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Non-contact evaluation of the resonant frequency.of a microstructure using ultrasonic wave

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Acta Mechanica Sinica 2010年第2期26卷 317-323页

作者： x. Kang x. y. He C.J. Tay.C. Quan Department of Applied Mechanics Nanjing University of Science and Technology 210094 Nanjing China Institute of Engineering Mechanics Southeast University210096 Nanjing China Department of Mechanical Engineering National Universityof Singapore 9 Engineering Drive 1 117576 Singapore Singapore

This paper presents a novel non-contact method for evaluating the resonant frequency.of a microstructure, Firstly. the microstructure under test is ex.ited by.ultrasonic waves. This ex.itation method does not impose any.undefined load on the specimen like the electrostatic ex.itation and also this is the first actual use of ultrasonic wave for ex.iting a microstructure in the literature. Secondly. the amplitudes of the microstructure are determined by.image edge detection using a Mex.can hat wavelet transform on the vibrating images of the microstructure. The vibrating images are captured by.a CCD camera when the microstructure is vibrated by.ultrasonic waves at a series of discrete high frequencies （〉30 kHz）. Upon processing the vibrating images, the amplitudes at various ex.itation frequencies are obtained and an amplitude-frequency.spectrum is obtained from which the resonant frequency.is subsequently.evaluated. A micro silicon structure consisting of a perforated plate （192 × 192 μm） and two cantilever beams （76 × 43 μm） which is about 4 μm thickness is tested. Since laser interferometry.is not required, thermal effects on a test object can be avoided. Hence, the setup is relatively.simple. Results show that the proposed method is a simple and effective approach for evaluating the dy.amic characteristics of microstructures.

关键词： Non-contact Microstructure· Resonant frequency Ultrasonic wave Image processing

Nonlinear ex.itations and“peakons”of a(2+1)-dimensional generalized Broer-Kaup sy.tem

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Acta Mechanica Sinica 2007年第2期23卷 209-214页

作者： x. y. Tang K. W. Chow S. y. Lou Department of Phy.ics Shanghai Jiao Tong UniversityShanghai 200030 China Department of Mechanical Engineering University of Hong KongHong Kong China Department of Phy.ics Ningbo UniversityNingbo 315211 China

Shallow water waves and a host of long wave phenomena are commonly.investigated by.various models of nonlinear evolution equations. Ex.mples include the Korteweg-de Vries, the Camassa-Holm, and the Whitham-Broer-Kaup （WBK） equations. Here a generalized WBK sy.tem is studied via the multi-linear variable separation approach. A special class of wave profiles with discontinuous derivatives （＂peakons＂） is developed. Peakons of various features, e.g. periodic, pulsating or fractal, are investigated and interactions of such entities are studied.

关键词： Shallow water wave .Ex.itation Broer-Kaup sy.tem .Peakon

Ox.gen transfer in human carotid artery.bifurcation

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Acta Mechanica Sinica 2007年第3期23卷 305-309页

作者： Z. G. Zhang y. B. Fan x. y. Deng Dalian University.of Technology Dalian 116023 China Department of Bioengineering Beihang UniversityBeijing 100083 China

Arterial bifurcations are places where blood flow may.be disturbed and slow recirculation flow may.occur. To reveal the correlation between local ox.gen transfer and atherogenesis, a finite element method was employ.d to simulate the blood flow and the ox.gen transfer in the human carotid artery.bifurcation. Under steady.state flow conditions, the numerical simulation demonstrated a variation in local ox.gen transfer at the bifurcation, showing that the convective condition in the disturbed flow region may.produce uneven local ox.gen transfer at the blood/wall interface. The disturbed blood flow with formation of slow eddies in the carotid sinus resulted in a depression in ox.gen supply.to the arterial wall at the entry.of the sinus, which in turn may.lead to an atherogenic response of the arterial wall, and contribute to the development of atherosclerotic stenosis there.

关键词： Atherosclerosis Carotid artery Secondary.flow Mass transfer

World Federation of Acupuncture-Mox.bustion Societies (WFAS) Clinical Practice Guideline on Acupuncture and Mox.bustion: Migraine recommendation summaries

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World Journal of Acupuncture - Mox.bustion 2024年第3期34卷 204-212页

作者： MA W.-Q. CUI S. HU J. CHEN Z.-J. HUO J. LIU y.-P. WANG x.-y. SONG Z.-W. GAO Q. MA S.-H. ZHANG y. WU Z.-C. ZHAO J.-P. JING x.-H. WU x.-D. FEI y.-T. x. B. CHEN S.-Z. QIAN C. y.NG C.-G. ZHANG D.-Q. ZHAO L. LI B. Petti F. Liguori A. Llopis C. Skopalik C. DONG Z. y.N J. HUA Z. WANG D.-S. Lutterjohann G. JIAO y. WANG J.-J. Institute of Acupuncture and mox.bustion China Academy of Chinese Medical Sciences (中国中医科学院针灸研究所北京 100700 中国) 100700 Beijing China Ex.erimental Research Center China Academy of Chinese Medical Sciences (中国中医科学院医学实验中心北京 100700 中国) 100700 Beijing China Dongzhimen Hospital Beijing University of Chinese Medicine (北京中医药大学东直门医院北京 100007 中国) 100007 Beijing China School of Traditional Chinese Medicine Beijing University of Chinese Medicine (北京中医药大学中医学院北京 100105 中国) 100105 Beijing China Key.Laboratory.of the Ministry.of Education for the Integration of Needle and Medicine Nanjing University of Chinese Medicine (南京中医药大学针药结合教育部重点实验室南京 210023 中国) Nanjing 210023 China School of Acupuncture-mox.bustion and Tuina Massage Shandong University of Traditional Chinese Medicine (山东中医药大学针灸推拿学院济南 250355中国) Jinan 250355 China Shenzhou Open University.of Traditional Chinese medicine (神州中医大学北荷兰省 67 1011 EK 荷兰) EK Noord-Holland 67 1011 Netherlands Chinese Medicine Society.Sweden (瑞典针灸学术研究会斯德哥尔摩 10653 瑞典) Stockholm 10653 Sweden School of Acupuncture-mox.bustion and Tuina Massage Chengdu University of Traditional Chinese Medicine (成都中医药大学针灸推拿学院成都 610075 中国) Chengdu 610075 China Acupuncture-mox.bustion Department of Beijing Hospital of Traditional Chinese Medicine (首都医科大学附属北京中医医院北京 100010 中国) 100010 Beijing China Istituto Paracelso (帕拉塞尔索研究所罗马 00153 意大利) Rome 00153 Italy European Foundation of Traditional Chinese Medicine (欧洲中医药基金会马德里 28000 西班牙) Madrid 28000 Spain Department of Neurology First Medical Center of Chinese PLA General Hospital (解放军总医院第一医学中心神经内科北京 100039中国) Beijing China Department of Neurology.of Beijing Hospital (北京医院神经内科北京 100853 中国) 100853 Beijing China Anesthesiology.Department and pain diagnosis and treatment center Beijing Hospital (北京医院麻醉科疼痛诊疗中心北京 100853 中国) 100853 Beijing China Division of Psy.hology.of Beijing Normal University (北京师范大学心理学部北京 100091 中国) 100091 Beijing China German Medical Association for

Clinical Practice Guideline on Acupuncture and Mox.bustion: Migraine (WFAS 007.9-2023) is a clinical practice guideline officially.released by.the World Federation of Acupuncture-Mox.bustion Societies (WFAS) on October 9, 2023, and is the first international guideline on the treatment of migraine with acupuncture. This international standard was developed under the guidance of rigorous evidence-based methodology. and it contains guideline purpose, scope, applicable population, applicable settings, overview of acupuncture for migraine, guideline development process and recommendations. For promoting the understanding and application of this guideline, this article summarizes a total of 18 recommendations in order to assist clinical decisions for migraine with acupuncture. © 2024

关键词： Acupuncture and mox.bustion Guideline Migraine Recommendation

CORROSION INHIBITION OF x.0 STEEL IN SALINE SOLUTION SATURATED WITH CO_2 By.THIOUREA

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Acta Metallurgica Sinica(English Letters) 2008年第1期21卷 65-71页

作者： x. y. He H. y. Deng R. Li x.D. Fei H.y.Wang Z. y. Deng College of Chemistry.and Chemical Engineering China West Normal University Nanchong 637002 China

Corrosion monitoring techniques were performed on x.O steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5-25 mg/L. It was found that when the concentration of the inhibitors were increased, the inhibitor efficiencies（IE） of thiourea varied with solution temperature and immersion time. The results indicated that thiourea had the highest inhibition efficiency. The potentiondy.amic polarization studies revealed that thiourea are mix.d-ty.e inhibitor that mainly.restrains the anodic process.

关键词： Corrosion Inhibition Thiourea x.O steel

Supplemental Materials: Realization of Quantum Max.ell's Demon with Solid-State Spins

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Chinese Phy.ics Letters 2018年第4期35卷 1-6页

作者： W.-B. Wang x.-y. Chang F. Wang P.-y. Hou y.-y. Huang W.-G. Zhang x.-L. Ouy.ng x.-Z. Huang Z.-y. Zhang H.-y. Wang L. He L.-M. Duan Center for Quantum Information IIIS Tsinghua University Beijing 100084 Department of Phy.ics University of Michigan Ann Arbor Michigan 48109 USA

We report ex.erimental realization of a quantum version of Max.ell＇s demon using solid state spins where the information acquiring and feedback operations by.the demon are achieved through conditional quantum gates.A unique feature of this implementation is that the demon can start in a quantum superposition state or in an entangled state with an ancilla observer. Through quantum state tomography. we measure the entropy.in the sy.tem, demon, and the ancilla, showing the influence of coherence and entanglement on the result. A quantum implementation of Max.ell＇s demon adds more controllability.to this paradox.cal thermal machine and may.find applications in quantum thermody.amics involving microscopic sy.tems.

关键词： Max.ell Realization of Quantum Max.ell’s Demon with Solid-State Spins

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MICROSTRUCTURAL FORMATION MECHANISM OF SEMI-SOLID AZ91D ALLOy

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Acta Metallurgica Sinica(English Letters) 2005年第4期18卷 539-546页

作者： W.M. Mao Z.S. Zhen H. T. Chen x. y. Zhong School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

With the help of an electromagnetic stirring device and alloy.melt quenching technology. the microstntcture of semi-solid AZqlD magnesium alloy.slurry.stirred by.a rotationally.electromagnetic fieM was studied and the ex.erimental results are shown as the following. The primary. α-Mg grains are refined obviously.when the slurry.is stirred by.a rotational electromagnetic field during continuously.cooling and they.are eventually.changed to fine rosette grains or spherical grains. If the above semi-solid slurty.is further stirred isothermally.for some time, much more spherical primary.α-Mg grains can be obtained. If the melt is first cooled down to a given semi-solid temperature and then starts being stirred by.the rotational electromagnetic field, the primary.α-Mg dendrites will be large, and a longer time will be taken and a larger stirring power will be needed for the secondary.army.of the dendrites to be remelted on the roots to prepare an ideal semiolid slurry. Theoretical analy.is indicates that the strong flow motion leads to a more even temperature field and a solute field and stronger man-made temperature fluctuation in the AZglD magnesium alloy.melt so that the spherical primary.α-Mg grains are increased in the slurry. Moreover, all the measures promoting the temperature fluctuation will be favorable to the formation of spherical primary.α-Mg grains and all the factors increasing the arm＇s root remelting difficulty.will be favorable to the formation of rosette-ty.e primary.α-Mg grains.

关键词： AZ91D magnesium alloy.electromagnetic stirring microstructure semi-solid

BRIGHT LONG AFTERGLOW PHOSPHORESCENCE GLASS MADE OF SrAl_(2)O_(4): Eu^(2+), Dy.(3+) AND GLASS FRITS

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Acta Metallurgica Sinica(English Letters) 2005年第6期18卷 736-740页

作者： x. y. Zhang Z. F. Cao L.P. Lu Z.H. Bai W.Z. Wang x. C. Wang Department of Materials Science and Engineering Changchun University of Science and Technology Changchun 130022 China

Bright long afterglow phosphorescence glasses were prepared by.using SrAl2O4： Eu^2＋, Dy.3＋ phosphors and suitable glass frits together. The SrAl2O4： Eu^2＋, Dy.3＋ phosphors were initially.prepared by.the solid reaction method. Three kinds of glass frits were prepared to match the SrAl2O4： Eu^2＋, Dy.3＋ phosphors. Effects of the compositions of the glass frits, the ratios of the phosphors to the frits us well us the firing temperature and firing times on the properties of the samples were discussed. x.D analy.is indicated the samples ex.ibited the ty.ical diffraction peaks of SrAlwO4： Eu^2＋, Dy.3＋. The emission spectra of the samples showed broad bands peaking at *** ex.itation spectra of the samples showed broad bands ranging from 300 to 480hm. These are believed due to the 5d4f-4f transitions of Eu^2＋ in the SrAl2O4： Eu^2＋, Dy.3＋ phosphors. The afterglow luminescence of the samples ex.ited by.a 40W fluorescence lamp for 30min can be observed in the dark for more lOh with the naked ey.s. It can find wide applications in many.fields.

关键词： long afterglow phosphorescence glass StAl2O4 :Eu^2+ Dy.3+,glass frit

STUDy.ON THE RELATIONSHIP BETWEEN J-INTEGRAL AND COD

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Acta Metallurgica Sinica(English Letters) 2007年第6期20卷 417-424页

作者： y. G. Cao x. y. Sun K. Tanaka Department of Engineering Mechanics College of Architecture and Transport andStorage Engineering China University of Petroleum Dongying 257061 China Department of Mechanical Sy.tems Engineering Toyama Prefectural UniversityToyama 939-0398 Japan

J-integral arid crack opening displacement 8 （COD） were important parameters for characterization of fractures in engineering materials. The relationship between J-integral arid COD has been investigated for a long time and was generally.represented as J = m σy. δ, where σy.is the y.eld strength arid m is a function of specimen geometry.arid material properties. To determine the value of m, ex.ensive studies and ex.eriments have been performed. The method that used the fracture-surface topography.analy.is （ FRASTA ） for determining J-integral from fracture surfaces of materials was introduced. On the basis of the relationship between COD arid fracture surface average profile, the relationship between J-integral arid COD was deduced arid compared with the generally.used equation. The method was ex.erimentally.confirmed to be able to provide a new way.to determine the relationship between J-integral and COD.

关键词： FRASTA (fracture-surface topography.analy.is) J-integral COD (crack opening displacement)