检索结果-南通市图书馆

头颈部基于快速自旋回波成像与平面回波成像的体素内不相干运动扩散加权成像的比较研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

国际医学放射学杂志 2018年第2期 239-240页

作者： R.Mikayama h.yabuuchi S.Sonoda K.Kobayashi K.Nagatomo M.Kimura 张琪 Department of health Sciences Graduate School of Medical Sciences Kyushu University

摘要目的本研究旨在比较头颈部基于快速自旋回波(TSE)扩散加权成像(DWI)和平面回波(EPI)DWI的影像质量、表观扩散系数(ADC)以及体素内不相干运动(IVIM)相关

关键词：体素内不相干运动 EPI ADC 加权成像 DWI 头颈部

钙化能否预测甲状腺乳头状癌病人接受131I治疗后淋巴结转移灶131I的浓聚?CT、131I全身扫描和18F-FDG PET/CT比较

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

国际医学放射学杂志 2010年第2期 203-203页

作者： K.Kaneko K.Abe S.Baba Y.Tanabe h.yabuuchi M.hatakenaka 袁瑛 Department of Clinical Radiology Graduate School of Medical SciencesKyushu UniversityFukuokaJapan

研究目的是阐明淋巴结钙化对甲状腺乳头状癌(PTC)病人131I治疗的预测价值。分析了19例PTC病人131I治疗期时CT上淋巴结钙化情况,并与131I全身核素扫描和

关键词：甲状腺乳头状癌淋巴结淋巴组织 FDG PET 病人

非小细胞肺癌:MR动态对比增强与扩散加权成像检测肺癌对化疗的早期反应

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

国际医学放射学杂志 2012年第1期 78-78页

作者： h.yabuuchi M.hatakenaka K.Takayama Y.Matsuo S.Sunami T.Kamitani 管宇 Department of Clinical Radiology Graduate School of Medical SciencesKyushu University3-1-1 MaidashiHigashi-kuFukuoka 812-8582Japan

目的评估MR动态对比增强成像和扩散加权成像检测非小细胞肺癌(NSCLC)病人对化疗早期反应的能力。材料与方法本研究经机构审查委员会审批并获得受试者书面

关键词：动态对比增强扩散加权 MR 早期反应成像检测小细胞肺癌

无症状女性触诊阴性乳腺癌非增强扩散加权和T2加权MRI的检出:与乳腺X线摄影和对比增强MRI的对照研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

国际医学放射学杂志 2011年第2期 188-188页

作者： h.yabuuchi Y.Matsuo S.Sunami T.Kamitani S.Kawanami T.Setoguchi 秦乃姗 Department of Clinical Radiology Graduate School of Medical SciencesKyushu University

目的对照比较无症状女性触诊阴性乳腺癌乳腺X线摄影(MMG)、动态增强MRI(DCE-MRI)和扩散加权联合T2加权的非增强MRI(DWI+T2WI)的病变检出能力。方法

关键词：乳腺 MRI 扩散加权MRI 触诊阴性乳腺癌筛查

Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 543-562页

作者： h.M.FEIZABAD M.h.YAS Department of Mechanical Engineering Razi UniversityKermanshah ***Iran

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent *** fibers are renowned for their good mechanical properties,abundance,and short cycle *** beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic *** different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the *** elastic properties of the composite are determined with the law of *** hamilton’s principle,the governing equations of motion are *** generalized differential quadrature method(GDQM)is then applied to the equations to obtain the *** achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam ***,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber ***,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(FG)beam elastic foundation generalized differential quadrature method(GDQM)

维普期刊数据库

holographic dark energy in non-conserved gravity theory

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期76卷 126-133页

作者： h R Fazlollahi Institute of Gravitation and Cosmology Peoples Friendship University of Russia(RUDN University)6 Miklukho-Maklaya StMoscow117198Russia

Recently, reconsidering the Rastall idea T_(μ;νν)^(v)=α_(,μ) through relativistic thermodynamics gives a new form for the scalar field α which led us to construct modern modified theory of gravity debugged ‘non-conserved gravity theory’ Fazlollahi 2023 Euro. Phys. J. C 83 923. This theory unlike other modified theories of gravity cannot directly explain the current acceleration expansion in the absence of the cosmological constant and or existence of other forms of dark energy. hence, in this study we have reinvestigated holographic dark energy Ρ_(X)~h^(2) in the non-conserved theory of gravity. In this context, the density and pressure of dark energy depend on the non-conserved term and density of the dust matter field. As shown, due to non-conservation effects on large-scale structures, unlike the original holographic model, our model onsets an acceleration epoch for the current Universe satisfies observations. Moreover, the interaction and viscous scenarios are studied for this model.

关键词： non-conserved gravity covariant form of thermodynamics holographic dark energy

维普期刊数据库

Novel synthesis of stabilized Bi1-x-yGdxDyyO1.5 solid electrolytes with enhanced conductivity for intermediate temperature solid oxide fuel cells（SOFCs）

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第10期42卷 1903-1911页

作者： Ahmed h.Ibrahim Yehia M.Abbas h.A.Ayoub Marwa h.Ali Mustafa Aldoori Materials Science Laboratory Physics DepartmentFaculty of ScienceSuez Canal University Ministry of higher Education and Scientific Research Aliraqia University

herein,we report the synthesis of a Dy-Gd co-doped cubic phase-stabilized Bi2O3solid electrolyte system via solid-state processing under atmospheric *** with Dy3+and Gd3+has been observed to significantly enhance the densification process during sintering for stabilization purposes,thereby improving the electrical properties of δ-Bi2O3-type *** synthesized ceramics were characterized using X-ray diffraction（XRD）,field emission scanning electron microscopy-energy dispersive X-ray spectroscopy（FESEM-EDX）,thermal gravimetry/differential thermal analysis（TG/DTA）,and the four-point probe technique（4PPT）.XRD analysis reveals that the samples Bi1-x-yGdxDyyO1.5（y=0.05/x=0.05,0.10,0,15,and 0.20,and x=0.05/y=0.10,0.15,and 0.20） exhibit a stable face-centered cubic δ-phase and a mixed-phase crystallographic *** XRD analysis of the stabilized δ-phase suggests that the prepared oxides show a face-centered cubic（FCC） structure with a space group of *** micrographs reveal that the composition Bi0.90Gd0.05Dy0.05O1.5has no significant ***,an evident increase in the pore formation is observed as the amount of Gd2O3increases until it reaches 20%.This finding suggests that dense pellets are formed during the sintering process at 900-1000℃.The DTA analyses were performed to verify the phase stability,which agrees with the XRD *** electrochemical performance of the synthesized Dy-Gd co-doped Bi2O3solid electrolyte system was evaluated and analyzed in detail by using the electrochemical impedance spectroscopy（EIS） technique,Based on EIS and conductivity measurements,Bi0.75Gd0.20Dy0.05O1.5exhibits the lowest activation energy of 0.519 eV and the highest conductivity value of 0.398 S/cm at 627℃compared to the other samples;this composition can be used as a solid electrolyte for intermediatetemperature solid oxide fuel cells（SOFCs）.

关键词： Electrochemical impedance spectroscopy (EIS) Fast Fourier transform (FFT) Rare earths Rietveld Solid oxide fuel cells (SOFCs) Solid-state processing

Convexification of hybrid AC-DC Optimal Power Flow with Line-Commutated Converters

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第2期10卷 617-628页

作者： hongyuan Liang Zhigang Li J.h.Zheng Q.h.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China

Line-commutated converter (LCC)-based high-voltage DC (hVDC) systems have been integrated with bulk AC power grids for interregional transmission of renewable power. The nonlinear LCC model brings additional nonconvexity to optimal power flow (OPF) of hybrid AC-DC power grids. A convexification method for the LCC station model could address such nonconvexity but has rarely been discussed. We devise an equivalent reformulation for classical LCC station models that facilitates second-order cone convex relaxation for the OPF of LCC-based AC-DC power grids. We also propose sufficient conditions for exactness of convex relaxation with its proof. Equivalence of the proposed LCC station models and properties, exactness, and effectiveness of convex relaxation are verified using four numerical simulations. Simulation results demonstrate a globally optimal solution of the original OPF can be efficiently obtained from relaxed model.

关键词： AC-DC power system convex relaxation linecommutated converter optimal power flow second-order cone programming

Shell-model representations of the microscopic version of the Bohr-Mottelson collective model

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

Communications in Theoretical Physics 2024年第8期76卷 79-90页

作者： h G Ganev Joint Institute for Nuclear Research DubnaRussia Institute of Mechanics Bulgarian Academy of SciencesSofiaBulgaria

The structure of the irreducible collective spaces of the group Sp(12,R),which many-particle nuclear states are classified according to the chain Sp(12,R)⊃U(6)⊃SO(6)⊃SU_(pn)(3)⊗SO(2)⊃SO(3)of the proton-neutron symplectic model(PNSM),is considered in *** chain of the PNSM was recently shown to correspond to a microscopic shell-model version of the Bohr-Mottelson collective *** construction of the relevant shell-model representations of the Sp(12,R)group along this chain is considered for three nuclei with varying collective properties and from different mass *** is shown that the SU_(pn)(3)basis states of the Sp(12,R)representations belonging to the SO(6)irreps with seniorityυ≥υ0,withυ0 denoting the maximal seniority SO(6)irrep contained in the Sp(12,R)bandhead,are always Pauli allowed,but organized in a different way into different SO(6)*** is in contrast to the case of filling the levels of the standard three-dimensional harmonic oscillator and using the plethysm *** the SU_(pn)(3)multiplets withinυhe present work are important for the practical application of the microscopic version of the Bohr-Mottelson collective model.

关键词： microscopic shell-model version of the Bohr-Mottelson model proton-neutron symplectic model Sp(12,R)dynamical algebra shell-model representations

维普期刊数据库