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Itinerant Topological Magnons in SU (2) Symmetric Topological Hubbard Models with Nearly Flat Electronic Bands

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Chinese Physics Letters 2021年第5期38卷 132-136页

作者： Zhao-Long Gu jian-xin li National Laboratory of Solid State Microstructures and Department of Physics Nanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China

We show that a suitable combination of flat-band ferromagnetism,geometry and nontrivial electronic band topology can give rise to itinerant topological *** SU(2) symmetric topological Hubbard model with nearly flat electronic bands,on a Kagome lattice,is considered as the *** model exhibits ferromagnetic order when the lowest electronic band is *** the numerical exact diagonalization method with a projection onto this nearly flat band,we can obtain the magnonic *** the flat-band limit,the spectra exhibit distinct dispersions with Dirac points,similar to those of free electrons with isotropic hoppings,or a local spin magnet with pure ferromagnetic Heisenberg exchanges on the same ***,the non-flatness of the electronic band may induce a topological gap at the Dirac points,leading to a magnonic band with a nonzero Chern *** intriguingly,this magnonic Chern number changes its sign when the topological index of the electronic band is reversed,suggesting that the nontrivial topology of the magnonic band is related to its underlying electronic *** work suggests interesting directions for the further exploration of,and searches for,itinerant topological magnons.

关键词： Itinerant Topological Magnons in SU Symmetric Topological Hubbard Models with Nearly Flat Electronic Bands

Serglycin in human cancers

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Chinese Journal of Cancer 2011年第9期30卷 585-589页

作者： xin-jian li Chao-Nan Qian State Key Laboratory of Oncology in South China Sun Yat-sen University Cancer Center Guangzhou Guangdong 510060 P. R. China Laboratory of Cancer and Developmental Cell Biology Van Andel Research Institute Grand Rapids MI 49503 USA.

Serglycin belongs to a family of small proteoglycans with Ser-Gly dipeptide repeats,and it is modified with different types of glycosaminoglycan side *** serglycin affects the retention and secretion of proteases,chemokines,or other cytokines by physically binding to these factors in secretory *** serglycin has been found to be released by several types of human cancer cells,and it is able to promote the metastasis of nasopharyngeal carcinoma *** can bind to CD44,which is another glycoprotein located in cellular ***'s function of promoting cancer cell metastasis depends on glycosylation of its core protein,which can be achieved by autocrine as well as paracrine secretion *** investigations are warranted to elucidate serglycin signaling mechanisms with the goal of targeting them to prevent cancer cell metastasis.

关键词：癌症人类鼻咽癌细胞分泌颗粒细胞内蛋白多糖趋化因子细胞因子

Atomic Coherent Trapping and Properties of Trapped Atom

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Communications in Theoretical Physics 2006年第3X期46卷 556-560页

作者： YANG Guo-jian XIA li-xin XIE Min Department of Physics Beijing Normal University Beijing 100875 China

Based on the theory of velocity-selective coherent population trapping, we investigate an atom-laser system where a pair of counterpropagating laser fields interact with a three-level atom. The influence of the parametric condition on the properties of the system such as velocity at which the atom is selected to be trapped, time needed for finishing the coherent trapping process, and possible electromagnetically induced transparency of an altrocold atomic medium, etc., is studied.

关键词： velocity selective coherent population trapping ultracold atom

Particle–hole fluctuations and possible superconductivity in doped α-RuCl_3

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Chinese Physics B 2019年第5期28卷 282-287页

作者： Bin-Bin Wang Wei Wang Shun-li Yu jian-xin li National Laboratory of Solid State Microstructures and Department of Physics Nanjing University

We study various particle–hole excitations and possible superconducting pairings mediated by these fluctuations in doped α-RuCl_3 by using multi-band Hubbard model with all t_(2g) orbitals. By performing a random-phase-approximation(RPA) analysis, we find that among all particle–hole excitations, the j_(eff)= 1/2 pseudospin fluctuations are dominant, suggesting the robustness of j_(eff)= 1/2 picture even in the doped systems. We also find that the most favorable superconducting state has a d-wave pairing symmetry.

关键词： superconductivity particle–hole fluctuations spin–orbit coupling α-RuCl3

Effect of decarburization annealing temperature and time on the carbon content, microstructure, and texture of grain-oriented pure iron

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International Journal of Minerals,Metallurgy and Materials 2017年第4期24卷 393-400页

作者： Hai-jun Wang Zhe Rong li Xiang Sheng-tao Qiu jian-xin li Ting-liang Dong National Engineering Research Center of Continuous Casting Technology Central Iron and Steel Research Institute Beijing 100081 China HeSteel Group Technology Research Institute Shijiazhuang 050023 China

In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron microscopy with electron-backscatter diffraction. The results showed that the efficiency of decarburization dramatically increased with increasing decarburization temperature. However,when the annealing temperature was increased to 825°C and 850°C,the steel's carbon content remained essentially unchanged at 0.002%. With increasing decarburization time,the steel's carbon content generally decreased. When both the decarburization temperature and time were increased further,the average grain size dramatically increased and the number of fine grains decreased; meanwhile,some relatively larger grains developed. The main texture types of the decarburized sheets were approximately the same: {001} and {112~115},with a γ-fiber texture. Furthermore,little change was observed in the texture. Compared with the experimental sheets,the texture of the cold-rolled sheet was very scattered. The best average magnetic induction(B_(800)) among the final products was 1.946 T.

关键词： pure iron decarburization annealing temperature annealing time carbon content microstructure texture

Effect of Impurity on the Doping-Induced in-Gap States in a Mott Insulator

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Chinese Physics Letters 2022年第5期39卷 82-86页

作者： Cheng-Ping He Shun-li Yu Tao Xiang jian-xin li National Laboratory of Solid State Microstructures and School of Physics Nanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China Institute of Physics National Laboratory for Condensed Matter PhysicsChinese Academy of SciencesBeijing 100190China Department of Physics University of Chinese Academy of SciencesBeijing 100190China Beijing Academy of Quantum Information Sciences Beijing 100193China

Motivated by the recent measurements of the spatial distribution of single particle excitation states in a hole-doped Mott insulator,we study the effects of impurity on the in-gap states,induced by the doped holes,in the Hubbard model on the square lattice by the cluster perturbation *** find that a repulsive impurity potential can move the in-gap state from the lower Hubbard band towards the upper Hubbard band,providing a good account for the experimental *** distribution of the spectral function in the momentum space can be used to discriminate the in-gap state induced by doped holes and that by the *** spatial characters of the in-gap states in the presence of two impurities are also discussed and compared to the experiment.

关键词： theory Hubbard momentum

EXPERIMENTAL INVESTIGATION ON WAVE RUN-UP CHARACTERISTICS ALONG COLUMNS AND AIR GAP RESPONSE OF SEMI-SUBMERSIBLE PLATFORM

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Journal of Hydrodynamics 2011年第5期23卷 625-636页

作者： SHAN Tie-bing YANG jian-min li xin XIAO Long-fei State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai 200240 China

This article mainly concentrates on a large-volume drilling semi-submersible platform, aiming to reveal wave run-up characteristics along square columns and give the relationship between air gap distributions and wave parameters. The tests with fixed model were conducted firstly on its encountering a series of monochromatic waves. A wide range of wave slope （H/L ） were selected to investigate the air gap response in detail. As can be seen, larger wave steepness will generally cause smaller air gap in the same wave period, which indicates nonlinear effects of incoming wave can amplify wave elevation. Model tests with mooring condition were also conducted in the same wave conditions. As was expected, the maximum relative wave elevation reduces obviously compared with the fixed one. However, wave shape close to columns show higher harmonic characteristics due to interaction between waves and the columns of semi-submersible platform. Meaningful conclusions from the model tests are drawn in this article, which is helpful in air gap design of floating offshore platform to a certain extent. In addition, the experimental results will provide an important reference for further research on validation and update of theoretical models of air gap.

关键词： wave run-up air gap diffraction-radiation effects wave steepness

The Effects of Solid Phase Additives on Sintering Properties of Alumina Bioceramic

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Journal of Wuhan University of Technology(Materials Science) 2003年第2期18卷 23-24页

作者：王欣宇 Wuhan University of Technology

In order to reduce the sintering temperature and improve the preparing conditions of alumina bioceramics,the Mg-Zr-Y composite solid phase additives were added into high purity Al 2O 3 micro-powder by chemical coprecipitation *** powder was shaped under 200MPa cold isostatic pressure,and then the biscuits were sintered at 1600℃ under normal *** sintered alumina materials were tested and the sintering mechanism was *** results show that physical properties of the material were improved *** Mg-Zr-Y composite solid additives could promote the sintering of alumina bioceramics and the mechanism is solid phase sintering.

关键词： alumina sintering additives property

Unveiling the charge density wave inhomogeneity and pseudogap state in 1T-TiSe_2

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Science Bulletin 2018年第7期63卷 426-432页

作者： Kai-Wen Zhang Chao-Long Yang Bin Lei Pengchao Lu Xiang-Bing li Zhen-Yu Jia Ye-Heng Song jian Sun Xianhui Chen jian-xin li Shao-Chun li National Laboratory of Solid State Microstructures School of Physics Nanjing University Hefei National Laboratory for Physical Science at Microscale and Department of Physics University of Science and Technology of China Collaborative Innovation Center of Advanced Microstructures Nanjing University

By using scanning tunneling microscopy(STM)/spectroscopy(STS), we systematically characterize the electronic structure of lightly doped 1 T-TiSe_2, and demonstrate the existence of the electronic inhomogeneity and the pseudogap state. It is found that the intercalation induced lattice distortion impacts the local band structure and reduce the size of the charge density wave(CDW) gap with the persisted 2 × 2 spatial modulation. On the other hand, the delocalized doping electrons promote the formation of pseudogap. Domination by either of the two effects results in the separation of two characteristic regions in real space, exhibiting rather different electronic structures. Further doping electrons to the surface confirms that the pseudogap may be the precursor for the superconducting gap. This study suggests that the competition of local lattice distortion and the delocalized doping effect contribute to the complicated relationship between charge density wave and superconductivity for intercalated 1 T-TiSe_2.

关键词： Charge density wave Pseudogap TiSe2 Scanning tunneling microscopy Scanning tunneling spectroscopy