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Shunli Ni Sheng Ma Yuhang Zhang Jie Yuan Haitao Yang Zouyouwei Lu Ningning Wang Jianping Sun Zhen Zhao Dong Li Shaobo Liu Hua Zhang Hui Chen Kui Jin Jinguang Cheng Li Yu Fang Zhou Xiaoli Dong Jiangping Hu Hong-Jun Gao Zhongxian Zhao 《中国物理快报》2021,(5):133-137
We systematically measure the superconducting(SC) and mixed state properties of high-quality CsV_3 Sb_5 single crystals with T_c~3.5 K.We find that the upper critical field H_(c2)(T) exhibits a large anisotropic ratio of H_(c2)~(ab)/H_(c2)~c~9 at zero temperature and fitting its temperature dependence requires a minimum two-band effective model.Moreover,the ratio of the lower critical field,H_(c1)~(ab)/H_(c1)~c,is also found to be larger than 1,which indicates that the in-plane energy dispersion is strongly renormalized near Fermi energy.Both H_(c1)(T) and SC diamagnetic signal are found to change little initially below T_c~3.5 K and then to increase abruptly upon cooling to a characteristic temperature of ~2.8 K.Furthermore,we identify a two-fold anisotropy of in-plane angular-dependent magnetoresistance in the mixed state.Interestingly,we find that,below the same characteristic T~2.8 K,the orientation of this two-fold anisotropy displays a peculiar twist by an angle of 60° characteristic of the Kagome geometry.Our results suggest an intriguing superconducting state emerging in the complex environment of Kagome lattice,which,at least,is partially driven by electron-electron correlation. 相似文献
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陈建平 《数学建模及其应用》2015,4(3):72-74
高通量测序技术的飞速发展让生物信息领域迎来了大数据时代。新技术在提供海量生物遗传信息的同时,也给分析这些数据带来了新的挑战。DNA序列比对是信息分析流程中的关键步骤,为后续的变异检测提供序列比对信息。2015“深圳杯”数学建模夏令营B题以DNA序列比对为研究课题,希望参赛学生给出序列快速比对的最佳方案。本文简要点评了各参赛队伍的解答情况,然后介绍了现有DNA序列比对软件中用到的算法和数据结构。 相似文献
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In condensed phases, a highly symmetric gas‐phase molecule lowers its symmetry under perturbation of the solvent, which is vital to a variety of structural chemistry related processes. However, the dynamical aspects of solvent‐mediated symmetry‐breaking events remain largely unknown. Herein, direct evidence for two types of solvent‐mediated symmetry‐breaking events that coexist on the picosecond timescale in a highly symmetric anion, namely, hexacyanocobaltate, is presented: 1) an equilibrium symmetry‐breaking event in which a solvent‐bound species having lowered symmetry undergoes a population exchange reaction with the symmetry‐retaining species; 2) a dynamic symmetry‐breaking event that is composed of many dynamic population‐exchange reactions under fluctuating solvent interactions. Ultrafast two‐dimensional infrared spectroscopy is used to simultaneously observe and dynamically characterize these two events. This work opens a new window into molecular symmetry and structural dynamics under equilibrium and non‐equilibrium conditions. 相似文献
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Chiral monolithic absorbent is successfully constructed for the first time by using optically active helical‐substituted polyacetylene and graphene oxide (GO). The preparative strategy is facile and straightforward, in which chiral‐substituted acetylene monomer (Ma), cross‐linker (Mb), and alkynylated GO (Mc) undergo copolymerization to form the desired monolithic absorbent in quantitative yield. The resulting monoliths are characterized by circular dichroism, UV–vis absorption, scanning electron microscopy (SEM), FT‐IR, Raman, energy‐dispersive spectrometer (EDS), X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), XPS, and thermogravimetric analysis (TGA) techniques. The polymer chains derived from Ma form chiral helical structures and thus provide optical activity to the monoliths, while GO sheets contribute to the formation of porous structures. The porous structure enables the monolithic absorbents to demonstrate a large swelling ratio in organic solvents, and more remarkably, the helical polymer chains provide optical activity and further enantio‐differentiating absorption ability. The present study establishes an efficient and versatile methodology for preparing novel functional materials, in particular monolithic chiral materials based on substituted polyacetylene and GO.
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