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动态MR成像骨盆测量的可重复性:一项多机构的研究

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国际医学放射学杂志 2009年第1期32卷 64-64页

作者： M.e. Lockhart J.R. Fielding h.e. richter L. Brubaker C.G. Salomon 王高峰 Department of Radiology University of Alabama at BirminghamBirminghamAL35249USA

目的为了评估动态MRI用于骨与软组织骨盆测量的可重复性，进行多中心初产妇研究。材料和方法本研究经机构审查委员会批准并遵从hIPPA的规定，所有受试者知情并同意。在6个临床机构中，对3组产后6～12个月的初产妇完成了1．5T标准化... 详细信息

目的为了评估动态MRI用于骨与软组织骨盆测量的可重复性，进行多中心初产妇研究。材料和方法本研究经机构审查委员会批准并遵从hIPPA的规定，所有受试者知情并同意。在6个临床机构中，对3组产后6～12个月的初产妇完成了1．5T标准化的动态骨盆多平面T测MRI扫描：第1组，经阴道分娩伴有肛门括约肌撕裂（93例）；

关键词：骨盆测量可重复性 MR成像动态MRI MRI扫描经阴道分娩肛门括约初产妇

Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(english.e.ition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-TALOOKOLAeI h.GhANDVAR e.JUMAeV S.KhATIR T.CUONG-Le School of Mechanical engineering Babol Noshirvani University of Technology Department of Mechanical engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for engineering Application and Technology Solutions Ho Chi Minh City Open University

This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. The strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. The curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

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碳纳米管纱的时间依赖电性能(英文)

新型炭材料 2015年第3期30卷 207-213页

作者： h.e. Misak S. Mall Air Force Institute of Technology Department of Aerospace engineering 2950 hobson Way Wright-Patterson AFB OH 45433-7765 USA Wichita State University Department of Meehanieal engineering 1845 Fairmount Wichita KS 67260-0133 USA

碳纳米管(CNTs)在电力转换领域具有潜在前景。本文表征碳纳米管纱随时间变化对电力的转换性能影响。通过建立I-V关系,结果表明存在3个区域,即线性、非线性和下降区域。线性区域表明呈现低且恒定电阻。当恒定电压处于I-V线性区域时,输出... 详细信息

碳纳米管(CNTs)在电力转换领域具有潜在前景。本文表征碳纳米管纱随时间变化对电力的转换性能影响。通过建立I-V关系,结果表明存在3个区域,即线性、非线性和下降区域。线性区域表明呈现低且恒定电阻。当恒定电压处于I-V线性区域时,输出电流强度不随时间而改变。然而,当恒定电压处于非线性区域时,电流强度以指数级下降后随时间而趋平。在恒电流测试下,电压仅在电流强度处于非线性区时增加。依赖时间的导电性能可通过短路来理解。短路发生在非线性区域的碳纳米管纱中炽热部位,会导致热性能降低。通过热图像、热重分析、扫描电镜和能谱分析等手段对碳纳米管纱进行分析。

关键词：碳纳米管纱电性能时间依赖铁球

Resonances-excitation Calculation Studies Investigation of △(3,3)in Ground State of ^(90)Zr Cold Finite heavy Nucleus at equilibrium and Under Large Compression

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Communications in Theoretical Physics 2011年第1期55卷 115-122页

作者： Mohammed h.e. Abu-Sei'leek Department of Physics Al-Jouf University

A non-relativistic microscopic mean field theory of finite nuclei is investigated where the nucleus is described as a collection of nucleons and delta resonances. The ground state properties of 90Zr nucleus have been investigated at equilibrium and large amplitude compression using a realistic effective baryon-baryon hamiltonian based on Reid Soft Core （RSC） potential. The sensitivity of the ground state properties is studied, such as binding energy, nuclear radius, radial density distribution, and single particle energies to the degree of compression. It is found that the most of increasing in the nuclear energy generated under compression is used to create the massive Δ particles. For 90Zr nucleus under compression at 2.5 times density of the normal nuclear density, the excited nucleons to Δ ＇s are increased sharply up to 14% of the total number of constituents. This result is consistent with the values extracted from relativistic heavy-ion collisions. The single particle energy levels are calculated and their behaviors under compression are examined too. A good agreement between results with.e.fective hamiltonian and the phenomenologieal shell model for the low lying single-particle spectra is obtained. A considerable reduction in compressibility for the nucleus, and softening of the equation of state with the inclusion of the Δ＇s in the nuclear dynamics are suggested by the results.

关键词： nuclear structure compressed finite nuclei Δ-resonance

Strengthening Cooperation Among Political Parties to Jointly Pursue the People's Wellbeing

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International Understanding 2021年第2期 1-6页

作者： h.e. Xi Jinping General Secretary of the Central Committee of The Communist Party of China And President of the People's Republic of China At the CPC and World Political Parties Summit Beijing

Keynote Address by *** Jinping General Secretary of the Central Committee of The Communist Party of China And President of the People’s Republic of China At the CPC and World Political Parties Summit Beijing,6 July 2021 Your excellencies leaders of political parties,Ladies and Gentlemen,Friends,It gives me great pleasure to join you,leaders of more than 500 political parties,political and other organisations from over 160 countries as well as the ten thousand and more representatives of political parties and various circles。

关键词： parties political Communist

Chinese Culture Today:Aspirations and Dreams

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China & The World Cultural exchange 2006年第1期72卷 4-11页

作者： h.e. Sun Jiazheng Minister of Culture of the People＇s Republlc of China

editor＇s note： During the Festival of China taking place in Washington D.C. in October, 2005, Chinese Minister of Culture Sun Jiazheng made a keynote speech in National Press Club, addressing political, cultural and media celebrities on China＇s policies and strategies for cultural development. The following Is the whole text of his speech.

关键词：《当代中国文化的追求与梦想》文化部长中国孙家正美国文化节 2005年文化交流华盛顿

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英语常用词语法词典

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Citizen sensors or extreme publics? Transparency and accountability interventions on the mobile geoweb

作者： h.e.·帕默(h.e. Palmer)

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International Journal of Digital earth 2014年第7期7卷 516-533页

作者： Y.Georgiadou J.h.Lungo C.richter Faculty of Geo-information Science and earth Observation(ITC) University TwenteEnschedeThe Netherlands College of Information and Communication Technologies(CoICT) University Dar es SalaamDar es SalaamTanzania

Transparency and Accountability(T&A)interventions are emergent social technologies in middle and low-income *** bring together citizen sensors,mobile communications,geo-browsers and social organization to raise public awareness on the extent of governance deficits,and monitor government’s(in)*** to their novelty,almost all we know about the effectiveness of T&A interventions comes from gray *** citizen sensors radically increase the transparency of the state,or are changes brought about by T&A interventions more likely to be incremental?We review the literature on transparency policies and describe their drivers,characteristics and supply-demand *** discuss promising cases of T&A interventions in east Africa,the empirical focus of an on-going collaborative research *** conclude that the effect of T&A interventions is more likely to be incremental and mediated by existing organizations and professional users who populate the space between the state and *** elements at the interface between supply and demand seem rather crucial for designers of T&A interventions:accountability-relevant data and extreme publics.

关键词： citizen sensors transparency accountability-relevant data extreme publics mobile geoweb

Influence of Fabric Parameters on Microstructure,Mechanical Properties and Failure Mechanisms in Carbon-Fibre Reinforced Composites

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Journal of Materials Science & Technology 2008年第6期24卷 953-959页

作者： B.Wielage D.richter h.Mucha Th.Lampke Chemnitz University of Technology Institute of Composite Materials and Surface TechnologyD-09107 ChemnitzGermany

The effects of fibre/matrix bonding, fabric density, fibre volume fraction and bundle size on microstructure, mechanical properties and failure mechanisms in carbon fibre reinforced composites （plastic and carbon matrix） have been investigated. The microstructure of unloaded and cracked samples was studied by optical microscopy and scanning electron microscopy （SeM）, respectively whereas the mechanical behaviour was examined by 3- point bending experiments. exclusively one type of experimental resole type phenolic resin was applied. A strong fibre/matrix bonding, which is needed for high strength of carbon fibre reinforced plastic （CFRP） materials leads to severe composite damages during the pyrolysis resulting in low strength, brittle failure and a very low utilisation of the fibres strain to failure in C/C composites. Inherent fabric parameters such as an increasing fabric density or bundle size or a reduced fibre volume fraction introduce inhomogenities to the CFRP＇s microstructure. Results are lower strength and stiffness whereas the strain to failure increases or remains unchanged. Tough.e.s is almost not affected. In C/C composites inhomogenities due to a reduced bundle size reduce strain to failure, strength, stiffness and tough.e.s. Vice versa a declining fibre volume fraction leads to exactly the opposite behaviour. Increasing the fabric density （weight per unit area） causes similar effects as in CFRPs.

关键词： CFRPs C/C Fibre/matrix bonding Fabric density Fibre volume fraction Roving size Microstructure Failure behaviour