检索结果-南通市图书馆

Electronic structure of O-doped SiGe calculated by DFT+U method

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2016年第12期25卷 377-389页

作者：赵宗彦杨雯杨培志 Faculty of materials Science and Engineering Kunming University of Science and Technology Yunnan Key laboratory of Micro/nano materials & Technology School of Materials Science and EngineeringYunnan University Key laboratory of advanced Technique & Preparation for Renewable Energy materials (Ministry of Education) Yunnan Normal University

To more in depth understand the doping effects of oxygen on SiGe alloys, both the micro-structure and properties of O-doped SiGe （including： bulk, （001） surface, and （110） surface） are calculated by DPT ＋ U method in the present work. The calculated results are as follows. （i） The （110） surface is the main exposing surface of SiGe, in which O impurity prefers to occupy the surface vacancy sites. （ii） For O interstitial doping on SiGe （110） surface, the existences of energy states caused by 0 doping in the band gap not only enhance the infrared light absorption, but also improve the behaviors of photo-generated carriers. （iii） The finding about decreased surface work function of O-doped SiGe （110） surface can confirm previous experimental observations. （iv） In all cases, O doing mainly induces the electronic structures near the band gap to vary, but is not directly involved in these variations. Therefore, these findings in the present work not only can provide further explanation and analysis for the corresponding underlying mechanism for some of the experimental findings reported in the literature, but also conduce to the development of μc-SiGe-based solar ceils in the future.

关键词： SiGe alloys 0 doping electronic structure density functional theory (DFT) calculations

Linewidth of electromagnetically induced transparency under motional averaging in a coated vapor cell

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第3期22卷 289-296页

作者：徐智翔曲伟智高然胡新华肖艳红 Department of Physics State Key Laboratory of Surface PhysicsLaboratory of Advanced Materialsand Key Laboratory of Micro and Nano Photonic Structures of Ministry of EducationFudan University Department of Material Science Fudan University

The linewidth of electromagnetically induced transparency（EIT） in a coated Rb vapor cell was studied under a magnetic field *** nonlinear broadening of the EIT linewidth with the magnetic field gradient was *** was found that the motional averaging of the field gradient was more pronounced at higher laser intensities and larger beam *** the same regime,there was a small linewidth decrease with the increasing magnetic field *** have established a Monte-Carlo model,which gave results in good qualitative agreement with our *** pictures for the above phenomena were also *** results provide an understanding of the EIT linewidth behavior under motional averaging,and should be useful for applications in quantum optics and metrology based on coated vapor cells.

关键词： electromagnetically induced transparency coated cell linewidth motional averaging

Hierarchical nanowires for high-performance electrochemical energy storage

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2014年第3期9卷 303-322页

作者：李硕董轶凡王丹丹陈伟黄磊石长玮麦立强 State Key laboratory of advanced Technology for materials Synthesis and Processing WUT Harvard Joint Nano Key Laboratory Wuhan University of Technology Wuhan 430070 China

nanowires are promising candidates for energy storage devices such as lithium-ion batteries, su- per（：*** and lithium-air batteries. However, simple-structured nanowires have some limitations hence the strategies to make improvements need to be explored and investigated. Hierarchical nanowires with enhanced periormanee have been considered as an ideal candidate for energy storage due to the novel structures and/or synergistic properties. This review describes some of the recent progresses in the hierarchical nanowire merits, classification, synthesis and performance in energy storage applieat, ions. Herein we discuss the hierarchical nanowires based on their structural design from three major categories, including exterior design, interior design and aligned nanowire assembly. This review also briefly outlines the prospects of hierarchical nanowires in morphology control, property enhancement and application versatility.

关键词： hierarchical nanowires exterior design interior design electrochemical performance energy storage

Exciton emissions of CdS nanowire array fabricated on Cd foil by the solvothermal method

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第1期30卷 369-373页

作者： Yong Li Peng-Fei Ji Ya-Juan Hao Yue-Li Song Feng-Qun Zhou Shu-Qing Yuan Key laboratory of nano Optoelectronic materials and Insulation materials Pingdingshan UniversityPingdingshan 467000China

nanowires have recently attracted more attention because of their low-dimensional structure, tunable optical and electrical properties for next-generation nanoscale optoelectronic devices. Cd S nanowire array, which is(002)-orientation growth and approximately perpendicular to Cd foil substrate, has been fabricated by the solvothermal method. In the temperature-dependent photoluminescence, from short wavelength to long wavelength, four peaks can be ascribed to the emissions from the bandgap, the transition from the holes being bound to the donors or the electrons being bound to the acceptors, the transition from Cd interstitials to Cd vacancies, and the transition from S vacancies to the valence band,respectively. In the photoluminescence of 10 K, the emission originated from the bandgap appears in the form of multiple peaks. Two stronger peaks and five weaker peaks can be observed. The energy differences of the adjacent peaks are close to 38 me V, which is ascribed to the LO phonon energy of Cd S. For the multiple peaks of bandgap emission, from low energy to high energy, the first, second, and third peaks are contributed to the third-order, second-order, and first-order phonon replica of the free exciton A, respectively;the fourth peak is originated from the free exciton A;the fifth peak is contributed to the first-order phonon replica of the excitons bound to neutral donors;the sixth and seventh peaks are originated from the excitons bound to neutral donors and the light polarization parallel to the c axis of hexagonal Cd S, respectively.

关键词： CdS nanowires array solvothermal method photoluminescence exciton emissions

Metastable amorphous chromium-vanadium oxide nanoparticles with superior performance as a new lithium battery cathode

在线全文

学校读者我要写书评

暂无评论

nano Research 2014年第11期7卷 1604-1612页

作者： Jinzhi Sheng Qidong Li Qiulong Wei Pengfei Zhang Qinqin Wang Fan Lv Qinyou An Wei Chen Liqiang Mai State Key laboratory of advanced Technology for materials Synthesis and Processing WUT-Harvard Joint Nano Key LaboratoryWuhan University of Technology Wuhan 430070 China

The main drawbacks of vanadium oxide as a cathode material are its low conductivity, low practical capacity and poor cycling stability. Adding Cr can improve its conductivity and a metastable amorphous state may provide higher capacity and stability. In this work, metastable amorphous Cr-V-O nano- particles have been successfully prepared through a facile co-precipitation reaction followed by annealing treatment. As a cathode material for lithium batteries, the metastable amorphous Cr-V-O nanoparticles exhibit high capacity （260 mAh/g at 100 mA/g between 1.5-4 V）, low capacity loss （more than 80% was retained after 200 cycles at 100 mA/g） and high rate capability （up to 3 A/g）.

关键词： Cr2V4O13 nanoparticles metastable amorphous structure lithium battery

Laser direct writing of flexible multifunctional airflow sensors on the Kevlar fabric

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

nano Research 2025年第1期18卷 443-454页

作者： Wei Wang Zi-Qing Chen Yong-Qi Li Yu-Long Wang Mei-Chen Liu Yun-Bo Ruan Yang Zhang Shu-Juan Liu Qiang Zhao College of Electronic and Optical Engineering and College of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China State Key laboratory of Organic Electronics and Information Displays and Jiangsu Key laboratory for Biosensors Institute of Advanced Materials(IAM)Nanjing University of Posts and TelecommunicationsNanjing 210023China Zhe Jiang Topsun Logistic Control CO. LTD.Yuhuan 317600China Department of Rehabilitation Medicine School of Acupuncture-Moxibustion and Tuina and School of Health Preservation and RehabilitationNanjing University of Chinese MedicineNanjing 210023China

The growing interest in flexible devices has emerged as a global trend due to their advantages in flexibility,lightweight structure,and wearability,addressing the limitations of traditional *** wearable airflow sensors have been previously reported,the development of flexible fabric-based airflow sensors capable of functioning in environments with open flames—critical for fire rescue operations—has yet to be explored,largely due to the poor fire resistance of conventional *** this work,we first present a flexible,wearable,and multifunctional airflow sensor with excellent fire-resistant properties,fabricated through a simple direct laser writing *** sensor maintains airflow detection capabilities even in the presence of open ***,the fabrication of fabric-based sensors involves complex procedures such as carbon materials doping or vapor-phase deposition,leading to lengthy preparation cycles and high ***,fabric-based devices are inherently prone to *** address these challenges,we introduce twice-vertical laser-induced graphene(TVLIG)as a sensitive and reliable component for fire-resistant airflow *** resulting TVLIG/Kevlar fabric can be integrated into various garments,particularly protective suits,to form sensitive and fire-resistant airflow sensors capable of detecting airflow velocity and direction in both two-dimensional(2D)and three-dimensional(3D)spaces during fire ***,the TVLIG patterns can be expanded to multifunctional platforms,such as glucose detection for injured individuals,offering further applications in rescue *** functional expansion reduces the burden on rescue personnel and streamlines device *** its outstanding sensing capabilities,fire resistance,and expandability,the developed flexible airflow sensor shows great potential for various real-world rescue scenarios,promising advancements in wearable sensing technology for rescue enginee

关键词： flexible airflow sensor direct laser writing twice-vertical laser-induced graphene fire accident rescue Kevlar fabric

Electrochemical engineering approach of high performance solid-state flexible supercapacitor device based on chemically synthesized VS_2 nanoregime structure

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2019年第4期28卷 79-88页

作者： Bidhan Pandit Lakshmana Kumar Bommineedi Babasaheb R.Sankapal nano materials and Device laboratory Department of Physics Visvesvaraya National Institute of Technology

Portable and furnished electronics appliances demand power efficient energy storage devices where electrochemical supercapacitors gain much more *** this concern,a simple,low-cost and industry scalable successive ionic layer adsorption and reaction(SILAR)approach has been adopted to deposit nanostructured VS_2onto flexible and light-weight stainless steel(SS)substrate towards supercapacitor *** nanocrystalline nature with hexagonal crystal structure has been confirmed for VS_2through structural *** VS_2electrode exhibits a maximum specific capacitance of 349 F g^(-1)with a super stable behavior in three-electrode liquid-state *** flexible symmetric solid-state supercapacitor(FSSC)device using gel electrolyte yields specific power of 1.5 k W kg^(-1)(specific energy of 25.9 Wh kg^(-1))with a widen voltage window of 1.6 V.A red LED has been glown for30 s using the system consisted of two devices in series ***,the system glows a combination of 21 red LEDs network with acronym‘VNIT’,demonstrating commercial *** attribution of device demonstration even under mechanical stress holds great promise towards advanced flexible electronics application.

关键词： Chemical method vs2 Supercapacitor Gel electrolyte Symmetric device

Lithiation-enhanced charge transfer and sliding strength at the silicon-graphene interface:A first-principles study

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2017年第3期30卷 254-262页

作者： Cheng Chang Xiaoyan Li Zhiping Xu Huajian Gao Applied Mechanics laboratory Department of Engineering Mechanics Center for Nano and Micro MechanicsCenter for Advanced Mechanics and Materials Tsinghua University School of Engineering Brown University

The application of silicon as ultrahigh capacity electrodes in lithiumion batteries has been limited by a number of mechanical degradation mechanisms including fracture, delamination and plastic ratcheting, as a result of its large volumetric change during lithiation and delithiation. Graphene coating is one feasible technique to mitigate the mechanical degradation of Si anode and improve its conductivity. In this paper, first-principles calculations are performed to study the atomic structure, charge transfer and sliding strength of the interface between lithiated silicon and graphene. Our results show that Li atoms segre- gate at the （lithiated） Si-graphene interface preferentially, donating electrons to graphene and enhancing the interfacial sliding resistance. Moreover, the interfacial cohesion and sliding strength can be further enhanced by introducing single-vacancy defects into graphene. These findings provide insights that can guide the design of stable and efficient anodes of silicon/graphene hybrids for energy storage applications.

关键词： Lithium-ion batteries Silicon anode Graphene coating Interracial sliding strength First-principles calculations

Simultaneous acquisition of Fe3O4 monocrystals:Tunable magnetic properties with various morphologies

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:materials International 2020年第1期30卷 41-46页

作者： Zemin Zheng Yiming Cao Zhe Li Huiyong Li Dafeng Hu Hao Jiang Xuemin Geng Jiangwei Lu Xudong Zhang Peng Yang Yanfen Wan School of materials Science and Engineering Yunnan Key Laboratory for Micro/nano Materials & TechnologyYunnan University Center for Magnetic materials and Devices & Key laboratory for advanced Functional and Low Dimensional materials of Yunnan Higher Education Institute Qujing Normal University

Fe3O4nanoparticles（NPs） with a face-centered cubic（fcc） structure and two different morphologies（nanospheres and nanoprisms） were synthesized by a facile one-step *** synthesized Fe3O4nanospheres and nanoprisms were monocrystalline and separable in a magnetic *** different volume ratios of oleylamine（OAm） to dibenzyl ether,the sizes of the prepared Fe3O4NPs ranged from 5 to 21 *** OAm amount in the synthesis can significantly control the morphology of *** the OAm content increased from 10 ml to 30 ml,the faceted nanoprisms shrank while the nanospheres *** an OAm content of 25 ml,the nanoprisms diminished while more hexagonal and sphere-like particles appeared,implying a critical point of morphology transition from triangle to *** magnetic properties also depended on the NP morphology and *** prepared Fe3O4NPs are promising candidates in medical applications such as magnetic resonance imaging,targeted drug delivery,blood purification,and tumor hyperthermia.

关键词： Fe 3 O 4 nanoparticles nanoprism nanosphere Superparamagnetic