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11.
为探究加强型Bi-2212超导股线的力学性能以及不锈钢包带对超导股线力学性能的影响,运用Ansys软件建立加强型Bi-2212超导股线的三维模型,采用有限元分析方法,对其机械结构进行仿真,模拟高温高压热处理后轴向受拉形变量和应力应变分布情况。仿真结果显示,在同样施加100 N拉力的情况下,与超导原线(Bi-2212超导线)相比,密绕Ni80Cr20包带后的加强型Bi-2212超导股线轴向受拉形变程度减小,约10%;应力应变均降低,约30%。采用Ni80Cr20作为外包带制成的加强型Bi-2212超导股线力学性能显著,是未来超导线发展方向之一。 相似文献
12.
Zhi‐Chao Jiang Yao‐Yu Xiao Xia Tong Yue Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(16):5386-5391
The ability to optically reconfigure an existing actuator of a liquid crystal polymer network (LCN) so that it can display a new actuation behavior or function is highly desired in developing materials for soft robotics applications. Demonstrated here is a powerful approach relying on selective polymer chain decrosslinking in a LCN actuator with uniaxial LC alignment. Using an anthracene‐containing LCN, spatially controlled optical decrosslinking can be realized through photocleavage of anthracene dimers under 254 nm UV light, which alters the distribution of actuation (crosslinked) and non‐actuation (decrosslinked) domains and thus determines the actuation behavior upon order‐disorder phase transitions. Based on this mechanism, a single actuator having a flat shape can be reconfigured in an on‐demand manner to exhibit reversible shape transformation such as self‐folding into origami three‐dimensional structures. Moreover, using a dye‐doped LCN actuator, a light‐fueled microwalker can be optically reconfigured to adopt different locomotion behaviors, changing from moving in the laser scanning direction to moving in the opposite direction. 相似文献
13.
对输电塔进行合理简化可以提高塔线体系动力学仿真的效率。本文给出自立塔梁柱简化模型的计算方法,并提出利用梁柱简化模型计算方法建立自立塔塔线体系整体模型,同时采用桁梁混合模型建立精细化塔线体系整体模型,对两种模型塔线体系静力特性及振型和固有频率等动力特性进行对比分析。以脱冰工况为例,采用生死单元技术将施加在输电线节点上的集中质量单元杀死来模拟脱冰,实现对塔线体系动力学响应的有限元模拟,研究塔线体系简化模型在动态响应中的适用性。结果表明,两种模型弯曲变形误差小,低阶的振型相同,固有频率值误差小,动力特性基本相同;脱冰工况下,自立塔节点位移和塔材内力时程曲线一致,在提高计算效率的情况下,能有效保证计算精度。 相似文献
14.
Yuan-Yuan Che Yanni Yue Ling-Zhi Lin Bingbing Pei Xuezu Deng Prof. Dr. Chao Feng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(38):16556-16561
Herein, we report a highly efficient and practical method for pyridine-derived heterobiaryl synthesis through palladium-catalyzed electrophilic functionalization of easily available pyridine-derived quaternary phosphonium salts. The nice generality of this reaction was goes beyond arylation, enabling facile incorporation of diverse carbon-based fragments, including alkenyl, alkynyl, and also allyl fragments, onto the pyridine core. Notably, the silver salt additive is revealed to be of vital importance for the success of this transformation and its pivotal role as transmetallation mediator, which guarantees a smooth transfer of pyridyl group to palladium intermediate, is also described. 相似文献
15.
Ruirui Xu Kun Wang Haoying Liu Prof. Dr. Weijun Tang Dr. Huaming Sun Prof. Dr. Dong Xue Prof. Dr. Jianliang Xiao Prof. Dr. Chao Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(49):22143-22148
A ruthenium-catalyzed formal anti-Markovnikov hydroamination of allylic alcohols for the synthesis of chiral γ-amino alcohols is presented. Proceeding via an asymmetric hydrogen-borrowing process, the catalysis allows racemic secondary allylic alcohols to react with various amines, affording enantiomerically enriched chiral γ-amino alcohols with broad substrate scope and excellent enantioselectivities (68 examples, up to >99 % ee). 相似文献
16.
Dr. Yaru Gong Chao Qin Yuteng Zhang Prof. Chunyi Sun Prof. Qinhe Pan Xinlong Wang Zhongmin Su 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(49):22218-22222
Systematic design and self-assembly of metal–organic polyhedra with predictable configurations has been a long-standing challenge in crystal engineering. Herein a concave polyoxovanadate cluster, [V6O6(OCH3)9(SO4)4]5−, which can be generated in situ under specific reaction conditions, is reported. Based on this cluster, a potential trivalent molecular building block, [V6O6(OCH3)9(SO4)(CO2)3]2−, can be obtained by the bridging-ligand-substitution strategy and it possesses appropriate angle information for the design of molecular cubes. Utilizing the face-directed assembly of the trivalent molecular building block and a diverse set of tetratopic carboxylate linkers, a series of metal–organic cubes ( VMOC-1 – VMOC-5 ) with the same topology but different functionalities and dimensions were designed and constructed. An inclusion study using VMOC-3 shows that they are potential molecular receptors for selective capture of size-matching polycyclic aromatic hydrocarbon guest molecules. 相似文献
17.
Qianqian Gao Dr. Yumeng Zhao Kangli Xu Dr. Chao Zhang Dr. Qian Ma Liqing Qi Dandan Chao Tingting Zheng Linlin Yang Dr. Yanyan Miao Prof. Da Han 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):23770-23774
A single-step method for isolation of specific cells based on multiple surface markers will have unique advantages because of its scalability, efficacy, and mildness. Herein, we developed multi-aptamer-mediated proximity ligation method on live cell membranes that leverages a multi-receptor co-recognition design for enhanced specificity, as well as a robust in situ signal amplification design for improved sensitivity of cell isolation. We demonstrated the promising efficacy of our method on differentiating tumor cell subtypes in both cell mixtures and clinical samples. Owing to its simple and fast operation with excellent cell isolation sensitivity and accuracy, this approach will have broad applications in biological science, biomedical engineering, and personalized medicine. 相似文献
18.
Cuixia Cui Yong Gao Dr. Jun Li Chao Yang Meng Liu Prof. Dr. Huile Jin Prof. Dr. Zhenhai Xia Prof. Dr. Liming Dai Prof. Dr. Yong Lei Prof. Dr. Jichang Wang Prof. Dr. Shun Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(20):8002-8007
Although tremendous efforts have been devoted to understanding the origin of boosted charge storage on heteroatom-doped carbons, none of the present studies has shown a whole landscape. Herein, by both experimental evidence and theoretical simulation, it is demonstrated that heteroatom doping not only results in a broadened operating voltage, but also successfully promotes the specific capacitance in aqueous supercapacitors. In particular, the electrolyte cations adsorbed on heteroatom-doped carbon can effectively inhibit hydrogen evolution reaction, a key step of water decomposition during the charging process, which broadens the voltage window of aqueous electrolytes even beyond the thermodynamic limit of water (1.23 V). Furthermore, the reduced adsorption energy of heteroatom-doped carbon consequently leads to more stored cations on the heteroatom-doped carbon surface, thus yielding a boosted charge storage performance. 相似文献
19.
20.
In the conventional scheme of generating strong mechanical squeezing by the joint effect between mechanical parametric amplification and sideband cooling, the resolved sideband condition is required so as to overcome the quantum backaction heating. In the unresolved sideband regime, to suppress the quantum backaction, a χ(2) nonlinear medium is introduced to the cavity. The result shows that the quantum backaction heating effect caused by unwanted counter-rotating term can be completely removed. Hence, the strong mechanical squeezing can be obtained even for the system far from the resolved-sideband regime. 相似文献