聚合体物理工程
王思庆
库马教授
博士学位芝加哥大学理学院(1987年)
美国物理学会研究员(1997年)
美国科学促进协会研究员(2014年)
美国物理学会成员
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取自亚马逊 终于自由 长链加入弹性化网络, |
好奇心是幸福之泉
因为我们好奇 每天都是节日
小王
YouTube链接最近系列讲解(29次讲解)非线性聚合体算法概论性并关闭备注.
聚合体物理YouTube频道开播40多场讲座,讲解聚合体文理学和机械学的方方面面
研究兴趣
聚合物和聚合物材料物理和工程学,包括持久聚合物,如PLA和PHA.聚合物融和矩形学和分子机理概念基础固态,有玻璃或半晶体素或“both”(即半晶体聚合物在玻璃转换温度下方)探索所有聚合物处理、结构与机械特性之间的关系
当前活动
当前研究共三集开发聚合物液态和固态机械特征统一框架:聚合液态学、玻璃聚合物和半晶状聚合物分子机理学以及塑料和弹性体骨折行为。数千亿磅聚合物因适当的机械特征而逐年消化。因此,更好地了解聚合物机械性能是聚合物科学和工程核心主题。我们对非线性聚合体理学的理解(非线性聚合体理学)威利2018提供宝贵的洞察力 来了解玻璃状半晶体聚合物 何时何以增软并抗固态骨折
第3集:塑料和弹性体断裂机械
Brittle fracture of polymers is typically described using linear-elastic fracture mechanics. The practice is predicated on the assertion that Griffith style energy balance argument applies. On the other hand, there is no conceptual difficulty to imagine sudden fracture without invoking any structural inhomogeneity: failure of load-bearing strands can occur sequentially, one strand at a time. In tensile extension, all loading elements are in series, permitting strain localization in the form of brittle fracture. Equipped with the understanding of the nature of brittle-ductile transition in glassy polymers (see Episode 2a below), we show that toughness of polymers including plastics and elastomers may be controlled by the inherent strength. This realization can be expected to simulate theoretical modeling to correlate mechanical strength with underlying chain network structure. The first efforts to examine the origin of fracture of glassy polymers have been recently described inarxiv.
第2b集:布里特尔大赛半晶体聚合物词性s级
Semicrystalline polymers can be conveniently classified into two groups depending on whether their glass transition temperature is above or below room temperature. According to this classification, polymers such as polyethylene and polypropylene belongs to class A and polyesters such as PET and poly(lactic acid) belong to class B. It is often noted that class B semicrystalline polymers (SCPs) are brittle (at room temperature) in presence of saturated crystallization while their counterparts, i.e., the same polymers in their amorphous glassy state can be ductile. Our current efforts are directed to develop a basic molecular-level understanding of mechanical behavior of semicrystalline polymers so that tough semicrystalline polymers can be manufactured without invoking any chemical changes. To establish a realistic model for mechanics of SCPs, it is indispensable for us to have a thorough understanding of the other two subjects listed below as 1.非线性融化Rhelogy2单质聚合物分子机理学。主题1和2a允许我们开发处理结构-财产关系,以便B类SCP可成为超粘性、光清晰耐热性,如最近例子所示-软质2021171457-1462.
第2a集:玻璃聚合器分子机械
最近我们才开始理解 如何思考
关键线索出自观察所有非聚合有机镜都易碎。自然问题出自聚合镜何以可通缩?聚合镜为密钥分子模型J.切姆物理类141,094905(2014);聚合体197,122445(2020)投放、疯狂和易动转换线程-order picture, polymer glasses are structural hybrids, made of a primary structure due to short-ranged inter-segmental attractions (causing vitrification) and long-ranged chain networking that can be extended to allow buildup of chain tension, plausibly corresponding to bond length and angle deviations from the equilibrium values. A polymer glass gains global plasticity and is ductile at a given temperature if its chain network can activate the glassy state globally. Conversely, if the chain network breaks down before it "finishes its job", a polymer glass is going to undergo brittle fracture. Here the chain network is envisioned in terms of junctions formed by at least two pairs of hairpins from different chains.
第1集非线性熔化参游
其中许多聚合物,如聚乙烯和聚丁二烯,都是混合式液体,高于熔化和玻璃转换温度过去十年的研究告诉我们,深相纠结聚合物,如高粘性液态,行为像瞬态固态,在启动变形或大步变形或大步变换或大步变换时经历内聚分解,新世界观出现J.切姆物理类127号064903(2007)..局部滴出现象导致松散定位,如剪裁和非二次松动。 一种新的世界观出现,我们开发出对剪切和扩展的变形统一处理法。 近十年来,从实验室发布约60篇论文并发布论文链表包括本类出版物手稿编译拒绝发布为什么EDT必须存在而不管实验难点,即独立于边际效应进一步响应环绕切带发生时的“争议性”。
一小时讨论会YouTube和Objective都提供阳台betway苹果总结六年密集研究后(介于2006至2012年)我们现在所知道的情况,Akron大学于2012年3月2日发布帮助理解新世界观与管模式标准范式之差,表达式强调需要解决因果关系问题:(a) 偏差出自和b) 链变差停止增加