排序方式: 共有24条查询结果,搜索用时 657 毫秒
1.
The effect of clay on the morphology and phase-separation behavior of poly(methyl methacrylate)/poly(styreneco-acrylonitrile)(PMMA/SAN) blends and the variation of clay dispersion have been investigated. With the evolution of phase separation in PMMA/SAN, most of the clays are first located at the boundaries between PMMA and SAN, and then gradually move to the PMMA-rich domain, owing to the affinity of clay to PMMA. The introduction of clay causes the increase of binodal and spinodal temperatures of PMMA/SAN and enlarges their metastable region, indicating the phase stabilizing effect of clay on the matrix. But the influence of clay on the cloud points obviously depends on the composition of PMMA/SAN. The selective adsorption of PMMA on the clay results in the difference between the composition of surface layer and that of polymer matrix. Hence, the clay plays the role of an agent changing the conditions of phase structure formation. 相似文献
2.
The effect of nanoclay on the phase-separation behavior of poly(methyl methacrylate)/poly(vinyl acetate)(PMMA/PVAc) blends has been mainly investigated by small-angle laser light scattering. It is found that the effect of clay on the thermodynamics and kinetics of phase-separation for PMMA/PVAc blends seems inconsistent. The kinetics phaseseparation rate decreases, while the thermodynamics parameters, cloud points Tc and delay time tD of isothermal phaseseparation also decrease, and the variation amplitude depends on the matrix composition. The affinity of clay to PMMA results in the composition difference between the border layer and the polymer matrix and further causes the concentration fluctuation at the early stage of phase separation to reduce Tc and tD. On the other hand, the decrease of phase-separation rate is caused by the mechanical barrier effect of clay on the macromolecular diffusion of blend matrix. Hence, such seemingly counterintuitive results on the thermodynamics and kinetics of phase-separation are attributed to different dominant factors. 相似文献
3.
4.
采用小角激光光散射(SALLS)并结合动态流变学方法,考察了气相法二氧化硅(SiO2)粒子的加入对聚甲基丙烯酸甲酯/苯乙烯-丙烯腈无规共聚物(PMMA/SAN)共混体系相行为的影响,得到了添加SiO2粒子前后的相图,发现SiO2粒子对基体相行为的影响与基体的组成有关.对PMMA/SAN(60/40)体系,加入SiO2粒子后相分离温度上升,但并未改变相分离机理,仍为亚稳单相分解过程(spinodal decomposition,SD);而对于PMMA/SAN(30/70)体系,加入SiO2粒子后却降低了体系的相分离温度.该现象可能是SiO2粒子和基体组分界面间组成与PMMA/SAN共混物基体组成的差异造成的. 相似文献
5.
Internet of Car, resulting from the Internet of Things , is a key point for the forthcoming smart city. In this article, GPS technology, 3G wireless technology and cloudprocessing technology are employed to construct a cloudprocessing network platform based on the Internet of Car. By this platform, positions and velocity of the running cars , information of traffic flow from fixed monitoring points and transportation videos are combined to be a virtual traffic flow data platform, which is a parallel system with real traffic flow and is able to supply basic data for analysis and decision of intelligent transportation system. 相似文献
6.
7.
物联网、云计算和移动互联网的出现和发展,促进了商务智能在ERP的应用,加速了企业信息化的进程.本文通过研究企业信息化,ERP和商务智能三者的联系,指出商务智能在ERP环境下的企业信息化存在的问题和机遇,并提出一种基于云计算的可行的商务智能的ERP系统. 相似文献
8.
高分子复杂体系的结构与流变行为 总被引:2,自引:0,他引:2
流变学测试对非均相体系的结构变化具有敏感响应,被认为是表征多相/多组分聚合物体系结构与性能极为有效的方法.本文主要依据作者及其合作者的工作,对近年来围绕非均相体系形态结构与流变响应所开展研究的最新结果进行了总结和评述,涉及LCST型高分子共混体系的相形态与黏弹松弛、嵌段共聚物的微结构与线性/非线性黏弹行为、聚烯烃剪切诱导结晶时间尺度与流变响应、填充聚合物体系的结构性能和流变行为.对多相/多组分高分子共混体系形态结构演变的特征流变响应的充分认识,将有助于优化非均相体系的形态结构与最终力学性能. 相似文献
9.
10.
一种新的基于粗集的增量式规则提取算法 总被引:1,自引:0,他引:1
通过引入属性值通配符,进而将规则表示为带通配体的样本--规则样本,并对粗集的知识约简方法稍作修改,使得加入新样本后更新规则库时能够充分利用已经获得的规则,尽量减小待简的决策表的数据量,避免每次从庞大的原始决策表开始约简,从而加快更新速度,减小计算量,只作少量修改,而不必再从头约简,最后结合个实例阐明了该方法的基本思路。 相似文献