检索结果-南通市图书馆

Resonant Raman scattering in GaN single crystals and GaN-based heterostructures: feasibility for laser cooling

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2013年第1期11卷 63-71页

作者： Yuj.e j. ding j.cob B. Khurgin Department of Electrical and Computer Engineering Lehigh University Department of Electrical and Computer Engineering The Johns Hopkins University

The recent progress on Raman scattering in GaN single crystals and GaN/A1N heterostructures is re- viewed. Anti-Stokes Raman scattering is used to determine electron-phonon scattering time and decay time constant for longitudinal-opticat phonons. In a typical high electron mobility transistor based on GaN/A1N heterostructures, strong resonances are reached for the first-order and second-order Raman scattering processes. Therefore, both Stokes and anti-Stokes Raman intensities are dramatically enhanced. The feasibility for laser cooling of a nitride structure is studied. A further optimization will enable us to reach the threshold for laser cooling. Raman scattering have potential applications in up-conversion lasers and laser cooling of nitride ultrafast electronic and optoelectronic devices.

关键词： GaN Ra Resonant Raman scattering in GaN single crystals and GaN-based heterostructures feasibility for laser cooling

A DiscreteMulti-Obj.ctive Squirrel Search Algorithm for Energy-Efficient Distributed Heterogeneous Permutation Flowshop with Variable Processing Speed

在线全文

学校读者我要写书评

暂无评论

Computers, Materials and Continua 2024年第1期81卷 1757-1787页

作者： Zeng L. ding Z. Shi j. Wang S. School of Electrical and Electronic Engineering Hubei University of Technology Wuhan 430068 China Hubei Key Laboratory for High-Efficiency Utilization of Solar Energy and Operation Control of Energy Storage System Hubei University of Technology Wuhan 430068 China Xiangyang Industrial Institute of Hubei University of Technology Xiangyang 441100 China

In the manufacturing industry, reasonable scheduling can greatly improve production efficiency, while excessive resource consumption highlights the growing significance of energy conservation in production. This paper studies the problem of energy-efficient distributed heterogeneous permutation flowshop problem with variable processing speed (DHPFSP-VPS), considering both theminimum makespan and total energy consumption (TEC) as obj.ctives. A discrete multi-obj.ctive squirrel search algorithm (DMSSA) is proposed to solve the DHPFSPVPS. DMSSA makes four improvements based on the squirrel search algorithm. Firstly, in terms of the population initialization strategy, four hybrid initialization methods targeting different obj.ctives are proposed to enhance the quality of initial solutions. Secondly, enhancements are made to the population hierarchy system and position updating methods of the squirrel search algorithm, making it more suitable for discrete scheduling problems. Additionally, regarding the search strategy, six local searches are designed based on problem characteristics to enhance search capability. Moreover, a dynamic predator strategy based on Q-learning is devised to effectively balanceDMSSA's capability for global exploration and local exploitation. Finally, two speed control energy-efficient strategies are designed to reduce TEC. Extensive comparative experiments are conducted in this paper to validate the effectiveness of the proposed strategies. The results of comparing DMSSA with other algorithms demonstrate its superior performance and its potential for efficient solving of the DHPFSP-VPS problem. © 2024 The Authors. Published by Tech Science Press.

关键词： Distributed heterogeneous permutation flowshop problem energy-efficient squirrel search algorithm muli-obj.ctive optimization variable processing speed

Mechanisms of High Coercivity in Ni/NiO Composite Films by Post Annealing

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

材料科学与工程学报 2007年第6期25卷 858-860页

作者： j.B. Yi j. ding Mansoor Bin Abdul j.lil B.H. Liu S. Thongmee j.H. Yin Z.L. Zhao Department of Materials Science and Engineering National University of Singapore 119260 Singapore Department of Electrical ＆ Computer Engineering National University of Singapore 119260 Singapore

A coercivity as large as 2.4 kOe has been achieved in the Ni/NiO composite film after an annealing under a magnetic field of 10 kOe and an O_2 partial pressure of 0.001 *** coercivity was attributed to the strong exchange coupling of Ni and *** grain size of Ni and NiO was observed after the *** enhanced coercivity is probably associated with the domain wall pinning by local energy minima,the distribution of Ni and NiO,and the domain structure in the interface of Ni/NiO generated under the presence of the magnetic field during the post-annealing.

关键词：矫顽性镍氧化镍复合薄膜焊后退火交换耦合

Dissociation cross sections ofψ(3770),ψ(4040),ψ(4160),andψ(4415)mesons with nucleons

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期76卷 93-112页

作者： Ruo-Qing ding Xiao-Ming Xu H j.Weber Department of Physics Shanghai UniversityBaoshanShanghai 200444China Department of Physics University of VirginiaCharlottesvilleVA 22904United States of America

We study the dissociation of ψ(3770), ψ(4040), ψ(4160), and ψ(4415) mesons in collision with nucleons, which takes place in high-energy proton-nucleus collisions. The quark interchange between a nucleon and a ■ meson leads to the dissociation of the ■ meson. We consider the reactions:■, and■, where R stands for ψ(3770), ψ(4040), ψ(4160), or ψ(4415). A reaction of a neutron and a ■ meson corresponds to a reaction of a proton and the ■ meson by replacing the up quark with the down quark and vice versa. Transition-amplitude formulas are derived from the S-matrix *** cross sections are calculated with the transition amplitudes for scattering in the prior form and in the post form. The cross sections relate to nodes in the radial wave functions of ψ(3770), ψ(4040), ψ(4160), and ψ(4415) mesons.

关键词： inelastic nucleon-charmonium scattering quark interchange relativistic constituent quark potential model

A REDUCED ORDER SCHWARZ METHOD FOR NONLINEAR MULTISCALE ELLIPTIC EQUATIONS BASED ON TWO-LAYER NEURAL NETWORKS

在线全文

学校读者我要写书评

暂无评论

j.urnal of Computational Mathematics 2024年第2期42卷 570-596页

作者： Shi Chen Zhiyan ding Qin Li Stephen j.Wright Mathematics Department University of Wisconsin-MadisonMadisonWI 53706USA Department of Mathematics University of California-BerkeleyBerkeley CA 94720USA Mathematics Department and Discovery Institute University of Wisconsin-Madison MadisonWI 53706USA Computer Sciences Department University of WisconsinMadisonWI 53706USA

Neural networks are powerful tools for approximating high dimensional data that have been used in many contexts,including solution of partial differential equations(PDEs).We describe a solver for multiscale fully nonlinear elliptic equations that makes use of domain decomposition,an accelerated Schwarz framework,and two-layer neural networks to approximate the boundary-to-boundarymap for the subdomains,which is the key step in the Schwarz ***,the boundary-to-boundary map requires solution of boundary-value elliptic problems on each *** leveraging the compressibility of multiscale problems,our approach trains the neural network offline to serve as a surrogate for the usual implementation of the boundary-to-boundary *** method is applied to a multiscale semilinear elliptic equation and a multiscale p-Laplace *** both cases we demonstrate significant improvement in efficiency as well as good accuracy and generalization performance.

关键词： Nonlinear homogenization Multiscale elliptic problem Neural networks Do-main decomposition

Theoretical and experimental study of a bi-stable piezoelectric energy harvester under hybrid galloping and band-limited random excitations

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

Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 461-478页

作者： Haitao LI Tianyu ZHENG Weiyang QIN Ruilan TIAN Hu ding j.C.j. Liqun CHEN Department of Engineering Mechanics North University of ChinaTaiyuan 030051China Department of Engineering Mechanics Northwestern Polytechnical UniversityXi'an 710072China Department of Engineering Mechanics Shijiazhuang Tiedao UniversityShijiazhuang 050043China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechnoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China School of Mechanical and Mechatronic Engineering University of Technology SydneyNew South Wales 2007Australia

In the practical environment,it is very common for the simultaneous occurrence of base excitation and *** the combined energy of vibration and wind with a single energy harvesting structure is *** this purpose,the effects of the wind speed and random excitation level are investigated with the stochastic averaging method(SAM)based on the energy *** results of the analytical prediction are verified with the Monte-Carlo method(MCM).The numerical simulation shows that the introduction of wind can reduce the critical excitation level for triggering an inter-well j.mp and make a bi-stable energy harvester(BEH)realize the performance enhancement for a weak base ***,as the strength of the wind increases to a particular level,the influence of the random base excitation on the dynamic responses is weakened,and the system exhibits a periodic galloping response.A comparison between a BEH and a linear energy harvester(LEH)indicates that the BEH demonstrates inferior performance for high-speed *** experiments are conducted to investigate the validity of the theoretical prediction and numerical *** experimental findings also show that strong random excitation is favorable for the BEH in the range of low wind ***,as the speed of the incoming wind is up to a particular level,the disadvantage of the BEH becomes clear and evident.

关键词： bi-stability inter-well response galloping band-limited random

PHYSICAL MODELING FOR THE MECHANISMS OF BEAD FORMATION DEFECTS BASED ON THE STABILITY OF LIQUID METAL

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2000年第1期13卷 123-127页

作者： S. Y. Yin L. Feng j. Z. ding and S. j. Chan( 1) Beij.ng Polytechnic University, Beij.ng 100022, China 2) National Key Laboratory of Advanced Wdlding Production Technology, HIT, Harbin 150001, China)

Based on the theory of stability of the liquid metal under the action of surface tension,a physical mod- el is established for the mechanisms of the bead formation deferct' humping', which is generated during high - speed welding.A boundary function is introduced to correct the model,theoretical results got by the model correspond well with the experimental phenomena. A two - dimensional conducting model is adoopted in the simulation of the temperature field during high - speed ***, the factors acting upon the stability of liquid metal are analyzed.

关键词： high - speed welding bead formation stability

Superior Latent Heat Eutectic Salt Na_(2)CO_(3)-Li_(2)CO_(3)-LiF for Thermal Energy Storage:Preparation and Performance Investigation

在线全文

学校读者我要写书评

暂无评论

j.urnal of Thermal Science 2024年第2期33卷 501-508页

作者： LI Weiwei MIAO Qi ZHANG Yelong ding Hongliang YANG Sa LAI Yuan FENG Daili ding Yulong j.N Yi TAN Linghua School of Chemistry and Chemical Engineering Nanjing University of Science&TechnologyNanjing210094China National Special Superfine Powder Engineering Research Center Nanjing University of Science and TechnologyNanjing210094China Nanj.ng j.nhe Energy Material Co. LtdNanjing210047China School of Chemical Engineering University of BirminghamBirminghamB152TTUK School of Energy&Environmental Engineering University of Science and Technology BeijingBeijing100083China

In this paper,a novel ternary eutectic salt Na_(2)CO_(3)-Li_(2)CO_(3)-LiF was designed and investigated for concentrated solar power(CSP).The FactSage software was used to predict the composition and eutectic point of Na_(2)CO_(3)-Li_(2)CO_(3)-*** microstructure,thermophysical properties,and thermal stability of eutectic salts were experimentally measured using various analytical *** a mass ratio of 57%:32%:11%,the eutectic salt exhibited excellent thermal storage properties with a fusion enthalpy of 413 j.g and a melting point of 426.8℃.The excellent thermal stability of the eutectic salt was reflected by a weight loss of only 0.8% at 600℃.

关键词： phase change materials ternary eutectic salt latent heat thermal stability

Liquid metal compartmented by polyphenol-mediated nanointerfaces enables high-performance thermal management on electronic devices

在线全文

学校读者我要写书评

暂无评论

InfoMat 2024年第1期6卷 83-95页

作者： Chaoj.n Zhang Yang Tang Tianyu Guo Yizhou Sang ding Li Xiaoling Wang Orlando j.Roj.s j.nling Guo BMI Center for Biomass Materials and Nanointerfaces College of Biomass Science and EngineeringSichuan UniversityChengduSichuanthe People's Republic of China Bioproducts Institute Departments of Chemical and Biological EngineeringThe University of British ColumbiaVancouverBritish ColumbiaCanada Institute of Development Studies Southwestern University of Finance and EconomicsChengduSichuanthe People's Republic of China National Engineering Laboratory for Clean Technology of Leather Manufacture Sichuan UniversityChengduSichuanthe People's Republic of China State Key Laboratory of Polymer Materials Engineering Sichuan UniversityChengduSichuanthe People's Republic of China

The exponentially increasing heat generation in electronic devices,induced by high power density and miniaturization,has become a dominant issue that affects carbon footprint,cost,performance,reliability,and *** metals(LMs)with high thermal conductivity are promising candidates for effective thermal management yet are facing pump-out and surface-spreading *** in the form of metallic particles can address these problems,but apparent alloying processes elevate the LM melting point,leading to severely deteriorated ***,we propose a facile and sustainable approach to address these challenges by using a biogenic supramolecular network as an effective diffusion barrier at copper particle-LM(EGaIn/Cu@TA)interfaces to achieve superior thermal *** supramolecular network promotes LM stability by reducing unfavorable alloying and fluidity *** EGaIn/Cu@TA exhibits a record-high metallic-mediated thermal conductivity(66.1 W m^(-1) K^(-1))and fluidic ***,mechanistic studies suggest the enhanced heat flow path after the incorporation of copper particles,generating heat dissipation suitable for computer central processing units,exceeding that of commercial *** results highlight the prospects of renewable macromolecules isolated from biomass for the rational design of nanointerfaces based on metallic particles and LM,paving a new and sustainable avenue for high-performance thermal management.

关键词： Electronic devices High thermal conductivity Liquid metals Natural polyphenols Thermal management