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First-principles study on the electronic structure of Pb_(10−x)Cu_(x)(PO_(4))_(6)O(x=0,1)

Journal of Materials Science & Technology 2024年第4期171卷 66-70页

作者： Junwen Lai Jiangxu Li Peitao Liu Yan Sun Xing-Qiu Chen Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Recently,Lee et *** the experimental discovery of room-temperature ambient-pressure super-conductivity in a Cu-doped lead-apatite(LK-99)(arXiv:2307.12008,arXiv:2307.12037).Remarkably,the claimed superconductivity can persist up to 400 K at ambient *** the experimental im-plication,the electronic structure of LK-99 has not yet been ***,we investigate the electronic structures of LK-99 and its parent compound using first-principles calculations,aiming to elucidate the doping effects of *** results reveal that the parent compound Pb_(10)(PO_(4))_(6)O is an insulator,while Cu doping induces an insulator-metal transition and thus volume *** band structures of LK-99 around the Fermi level are featured by a half-filled flat band and a fully-occupied flat *** two very flat bands arise from both the 2p orbitals of 1/4-occupied O atoms and the hybridization of the 3d orbitals of Cu with the 2p orbitals of its nearest-neighboring O ***,we observe four van Hove singularities on these two flat ***,we show that the flat band structures can be tuned by including electronic correlation effects or by doping different *** find that among the considered doping elements(Ni,Cu,Zn,Ag,and Au),both Ni and Zn doping result in the gap opening,whereas Au exhibits doping effects more similar to Cu than *** work establishes a foundation for fu-ture studies to investigate the role of unique electronic structures of LK-99 in its claimed superconducting properties.

关键词： First-principles calculations Density functional theory Electronic structur e Superconductivity Flat bands Strongly correlated electrons

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Double-check in Lizard Age Estimation:Use of Phalanx Bone and Keratin Claw Sheath Lamellas

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Asian Herpetological Research 2024年第1期15卷 59-61页

作者： Eduard GALOYAN Natalia SOPILKO Anna KOVALYEVA Anna CHAMKINA A.N.Severtsov institute of Ecology and Evolution Moscow 119071Russia Lomonosov Moscow State University Leninskie Gori 1Moscow 119991Russia

Dear Editor,The problem of age estimation in amphibians and reptiles with annual fluctuations of growth pattern has been considered to be mostly solved since the skeletochronological method was introduced(Kleinenberg and Smirina,1969).This method is based on counting the number of lines of arrested growth(LAGs)—cyclical growth marks that are usually formed annually and characterized by different optical aspects within the tubular bones.

关键词： estimation method usual

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Polycomb and trithorax:Their yin-yang dynamics in plants

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Molecular Plant 2024年第6期17卷 845-847页

作者： Fan Xu Daolei Zhang Liang Le Li Pu Biotechnology Research institute Chinese Academy of Agricultural SciencesBeijing 100081China School of Life Science Inner Mongolia UniversityHohhot 010021China

Polycomb(PcG)and trithorax(trxG)are two groups of conserved epigenetic complexes that maintain active and repressive states of target genes by altering their chromatin states to regulate plant development and stress *... 详细信息

关键词： maintain complexes states

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Dendrimers-merging biomimics and photoenergy conversion

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Science China Chemistry 2015年第3期58卷 390-399页

作者： Xinyang Liu Yi Zeng Xiaohui Zhang Tianjun Yu Jinping Chen Yi Li Key Laboratory of Photochemical Conversion and Optoelectronic Materials technical institute of Physics and Chemistry Chinese Academy of Sciences

Dendrimers are well-defined tree-like macromolecules possessing numerous chain ends emanating from a single core, which makes them attractive candidates for mimicking light-harvesting systems and hydrogenases. Photoinduced electron and energy transfers are main processes involved in light-harvesting and photocatalysis. In this review, the general concepts of design strategies and recent developments of photofunctional dendrimers in biomimics of light-harvesting systems and hydrogenases are discussed. The energy transfer and electron transfer processes in light-harvesting dendrimers and the effect of dendritic structures in photochemical hydrogen production are illustrated.

关键词： photofunctional dendrimers light-harvesting hydrogen production energy transfer electron transfer

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Phosphorylation-driven aggregative proteins in neurodegenerative diseases:implications and therapeutics

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Neural Regeneration Research 2024年第5期19卷 966-968页

作者： Alba Espargaró Raimon Sabate Department of Pharmacy and Pharmaceutical Technology and Physical-Chemistry School of PharmacyUniversity of BarcelonaBarcelonaSpain institute of Nanoscience and Nanotechnology(IN2UB) University of BarcelonaBarcelonaSpain

Protein aggregation is related to a large number of neurodegenerative *** in some cases,aggregation is induced by hyperphosphorylation of a given *** is the case of tau,TAR DNA-binding protein 43(TDP-43),amyloid-beta peptides(Aβ)and alpha-synuclein(α-syn),which play a key pathogenic role in Alzheimer’s disease(AD),Parkinson’s disease(PD)and amyotrophic lateral sclerosis,among others(Tenreiro et al.,2014;Chiti and Dobson,2017).In this perspective,we will discuss both the relationship between phosphorylation and amyloid aggregation as well as current and future therapeutic strategies aimed at inhibiting specific kinases involved in the phosphorylation step or inhibiting subsequent protein aggregation.

关键词： tau Aβ Alzheimer

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Oncostatin M:a love-hate relationship in neuroinflammation

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Neural Regeneration Research 2024年第12期19卷 2571-2572页

作者： Doryssa Hermans Niels Hellings Bieke Broux University MS Center Campus DiepenbeekDiepenbeekBelgium Neuro-Immune Connections and Repair Lab Department of Immunology and InfectionBiomedical Research InstituteHasselt UniversityDiepenbeekBelgium

Oncostatin M and multiple sclerosis:Every 5minutes,someone in the world is diagnosed with multiple sclerosis(MS),a chronic inflammatory and degenerative disease of the central nervous system(CNS).MS appears in unpredictable episodes of symptoms,which are highly patient-dependent,but often include visual impairment,muscle weakness/spasms,fatigue,cognitive difficulties,and *** sexual dysfunction.

关键词： visual bladder someone

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Thermodynamics and characterization of shape memory Cu-Al-Zn alloys

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Transactions of Nonferrous Metals Society of China 2015年第8期25卷 2630-2636页

作者： Lidija GOMIDZELOVIC Emina POZEGA Ana KOSTOV Nikola VUKOVIC Vesna KRSTIC Dragana ZIVKOVIC Ljubisa BALANOVIC Mining and Metallurgy institute Faculty of Mining and Geology University of Belgrade technical Faculty in Bor University of Belgrade

The thermodynamic properties and the microstructure, hardness and electrical conductivity of shape memory alloys （SMAs） belonging to ternary Cu？Al？Zn system were studied by Muggianu model and experiment, respectively. The isothermal section of phase diagram at 293 K was calculated using Thermo-Calc software. Experiments were conducted by X-ray diffraction, light optic microscopy, scanning electron microscopy with energy dispersive X-ray spectrometry, hardness and electrical conductivity measurements. The calculated values of thermodynamic properties indicate that Cu shows good miscibility with Al and Zn in all investigated alloys. The microstructural analysis of samples reveals that the structure consists of large and polygonal grains.

关键词： thermodynamics shape memory alloy Cu-Al-Zn alloys hardness electrical conductivity

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Progress in quantum well and quantum cascade infrared photodetectors in SITP

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Chinese Physics B 2019年第2期28卷 39-48页

作者： Xiaohao Zhou Ning Li Wei Lu State key Laboratory for Infrared Physics Shanghai Institute of Technical Physics(SITP)Chinese Academy of Sciences

This paper presents a review of recent advances in quantum well and quantum cascade infrared photodetectors developed in Shanghai institute of technical Physics, Chinese Academy of Sciences(SITP/CAS). Firstly, the temperature-and bias-dependent photocurrent spectra of very long wavelength(VLW) GaAs/AlGaAs quantum well infrared photodetectors(QWIPs) are studied using spectroscopic measurements and corresponding theoretical calculations in detail. We confirm that the first excited state, which belongs to the quasi-bound state, can be converted into a quasi-continuum state induced by bias and temperature. Aided by band structure calculations, we propose a model of the double excited states that determine the working mechanism in VLW QWIPs. Secondly, we present an overview of a VLW QWIP focal plane array(FPA)with 320×256 pixels based on the bound to quasi-bound(BTQB) design. The technology of the manufacturing FPA based on the QWIP structures has been demonstrated. At the operating temperature of 45 K, the detectivity of QWIP FPA is larger than 1.4×10^(10) cm·Hz^(1/2)/W with a cutoff wavelength larger than 16 μm. Finally, to meet the needs of space applications, we proposed a new long wavelength quantum cascade detector with a broadband detection ranging from 7.6 μm to 10.4 μm. With a pair of identical coupled quantum wells separated by a thin barrier, acting as absorption regions, the relative linewidth(?E/E) of response can be dramatically broadened to 30.7%. It is shown that the spectral shape and linewidth can be tuned by the thickness of the thin barrier, while it is insensitive to the working temperature. The device can work above liquid nitrogen temperature with a peak responsivity of 63 mA/W and Johnson noise limited detectivity of 5.1×10~9 cm·Hz^(1/2)/W.

关键词： infrared photodetectors quantum well focal plane array detectivity broadband response

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Strong metal-support interaction between AuPd nanoparticles and oxygen-rich defect ZrO_(2) for enhanced catalytic 5-hydroxymethylfurfural oxidation

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Chinese Chemical Letters 2024年第2期35卷 507-511页

作者： Yunlei Zhang Yiran Liu Wen Guan Mengxue Cao Yao Chen Pengwei Huo institute of Green Chemistry and Chemical Technology School of Chemistry and Chemical EngineeringJiangsu UniversityZhenjiang 212013China School of the Environment and Safety Jiangsu UniversityZhenjiang 212013China

The unique properties of metal oxide surfaces,crystal surfaces and defects play vital roles in biomass upgrading *** this work,hierarchical porous bowl-shaped ZrO_(2)(HB-ZrO_(2))with mixed crystal phase was designed and employed as the support for loading AuPd bimetal with different proportions to synthesize AuPd/HB-ZrO_(2) *** effects of surface chemistry,oxygen defects,bimetal interaction and metal-support interaction of AuPd/HB-ZrO_(2) on catalytic performance for the selective oxidation of 5-hydroxymethylfurfural(HMF)to 2,5-furandicarboxylic acid(FDCA)were systematically *** Au 2 Pd1/HB-ZrO_(2) catalyst afforded a satisfactory FDCA yield of 99.9%from HMF oxidation using O_(2) as the oxidant in water,accompanied with an excellent FDCA productivity at 97.6 mmol g^(−1) h^(−1).This work offers fresh insights into rationally designing efficient catalysts with oxygen-rich defects for the catalytic upgrading of biomass platform chemicals.

关键词： 5-Hydroxymethylfurfural oxidation 2,5-Furandicarboxylic acid Oxygen-rich defect ZrO_(2) AuPd bimetal Bowl-shaped structure

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Unveiling the pressure-driven metal–semiconductor–metal transition in the doped TiS_(2)

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Chinese Physics B 2024年第6期33卷 63-67页

作者：陈佳骏吕心邓李思敏但雅倩黄艳萍崔田 institute of High Pressure Physics School of Physical Science and TechnologyNingbo UniversityNingbo 315211China State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Conventional theories expect that materials under pressure exhibit expanded valence and conduction bands,leading to increased electrical ***,we report the electrical properties of the doped 1T-TiS_(2) under high pressure by electrical resistance investigations,synchrotron x-ray diffraction,Raman scattering and theoretical *** to 70 GPa,an unusual metal-semiconductor-metal transition *** first-principles calculations suggest that the observed anti-Wilson transition from metal to semiconductor at 17 GPa is due to the electron localization induced by the intercalated Ti *** electron localization is attributed to the strengthened coupling between the doped Ti atoms and S atoms,and the Anderson localization arising from the disordered *** pressures exceeding 30.5 GPa,the doped TiS_(2) undergoes a re-metallization transition initiated by a crystal structure phase *** assign the most probable space group as P2_(1)2_(1)2_(1).Our findings suggest that materials probably will eventually undergo the Wilson transition when subjected to sufficient pressure.

关键词： high pressure transition metal dichalcogenides doped TiS_(2) electronic phase transition

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