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多层CT基于单纯面积测量评价左心室容积

国际医学放射学杂志 2010年第5期 494-495页

作者： C.L.Schlett D.C.Kwait a.a.mahabadi F.Bamberg C.J.O.Donnell U.Hoffmann 李秋云 Cardiac MR PET CT Program Massachusetts General Hospitaland Harvard Medical School

关键词：多层CT 左心室左心室大小心胸比率直接横断位心脏直径 Framingham心脏研究

联合FDG PET/MR成像评估急性心肌梗死再灌注中心肌存活情况

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国际医学放射学杂志 2015年第5期 479-479页

作者： F.Nensa T.Poeppel E.Tezgah P.Heusch K.Nassenstein a.a.mahabadi 李伟 Department of Diagnostic and Interventional Radiology and Neuroradiology University Hospital EssenUniversity of Duisburg-Essen

摘要目的比较急性心肌梗死再灌注病人中心肌脱氧葡萄糖(FDG)摄取降低的区域与心内膜表面积(ESA)法标记得到的风险区域的大小。材料与方法本研究得到当地机构伦理委员会通过。所有病人在检查前给予书面知情同意书。25例病人[(54±14)岁]... 详细信息

摘要目的比较急性心肌梗死再灌注病人中心肌脱氧葡萄糖(FDG)摄取降低的区域与心内膜表面积(ESA)法标记得到的风险区域的大小。材料与方法本研究得到当地机构伦理委员会通过。所有病人在检查前给予书面知情同意书。25例病人[(54±14)岁]在急性冠状动脉阻塞及介入再灌注后进行前瞻性心脏PET/MRI。在随后的钆对比剂增强检查中,

关键词：急性心肌梗死再灌注病人 ESA FDG PET/MR 区域面积 PET

Enhancement of current density using effective membranes electrode assemblies for water electrolyser system

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Journal of Energy Chemistry 2016年第1期25卷 77-84页

作者： Swaminathan Seetharaman Subash Chandrabose Raghu Kambiz Ansari mahabadi Institute of Materials Research & Engineering A*STAR (Agency for Science Technology and Research) 3 Research Link Singapore 117 602 Singapore School of Civil and Environmental Engineering Nanyang Technological University Block N1 Nanyang Avenue Singapore 639 798 Singapore

The goal of this study was to develop and design a composite proton exchange membrane（PEM） and membrane electrode assembly（MEA） that are suitable for the PEM based water electrolysis system. In particular,it focuses on the development of sulphonated polyether ether ketone（SPEEK） based membranes and caesium salt of silico-tungstic acid（Cs Si WA） matrix compared with one of the transition metal oxides such as titanium dioxide（TiO2）, silicon dioxide（SiO2） and zirconium dioxide（ZrO2）. The resultant membranes have been characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, ion exchange capacity（IEC）, water uptake and atomic force microscopy. Comparative studies on the performance of MEAs were also conducted utilizing impregnation-reduction and conventional brush coating methods. The PEM electrolysis performance of SPEEK-Cs Si WA-ZrO2 composite membrane was more superior than that of other membranes involved in this study. Electrochemical characterization shows that a maximum current density of 1.4 A/cm^2 was achieved at 60 °C, explained by an increased concentration of protonic sites available at the interface.

关键词： Composite membrane Membrane electrode assembly Impregnation reduction method Brush coating method Electrolysis

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Three-dimensional FDEM numerical simulation of failure processes observed in Opalinus Clay laboratory samples

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Journal of Rock Mechanics and Geotechnical Engineering 2014年第6期6卷 591-606页

作者： Omid mahabadi Patrick Kaifosh Paul Marschall Tim Vietor Geomechanica Inc. 90 Adelaide St W Suite 300 Toronto ON M5H 3V9 Canada National Cooperative for the Disposal of Radioactive Waste (NAGRA) Wettingen Switzerland

This study presents the first step of a research project that aims at using a three-dimensional （3D） hybridfinite-discrete element method （FDEM） to investigate the development of an excavation damaged zone（EDZ） around tunnels in a clay shale formation known as Opalinus Clay. The 3D FDEM was first calibratedagainst standard laboratory experiments, including Brazilian disc test and uniaxial compression test. Theeffect of increasing confining pressure on the mechanical response and fracture propagation of the rockwas quantified under triaxial compression tests. Polyaxial （or true triaxial） simulations highlighted theeffect of the intermediate principal stress （s2） on fracture directions in the model： as the intermediateprincipal stress increased, fractures tended to align in the direction parallel to the plane defined by themajor and intermediate principal stresses. The peak strength was also shown to vary with changing s2. 2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

关键词： Three-dimensional(3D) hybrid finitediscrete element method(FDEM) Intermediate principal stress Discrete element methods True triaxial behaviour Failure envelope

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Numerical simulation of hydraulic fracturing and associated microseismicity using finite-discrete element method

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Journal of Rock Mechanics and Geotechnical Engineering 2014年第6期6卷 574-581页

作者： Qi Zhao Andrea Lisjak Omid mahabadi Qinya Liu Giovanni Grasselli Department of Civil Engineering University of TorontoToronto ON Canada Geomechanica Inc. Toronto ON Canada Department of Physics University of TorontoToronto ON Canada

Hydraulic fracturing （HF） technique has been extensively used for the exploitation of unconventional oiland gas reservoirs. HF enhances the connectivity of less permeable oil and gas-bearing rock formationsby fluid injection, which creates an interconnected fracture network and increases the hydrocarbonproduction. Meanwhile, microseismic （MS） monitoring is one of the most effective approaches to evaluatesuch stimulation process. In this paper, the combined finite-discrete element method （FDEM） isadopted to numerically simulate HF and associated MS. Several post-processing tools, includingfrequency-magnitude distribution （b-value）, fractal dimension （D-value）, and seismic events clustering,are utilized to interpret numerical results. A non-parametric clustering algorithm designed specificallyfor FDEM is used to reduce the mesh dependency and extract more realistic seismic *** results indicated that at the local scale, the HF process tends to propagate following the rockmass discontinuities; while at the reservoir scale, it tends to develop in the direction parallel to themaximum in-situ stress. 2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

关键词： Hydraulic fracturing(HF) Numerical simulation Microseismic(MS) Finite-discrete element method(FDEM) Clustering Kernel density estimation(KDE)

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Cochlear Synaptopathy Following Noise Exposure in Guinea Pigs: Its Electrophysiological and Histological Assessments

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Sound & Vibration 2020年第3期54卷 163-177页

作者： Parvane Mahdi Akram Pourbakht Vahid Pirhajati mahabadi Alireza Karimi Yazdi Mahtab Rabbani Anari Mohammad Kamali Rehabilitation Research Center Department of AudiologySchool of Rehabilitation SciencesIran University of Medical SciencesTehran15459-13487Iran Department of Neurosciences School of MedicineIran University of Medical SciencesTehran14496-14535Iran Department of Otorhinolaryngology Tehran University of Medical SciencesTehran14197-33141Iran Department of Rehabilitation Management Iran University of Medical SciencesTehran15459-13487Iran

Exposure to high level of noise,may cause the permanent cochlear synaptic *** present study,a model of noise induced cochlear synaptopathy was established and the electrophysiological and histological metrics for its assessment was designed.6 guinea pigs were subjected to a synaptopathic noise(octave band of 4 kHz at 104 dB SPL,for 2-h).The amplitude growth curve of Auditory Brainstem Response(ABR)wave-I and wave-III latency shift in presence of noise were *** indexes were considered in pre-exposure,1 day post exposure(1DPE),1 week post exposure(1WPE)and 1 month post exposure(1MPE)to ***,the samples were histologically *** wave-I amplitude was different between pre and 1DPE(p-value≤0.05).However,at 1WPE,it was recovered at low intensities but at 70 dB SPL and above,the differences persisted even till *** masked ABR,the latency shift of wave-III was different between pre and 3 post exposure assessments(p-value≤0.05).Electro-microscopic analysis confirmed the synaptic degeneration,as the ribbons were larger than normal,hollow inside,and spherical and irregular in shape,also,the post synaptic density was abnormally thick and missed its flat *** data revealed that noise at level below that can produce permanent hearing loss,can incur synaptic ***,noise is considered to be more damaging than previously ***,designing tools for clinical assessment of synaptopathy is beneficial in comprehensive auditory evaluation of those with history of noise exposure and also in hearing protection planning.

关键词： Cochlear synaptopathy noise induced hearing loss hidden hearing loss excitotoxicity hearing protection

4H-SiC SOI-MESFET with a Step in Buried Oxide for Improving Electrical Performance

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4H-SiC SOI-MESFET with a Step in Buried Oxide for Improving ...

Results of the Measurement of the Collimator Hole Angulation for Different Collimators of SPECT with Adaptive Quality Control Phantom

2011 IEEE International Conference on Computer Science and Automation Engineering(CSAE 2011)

作者： Hamid Amini Moghadam Ali A.Orouji S.E.Jamali mahabadi mahabadi Department of Electrical Engineering Semnan University Semnan Iran Department of Electrical Engineering Semnan University Semnan Iran

This paper introduces a novel 4H-SiC SOI-MESFET with a step in buried oxide （SSOI-MESFET） for improving breakdown *** investigate the improvement in device performance with two-dimensional and two-carrier device *** simulation results show that breakdown voltage of SSOI-MESFET is higher than conventional Bulk-MESFET （CB-MESFET） and conventional 4H-SiC SOI-MESFET （CSOI-MESFET）.In this study we have shown that saturation current of the proposed structure is higher than CB-MESFET.

关键词： SiC-MESFET high voltage silicon-on-insulator

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Modern Instrumentation 2012年第4期1卷 49-53页

作者： Hossein Zamani Zeinali Ehsan Masumi Goodarzi Hamid Ravanbakhsh Ali Asgher Sardarpour Narjes Abagheri mahabadi Soghra Moradkhani Fatemeh Dolatshah Davood Rahi Agricultural Medical and Industrial Research School Nuclear Science and Technology Research Institute Department of Physics Peyambare Azam Institute Islamic Azad University of Tehran

The Adaptive Quality Control Phantom (AQCP) is the computer-controlled phantom which positions and moves a radioactive source in the Field of View (FOV) of an imaging nuclear medicine device on a definite path to produce any spatial distribution of gamma rays to perform the QC Tests such as the Collimator Hole Angulation (CHA) of Single Photon Emission Computer Tomography (SPECT). The collimator hole angulation for seven collimators were measured with the method by using a point source and computer-controlled cylindrical positioning. In this method the displacement of the image of a point source examined as the AQCP move point source vertically away from the collimator face. The results of the high-accuracy measurement method of CHA show that the measurement accuracy for absolute angulation errors is better than ±0.024°. The Root Mean Square (RMS) of CHA for LEHR, LEHS, LEUHR, MEGP-250, MEGP-300, MEGP-360 and HEPH collimators of SMV dual heads camera were measured to be 0.290°, 0.292°, 0.208°, 0.194°, 0.181°, 0.177°, 0.150°, respectively. The Root Mean Square (RMS) of CHA for LEGP, MEGP and HEGP collimators of GE Millennium MG were measured to be 0.154°, 0.220° and 0.202° respectively. It is to be added in this connection that the measured RMS of CHA for LEHR collimator with the distance variation from the collimator’s surface +/– 1 mm has been varied +/– 0.04 degree.

关键词： Nuclear Medicine Adaptive Quality Control Phantom Collimator hole Angulation

天然气水合物饱和度对含水合物沉积物渗透性的影响

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海洋地质 2020年第3期36卷 1-11页

作者： Nariman mahabadi Sheng Dai Yongkoo Seol 蔡庆芳(翻译) 严杰(校对) 于淼(校对) 不详广州海洋地质调查局

含水合物沉积物的渗透性很大程度影响水合物的分解过程以及产气速率和效率。由于试验条件和试验程序等多种因素的影响,所报道的渗透率值普遍存在很大的差异。利用数值模拟含水合物藏的经济开发,渗透率的准确测量对于预测长期产气量具有... 详细信息

含水合物沉积物的渗透性很大程度影响水合物的分解过程以及产气速率和效率。由于试验条件和试验程序等多种因素的影响,所报道的渗透率值普遍存在很大的差异。利用数值模拟含水合物藏的经济开发,渗透率的准确测量对于预测长期产气量具有重要意义。在本研究中,氧杂环戊烷(THF)水合物在沉积物中形成,表现出孔隙-填充模式的孔隙习性,并将水渗透率量化为水合物饱和度的函数。结果表明,随着水合物饱和度的增加,渗透率降低。根据以Kozeny颗粒包裹和孔隙-充填模式为边界的实测结果,建议采用经验滲透率模型参数,用于长期水合物分解数值模拟。波速测量结果揭示了当Sh0.6时孔隙充填规律向块状、承重孔隙的逐渐过渡。利用互补孔隙网络模型得到的数值模拟结果表明,沉积物中的THF水合物可能形成平均斑块大小为4个孔隙的小族。

关键词：水渗透率含水合物沉积物水合物饱和度波速孔隙网络模型孔隙习性