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151.
选取n次轴对称葵花型索穹顶结构的1/n,将空间轴对称结构等效为一次超静定平面桁架结构.给出了葵花型索穹顶结构撑杆不在同一径向上的内力和位移处理方法,推导了力法求解约束力的计算公式,提出了小变形时各点位移计算的位移传递矩阵和计算公式.最后,通过一个算例介绍了该方法的计算过程并与有限元计算结果进行了比较,内力和位移误差均在工程设计要求内,验证了方法的正确性和准确性. 相似文献
152.
Cardiac fibrosis is a common pathophysiologic process in nearly all forms of heart disease which refers to excessive deposition of extracellular matrix proteins by cardiac fibroblasts. Activated fibroblasts are the central cellular effectors in cardiac fibrosis, and fibrotic remodelling can cause several cardiac dysfunctions either by reducing the ejection fraction due to a stiffened myocardial matrix, or by impairing electric conductance. Recently, there is a rising focus on the proteomic studies of cardiac fibrosis for pathogenesis elucidation and potential biomarker mining. This paper summarizes the current knowledge of molecular mechanisms underlying cardiac fibrosis, discusses the potential of imaging and circulating biomarkers available to recognize different phenotypes of this lesion, reviews the currently available and potential future therapies that allow individualized management in reversing progressive fibrosis, as well as the recent progress on proteomic studies of cardiac fibrosis. Proteomic approaches using clinical specimens and animal models can provide the ability to track pathological changes and new insights into the mechanisms underlining cardiac fibrosis. Furthermore, spatial and cell-type resolved quantitative proteomic analysis may also serve as a minimally invasive method for diagnosing cardiac fibrosis and allowing for the initiation of prophylactic treatment. 相似文献
154.
155.
Local quantum uncertainty and interferometric power were introduced by Girolami et al. as geometric quantifiers of quantum correlations. The aim of the present paper is to discuss their properties in a unified manner by means of the metric adjusted skew information defined by Hansen. 相似文献
156.
《Mendeleev Communications》2021,31(5):706-708
Acyclovir release from its composites with unmodified silica at pH 1.6 and 7.4 follows zero order kinetics for two days. Modification of the silica matrix with phenyl groups leads to dramatic decrease in the drug release level at pH 7.4 compared with pH 1.6 as well as to heterogeneous phase state of acyclovir in the phenyl modified composite with high loading of the drug. 相似文献
157.
Ping Lv Xin Shen Zhiliyu Cui Bo Li Qiangqiang Xu Zhuo Yu Weijie Lu Haonan Shao Yan Ge Zhenhui Qi 《Journal of polymer science. Part A, Polymer chemistry》2021,59(23):3001-3008
Fiber-reinforced-concrete (FRC) mechanism refers short discrete fibers that are uniformly distributed and randomly oriented, which offers an effective way to improve the mechanical performance of concrete. In the design of supramolecular polymers, an analogous concept of FRC appears to have been considered very rarely-although fibrous structure has been frequently observed/generated during the supramolecular polymerization. In this work, we apply the alkane thermosets, octadecane (C18H38) and tetracosane (C24H50), taking the role of “concrete”, and the low-molecular-weight monomer with long alkyl chains as the essential “fiber” component, to fabricate the “fiber reinforced supramolecular polymer”. Very much like FRC mechanism in material science, the resulting fiber reinforced supramolecular polymer thus exhibit unusually high mechanical strength and stiffness, which is unprecedented in the conventional supramolecular strategy. 相似文献
158.
利用有限元方法求解:S-参数矩阵,研究了过模慢波结构对圆波导TM01,TM02模的反射特性,分析了在慢波结构末端加入谐振腔后,由于两端口的不对称性而造成的对反射特性影响。结果表明,在TM01的π模频率附近,慢波结构和谐振腔组成的系统对无谐振腔一侧端口入射TM01模的反射增大,而对有谐振腔一侧端口入射TM01模的反射减小。根据计算结果,解释了普通多波切伦柯夫振荡器所用慢波结构周期数较多的原因,说明了在多波切伦柯夫振荡器中引入谐振腔后,不但可以减少所用慢波结构周期数,而且有利于提高微波输出效率。 相似文献
159.
160.
S1 nuclease fromAspergillus oryzae (EC 3.1.30.1) was coupled to gelatin-alginate composite matrix using the residual free aldehyde groups on the surface of
glutaraldehyde crosslinked matrix. The immobilized enzyme retained approximately 10% activity of the soluble enzyme. When
partially purified enzyme was bound to the matrix, the immobilized preparation did not show any detectable enzyme activity.
However, the activity could be restored when the coupling was carried out in the presence of a coprotein or substrate. The
optimum pH of the immobilized S1 nuclease shifted to 3.8 from 4.3 for the soluble enzyme. Also, optimum temperature increased
to 65°C after immobilization. Bound S1 nuclease showed increased pH and temperature stabilities. Immobilization brought about
a twofold decrease in the Michaelis-Menton constant (K
m). 相似文献