共查询到20条相似文献,搜索用时 762 毫秒
1.
为了提高毫米波铝合金腔体整体的防护能力及焊接能力,采用整体化学氧化和局部电镀镍-银-搪锡技术,解决了整体电镀金层薄、孔隙率高、易产生小孔电偶腐蚀的问题.结果显示:此法处理后的毫米波铝合金腔体可通过96 h盐雾试验和240 h湿热试验,且镀银层经搪锡后,封闭了镀层微孔,抗蚀能力及其他性能均满足使用要求. 相似文献
2.
总结了国内外沥青材料自修复的研究现状及进展,从自修复机理、自修复能力影响因素及评价方法等方面来介绍沥青材料自修复能力的概况,并指出了国内外现有研究存在的主要问题;随后,概述了提高沥青材料自修复能力的方法:电磁感应加热法、微波加热法、微胶囊法、光催化修复法等先进技术,并指出各种方法的缺陷;最后,根据国内外现有研究,提出了下阶段研究的重点应为:根据自修复机理及影响因素,进行基质沥青选择及沥青混合料的组成优化设计,为真正实现自修复沥青路面提供理论基础. 相似文献
3.
4.
玻璃纤维增强复合材料抗爆容器的研究进展 总被引:1,自引:0,他引:1
综述了国内外树脂基玻璃纤维增强复合材料抗爆容器的主要研究成果,对纤维材料及粘合剂的选取、纤维缠绕方式、壳体的动态响应及失稳抑制、容器的抗爆能力和尺度效应等方面进行了较全面的总结.简要介绍了其在航空航天、工业及国防等领域的应用情况. 相似文献
5.
6.
7.
8.
9.
10.
11.
目前产品认证通行的第5种认证模式是通过试验的方式判断认证产品是否满足认证要求。模块式多联机是空调中普遍采用的机型,对试验室测试能力要求高并且测试本身非常困难。本文探讨将单机组试验数据与多机组计算结合的方法用于判断模块式多联机组是否能够达到认证要求。针对同种机型室外机组成的模块机和不同种机型室外机组成的模块机,在对单台机组的试验数据进行分析的基础上,通过多种数据组合、计算,得出模块机的IPLV(C)值,以此证明,组合后模块机组的IPLV(C)值是可以通过计算得出,满足认证需求。 相似文献
12.
变频空调器保护点设计的可靠性试验研究 总被引:1,自引:0,他引:1
通过对变频空调器的排气温度、IPM功率模块温度、电源模块温度、冷凝器中部温度、电流随空调器频率变化以及室外环境温度变化规律的试验研究,提出一种变频空调器保护点设计方法。 相似文献
13.
研制一种可全年供冷的节能型风冷冷水机组,机组由蒸气压缩制冷系统和自然冷却制冷系统组成,这2个系统根据环境温度进行切换。根据北京市典型年室外干球逐时气象资料计算获得机组全年能源消耗效率APF,当进/出水温度12/7℃工况时其值为3.263,进/出水温度15/10℃工况时其值为3.675。仿真与试验研究结果表明,机组在43~-15℃环境温度范围内能够安全稳定连续地运行,且机组的节能效果明显,在节能减排方面具有积极的意义。 相似文献
14.
15.
Florence Delor-Jestin Namrata S Tomer Raj Pal Singh Jacques Lacoste 《Science and Technology of Advanced Materials》2008,9(2)
Most applications of silicones are linked to their hydrophobic properties and (or) their high resistance to ageing (e.g. thermal ageing and photoageing). However, when placed in extreme environments, these materials can fail as in the case of epoxy/fiber glass composite powerlines insulators, where crosslinked polymethylsyloxanes (PDMSs) are used as the protective envelope (housing) of the insulator. We report on the behavior of both pure/noncrosslinked PDMSs and typical formulations used in industrial insulators, i.e. containing peroxide crosslinked PDMS, alumina trioxide hydrated (ATH) and silica. Special attention is paid on both (i) the sources of potential degradation and (ii) the best analytical methods that can be applied to the study of very complex formulations. (i) Aside from conventional types of ageing such as photo-ageing and thermal, hydrolytic, and service life ageings, treatments with acidic vapors, plasma and ozone possibly generating species from the reaction of a high electric field with air were also performed, which allowed to accelerate electrical and out-door ageings and to obtain differently aged materials. (ii) Aside from conventional analytical methods of polymer degradation such as FTIR/ATR spectroscopy and SEC, TG, hardness measurements, more specific methods like photo/DSC, TG/IR, thermoporosimetry, resistivity and density measurements were also performed to characterize the chemical and physical evolutions of polymer materials. In particular, it was found that treatment with nitric acid vapor has detrimental effects on the properties of both fire retardants (e.g. ATH) and PDMSs, affecting the hardness and resistivity of the formulated material. 相似文献
16.
AbstractMost applications of silicones are linked to their hydrophobic properties and (or) their high resistance to ageing (e.g. thermal ageing and photoageing). However, when placed in extreme environments, these materials can fail as in the case of epoxy/fiber glass composite powerlines insulators, where crosslinked polymethylsyloxanes (PDMSs) are used as the protective envelope (housing) of the insulator. We report on the behavior of both pure/noncrosslinked PDMSs and typical formulations used in industrial insulators, i.e. containing peroxide crosslinked PDMS, alumina trioxide hydrated (ATH) and silica. Special attention is paid on both (i) the sources of potential degradation and (ii) the best analytical methods that can be applied to the study of very complex formulations. (i) Aside from conventional types of ageing such as photo-ageing and thermal, hydrolytic, and service life ageings, treatments with acidic vapors, plasma and ozone possibly generating species from the reaction of a high electric field with air were also performed, which allowed to accelerate electrical and out-door ageings and to obtain differently aged materials. (ii) Aside from conventional analytical methods of polymer degradation such as FTIR/ATR spectroscopy and SEC, TG, hardness measurements, more specific methods like photo/DSC, TG/IR, thermoporosimetry, resistivity and density measurements were also performed to characterize the chemical and physical evolutions of polymer materials. In particular, it was found that treatment with nitric acid vapor has detrimental effects on the properties of both fire retardants (e.g. ATH) and PDMSs, affecting the hardness and resistivity of the formulated material. 相似文献
17.
从失效案例探讨钢制紧固件的氢脆问题 总被引:3,自引:0,他引:3
讨论了影响钢制紧固件氢脆敏感性的主要因素。分析认为,设计上要充分考虑材料强度对氢脆敏感性的影响,尽量降低其强度水平;要采用合适的热处理工艺,以减少晶界脆化元素,抑制薄膜状碳化物的形成,从而获得氢脆敏感性小的显微组织;在加工及装配过程中,应尽可能避免在零件表面产生机械损伤;要采用低氢脆电镀工艺,必要时采用无氢脆的达克罗等涂覆方法;电镀后要采用合理的除氢工艺,进行严格除氢处理;对于重复使用件,在酸洗去除镀层后要先进行除氢处理,然后电镀,再除氢。 相似文献
18.
鲁迪 《制冷空调与电力机械》2010,31(3):45-47,35
介绍了该节能办公楼暖通空调的节能设计:冷热源采用地源热泵,空调系统采用带全热交换器新风机组加无级调速无刷直流风机盘管系统及地板送风变风量空调系统;对比分析了采用这些系统对节能减排的意义。 相似文献
19.
晋焦高速公路路堑开挖大爆破 总被引:1,自引:1,他引:0
在公路路堑切槽开挖硐室控制大爆破中,采用较大不耦合比较进行松动控制爆破。在较为复杂的地质地形条件下,通过合理地选择爆破方案和设计爆破网路,使爆破取得成功,有效地控制了爆破效果和安全。 相似文献
20.
在城市建筑控爆中,因周围环境条件限制,采用通常的沿矩形建筑平面长短轴方向倾倒的方法不适用,只有沿建筑平面对角线方向倾倒。本文介绍了沿矩形建筑平面对角方向倾倒的一个工程爆破实例 相似文献