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国外大电机 2011年第2期 35-39页

作者： h.katayama[日]（等）胡刚（译）关玉薇（校）

为满足全球环境和谐和减少寿命周期成本的要求，作者开发了一种具有更高效率和更大容量的发电机，它的定子线圈采用间接氢冷，以代替到目前为止这个容量范围必须采用的直接水冷方式。这种发电机不使用冷却水，因而有节省空间和实现布局... 详细信息

为满足全球环境和谐和减少寿命周期成本的要求，作者开发了一种具有更高效率和更大容量的发电机，它的定子线圈采用间接氢冷，以代替到目前为止这个容量范围必须采用的直接水冷方式。这种发电机不使用冷却水，因而有节省空间和实现布局简单的可能，并消除了水冷发电机特有的风险，例如定子冷却回路堵塞和冷却水泄露。另外，间接氢冷的定子线圈不需要在横截面上预留冷却回路，从而使间接氢冷的发电机有可能实现更高的效率。作者开发了一种用于定子线圈的hTC（高导热）绝缘材料，并从2000年开始将其应用于间接氢冷发电机。2009年，作者开发并制造了用于900MW并列双轴式热电厂的2p-60hz．670MVA主发电机和4p－60hz．370MVA次级发电机。作为间接氢冷发电机，主发电机的容量为世界最大，两种发电机的发电效率都超过了991％。氢气的冷却能力比水小，为了将间接氢冷的方法运用到过去需要直接水冷的60hz－670MVA发电机上，总结出一蝗技术上的挑战并予以解决，比如端电压和定子电流间的平衡、定转子冷却方式的优化、定子机座的验证、氢密封和定子线圈的端部支撑结构。新开发的发电机在2009年2月按照标准进行了工厂试验，两台电机均达到预估的性能并满足规范的要求。

关键词：间接氢冷 hTC(高导热率) 定子绝缘

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存在各种技术问题的老汽轮发电机的成功更新

国外大电机 2007年第4期 10-13页

作者： h.katayama[日] 黄春阳（译）王永春（校）

某热电厂运行了近30年的350MW汽轮发电机已表现出老化迹象。遇到的问题包括：铁心松动、铁心压圈过热和出现裂纹、铁心端部松动、定子线圈端部振动过大和主绝缘出现裂纹、定子线圈空心导线阻塞和热敏感导致的转子振动。已对出现问题开... 详细信息

某热电厂运行了近30年的350MW汽轮发电机已表现出老化迹象。遇到的问题包括：铁心松动、铁心压圈过热和出现裂纹、铁心端部松动、定子线圈端部振动过大和主绝缘出现裂纹、定子线圈空心导线阻塞和热敏感导致的转子振动。已对出现问题开展了一系列研究并提出最佳处理方案，把额定功率350MW提高到400MW。现有的汽轮发电机的转子和定子铁心通过氢气冷却，定子绕组由除离子水冷却，为了克服运输重量限制，定子制造成为内外机座两部分。为了解决存在的问题并提高机组容量，仔细研究了各种解决方案，包括定子／转子绕组重新下线和铁心重新叠片，更换内机座和转子等部件。也研究了保留现有基础和辅助系统，用氢冷发电机更换现有机组的方案。全氢冷发电机和水冷发电机相比有多项优势，其中包括：简化冷却系统使维护简单；消除了水冷定子线圈漏水和空心导线堵塞等问题，节省了辅助冷却水系统动力需求。全面分析得出结论：为了简化维护并降低运行费用，解决现有问题使之能再运行30年的最有效方法是，用全氢冷发电机替换现有机组。本文叙述了对现有机组的研究对策和用全氢冷发电机替换的成功经验。

关键词：汽轮发电机翻新直接氢冷高导热定子绝缘

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高铬钢的脱磷新工艺

大型铸锻件 1986年第2期 7-13页

作者： M．Kosugi K．Morinaka Y．hirose h.katayama 胡庆渝（译）日本不详

根据试验研究结果,已为车间生产成功地开发了一项有效的高铬钢液的脱磷工艺。这种新工艺,是把电炉冶炼的合金化钢液注入钢包后,用Ca_2C-CaF_2渣进行脱磷反应,脱磷后,再进行脱碳和精炼。此外,对脱磷渣的安全处理方法也作了研究。

关键词：脱磷工艺高铬钢车间生产电炉冶炼安全处理铜液合金化脱磷渣

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东芝汽轮发电机机器人检测技术

国外大电机 2022年第4期 1-4页

作者： [日本]h.katayama 李明阳(译) 程广福(校) 不详

0引言在对发电机进行常规检查时,必须先拆出转子,然后才能由具有资质的检测人员进行检查。整个过程通常耗时一个月左右,如何缩短检查时间延长检查周期就成为了有效提高发电机供电时间所面临的挑战。近年来,机器人检测技术不断发展,现在... 详细信息

0引言在对发电机进行常规检查时,必须先拆出转子,然后才能由具有资质的检测人员进行检查。整个过程通常耗时一个月左右,如何缩短检查时间延长检查周期就成为了有效提高发电机供电时间所面临的挑战。近年来,机器人检测技术不断发展,现在已经能够实现在不拆转子的情况下进行快速/详细的检查。然而,在检测定子内部设有隔离挡板的大型火电机组时,隔离挡板会阻碍机器人的检查活动。目前,一种新式的机器人已经被开发出来,这种新机器人可以在转子表面爬行,用支撑臂撑住定子来实施对已插人转子的大型火电发电机的详细检查。此外,这种新的检测机器人可以进行无损检测,采用干式超声波接触技术对转子进行检查。总之,针对发电机所有的检查工作,都可以由这种机器人来完成,而无需拆卸转子。

关键词：机器人供电时间大型火电机组检查周期无损检测常规检查汽轮发电机检测技术

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

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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)

holographic dark energy in non-conserved gravity theory

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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

Novel synthesis of stabilized Bi_(1-x-y)Gd_(x)Dy_(y)O_(1.5) solid electrolytes with enhanced conductivity for intermediate temperature solid oxide fuel cells(SOFCs)

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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 University41522IsmailiaEgypt Ministry of higher Education and Scientific Research Aliraqia University10011BaghdadIraq

herein,we report the synthesis of a Dy-Gd co-doped cubic phase-stabilized Bi_(2)O_(3) solid electrolyte system via solid-state processing under atmospheric *** with Dy^(3+) and Gd^(3+) has been observed to significantly enhance the densification process during sintering for stabilization purposes,thereby improving the electrical properties of δ-Bi_(2)O_(3)-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 Bi_(1-x-y)Gd_(x)Dy_(y)O_(1.5)(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 Bi_(0.90)Gd_(0.05)Dy_(0.05)O_(1.5) has no significant ***,an evident increase in the pore formation is observed as the amount of Gd_(2)O_(3) increases 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 Bi_(2)O_(3)solid electrolyte system was evaluated and analyzed in detail by using the electrochemical impedance spectroscopy(EIS) technique,Based on EIS and conductivity measurements,Bi_(0.75)Gd_(0.20)Dy_(0.05)O_(1.5) exhibits 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： Solid oxide fuel cells(SOFCs) Rare earths Solid-state processing Rietveld Fast Fourier transform(FFT) Electrochemical impedance spectroscopy(EIS)

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

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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

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

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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