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国际医学放射学杂志 2024年第3期 374-375页

作者： j.ma K.Chen S.Li L.Zhu Y.Yu j.Li 梁媛

摘要目的术前准确评估保乳手术切缘阳性的风险，有助于制定手术计划。该项多中心验证研究开发了一种基于MRI的影像组学模型来预测手术切缘状态。方法回顾性

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A Study of the Influence of Solid Particles on Boiling Hysteresis

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journal of Thermal Science 1992年第1期1卷 41-45页

作者： M.H.Shi j.ma Southeast University Nanjing 210018China

Experiments have been performed to determine the effects on boiling hysteresis of locally fluidized particles contained in a liquid that serves as coolant for electronic *** results show that Iocally fluidized particl... 详细信息

关键词：固态粒子热磁效应微电子电路

Synthesis and Characterization of Mesoporous Alumina via a Reverse Precipitation Method

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journal of materials Science & Technology 2012年第6期28卷 572-576页

作者： Y.S.Wu j.ma F.Hu M.C.Li College of materials Science and Engineering Shenyang University of TechnologyShenyang 110870China

Mesoporous aluminaΥ-AI203 with high specific surface area and large pore volume is prepared by using a facile reverse precipitation method from sodium aluminate and nitric acid. The effects of terminal pH value, aging time and thermal stability on the characterization of Υ-Al2Oa are studied by means of X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, Brunauer-Emmett-Teller （BET） method and scanning electron microscopy （SEM）. The results show that Υ-A1203 with better properties can be obtained by changing the preparation parameters. High BET surface area of 340 m2/g can be obtained by calcining at 500℃ for 4 h with large pore volume of 0.90 cm3/g and average pore size of 7.6 nm. After calcining at 1000°, the surface area is still 86 m2//g and the pore volume is 0.37 cm31/g.

关键词： Mesoporous alumina Reverse precipitation Thermal stability

Optimal Split Ratio in Small High Speed PM machines Considering Both Stator and Rotor Loss Limitations

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CES Transactions on Electrical machines and Systems 2019年第1期3卷 3-11页

作者： j.ma Z.Q.Zhu Department of Electrical and Electronic Engineering The University of SheffieldSheffieldS13JDU.K.

The split ratio which is defined as the ratio between rotor and stator outer diameters is critical for permanent magnet(PM)*** this paper,the split ratio in small high speed PM machines is optimized analytically by considering both stator and rotor loss *** this way,the thermal constrains in both stator and rotor parts can be taken into *** shows that both losses can significantly affect the optimal split ratio and the machine *** considering the influence of rotor losses,especially the rotor eddy current loss,the optimal split ratio is increased significantly in certain *** output torque is calculated analytically and the influences of several key design parameters on the optimal split ratio,***/pole combinations and magnet materials,are also investigated in ***,finite element(FE)analyses are carried out for validating of the analytical model.

关键词： Index Terms-High speed permanent magnet split ratio.

Effect of alloying elements on mechanical properties in Cu-15%Cr in-situ composites

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中国有色金属学会会刊：英文版 2004年第2期14卷 284-290页

作者： H.G.Suzuki j.ma K.Mihara S.Sakai S.Sun japan Society for Promotion of Science Department of Materials Science and EngineeringFurukawa Electric COFurukawa Electric CONational Institute for Materials Science 4-1-8 Hon-machi Kawaguchi332-0012 JapanDepartment of Materials Science and EngineeringTsinghua UniversityBeijing 100084 China Tsinghua UniversityBeijing 100084China LTDNikko 321-0014JapanLTDNikko 321-0014JapanTsukuba 305-0047Japan

The effects of alloying elements on the mechanical properties as well as electrical conductivity in Cu-15%Cr(mass fraction) in-situ composites were systematically studied and high strength and high electrical conductive Cu base in-situ composites have been developed. The best combination is the addition of 0.1% to 0.2% Zr, Ti, or Sn in Cu-15%Cr in-situ composite, thermomechanical treatment to refine the microstructure and optimizing the precipitation of second phase. The strength is controlled by high density of dislocations in the Cu matrix, the lamellar spacing of the second phase, and the fine Cr precipitates. The aging treatment to reduce solute atoms has a beneficial effect on the increase of electrical conductivity. The addition of Zr, or Ti of about 0.15% to 0.2% promotes the precipitation of Cr particles.

关键词： CuCr合金铜合金内生复合材料机械性能合金化电导率

Effect of Rotation Rate on Microstructure and Mechanical Properties of Friction Stir Spot Welded DP780 Steel

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journal of materials Science & Technology 2016年第4期32卷 326-332页

作者： G.M.Xie H.B.Cui Z.A.Luo W.Yu j.ma G.D.Wang State Key Laboratory of Rolling and Automation Northeastern University

DP780 steel sheets consisting of ferrite and martensite were successfully friction stir spot welded （FSSW） at the rotation rates of 500 to 1500 r/min using a W-Re alloy tool, The effect of rotation rate on micro- structure and mechanical properties of the FSSW DP780 was investigated. The peak temperatures in the welds at various rotation rates were identified to be above A3 temperature. FSSW caused the dynamic recrystallization in the stir zone （SZ）, thereby producing the fine equiaxed grain structures. At the higher rotation rates of≥1000 r/min, a full martensitic structure was observed throughout the SZs, whereas at the lower rotation rate of 500 r/min, the SZ consisted of a fine dual phase structure of ferrite and mar- tensite due to the action of deformation induced ferrite transformation. The maximum average failure load as high as 18.2 kN was obtained at the rotation rate of 1000 r/min and the fracture occurred at the thinned upper sheet.

关键词： Friction stir spot weldingDual phase steelMicrostructureDeformation induced ferritetransformationMechanical property

Micro injection of metallic glasses parts under ultrasonic vibration

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journal of materials Science & Technology 2017年第7期33卷 703-707页

作者： X.Liang j.ma X.Y.Wu B.Xu F.Gong j.G.Lei T.j.Peng R.Cheng Guangdong Provincial Key Laboratory ofMicro/Nano Optomechatronics Engineering College of Mechatronics and Control and Engineering Shenzhen University Shenzhen 518060 China Shenzhen ESUN Exhibition Company Limited Shenzhen 518048. China

This work investigates the evolution of structure and mechanical performance of metallic glasses（MGs）under a proposed rapid forming approach. Through the unique ultrasonic-assisted micro injection method, micro MGs parts with fine dimensional accuracy were successfully fabricated. The temperature during the micro injection is higher than the glass transition temperature and lower than the crystallization temperature. Differential scanning calorimeter curve and X-ray diffraction pattern show that the MGs micro parts keep the amorphous nature after the ultrasonic-assisted micro injection. Our results propose a novel route for the fast forming of MGs and have promising applications in the rapid fabrication of micro scale products and devices.

关键词： Metallic glasses Micro injection Ultrasonic vibration

OBSERVATION OF MYO-INOSITOL CONCENTRATIONS IN BIPOLAR DISORDER PATIENTS RECEIVING SODIUM VALPROATE:An in vivo Proton MR Spectroscopy Quantitative Study

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波谱学杂志 2002年第1期19卷 96-97页

作者： R.H.WU P.SILVERSTONE j.ma H.Kim H.B.RAO X.H.XU Shantou University Medical College China University of Alberta Canada University of Alberta Canada Dalian Medical University China Shantou University Medical College China

Introduction:Previous magnetic resonance spectroscopy (MRS) studies have suggested that lithium used in patients with bipolar disorder may alter brain myo-inositol concentrations.

关键词： MR OBSERVATION OF MYO-INOSITOL CONCENTRATIONS IN BIPOLAR DISORDER PATIENTS RECEIVING SODIUM VALPROATE MYO

Universal insertion of molecules in ionic compounds under pressure

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National Science Review 2024年第1期11卷 120-128页

作者： Feng Peng Yanming ma Chris j.Pickard Hanyu Liu maosheng Miao College of Physics and Electronic Information Luoyang Normal University Department of Chemistry and Biochemistry California State University Northridge State Key Laboratory of Superhard materials & Key Laboratory of material Simulation Methods and Software of Ministry of Education College of Physics Jilin University International Center of Future Science Jilin University Department of materials Science & Metallurgy University of Cambridge Advanced Institute for materials Research Tohoku University Department of Earth Science University of California Santa Barbara

Using first-principles calculations and crystal structure search methods, we found that many covalently bonded molecules such as H2, N2, CO2, NH3, H2O and CH4may react with NaC l, a prototype ionic solid,and form stable compounds under pressure while retaining their molecular structure. These molecules,despite whether they are homonuclear or heteronuclear, polar or non-polar, small or large, do not show strong chemical interactions with surrounding Na and Cl ions. In contrast, the most stable molecule among all examples, N2, is found to transform into cyclo-N5-anions while reacting with NaC l under high pressures. It provides a new route to synthesize pentazolates, which are promising green energy materials with high energy density. Our work demonstrates a unique and universal hybridization propensity of covalently bonded molecules and solid compounds under pressure. This surprising miscibility suggests possible mixing regions between the molecular and rock layers in the interiors of large planets.

关键词： molecule-solid hybrid materials high-pressure crystal structure prediction density functional theory planet interior

ESTImaTION OF RELATIVE BLOOD VOLUME IN HEAD AND NECK TUMORS

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波谱学杂志 2002年第1期19卷 101-102页

作者： R.H.WU R.Bruening j.ma C.BERCHTENBREITHER R.jUND H.B.RAO X.H.XU M.REISER Shantou University Medical College China Klinikum GrosshadernUniversity of MunichGermany Klinikum Grosshadern University of MunichGermany Dalian Medical University China Shantou University Medical College China

Introduction: The calculation of relative blood volume in head and neck tumor with MR imaging is anew approach that may provide additional hemodynamic information relevant to both untreated and treated tumors. This hemodynamic information is especially useful for the differentiation between viable tumor and postsurgical changes or radiation induced scar, and is also beneficial for tumor staging and tumor biopsy.

关键词： maps ESTImaTION OF RELATIVE BLOOD VOLUME IN HEAD AND NECK TUMORS