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排序方式: 共有583条查询结果,搜索用时 15 毫秒
81.
材料的表面能与粘接界面的酸碱作用 总被引:5,自引:2,他引:3
综述了作者对材料表面能与粘接界面的酸碱作用的研究简况,主要内容包括:(1) 聚合物表面能的测算;(2) 金属与无机非金属材料表面能的测算;(3) 丙烯酰胺( 丙烯酸) - 天然橡胶接枝聚合物的酸碱作用;(4) 界面酸碱作用对聚合物抗凝血性能的影响;(5) 硅烷偶联剂酸碱作用的研究;(6) E V A 泡沫材料粘接界面的酸碱作用等。介绍了各有关的研究方法及主要研究结果。 相似文献
82.
分析了100E1、100E3两台中间冷却器运行性能不理想的原因,指出改造的唯一途径是更换两台新间冷器,阐述新间冷器的结构特点及运行结果。 相似文献
83.
流变法铸造石墨铝挤压铸造工艺参数的正交试验研究 总被引:2,自引:0,他引:2
本文采用正交试验法研究了用流变法制造石墨铝复合材料的挤压铸造工艺参数,分析讨论了几种工艺参数对石墨铝内耗值的影响。 相似文献
84.
单层卫星网络由于轨道高度和覆盖能力的不同,以至构成通信的单层系统往往不能满足不同业务服务质量的需求。分析了Walkerdelta型星座构建多层卫星通信网络的拓扑结构和ISL性能,提出了在统计分布模型下的多层卫星自适应路由策略,综合考虑了路径时延和ISL链路负载。仿真结果表明了多层网络自适应路由策略能够更加有效地分配网络通信量,网络具有较小的丢包率、网络平均归一化链路负载和特定路径综合路径权重,有利于降低网络平均阻塞概率和特定路径阻塞概率,获得更高的可靠性,较传统的单层非自适应路由更加有效、可靠。 相似文献
85.
Vladimir I Lozinsky Lilija G Damshkaln Rupert Brown Ian T Norton 《Polymer International》2000,49(11):1434-1443
In this study of freeze–thaw‐induced gelation of aqueous locust bean gum (LBG) solutions we found that gel formation proceeded through at least two kinetic stages. Initially, rather weak spongy cryostructurates were formed as a result of freezing the system, but their strength and thermostability (fusion temperature) could be increased considerably by means of thawing out the system sufficiently slowly. Preparation of LBG cryogels in the presence of chaotropic (urea) and anti‐chaotropic (sodium sulfate) substances showed that the major mechanism responsible for stabilization of junction zones in these gel materials was hydrogen bonding. Therefore, use of the agents facilitating formation of hydrogen bonds enabled the gelation of LBG solutions without the need for synergistic polymers or cryogenic treatments. © 2000 Society of Chemical Industry 相似文献
86.
一种基于H.264/AVC的帧间模式快速判决算法 总被引:6,自引:2,他引:4
新的视频编码标准H.264/AVC能够获得较高的编码效率是以增加运算复杂度为代价的,1个帧间宏块(MB)的可选编码模式包括7种块尺寸的帧间预测模式和2种块尺寸的帧内预测模式,其校验模型仅给出一种复杂的全搜索方法来确定最佳模式。本文提出一种快速模式判决算法,将全部模式进行分类,通过判别MB的一致性和比较MB的空时相关性逐类型比较,可有效减少判决的模式数量。实验结果表明,这种方法能够在保持视频质量的同时,节省约35%的编码时间。 相似文献
87.
This article is the first part of a three‐article series and it deals with full‐scale tests of a load‐carrying box girder. The two other articles present more details on smaller sub‐component levels as well as cap specimens (article 2) and shear webs (article 3). This article also links to the two other articles and brings the main results from them into relevance for a wind turbine blade designer. The investigated failure modes in all three articles relate to the Brazier effect, which is expected to be the key dominating failure mechanism in future wind turbine blade designs. The Brazier effect may also have a significant impact on present wind turbine blades. In this article, a 34 m long load‐carrying box girder has been tested in static flap‐wise bending, and it has been demonstrated that, for this design, the Brazier effect is a critical phenomenon of great relevance for the ultimate failure strength. The box girder has been evaluated with and without a cap (wire) reinforcement. The cap reinforcement is one out of seven inventions Risø DTU published in 2008, which are all intended to result in a lighter and more reliable blade design. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
88.
楼梯作为结构的一种支撑,对结构的整体性能有着重要影响。以实际工程为背景,采用ETABS软件建立了考虑楼梯构件和不考虑楼梯构件两个钢框架模型,分析了在地震作用下楼梯构件对钢框架结构整体受力性能的影响。计算结果表明,楼梯构件作为一种支撑,具有较大的刚度,对结构的周期、振型、层剪力和层间位移都有很大的影响,必须合理布置楼梯,分析中应考虑其影响,设计中应加强重视。更多还原 相似文献
89.
Analysis of microstructure and performance of temper bead welded joints for SA508-3steel by Quenching and Tempering mode
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The HAZ microstructure and performance of Quenching and Tempering mode temper bead welding and general welded joints which were made on SA508-3 steel of 60 mm thickness were compared in this article.The result shows that tempering sorbite which has excellent overall performance was obtained in both modes.The microstructure of Quenching and Tempering mode welded joints got more fine grain.Even though the hardness of tempering bead welded joints is higher than the general one,it still meets the standards which is lower than 350 HV.The impact absorbing energy of each district of tempering bead welded joints HAZ reached 170 J, which is equal to general one. 相似文献
90.
《Journal of Nuclear Science and Technology》2013,50(3):223-232
An interfacial friction model for two-fluid model code has been developed for the counter- current gas-liquid flow limitation at hot leg in a pressurized water reactor. Firstly, using a typical two-fluid model code TRAC-PF1/MOD1, we analyzed whether the interfacial friction model under countercurrent stratified flow by Ohnuki et al., which has been verified with an envelope model at steady state, functions well for the dynamic calculation with the two-fluid model code or not. It was found from the analyses that the model by Ohnuki et al. should be combined with a suitable interfacial friction model for the slug flow regime in hot leg. Based on flow observation in a small scale air-water experiment, models at the bend of hot leg and in the roll wave regime in the horizontal flow path of hot leg were newly developed as the model in the slug flow regime and the slug flow model was combined with the model by Ohnuki et al., The validity of the present model was confirmed with the data under various conditions of scales, pressures and fluid combinations (inner diameter: 0.025~0.75m, pressure: 0.1~7.1 MPa and air-water or steam-water). 相似文献