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A new direct band gap silicon allotropeο-Si32

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Chinese Physics B 2022年第2期31卷 516-521页

作者： Xin-Chao Yang Qun Wei mei-guang zhang Ming-Wei Hu Lin-Qian Li Xuan-Min Zhu School of Physics and Optoelectronic Engineering Xidian UniversityXi’an 710071China College of Physics and Optoelectronic Technology Baoji University of Arts and SciencesBaoji 721016China School of Information Guizhou University of Finance and EconomicsGuiyang 550025China

Silicon is a preferred material in solar cells,and most of silicon allotropes have an indirect band ***,it is important to find new direct band gap *** the present work,a new direct band gap silicon allotrope of o-Si32 is *** elastic constants,elastic anisotropy,phonon spectra,and electronic structure of o-Si32 are obtained using first-principles *** results show that o-Si32 is mechanically and dynamically stable and is a direct semiconductor material with a band gap of 1.261 e V.

关键词： first-principles calculation elastic anisotropy silicon

A novel hybrid 8p-sp2 metallic carbon allotrope

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Frontiers of physics 2018年第5期13卷 141-146页

作者： Qun Wei Quan zhang mei-guang zhang Hai-Yan Yan Li-Xin Guo Bing Wei School of Physics and Optoelectronic Engineering Xidian University Xi'an 710071 China School of Microelectronics Xidian University Xi'an 710071 China College of Physics and Optoelectronic Technology Nonlinear Research Institute Baoji University of Arts and Sciences Baoji 721016 China College of Chemistry and Chemical Engineering Baoji University of Arts and Sciences Baoji 721013 China

In this paper, we propose a novel hybrid sp-sp2 monoclinic carbon allotrope mC12. This allotrope is a promising light metallic material, the mechanical and electronic properties of which are studied based on first-principles calculations. The structure of this new mC12 is mechanically and dynamically stable at ambient pressure and has a low equilibrium density due to its large cell volume. Furthermore, calculations of the elastic constants and moduli reveal that mC12 has a rigid mechanical property. Finally, it exhibits metallic characteristics, owing to the mixture of sp-sp2 hybrid carbon atoms.

关键词： metallic carbon allotrope first-principles calculations mechanical and electronicproperties

Pressure-induced phase transition and electronic structure evolution in layered semimetal HfTe_(2)

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Chinese Physics B 2023年第8期32卷 349-354页

作者：张美光陈磊冯龙拓换换张云魏群李培芳 College of Physics and Optoelectronic Technology Collaborative Innovation Center of Rare-Earth Functional Materials and Devices DevelopmentBaoji University of Arts and SciencesBaoji 721016China School of Physics Xidian UniversityXi'an 710071China College of Mathematics and Physics Inner Mongolia Minzu UniversityTongliao 028043China

Motivated by the recent experimental work,the pressure-induced structural transition of well-known two-dimensional(2D)1T-Hf Te_(2)was investigated up to 50 GPa through the advanced CALYPSO structure search technique combined with the first-principles *** calculations suggested that the 1T-Hf Te_(2)will first transform to C2/m phase at 3.6 GPa with a volume reduction of 7.6%and then to P62m phase at 9.6 GPa with a volume collapse of 4.6%.The occurrences of 3D C2/m and P62m phases mainly originated from the enhanced Te-Te interlayer coupling and the drastic distortions of Hf-Te polyhedrons in P3m1 phase under ***,the coordination number of Hf atoms increased from six in P3m1 to eight in C2/m and eventually to nine in P62m at elevated *** metallic and semimetallic nature of C2/m and P62m phases were characterized,and the evidence of the reinforced covalent interactions of Te-Hf and Te-Te orbitals in these two novel high-pressure phases were manifested by the atom-projected electronic DOS and Bader charge.

关键词： transition metal dichalcogenides pressure-induced phase transition crystal structure electronic structure

Elastic and thermodynamic properties of Re_2N at high pressure and high temperature

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Transactions of Nonferrous Metals Society of China 2013年第12期23卷 3714-3721页

作者：张美光闫海燕魏群黄多辉宝鸡文理学院物理与信息技术系宝鸡721016 宝鸡文理学院化学化工学院宝鸡721013 西安电子科技大学物理与光电工程学院西安710071 宜宾学院四川省计算物理重点实验室宜宾644007

First principles calculations are preformed to systematically investigate the elastic and thermodynamic properties of Re2N at high pressure and high temperature. The Re2N exhibits a clear elastic anisotropy and the elastic constants C11 and C33 vary rapidly in comparison with the variations in C12, C13 and C44 at high pressure. In addition, bulk modulus B, elastic modulus E, and shear modulus Gas a function of crystal orientations for Re2N are also investigated for the first time. The tensile directional dependences of the elastic modulus obey the following trend： [0001] [1211] [1010] [1011]EEEE〉〉〉 . The shear moduli of Re2N within the （0001） basal plane are the smallest and greatly reduce the resistance of against large shear deformations. Based on the quasi-harmonic Debye model, the dependences of Debye temperature, Grüneisen parameter, heat capacity and thermal expansion coefficient on the temperature and pressure are explored in the whole pressure range from 0 to 50 GPa and temperature range from 0 to 1600 K.

关键词： Re2N transition metal nitrides elastic properties thermodynamic properties

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复发性卵巢癌的药物治疗及进展

中国现代医学杂志 2021年第1期31卷 38-44页

作者：王雪张广美何征秦哈尔滨医科大学附属第一医院妇产科黑龙江哈尔滨150001

卵巢癌在女性妇科肿瘤中死亡率第一,且复发率高。复发性卵巢癌无法治愈,目前复发性卵巢癌的治疗以改善患者生活质量,延长患者无进展生存期及总生存期为目的。分子靶向治疗复发性卵巢癌是研究热点,靶向药物包括抗血管生成药物、聚二磷酸... 详细信息

卵巢癌在女性妇科肿瘤中死亡率第一,且复发率高。复发性卵巢癌无法治愈,目前复发性卵巢癌的治疗以改善患者生活质量,延长患者无进展生存期及总生存期为目的。分子靶向治疗复发性卵巢癌是研究热点,靶向药物包括抗血管生成药物、聚二磷酸腺苷核糖聚合酶抑制剂及免疫检查点抑制剂。该文重点对复发性卵巢癌的药物治疗进展进行综述。

关键词：卵巢肿瘤抗血管生成药物聚二磷酸腺苷核糖聚合酶抑制剂免疫检查点抑制剂

Unraveling brain aging through the lens of oral microbiota

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Neural Regeneration Research 2025年第7期20卷 1930-1943页

作者： Qinchao Hu Si Wang Weiqi zhang Jing Qu guang-Hui Liu State Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijingChina Hospital of Stomatology Guanghua School of StomatologyGuangdong Provincial Key Laboratory of StomatologySun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Advanced Innovation Center for Human Brain Protection and National Clinical Research Center for Geriatric Disorders Xuanwu HospitalCapital Medical UniversityBeijingChina Aging Translational Medicine Center International Center for Aging and CancerBeijing Municipal Geriatric Medical Research CenterXuanwu HospitalCapital Medical UniversityBeijingChina CAS Key Laboratory of Genomic and Precision Medicine Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijingChina University of Chinese Academy of Sciences BeijingChina Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijingChina Aging Biomarker Consortium BeijingChina State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijingChina Beijing Institute for Stem Cell and Regenerative Medicine BeijingChina

The oral cavity is a complex physiological community encompassing a wide range of *** of oral microbiota can lead to various oral infectious diseases,such as periodontitis and tooth decay,and even affect systemic health,including brain aging and neurodegenerative *** studies have highlighted how oral microbes might be involved in brain aging and neurodegeneration,indicating potential avenues for intervention *** this review,we summarize clinical evidence demonstrating a link between oral microbes/oral infectious diseases and brain aging/neurodegenerative diseases,and dissect potential mechanisms by which oral microbes contribute to brain aging and *** also highlight advances in therapeutic development grounded in the realm of oral microbes,with the goal of advancing brain health and promoting healthy aging.

关键词： Alzheimer's disease brain aging multiple sclerosis neurodegeneration neurodegenerative diseases oral microbiota Parkinson's disease periodontitis bacteria Porphyromonas gingivalis

Microstructural evolution during the progressive transformation-induced plasticity effect in a Fe-0.1C-5Mnmedium manganese steel

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 369-379页

作者： mei zhang Wenhao Li Yangfei Chen Yang Jiang Xiaofei Guo Han Dong School of Materials Science and Engineering Shanghai UniversityShanghai 200444China State Key Laboratory of Advanced Special Steel Shanghai UniversityShanghai 200444China

The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel(Fe-0.10C-5Mn)was investigated during uniaxial tensile ***-situ observations under scanning electron microscopy,transmission electron microscopy,and X-ray diffraction analysis were conducted to characterize the progressive transformation-induced plasticity process and associated fracture initiation *** findings were discussed with the local strain measurements via digital image *** results indicated that Lüders band formation in the steel was limited to 1.5%strain,which was mainly due to the early-stage martensitic phase transformation of a very small amount of the less stable large-sized retained austenite(RA),which led to localized stress concentrations and strain hardening and further retardation of *** small-sized RA exhibited high stability and progressively transformed into martensite and contributed to a stably extended Portevin-Le Chatelier *** volume fraction of RA gradually decreased from 26.8%to 8.2%prior to *** the late deformation stage,fracture initiation primarily occurred at the austenite/martensite and ferrite/martensite interfaces and the ferrite phase.

关键词： medium-Mn steel retained austenite progressive transformation-induced plasticity effect local strain fracture initiation