检索结果-南通市图书馆

Enhanced scattering of acoustic waves at interfaces

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2012年第3期7卷 319-323页

作者： Li Zhao Bin Liu Yin-hao Gao Yan-jiao Zhao Ji-ping Huang Department of Physics and State Key Laboratory of Surface Physics Fudan UniversityShanghai 200433China School of Machinery and Electricity Henan Institute of Science and TechnologyXinxiang 453003China Advanced Materials Laboratory Fudan UniversityShanghai 200438China

We propose a general method to realize a total scattering of an incident acoustic wave at interfaces between different media while allowing the flow of air, fluids and/or particles. This originates from the enlargement of the equivalent acoustic scattering cross section of an embedded object coated with acoustic metamaterials, which causes the coated object to behave as a scatterer bigger than its physical size. We theoretically design a model circular cylindrical object coated with such meta- materials whose properties are determined according to two different, but identical, methods. The desired function is confirmed for both far-field and near-field cases with full wave simulations based on the finite element method. This work reveals a promising way to achieve noise shielding and naval camouflage.

关键词： superscattering acoustic waves finite element simulations

MODELING OF POWER TRANSMISSION THROUGH AN ELASTIC WALL BY PIEZOELECTRIC TRANSDUCERS AND acoustic waves

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

MODELING OF POWER TRANSMISSION THROUGH AN ELASTIC WALL BY PI...

Analytical Solution for waves Propagation in Heterogeneous acoustic/Porous Media. Part I: The 2D Case

第三届全国压电和声波理论及器件技术研讨会

作者： Zeng-tao YANG,Shao-hua GUO Institute of Mechanics and Sensing Technology,School of Civil Engineering and Architecture Central South University,Changsha,Hunan 410083,China Yuan-tai HU Department of Mechanics,Huazhong University of Science and Technology,Wuhan,Hubei 430074,China Jia-shi YANG Department of Engineering Mechanics,University of Nebraska,Lincoln,NE 68588-0526,USA

We present our recent modeling results on power transmission through an elastic wall by piezoelectric transducers and acoustic waves,This includes the case of finite piezoelectric transducers on plates,power transmiss... 详细信息

关键词： Piezoelectricity transducer acoustic waves

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Communications in Computational Physics 2010年第3期7卷 171-194页

作者： Julien Diaz Abdelaaziz Ezziani Project-team Magique-3D INRIA Bordeaux Sud-Ouest LMA Pau CNRS UMR 5142I.P.R.A-Universit´e de Pau et des Pays de l’Adouravenue de l’Universit´e BP 1155-64013 PAU CEDEXFrance

Thanks to the Cagniard-de Hoop’s method we derive the solution to theproblem of wave propagation in an infinite bilayered acoustic/poroelastic media, wherethe poroelastic layer is modelled by the biphasic Biot’s model. This first part is dedi-cated to solution to the two-dimensional problem. We illustrate the properties of thesolution, which will be used to validate a numerical code.

关键词： Biot’s model poroelastic waves acoustic waves acoustic/poroelastic coupling ana-lytical solution Cagniard-de Hoop’s technique 2D

Biomedical microwave-induced thermoacoustic imaging

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 Innovative Optical Health Sciences 2022年第4期15卷 13-48页

作者： Qiang Liu Xiao Liang Weizhi Qi Yubin Gong Huabei Jiang Lei Xi Department of Biomedical Engineering Southern University of Science and Technology Shenzhen Guangdong518055P.R.China Guangdong Provincial Key Laboratory of Advanced Biomaterials Department of Biomedical Engineering Southern University of Science and Technology Shenzhen Guangdong518055P.R.China School of Electrical Science and Engineering University of Electronic Science and Technology of China Chengdu Sichuan610054P.R.China Department of Medical Engineering University of South Florida TampaFL 33620USA

Microwave induced thermoacoustic imaging(MTAI)has emerged as a potential biomedical imaging modality with over 20-year *** typically employs pulsed microwave as the pumping source,and detects the microwave-induced ultrasound wave via acoustic ***,it features high acoustic resolution,rich elect romagnetic contrast,and large imaging *** from these unique advantages,MTAI has been extensively applied to various fields including pathology,biology,material and *** now,MTAI has been deployed for a wide range of biomedical applications,including cancer diagnosis,joint evaluation,brain in-vestigation and *** paper provides a comprehensive review on(1)essential physics(endogenous/exogenous contrast mechanisms,penetration depth and resolution),(2)hardware configurations and software implementations(excit ation source,antenna,ultrasound detector and image recovery algorithm),(3)animal studies and clinical applications,and(4)future directions.

关键词： Thermoacoustic imaging biomedical imaging electromagnetic radiation acoustic waves biomedical image processing

Measuring bulk and surface acoustic modes in diamond by angle-resolved Brillouin spectroscopy

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(Physics,Mechanics & Astronomy) 2021年第8期64卷 78-84页

作者： YaRu Xie ShuLiang Ren YuanFei Gao XueLu Liu PingHeng Tan Jun Zhang State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Beijing Academy of Quantum Information Science Beijing 100193China CAS Center of Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100049China

The acoustic modes of diamond are not only of profound significance for studying its thermal conductivity, mechanical properties, and optical properties, but also play a definite role in the performance of high-frequency and high-power acoustic wave devices. Here, we report on the bulk acoustic waves(BAWs) and surface acoustic waves(SAWs) of single-crystal diamond using angle-resolved Brillouin light scattering(BLS) spectroscopy. We identify two high-speed surface skimming bulk waves(SSBW) with acoustic velocities of 1.277×10^(6) and 1.727×10^(6) cm/s, respectively. Furthermore, we obtain the relationship between the velocity of arbitrary BAWs and that of BAWs propagating along the high-symmetric axis at different incident angles. In the community of diamond-based acoustic studies, our results may provide a valuable reference for fundamental research and device engineering.

关键词： diamond acoustic waves angle-resolved Brillouin spectroscopy

A three-dimensional hydroelasticity theory for ship structures in acoustic field of shallow sea

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2013年第6期25卷 929-937页

作者：邹明松吴有生刘艳敏林长刚 China Ship Scientific Research Center

Nowadays the development of green ship technology requires the vibration and noise control of oceangoing ships. The three-dimensional hydroelasticity theory of ships was previously extended to include the effect of fluid compressibility. This enables the dynamic responses and the acoustic radiations of a ship excited by onboard machineries or fluid fluctuation loads to be predicted. In this paper the hydroelastic analysis and sonoelastic analysis methods are fixrther incorporated with the Green＇s function in the Pekeris ocean hydro-acoustic waveguide model to work out a three-dimensional sonoelastic analysis method for ships in the ocean hydro-acoustic environment. As examples, the sound radiations of a floating elastic spherical shell excited by a concentrated force and a traveling LNG ship excited by the propeller induced pulsating forces acting on the wetted bottom plate of the stem in the shallow sea environment are predicted. The influences of the free surface and the sea bed on the generalized hydrodynamic coefficients and the acoustic pressure distributions in fluid domain are illustrated and discussed.

关键词： hydroelasticity sonoelasticity acoustic waves shallow sea environment LNG ship

Multi-channel surface acoustic wave device and its application on all-fiber acousto-optic modulation

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2010年第1期8卷 107-110页

作者：赵路明赵启大 Institute of Physics Nankai University Institute of Modern Optics Nankai University

The interaction of multi-channel surface acoustic waves （SAWs） and a guided optical wave in fiber is studied, and the corresponding coupled wave equations are derived. A novel two-channel SAW all-fiber acousto-optic... 详细信息

关键词： acoustic waves acoustics Acoustoelectric effects Wave equations

The role of refocusing in dynamic X-wave formation during femtosecond laser filamentation in water

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2010年第2期8卷 244-247页

作者：徐俊杰徐晗熊辉程亚徐至展刘伟伟陈瑞良 State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences Key Laboratory of Opto-Electronic Information Science and Technology Centre d'Optique Photonique er Laser(COPL)and Departement de Physiquede Genie Physique et d'OptiqueUniversite LavalQuebec

With the evolution of a laser pulse in water, the formation of a nonlinear X wave during femtosecond filamentation is investigated based on numerical simulations. In particular, we analyze the far-field angularly resolved spectra obtained for different temporal portions of the ultrashort pulse during its propagation. Our result shows that the refocusing of ultrashort pulse leads to the formation of dynamic X wave which essentially manifests itself as conical emission.

关键词： acoustic waves Computer simulation Light propagation Ultrashort pulses

acoustic elliptical cylindrical cloaks

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2009年第3期18卷 1123-1126页

作者：马华屈绍波徐卓王甲富 The College of Science Air Force University of Engineering Electronic Materials Research Laboratory Key Laboratory of Ministry of EducationXi'an Jiaotong University

By making a comparison between the acoustic equations and the 2-dimensional （2D） Maxwell equations, we obtain the material parameter equations （MPE） for acoustic elliptical cylindrical cloaks. Both the theoretical results and the numerical results indicate that an elliptical cylindrical cloak can realize perfect acoustic invisibility when the spatial distributions of mass density and bulk modulus are exactly configured according to the proposed equations. The present work is the meaningful exploration of designing acoustic cloaks that are neither sphere nor circular cylinder in shape, and opens up possibilities for making complex and multiplex acoustic cloaks with simple models such as spheres, circular or elliptic cylinders.

关键词： invisibility cloaks metamaterials acoustic waves