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Peak structure in the interlayer conductance of Moirésuperlattices

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Chinese Physics B 2024年第10期33卷 376-380页

作者： Yizhou Tao Chao Liu Mingwen Xiao henan Fang College of Electronic and Optical Engineering&College of Flexible Electronics(Future technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China department of Physics Nanjing UniversityNanjing 210093China

We investigate the peak structure in the interlayer conductance of Moirésuperlattices using a tunneling theory wedeveloped *** theoretical results predict that,due to the resonance of two different partial waves,the doublepeakstructure can appear in the curve of the interlayer conductance versus twist ***,we study the influencesof the model parameters,i.e.,the chemical potential of electrodes,the thickness of Moirésuperlattice,and the strength ofinterface potential,on the peak structure of the interlayer *** particular,the parameter dependence of the peakstructure is concluded via a phase diagram,and the physical meanings of the phase diagram is ***,thepotential applications of the present work is discussed.

关键词： Moirésuperlattice interlayer conductance electronic transport twistronics

Hemispherical resonator with low subsurface damage machined by small ball-end fine diamond grinding wheel:A novel grinding technique

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Chinese Journal of Aeronautics 2024年第5期37卷 570-585页

作者： Biao QIN henan LIU Jian CHENG Jinchuan TIAN Jiangang SUN Zihan ZHOU Chuanzhen MA Mingjun CHEN State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China Center for Precision Engineering Harbin Institute of TechnologyHarbin 150001China

As for the ultra-precision grinding of the hemispherical fused silica resonator,due to the hard and brittle nature of fused silica,subsurface damage(SSD)is easily generated,which enormously influences the performance of such ***,ultra-precision grinding experiments are carried out to investigate the surface/subsurface quality of the hemispherical resonator machined by the small ball-end fine diamond grinding *** influence of grinding parameters on the surface roughness(SR)and SSD depth of fused silica samples is then *** experimental results indicate that the SR and SSD depth decreased with the increase of grinding speed and the decrease of feed rate and grinding *** addition,based on the material strain rate and the maximum undeformed chip thickness,the effect of grinding parameters on the subsurface damage mechanism of fused silica samples is ***,a multi-step ultra-precision grinding technique of the hemispherical resonator is proposed based on the interaction influence between grinding depth and feed ***,the hemispherical resonator is processed by the proposed grinding technique,and the SR is improved from 454.328 nm to 110.449 nm while the SSD depth is reduced by 94%from 40μm to 2.379μ*** multi-step grinding technique proposed in this paper can guide the fabrication of the hemispherical resonator.

关键词： Fused silica Ultra-precision grinding Hemispherical resonator Subsurface damage Grinding technique

Structure Regulation of Electric Double Layer via Hydrogen Bonding Effect to Realize High-Stability Lithium-Metal Batteries

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Energy & Environmental Materials 2024年第3期7卷 72-83页

作者： Sheng Liu Chaozhu Shu Yu Yan Dayue Du Longfei Ren Ting Zeng Xiaojuan Wen Haoyang Xu xinxiang Wang Guilei Tian Ying Zeng College of Materials and Chemistry&Chemical Engineering Chengdu University of Technology1#DongsanluErxianqiaoChengdu 610059China institute of Fundamental and Frontier sciences University of Electronic Science and Technology of ChinaChengdu 611731China State Key Laboratory of Polymer Materials Engineering Polymer Research InstituteSichuan UniversityChengdu 610065China

The interfacial chemistry of solid electrolyte interphases(SEI)on lithium(Li)electrode is directly determined by the structural chemistry of the electric double layer(EDL)at the ***,a strategy for regulating the structural chemistry of EDL via the introduction of intermolecular hydrogen bonds has been proposed(p-hydroxybenzoic acid(pHA)is selected as proof-of-concept).According to the molecular dynamics(MD)simulation and density functional theory(DFT)calculation results,the existence of hydrogen bonds realizes the anion structural rearrangement in the EDL,reduces the lowest unoccupied molecular orbital(LUMO)energy level of anions in the EDL,and the number of free solvent molecules,which promotes the formation of inorganic species-enriched SEI and eventually achieves the dendrite-free Li *** on this strategy,Li‖Cu cells can stably run over 185 cycles with an accumulated active Li loss of only 2.27 mAh cm^(-2),and the long-term cycle stability of Li‖Li cells is increased to 1200 *** addition,the full cell pairing with the commercial LiFePO_(4)(LFP)cathodes exhibits stable cycling performance at 1C,with a capacity retention close to 90%after 200 cycles.

关键词： electric double layer electrolyte additives intermolecular hydrogen bonds Li metal batteries p-Hydroxybenzoic acid

Optimizing 2D-metal contact in layered Tin-selenide via native oxide modulation

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Nano Research 2024年第4期17卷 3014-3020页

作者： Yue Zheng Qi You Zhentian Yin Jian Tang Ke Jiang Zihao Xie henan Li Cheng Han Yumeng Shi International Collaborative Laboratory of 2D Materials for Optoelectronics science and technology of Ministry of Education Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China College of Electronics and Information Engineering Shenzhen UniversityShenzhen 518060China

The discovery of two-dimensional(2D)semiconductor has opened up new avenues for the development of short-channel field-effect transistors(FETs)with desired electrical *** them,orthorhombic tin-selenide(SnSe)has garnered increasing attention due to its potential applications in a variety of electronic,optoelectronic,and thermoelectric ***,the realization of high-performance SnSe FETs with low contact resistance(Rc)remains a ***,we systematically investigate the contact of few-layer SnSe FETs through the modulation of native oxide on SnSe by using different *** is found that chromium(Cr)-contacted devices possess the best FET performance,such as electron mobility up to 606 cm^(2)/(V·s)at 78 K,current on/off ratio exceeding 1010,and saturation current of~550μA/μm,where a negligible Schottky barrier(SB)of~30 meV and a low contact resistance of~425Ωμm are achieved.X-ray photoelectron spectroscopy(XPS)and cross-sectional electron dispersive X-ray spectroscopy(EDX)results further reveal that the improved contact arises from the Cr-induced reduction of native oxide(SnOx)to Sn,which thins the tunneling barrier for efficient electron *** findings provide a deep insight into the 2D-metal contact of SnSe and pave the way for its applications in future nanoelectronics.

关键词： few-layer SnSe field-effect transistors(FETs) Cr contact native oxide contact resistance(Rc) Schottky barrier(SB)

Electronic structure and spin state regulation of vanadium nitride via a sulfur doping strategy toward flexible zinc-air batteries

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Journal of Energy Chemistry 2024年第2期89卷 239-249,I0007页

作者： Daijie Deng Honghui Zhang Jianchun Wu Xing Tang Min Ling Sihua Dong Li Xu henan Li Huaming Li institute for Energy Research Institute of Quantum and Sustainable TechnologySchool of Chemistry and Chemical EngineeringSchool of Materials Science and EngineeringJiangsu Province and Education Ministry Co-Sponsored Synergistic Innovation Center of Modern Agricultural EquipmentJiangsu UniversityZhenjiang 212013JiangsuChina Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province Nanjing 210023JiangsuChina Zhenjiang Kangyuan Electrical Appliance Co. Ltd.Zhenjiang 212013JiangsuChina College of Chemical and Biological Engineering Zhejiang UniversityHangzhou 310027ZhejiangChina YTO Group Corporation Dongfanghong(henan)Agricultural Service technology Co. Ltd.Luoyang 471033HenanChina

Owing to the distinctive structural characteristics,vanadium nitride(VN)is highly regarded as a catalyst for oxygen reduction reaction(ORR)in zinc-air batteries(ZABs).However,VN exhibits limited intrinsic ORR activity due to the weak adsorption ability to O-containing ***,the S-doped VN anchored on N,S-doped multi-dimensional carbon(S-VN/Co/NS-MC)was constructed using the solvothermal and in-situ doping *** sulfur atoms into VN species alters the electron spin state of vanadium in the S-VN/Co/NS-MC for regulating the adsorption energy of vanadium sites to oxygen *** introduced sulfur atoms polarize the V 3d_(z)^(2) electrons,shifting spin-down electrons closer to the Fermi level in the S-VN/Co/***,the introduction of sulfur atoms into VN species enhances the adsorption energy of vanadium sites for oxygen ****OOH dissociation transitions from being unspontaneous on the VN surface to a spontaneous state on the S-doped VN ***,the ORR barrier on the S-VN/Co/NS-MC surface is *** S-VN/Co/NS-MC demonstrates a higher half-wave potential and limiting current density compared to the VN/Co/*** S-VN/Co/NS-MC-based liquid ZABs display a power density of 195.7 m W cm^(-2),a specific capacity of 815.7 m A h g^(-1),and a cycling stability exceeding 250 *** S-VN/Co/NS-MC-based flexible ZABs are successfully employed to charge both a smart watch and a mobile *** approach holds promise for advancing the commercial utilization of VN-based catalysts in ZABs.

关键词： S-doped VN Electronic structures Spin state regulation Oxygen reduction reaction Zinc-air batteries

Chaotic attitude and reorientation maneuver for completely liquid-filled spacecraft with flexible appendage

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Acta Mechanica Sinica 2009年第2期25卷 271-277页

作者： B. Yue department of Mechanics, School of science,Beijing institute of technology, 100081 Beijing, china department of Mechanics School of Science Beijing Institute of Technology 100081 Beijing China

The present paper investigates the chaotic attitude dynamics and reorientation maneuver for completely viscous liquid-filled spacecraft with flexible appendage. All of the equations of motion are derived by using Lagrangian mechanics and then transformed into a form consisting of an unperturbed part plus perturbed terms so that the system＇s nonlinear characteristics can be exploited in phase space. Emphases are laid on the chaotic attitude dynamics produced from certain sets of physical parameter values of the spacecraft when energy dissipation acts to derive the body from minor to major axis spin. Numerical solutions of these equations show that the attitude dynamics of liquid-filled flexible spacecraft possesses characteristics common to random, non- periodic solutions and chaos, and it is demonstrated that the desired reorientation maneuver is guaranteed by using a pair of thruster impulses. The control strategy for reorientation maneuver is designed and the numerical simulation results are presented for both the uncontrolled and controlled spins transition.

关键词： Nonlinear attitude dynamics Attitude reorientation maneuver Control strategyLiquid-filled spacecraft

Construction and characterization of the transformation-competent artificial chromosome (TAC) libraries of Leymus multicaulis

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science china(Life sciences) 2008年第7期51卷 604-613页

作者： XU YueYu 1,2,3,ZHOU YuLei 4,5 ,SONG LinLin 6 ,ZHANG Yan 3 &ZHAO MaoLin 1 1 Beijing Agro-Biotechnology Research Center,Beijing Academy of Agriculture and Forestry science,Beijing 100097,china 2 department of Chemistry and Chemical Engineering,Hunan institute of Engineering,Xiangtan 411104,china 3 College of Life science,Capital Normal University,Beijing 100037,china 4 College of Life science,Zhongkai University of Agriculture and technology,Guangzhou 510225,china 5 College of Grassland science,Gansu Agricultural University,Lanzhou 730070,china 6 department of biology,henan institute of science and technology,xinxiang 4.3003,china 1. Beijing Agro-Biotechnology Research Center Beijing Academy of Agriculture and Forestry Science Beijing 100097 China 2. department of Chemistry and Chemical Engineering Hunan Institute of Engineering Xiangtan 411104 China 3. College of Life science Capital Normal University Beijing 100037 China 4. College of Life science Zhongkai University of Agriculture and Technology Guangzhou 510225 China 5. College of Grassland science Gansu Agricultural University Lanzhou 730070 China 6. department of biology Henan Institute of Science and Technology Xinxiang 453003 China

Transformation-competent artificial chromosome system is able to clone and transfer genes efficiently in *** order to clone genes highly tolerant to barley yellow dwarf virus(BYDV),Aphids,drought and salt from Leymus multicaulis,the two TAC genomic libraries I and II were constructed in vector pYLTAC17 and pYLTAC747H/sacB,which contain about 165000 and 236000 recombinant clones *** genome coverage of the two libraries was totally estimated to be about 3―5 haploid genome equivalents,as size selection of genomic DNA fragments was approximately from 9 to 300 *** of the genomic libraries were collected as bulked pools each containing 500 clones or so,stored in twelve 96-deep-well plates and then were gridding in triplicate onto a high-density colony hybridization filter with a 3×3 pattern using a GeneTAC?G3 arraying robot after being transferred manually into three 384-well *** 2501 and 2890 clones of Library in pYLTAC17 and in pYLTAC747H/sacB were stored individually in fourteen 384-well plates and then were automatically gridding in duplicate onto a high-density colony hybridization filter with a 6×6 pattern after a replication of *** positive clones were detected by using the probe glutahione reductase gene of *** libraries constructed here can be used to isolate genomic clones containing target genes,and to carry out genome walking for positional *** the target TAC clones were isolated,they could be immediately transferred into plant genomes with the Agrobacterium system.

关键词： Leymus multicaulis megabase-size DNA transformation-competent artificial chromosome(TAC) genomic library

OBSERVATIONS ON DEFORMATION BEHAVIOR OF HIGH PERFORMANCE FIBERS BY POLARIZING OPTICAL MICROSCOPY

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Chinese Journal of Polymer science 2000年第1期18卷 81-86页

作者： Chang-fa Xiao Yu-feng Zhang department of Materials science, Tianjin institute of Textile science and technology, Tianjin 300160, china Tianjin Inst Text Sci & Technol Dept Mat Sci Tianjin 300160 Peoples R China

By means of polarizing optical microscopy (POM), deformation behavior of four kinds of fibers, i.e, ultra high molecular weight polyethylene (UHMW-PE) fiber, polyvinyl alcohol (PVA) fiber, polyethylene terephthalate (PET) fiber, and wholly aromatic (rho-hydroxybenzoic acid/2-hydroxy-6-naphthoic acid) copolyester [P(HBA/HNA)]/PET (ACPET blend) fiber, in axial compression, axial impacting, and bending was observed. In compression, kink bands formed at an angle of 55-60 degrees ro the fiber axis in 10-times-drawn UHMW-PE fiber, 75-80 degrees in 40-times-drawn sample, 80 degrees in PVA fiber, and 90 degrees in the ACPET blend fiber. In impacting and bending, band angles of UHMW-PE, PVA and PET fibers are nearly the same as those formed in compression, indicating that slip systems do not change. For any of the four kinds of fiber, band spacing exhibits great differences in compression, in impacting, and in bending, which may be attributed to the differences in the degrees of strain or stress concentration.

关键词： high performance fiber axial compression axial impacting bending

Interlayer exciton dynamics of transition metal dichalcogenide heterostructures under electric fields

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Nano Research 2024年第5期17卷 4555-4572页

作者： Jian Tang Yue Zheng Ke Jiang Qi You Zhentian Yin Zihao Xie henan Li Cheng Han Xiaoxian Zhang Yumeng Shi International Collaborative Laboratory of 2D Materials for Optoelectronics science and technology of Ministry of Education Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China College of Electronics and Information Engineering Shenzhen UniversityShenzhen 518060China Key Laboratory of Luminescence and Optical Information Ministry of EducationInstitute of Optoelectronic TechnologyBeijing Jiaotong UniversityBeijing 100044China

Stacking single layers of atoms on top of each other provides a fundamental way to achieve novel material systems and engineer their physical properties,which offers opportunities for exploring fundamental physics and realizing next-generation optoelectronic *** the two-dimensional(2D)-stacked systems,transition metal dichalcogenide(TMDC)heterostructures are particularly attractive because they host tightly-bonded interlayer excitons which possess various novel and appealing *** interlayer excitons have drawn significant research attention and hold high potential for the application in unique optoelectronic devices,such as polarization-and wavelength-tunable single photon emitters,valley Hall transistors,and possible high-temperature *** development of these devices requires a comprehensive understanding of the fundamental properties of these interlayer excitons and the impact of electric fields on their *** this review,we summarize the recent advances on the understanding of interlayer exciton dynamics under electric fields in TMDC *** put emphasis on the electrical modulation of interlayer excitons’emission,the valley Hall transport of charge carriers after the separation of interlayer excitons by an electric field,and the correlation physics of interlayer excitons and charges under electrical doping and *** and perspectives are finally discussed for the application of TMDC heterostructures in future optoelectronics.

关键词： interlayer exciton transition metal dichalcogenide(TMDC)heterostructures circular polarization valley Hall effect strong coupling