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21.
Two-dimensional van der Waals magnetic materials are intriguing for applications in the future spintronics devices, so it is crucial to explore strategy to control the magnetic properties. Here, we carried out first-principles calculations and Monte Carlo simulations to investigate the effect of biaxial strain and hydrostatic pressure on the magnetic properties of the bilayer CrI3. We found that the magnetic anisotropy, intralayer and interlayer exchange interactions, and Curie temperature can be tuned by biaxial strain and hydrostatic pressure. Large compressive biaxial strain may induce a ferromagneticto-antiferromagnetic transition of both CrI3 layers. The hydrostatic pressure could enhance the intralayer exchange interaction significantly and hence largely boost the Curie temperature. The effect of the biaxial strain and hydrostatic pressure revealed in the bilayer CrI3 may be generalized to other two-dimensional magnetic materials. 相似文献
22.
The collisional dynamics of two symmetric droplets with equal intraspecies scattering lengths and particle number density for each component is studied by solving the corresponding extended Gross−Pitaevskii equation in two dimensions by including a logarithmic correction term in the usual contact interaction. We find the merging droplet after collision experiences a quadrupole oscillation in its shape and the oscillation period is found to be independent of the incidental momentum for small droplets. With increasing collision momentum the colliding droplets may separate into two, or even more, and finally into small pieces of droplets. For these dynamical phases we manage to present boundaries determined by the remnant particle number in the central area and the damped oscillation of the quadrupole mode. A stability peak for the existence of droplets emerges at the critical particle numberNc ≃ 48 for the quasi-Gaussian and flat-top shapes of the droplets. 相似文献
23.
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
24.
Czechoslovak Mathematical Journal - The irregularity of a graph G = (V, E) is defined as the sum of imbalances ∣du ? dv∣ over all edges uv ∈ E, where du denotes the degree... 相似文献
25.
Hu Guanqun Huang Rui Wang Hongli Zhao Qiuping Zhang Xingkai 《Journal of Solid State Electrochemistry》2022,26(5):1313-1322
Journal of Solid State Electrochemistry - Electroless nickel-phosphorus plating is an important surface treatment method for copper due to its good corrosion resistance and nonmagnetic properties.... 相似文献
26.
针对拼接干涉测量技术除了引入拼接误差,还将引入机械运动误差的问题,为此提出一种X射线反射镜的非零位干涉测量方法,无需拼接便可实现零回程误差的高精度干涉测量。利用一块高精度平面镜来标定干涉系统在全视场范围内的回程误差。通过将待测非球面镜划分成多个子孔径,每个子孔径可近似看作一个平面,这样可以从标定数据库中找到该子孔径所对应的回程误差,通过简单的矩阵拼接可得到整个待测非球面镜的回程误差。以X射线椭圆柱面反射镜为例进行实验,实现X射线椭圆柱面反射镜非零位干涉测量面形的回程误差有效标定,相比于拼接干涉测量方法二者结果一致性较好,证实所提方法的正确性。 相似文献
27.
Lianghao Song Tiantian Xu Daowei Gao Prof. Xun Hu Prof. Cuncheng Li Prof. Shun Li Prof. Guozhu Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(26):6621-6627
CeO2-based catalysts are widely studied in catalysis fields. Developing one novel synthetic approach to increase the intimate contact between CeO2 and secondary species is of particular importance for enhancing catalytic activities. Herein, an interfacial reaction between metal–organic framework (MOF)-derived carbon and KMnO4 to synthesize CeO2−MnO2, in which carbon is derived from the pyrolysis of Ce-MOFs under an inert atmosphere, is described. The MOF-derived carbon is found to restrain the growth of CeO2 crystallites under a high calcination temperature and, more importantly, intimate contact within CeO2/C is conveyed to CeO2/MnO2 after the interfacial reaction; this is responsible for the high catalytic activity of CeO2−MnO2 towards CO oxidation. 相似文献
28.
Xuan Zhang Xianhe Fang Miao Xu Yibo Lei Zibo Wu Xiangdong Hu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(23):7927-7931
Enantioselective total syntheses of pseudopteroxazole ( 1 ) and ileabethoxazole ( 2 ) are presented. The two original stereocenters were constructed in excellent enantioselectivity and good diastereoselectivity through Carreira's asymmetric dual catalytic allylation, which shows potential for accessing diastereoisomers at C2 and C3 of 1 and 2 . Cationic cyclizations of 13 and 24 demonstrated an effective pathway for the construction of the opposite configurations at C1 in 1 and 2 . Additionally, an approach for the introduction of methyl at C4 is a feasible solution for structural modifications at C4 in 1 and 2 . 相似文献
29.
Cong Hu Bingyang Dong Li Liu 《Journal of polymer science. Part A, Polymer chemistry》2019,57(12):1333-1343
We report on the preparation of reduction‐responsive amphiphilic block copolymers containing pendent p‐nitrobenzyl carbamate (pNBC)‐caged primary amine moieties by reversible addition–fragmentation chain transfer (RAFT) radical polymerization using a poly(ethylene glycol)‐based macro‐RAFT agent. The block copolymers self‐assembled to form micelles or vesicles in water, depending on the length of hydrophobic block. Triggered by a chemical reductant, sodium dithionite, the pNBC moieties decomposed through a cascade 1,6‐elimination and decarboxylation reactions to liberate primary amine groups of the linkages, resulting in the disruption of the assemblies. The reduction sensitivity of assemblies was affected by the length of hydrophobic block and the structure of amino acid‐derived linkers. Using hydrophobic dye Nile red (NR) as a model drug, the polymeric assemblies were used as nanocarriers to evaluate the potential for drug delivery. The NR‐loaded nanoparticles demonstrated a reduction‐triggered release profile. Moreover, the liberation of amine groups converted the reduction‐responsive polymer into a pH‐sensitive polymer with which an accelerated release of NR was observed by simultaneous application of reduction and pH triggers. It is expected that these reduction‐responsive block copolymers can offer a new platform for intracellular drug delivery. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1333–1343 相似文献
30.
Dr. Lan Hu Prof. Dr. Yan Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(32):7702-7710
Outcomes of chemical reactions are generally dominated by the intrinsic reactivities of reaction partners, but enzymes frequently override such constraints to transform less reactive molecules in the presence of more reactive ones. Despite the attractiveness of such catalysis, it is difficult to build synthetic catalysts with these features. Micellar imprinting is a powerful method to create template-complementary binding sites inside protein-sized water-soluble nanoparticles. When a photocleavable functional monomer was used to bind two phosphonate/phosphate templates as transition-state analogues, active sites with predetermined size and shape were formed inside doubly cross-linked micelles through molecular imprinting. Postmodification replaced the binding group with a catalytic pyridyl group, forming highly selective artificial esterases. The catalysts displayed enzyme-like kinetics and turnover numbers that were in the hundreds. The selectivity of the catalysts, derived from the substrate-complementary imprinted active sites, enabled transformation of less reactive esters in the presence of more reactive ones. 相似文献