检索结果-南通市图书馆

Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1033-1050页

作者： T.I.TOLUWALOJU C.K.THEIN D.HALIM Department of Mechanical Materials and Manufacturing EngineeringUniversity of Nottingham Ningbo ChinaNingbo 315100Zhejiang ProvinceChina Nottingham ningbo China Beacons of Excellence Research and innovation institute University of Nottingham Ningbo ChinaNingbo 315048Zhejiang ProvinceChina

The levered-dual response(LEDAR)Coulomb-damped system attains near resonant vibration isolation by differential preloads/offsets in linear *** takes the advantages of both the preloads/offsets in linear springs and the guiderail friction for realizing different levels of vibration *** isolation capacities are investigated on the strategies with both the horizontal and vertical guiderails,with the horizontal rail only,and without *** compressive preloads generally result in the consumption of most of the initial excitation energy so as to overcome the potential *** isolation onsets at the frequency ratio of 1∓0.095 on the left-hand side(LHS)and the right-hand side(RHS)of the lever are relative to the load plate *** observed near resonant isolation thus makes the LEDAR system a candidate for the isolation of the mechanical systems about resonance while opening a path for simultaneous harvesterisolation functions and passive functions at extreme frequencies.

关键词： lever ratio Coulomb damping preload tension/compression isolation band/depth offset potential

Significant effect of ordered micro-domain on cell boundary phase distribution and demagnetization curve squareness of Sm_(2)Co_(17)-type magnet

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第4期43卷 1724-1735页

作者： Zhuang Liu Hai-Chen Wu Chao-Yue Zhang Chao-Qun Zhu Guo-Xin Chen Huan-Ming Lu Ren-Jie Chen Aru Yan CISRI&NIMTE Joint innovation Center for Rare Earth Permanent Magnets Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China University of Chinese Academy of Sciences Beijing100049China Analytical Center Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China

Cu-rich cell boundary phase is difficult to precipitate evenly,resulting in a generally poor demagnetization curve squareness for Fe-rich Sm_(2)Co_(17)-type magnet,which is a key factor limiting the further improvement of magnetic energy *** this study,we report that nanoscale strip-like ordered micro-domains distributed in1:7H disordered matrix phase of the solid solution precursor is a new factor significantly affecting the precipitation and distribution of the cell boundary *** strip-like and continuous micro-twin structure with twin boundaries neatly perpendicular to the C-axis is observed after sintering *** solution treatment,sequential and long strip-like micro-twins gradually transform into disordered state along the basal plane,forming narrow disordered 1:7H(TbCu_(7)-type structure)phase between the separated strip-like ordered *** disordering transformation takes place via broken down of the long strip-like ordered micro-domains,which is accomplished by narrowing along the width direction followed by reduction of the ***,a new model revealing the effect of the ordered micro-domains on the formation of the cell boundary phase is *** boundaries enriched in Cu have already existed in the precursor with long strip-like ordered ***,the Cu-rich cell boundary phase acting as strong pinning centers cannot be precipitated homogeneously and distributed continuously after aging,resulting in a poor demagnetization curve squareness of Sm_(2)Co_(17)-type *** results indicate that significant broken down of the nanoscale ordered micro-domains in solution precursor is the key factor improving the distribution of cell boundary phase in Sm_(2)Co_(17)-type magnets.

关键词： Sm_(2)Co_(17) magnets Solution precursor Ordered micro-domains Disordering transformation Cellular structure

Effect of In doping on the evolution of microstructure,magnetic properties and corrosion resistance of NdFeB magnets

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第3期33卷 623-629页

作者：李豫豪范晓东贾智范璐丁广飞刘新才郭帅郑波曹帅陈仁杰闫阿儒 School of materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China CISRI & NIMTE Joint innovation Center for Rare Earth Permanent Magnets Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China University of Chinese Academy of Sciences Beijing 100049China

The grain boundary phase affects the magnetic properties and corrosion resistance of sintered NdFeB *** this work,a small amount of In was added to NdFeB magnets by induction melting to systematically investigate its effect on the evolution of the microstructure,magnetic properties and corrosion resistance of NdFeB *** analysis illustrated that minor In addition generated more grain boundary phases and an abundant amorphous phase at the triple-junction grain *** the addition of In failed to enhance the magnetic isolation effect between adjacent matrix grains,its incorporation fortuitously elevated the electrochemical potential of the In-containing ***,during corrosion,an In-rich precipitate phase formed,hindering the ingress of the corrosive medium into the ***,this significantly bolstered the corrosion resistance of the sintered NdFeB *** phase formation,magnetic properties and corrosion resistance of In-doped NdFeB magnets are detailed in this work,which provides new prospects for the preparation of high-performance sintered NdFeB magnets.

关键词： In-doping NdFeB magnets magnetic properties corrosion resistance

Exceptional mechanical performance and macroscale superlubricity enabled by core-shell-like MoS_(2)/B_(4)C film

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第7期67卷 2018-2030页

作者： REN SiMing GAO ZhenRong FAN Xin WANG HaiXin WANG LiPing Key Laboratory of Advanced Marine materials Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China

Molybdenum disulfide(MoS_(2)) films are widely deployed in industrial applications owing to their inherent interlayer slip characteristics, offering energy consumption savings and prolonged mechanical part performance. Nevertheless, their practical utility is limited by environmental constraints and the limitations of preparation techniques, which hinder the attainment of robust superlubricity(friction coefficient < 0.01). Herein, through magnetron sputtering technology, we synthesize a core-shell-like nanocomposite composed of MoS_(2)nanosheets encapsulating B_(4)C. The core-shell-like structure enables the resulting films to preferentially grow crystalline MoS_(2), providing them with outstanding mechanical properties and efficient lubrication over a wide range of temperatures. Remarkably, such film achieves robust macroscale superlubricity and an ultralow wear rate(1.7 ×10^(-8)mm^(3)N-1m^(-1)) under high contact stress in a mild vacuum environment. This noteworthy outcome is primarily attributable to the self-segmentation of the macroscale contact interface during the friction process, involving:(1) a large amount of wear debris is embedded into the wear track to create extensive micro-sized asperities;(2) a nanolayer of amorphous carbon enriched with oxide nanoparticles is formed on the uppermost part of these asperities;(3) numerous incommensurate nanocontacts comprising nanoparticles and highly oriented MoS_(2)nanosheets are established, culminating in the achievement of robust superlubricity. Our pioneering design, coupled with the elucidation of the underlying superlubricity mechanism, holds significant promise for advancing the development of robust and high-performance lubricants.

关键词： MoS_(2)/B_(4)C nanocomposites core-shell-like structure H/E ratio high-temperature friction macroscale superlubricity

Carrier transport barrier in AlGaN-based deep ultraviolet LEDs on offcut sapphire substrates

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2024年第2期22卷 148-158页

作者：陈秋爽陈荔陈聪高歌郭炜叶继春 ningbo institute of materials Technology and Engineering Ningbo 315201China University of Chinese Academy of Sciences Beijing 100049China

AlGaN-based light-emitting diodes(LEDs)on offcut substrates enhance radiative emission via forming carrier localization centers in multiple quantum wells(MQWs).This study introduces the carrier transport barrier concept,accessing its impact on the quantum efficiency of LEDs grown on different offcut sapphire substrates.A significantly enhanced internal quantum efficiency(IQE)of 83.1%is obtained from MQWs on the 1°offcut sapphire,almost twice that of the controlled 0.2°offcut ***,1°offcut LEDs have higher turn-on voltage and weaker electroluminescence than 0.2°*** calculations demonstrate the existence of a potential barrier on the current path around the step-induced Ga-rich ***-rich stripes reduce the turn-on voltage but restrict sufficient driving current,impacting LED performance.

关键词： carrier localization step-bunching potential barrier offcut substrate DUV LEDs

Proton‑Prompted Ligand Exchange to Achieve High‑Efficiency CsPbI_(3) Quantum Dot Light‑Emitting Diodes

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第6期16卷 53-62页

作者： Yanming Li Ming Deng Xuanyu Zhang Lei Qian Chaoyu Xiang Laboratory of Advanced Nano‑Optoelectronic materials and Devices Qianwan Institute of CNITECHNingbo 315300People’s Republic of China Division of Functional materials and Nanodevices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201People’s Republic of China Zhejiang Provincial Engineering Research Center of Energy Optoelectronic materials and Devices Ningbo Institute of Materials Technology&EngineeringChinese Academy of SciencesNingbo 315201People’s Republic of China Faculty of Electrical Engineering and Computer Science Ningbo UniversityNingbo 315211ZhejiangPeople’s Republic of China University of Nottingham ningbo China Ningbo 315100People’s Republic of China

CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting ***,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improvement of device *** in-situ ligand replacement and ligand exchange after synthesis were often difficult to ***,we proposed a new ligand exchange strategy using a proton-prompted insitu exchange of short 5-aminopentanoic acid ligands with long-chain oleic acid and oleylamine ligands to obtain stable small-size CsPbI_(3)*** exchange strategy maintained the size and morphology of CsPbI_(3)QDs and improved the optical properties and the conductivity of CsPbI_(3)QDs *** a result,high-efficiency red QD-based light-emitting diodes with an emission wavelength of 645 nm demonstrated a record maximum external quantum efficiency of 24.45%and an operational half-life of 10.79 h.

关键词： CsPbI_(3) perovskite quantum dots Light-emitting diodes Ligand exchange Proton-prompted in-situ exchange

Ambient-Condition Strategy for Production of Hollow Ga_(2)O_(3)@rGO Crystalline Nanostructures Toward Efficient Lithium Storage

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental materials 2024年第2期7卷 75-82页

作者： Dongdong Zhang Qiliang Wei Haili Huang Lan Jiang Jie Teng Ruizhi Yu Qing Zhang Shengxing Liu Lin Wang Weiyou Yang institute of Micro/Nano materials and Devices Ningbo University of TechnologyNingbo 315211China College of materials Science and Engineering Hunan UniversityChangsha 410082China

Crystallineγ-Ga_(2)O_(3)@rGO core-shell nanostructures are synthesized in gram scale,which are accomplished by a facile sonochemical strategy under ambient *** are composed of uniformγ-Ga_(2)O_(3)nanospheres encapsulated by reduced graphene oxide(rGO)nanolayers,and their formation is mainly attributed to the existed opposite zeta potential between the Ga_(2)O_(3)and *** as-constructed lithium-ion batteries(LIBs)based on as-fabricatedγ-Ga_(2)O_(3)@rGO nanostructures deliver an initial discharge capacity of 1000 mAh g^(-1)at 100 mA g^(-1)and reversible capacity of 600 mAh g^(-1)under 500 mA g^(-1)after 1000 cycles,respectively,which are remarkably higher than those of pristineγ-Ga_(2)O_(3)with a much reduced lifetime of 100 cycles and much lower *** situ XRD and XPS analyses demonstrate that the reversible LIBs storage is dominant by a conversion reaction and alloying mechanism,where the discharged product of liquid metal Ga exhibits self-healing ability,thus preventing the destroy of ***,the rGO shell could act robustly as conductive network of the electrode for significantly improved conductivity,endowing the efficient Li storage *** work might provide some insight on mass production of advanced electrode materials under mild condition for energy storage and conversion applications.

关键词： ambient condition core-shell nanostructures Ga_(2)O_(3) Li-ion batteries rGO

Optical grade (Gd_(0.95-x)Lu_(x)Eu_(0.05))_(3)Al_(5)O_(12) ceramics with near-zero optical loss: Effects of Lu^(3+) doping on structural feature, microstructure evolution, and far-red luminescence

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第1期13卷 113-123页

作者： Zhigang Sun Ji-Guang Li Huiyu Qian Yoshio Sakka Tohru SSuzuki Bin Lu School of materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China Research Center for Electronic and Optical materials National Institute for Materials ScienceIbaraki 305-0044Japan Key Laboratory of Photoelectric Detection materials and Devices of Zhejiang Province Ningbo 315211China

A chemical co-precipitation strategy was employed to synthesize a series of(Gd_(0.95−x)Lu_(x)Eu_(0.05))_(3)Al_(5)O_(12)(x=0.1−0.95)powder phosphors,followed by vacuum sintering to achieve transparent garnet ceramic *** density functional theory indicated Lu_(3)Al_(5)O_(12) was formed in priority compared with Gd_(3)Al_(5)O_(12) during solid-phase *** high-temperature sintering,the Lu^(3+)substitution for Gd^(3+)suppressed point mass diffusion leading to a smaller grain *** in-line transmittances of bulk specimens with x=0.1,0.3,0.5,0.7,and 0.95 nm were~83.5%,80.1%,68.8%,73.7%,and 82.2%at 710 nm(Eu^(3+)emission center),respectively,among which the sample of x=0.1 exhibited the optical grade with near-zero optical loss in agreement with the defect-free single crystal(~100%of the theoretical transmittance).The resulting particle and ceramic materials both presented characteristic Eu^(3+)emission arising from 5D0→7FJ(J=1−4)transition,where the dominant far-red emission at~710 nm arising from ^(5)D_(0)→^(7)F_(4) transition overlapped with the absorption of phytochrome(PFR).The photoluminescence excitation and photoluminescence intensities of(Gd_(0.95−x)Lu_(x)Eu_(0.05))_(3)Al_(5)O_(12) powders and ceramics generally increased at a higher Gd^(3+)/Lu^(3+)***^(3+)dopants delayed the fluorescence lifetime while the bulk samples had shorter lifetime compared to the particle *** transparent(Gd_(0.85)Lu_(0.1)Eu_(0.05))3Al_(5)O_(12) ceramic phosphor exhibited good thermal stability with a high thermal quenching temperature above 533 *** designed ceramic phosphor-converted light-emitting diode had a saturation injection current of 435 mA and a current-dependent color rendering *** importantly,our report marked the developmental stage of transparent ceramic materials towards zero optical loss.

关键词： transparent ceramics garnet phosphors light-emitting diode(LED) optical properties Gibbs free energy

Facile access to C-N bonds via unexpected side reactions of Knoevenagel condensation and their application in high-efficiency organic solar cells

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

Science China Chemistry 2024年第1期67卷 323-329页

作者： Daobin Yang Shuncheng Yang Hongqian Wang Lin Xie Pengyu Yan Ziyi Ge Zhejiang Engineering Research Center for Energy Optoelectronic materials and Devices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China School of materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China Center of materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The construction of C-N bonds is of great importance in the fields of biology,medicine,chemistry and materials ***,the replacement of organic base from pyridine to piperidine in the Knoevenagel condensation process unexpectedly yields a series of novel organic molecules containing C-N ***,the synthesis method does not require any external transition-metals catalysis,and photo-/***,when the new compound 1b is added as a third component to a well-known binary system of PM6:Y6,the efficiency of the organic solar cell is significantly improved,resulting in an outstanding efficiency of 18.0%,which is one of the highest values reported to date for PM6:Y6-based ternary organic solar cells.

关键词： C-N bonds Knoevenagel condensation cross-coupling reaction third component organic solar cells

Nonlinear photonic quasi-periodic spiral

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2024年第3期22卷 112-117页

作者：曾静王森赵如薇刘永兴徐铁峰盛艳徐天翔 Laboratory of Infrared materials and Devices Research Institute of Advanced TechnologiesNingbo UniversityNingbo 315211China Zhejiang Key Laboratory of Photoelectric materials and Devices Ningbo UniversityNingbo 315211China ningbo institute of Oceanography Ningbo 315832China Department of Quantum Science and Technology Research School of PhysicsAustralian National UniversityCanberraACT 2601Australia

The design of nonlinear photonic Vogel's spiral based on quasi-crystal theory was *** main parameters of Vogel's spiral were arranged to obtain multi-reciprocal *** structure was fabricated by the near-infrared femtosecond laser poling technique,forming a nonlinear photonic structure,and multiple ring-like nonlinear Raman±Nath second-harmonic generation processes were realized and analyzed in *** structure for the cascaded thirdharmonic generation process was *** results could help deepen the understanding of Vogel's spiral and quasi-crystal and pave the way for the combination of quasi-crystal theory with more aperiodic structures.

关键词： nonlinear photonic quasi-crystal second-harmonic generation Vogel's spiral nonlinear Raman-Nath diffraction femtosecond laser poling