了解决目前广泛使用的酚醛树脂结合的镁质干式料危害环境和工人健康的问题,首先通过对比单独使用酚醛树脂、葡萄糖、水玻璃、柠檬酸为结合剂的干式料的脱模强度,初步确定以葡萄糖代替酚醛树脂作为环保型干式料的结合剂;然后与酚醛树脂结合的干式料对比,研究了以不同比例的葡萄糖和水玻璃为复合结合剂的干式料低温、中温、高温处理后的性能指标。结果表明:用5%(w)葡萄糖+1%(w)水玻璃复合结合剂代替酚醛树脂制备干式料,低温和高温处理后干式料的性能与酚醛树脂结合的基本相同,中温性能优于酚醛树脂结合的,复合结合剂试样产生的烟气明显少于酚醛树脂结合的,可以达到环保的目的,是一套可行方案。 相似文献
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综述了超声波法制备高吸水树脂研究进展,包括超声波法制备合成聚合物系列高吸水树脂、超声波法制备天然多糖交联型高吸水树脂、超声波法制备接枝天然多糖型高吸水树脂等。最后指出了超声波法制备高吸水树脂研究需要加强的几个方向:即加强超声波法制备各种类型高吸水树脂的实验研究;加强超声辐射产生设备的革新研究;降低成本,扩大应用领域。 相似文献
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马聪鹤;柴云;张普玉 《中国塑料》2011,25(10):34-37
以辛酸亚锡为催化剂、乙二醇为引发剂、L-丙交酯和ε-己内酯为反应单体,采用开环聚合的方法合成一系列单体配比不同的共聚物PCLA。采用红外分析、核磁共振分析表征了PCLA的结构,采用差示扫描量热仪和凝胶渗透色谱仪分析了PCLA的热性能和相对分子质量,通过测量接触角观察了PCLA的亲水性。结果表明,引发剂乙二醇的使用以及改变单体配比可以调节PCLA的分子结构、相对分子质量和热性能,对其亲水性影响不大。 相似文献
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The cure of an epoxy resin system, based upon a diglycidyl ether of bisphenol‐A (DGEBA) with HY917 (an acid anhydride hardener) and DY073 (an amine–phenol complex that acted as an accelerator), was investigated using a conventional differential scanning calorimeter and a microwave‐heated power‐compensated calorimeter. Dynamic cure of the epoxy resin using four different heating rates and isothermal cure using four different temperatures were carried out and the degree of cure and reaction rates were compared. The cure kinetics were analyzed using several kinetics models. The results showed different activation energies for conventional and microwave curing and suggested different reaction mechanisms were responsible for curing using the two heating methods. Resins cured using conventional heating showed higher glass transition temperatures than did those cured using microwave heating. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2054–2063, 2007 相似文献
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在研制U形件泡沫塑料芯材过程中,用直接加热成型法制备效果差、易断裂和报废率高。分析研究了泡沫塑料性能,利用泡沫塑料吸湿性能的可逆性,采用湿热成型法制备出符合要求的泡沫塑料芯材。 相似文献
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The objective of this study is to compare the spinnability, morphology, structure, mechanical properties, and cell compatibility of the silk fibroin nanofiber nonwoven electrospun fabrics using aqueous (AQ) solution and formic acid (FA) solution. The lower limit concentration was 5?wt% and 3?wt% of AQ solution and FA solution for electrospinning, respectively. The fiber diameter of electrospun fabric using FA solution was larger than that using aqueous solution at the same concentration. The secondary structure contents of silk fabrics were same between AQ and FA solutions. FA was remained in silk nanofibers, and the remained FA could be neutralized. Young’s modulus and cell adhesion on electrospun fabric using FA was lower than that using AQ solution. On the contrary, lower cell proliferation rate on electrospun fabric using FA was kept even after neutralization. 相似文献
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Segmented Polyurethanes were prepared by chain extending the prepolymers based on poly(tetramethylene oxide)glycol and tolylene diisocyanate using fluorescein. The polymers were characterized using FTNMR and FTIR. Thermal stability of the polymers was studied using a thermogravimetric analyzer, and the glass transition temperature of the polymers was determined using a differential scanning calorimeter. Tensile strength and percentage of elongation of these segmented polyurethanes were evaluated using a Universal Testing Machine. © John Wiley & Sons, Inc. 相似文献