首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
介绍了整流机组的技术改造内容。通过改造,提高了装备技术水平,简化了操作,提高了供电的平稳性和安全性;降低了电力损耗;节约了能源。  相似文献   

2.
氯乙酸氨解法生产甘氨酸的工艺优化探讨   总被引:1,自引:0,他引:1  
李世群 《江西化工》2007,(1):119-120
本文介绍了氯乙酸氨解法生产甘氨酸的工艺及其优化.通过优化的氯乙酸氨解法,缩短了工艺路线,减少了固定投资,降低了生产成本,提高了生产安全性.  相似文献   

3.
ZnO和金属单质催化尿素醇解法制备碳酸二甲酯的研究   总被引:9,自引:0,他引:9  
使用不同方法制备ZnO催化剂并对其催化活性进行了比较,选出了高催化活性的催化剂,找到了合成碳酸二甲酯(DMC)的最佳工艺条件并且对催化剂进行了XRD和SEM表征.同时对3种金属单质进行了活性比较,得到镁粉有高的催化活性,并提出了镁粉催化反应的机理.同时,本实验还优化了通气方式.  相似文献   

4.
差一点先生     
差一点先生,18岁那年,差一点考取大学。虽然平时学习吊儿郎当了点,高考总分差了一大截,不过,分数摊到每门功课上,其实只差了一点。差一点先生因此常常懊丧地对人说,如果俺考取了大学,指不定现在成了享誉世界的化学家,还获得了诺  相似文献   

5.
列举了某公司尼龙生产线己二酸装置氧化反应器搅拌在多年运行中常见的损坏形式.分析了原因,提高了对氧化反应器搅拌的重视程度,及时对其采取预防措施.这些举措延长了搅拌器的使用寿命,保证了尼龙六六盐生产线的平稳运行,减少了生产成本,提高了经济效益.  相似文献   

6.
概述了石墨烯(GNs)的定义及发展史,介绍了GNs的特性及表征方法,详细介绍了GNs的9种制备方法.最后综述了GNs在聚合物中的应用情况,展望了GNs未来的应用前景.  相似文献   

7.
介绍了中药化妆品的基本概念,总结了国内外中药化妆品的应用现状,并概述了其发展趋势。同时,指出了中药化妆品的发展瓶颈,总结了中医药理论在化妆品中的应用,并提出了一些发展性的建议。  相似文献   

8.
介绍了PUMP-200新型乳液泵组装机的工作原理及特点,通过比较和分析,说明了该新机的运用,节省了大量的人力物力,降低了能耗,大大缩短了产品交货期,实现了产品质量的稳定,提高了生产效率,经济效益显著。  相似文献   

9.
焙烧炉燃烧系统油改天然气研究与应用   总被引:1,自引:0,他引:1  
张斌 《炭素》2010,(1):46-48
介绍了炭素焙烧炉燃烧系统由燃油改为天然气的过程,以及使用效果和效益分析,真正实现了清洁生产,达到了理想的节能效果,改善了工艺水平、降低了生产成本、提高了生产效率、净化了工作环境。  相似文献   

10.
锂离子电池隔膜的市场与技术发展   总被引:1,自引:0,他引:1  
概述了锂离子电池隔膜技术的发展,分析了市场需求,介绍了国内主要生产企业目前状况,探讨了发展趋势。  相似文献   

11.
FriedelCrafts Reaction as a simple and convenient approach to the surface modification of aramid fiber was introduced in this paper. Epoxy chloropropane was chosen as the treatment reagent to modify aramid fibers surface via Graft reaction. After the modification, the interfacial properties of aramid/epoxy composites were investigated by the single fiber pull-out test (SFP), and the mechanical properties of aramid fibers were investigated by the tensile strength test. The results showed that the interfacial shear strength (IFSS) value of aramid/epoxy composites was enhanced by about 50%, and the tensile strength of aramid fibers had no obvious damage. The crystalline state of aramid fibers was determined by X-ray diffraction instrument (XRD), and the results showed that there were not any distinct crystal type varieties. The surface elements of aramid fibers were determined by X-ray photoelectron spectroscopy (XPS), the analysis of which showed that the oxygen/carbon ratio of aramid fiber surface increased obviously. The possible changes of the chemical structure of aramid fibers were investigated via Fourier transform infrared spectrum (FTIR), and the analysis of which showed that the epoxy functional groups were grafted into the molecule structure of aramid fibers. The surface morphology of aramid fibers was analyzed by Scanning electron microscope (SEM), and the SEM results showed that the physical structure of aramid fibers was not etched or damaged obviously. The surface energy of aramid fibers was investigated via the dynamic capillary method, and the results showed that the surface energy was enhanced by 31.5%, and then the wettability degree of aramid fiber surface was enhanced obviously too. All of the results indicated that this novel chemical modification approach not only can improve the interfacial bonding strength of aramid/epoxy composites remarkably, but also have no negative influence on the intrinsic tensile strength of aramid fibers.  相似文献   

12.
利用玻璃纤维和芳纶纤维的混杂纤维增强酚醛泡沫,考察了玻璃纤维和芳纶纤维的混杂比对酚醛泡沫的压缩强度、弯曲强度和冲击强度的影响。结果表明,玻璃纤维能够大幅提高酚醛泡沫的压缩强度,且在混杂纤维增强的酚醛泡沫中,压缩强度随着玻璃纤维所占的比重的增加而增大;芳纶纤维能够大幅提高酚醛泡沫的冲击强度,且在混杂纤维增强的酚醛泡沫中,冲击强度随着芳纶纤维所占的比重的增加而增大;玻璃纤维和芳纶纤维均可提高酚醛泡沫的弯曲强度,但当二者以1∶1(质量比,下同)的比例混杂增强酚醛泡沫时,复合酚醛泡沫的弯曲强度达到最大,此时出现了两种纤维最优的混杂协同效应。  相似文献   

13.
Good wetting of reinforced fiber by resin was a main factor in the improvement of the interface adhesion of their composites. Ultrasound with a frequency of 20 kHz was used to improve the wettability between aramid fibers and epoxy resin during the winding process of the composites. The effects of ultrasound on the viscosity and surface tension of epoxy resin and on the surface characteristics of aramid fibers were investigated. The wettability of aramid fibers and treated epoxy resin under different conditions and of aramid fibers and epoxy resin under ultrasonic online treatment were compared. The results indicated that the main action of ultrasound was to force epoxy resin to impregnate aramid fibers, in addition to the influence of ultrasound on the properties of epoxy resin and aramid fibers. The results of microdebond testing showed that the interfacial shear strength (IFSS) of aramid/epoxy composites could be 26% higher than that of untreated composites because of the improved wettability between aramid fibers and epoxy resin subjected to ultrasonic online treatment. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006  相似文献   

14.
Short aramid fibers have been successfully used to reinforce the interface adhesive property between carbon fiber/epoxy composites and aluminum foam, and to form aramid‐fiber “composite adhesive joints.” In this study, to further improve the reinforcing effect of the aramid‐fiber‐reinforced adhesive joints, aramid fibers were ultrasonic treated to conduct different surface conditions. Critical energy release rate of the carbon fiber/aluminum foam sandwich beams with as‐received and treated interfacial aramid fibers were measured to study the influence of the surface treatment on aramid fibers. It was found that reinforcements in critical energy release rate were achieved for all samples with treated aramid fiber as measured under double cantilever beam condition. The interfacial characteristics of the short aramid fibers with different surface condition were investigated and discussed based on scanning electron microscopy observations. It is suggested that advanced bonding between aramid fibers and epoxy resin was conducted after surface treatment, and more energy was therefore absorbed through fiber bridging during crack opening and extension process. POLYM. COMPOS., 36:192–197, 2015. © 2014 Society of Plastics Engineers  相似文献   

15.
为了改善芳纶纤维复合材料的界面粘结性能,合成了一种新型树脂(AFR)作为基体,以未经任何表面处理的芳纶纤维作增强材料,制备了芳纶纤维/AFR复合材料。采用测定表面能、接触角、层间剪切强度、横向拉伸性能和扫描电镜观察形貌等方法,从宏观和微观等方面研究了芳纶纤维/AFR复合材料的界面粘结性能。结果表明,AFR树脂与芳纶纤维有相近的表面能,AFR树脂溶液与芳纶纤维的接触角为42.8°,而环氧树脂(EP)与芳纶纤维的接触角为68°,说明AFR树脂对芳纶纤维的润湿性优于EP树脂;芳纶/AFR复合材料的层间剪切强度、横向拉伸强度和纵向拉伸强度分别为74.64MPa、25.34MPa和2256MPa,比芳纶/EP复合材料的相应强度分别提高了28.7%、32.5%和13.4%,其复合材料破坏面的形貌也说明芳纶纤维与AFR树脂之间的界面粘结性能较好。  相似文献   

16.
对位芳纶生产和应用技术进展(Ⅱ)   总被引:1,自引:0,他引:1  
简介对位芳纶的供需和研发概况;着重叙述PPTA型芳纶、共聚型芳纶、俄罗斯芳纶等重要对位芳纶产品以及PBO纤维、M5纤维等相关高性能纤维的生产技术和主要性能,探讨了开发生产高性能纤维的通用技术;分析了对位芳纶应用的现状和技术;探讨对位芳纶生产技术和应用技术的发展趋势。  相似文献   

17.
利用L-3,4-二羟基苯丙氨酸(L-DOPA)的氧化自聚合,在杂环芳纶表面修饰聚L-3,4-二羟基苯丙氨酸(PDOPA)活性涂层来提高芳纶的表面活性及耐紫外辐照性能。结果表明:改性后芳纶表面粗糙度显著提高,同时,PDOPA涂层上大量的羧基、羟基等活性单元均有利于增强与环氧树脂的机械锁合力,改性后芳纶/环氧树脂复合材料的界面剪切强度提高了32.0%。此外,上述改性过程对杂环芳纶本身力学性能影响较小,纤维的拉伸强度保持率可以达到100%,基本实现了无损改性。同时,由于PDOPA的保护作用,改性后芳纶的耐紫外辐射性能显著提高;经过168 h紫外线辐照处理后,其拉伸强度保持率可达到92.5%,显著提升了杂环芳纶的耐紫外线辐照特性。  相似文献   

18.
对位芳纶生产和应用技术进展(Ⅰ)   总被引:4,自引:0,他引:4  
简介对位芳纶的供需和研发概况,着重叙述PPTA型芳纶、共聚型芳纶、俄罗斯芳纶等重要对位芳纶产品以及PBO纤维、M5纤维等相关高性能纤维的生产技术和主要性能,探讨了开发生产高性能纤维的通用技术;分析了对位芳纶应用的现状和技术;预测对位芳纶生产技术和应用技术的发展趋势。  相似文献   

19.
芳纶表面化学改性技术研究现状   总被引:3,自引:1,他引:2  
概述了芳纶表面化学改性的方法。从芳纶分子结构的特点出发,论述了芳纶表面化学刻蚀及化学接枝等化学改性技术的原理、特点和应用效果;详述了基于芳纶结构中苯环上的硝化还原反应、氯磺化反应和酰胺基上的水解反应、氢取代反应、金属化反应等的反应原理及应用效果。指出多种化学改性技术的交叉应用将成为芳纶表面化学改性的趋势。  相似文献   

20.
俞波 《合成技术及应用》2005,20(4):33-39,47
简介对位芳纶的供需和研发概况;着重叙述PPTA型芳纶、共聚型芳纶、俄罗斯芳纶等重要对位芳纶产品以及PBO纤维、M5纤维等相关高性能纤维的生产技术和主要性能,探讨了高性能纤维开发生产的通用技术;分析了对位芳纶的应用现状和技术;探讨对位芳纶生产技术和应用技术的发展趋势。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号