检索结果-南通市图书馆

Finite Element Simulation on Thermal Fatigue of a Turbine Blade with Thermal Barrier Coatings

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2014年第4期30卷 371-380页

作者： L.Yang q.x.liu Y.C.Zhou W.G.Mao C.Lu Key Laboratory of Low Dimensional Materials & Application Technology(Ministry of Education) Xiangtan University Faculty of Materials Optoelectronic & PhysicsXiangtan University Department of Mechanical Engineering Curtin University

In this paper, a finite element model was developed for a turbine blade with thermal barrier coatings to investigate its failure behavior under cyclic thermal loading. Based on temperature and stress fields obtained from finite element simulations, dangerous regions in ceramic coating were determined in terms of the maximum principal stress criterion. The results show that damage preferentially occurs in the chamfer and rabbet of a turbine blade with thermal barrier coatings and its thermal fatigue life decreases with the increase of thermal stress induced by high service temperature.

关键词： Turbine blade Thermal barrier coatings Finite element model Thermal fatigue Life prediction

维普期刊数据库

Pb-DOPING EFFECTS ON THE DIELECTRIC AND PYROELECTRIC PROPERTIES OF(Sr,Pb)TiO_(3)SYSTEM

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Dielectrics 2012年第1期2卷 78-85页

作者： Y.P.JIANG x.G.TANG Y.C.ZHOU q.x.liu Key Laboratory of Low Dimensional Materials and Application Technology Xiangtan University Xiangtan 411105P.R.China School of Physics&Optoelectric Engineering Guangdong University of Technology Guangzhou Higher Education Mega Center Guangzhou 510006 P.R.China

Lead strontium titanate(Sr_(1-x)Pbx)TiO_(3)(0.20≤x≤0.45,step=0.05)ceramics were prepared by conventional mixed oxide *** x-ray diffraction patterns indicate that the prepared samples have perovskite-type *** the increase of Pb content,there is a tendency from the cubic to tetragonal *** scanning electron microscopy micrographs reveal that the addition of Pb can affect *** dependent temperature dielectric permittivity and dielectric loss were investigated in the frequency range from 100 Hz to *** maximum peak of the dielectric permittivity versus temperature curve was broadened and a frequency dispersion of the dielectric permittivity was observed for the(Sr_(0.8)Pb_(0.2))TiO_(3)*** results obtained at the frequency of 10 kHz reveal the Curie temperature linearly increased with the lead *** curves of temperature versus inverse dielectric permittivity at 10 kHz for(Sr_(1-x)Pbx)TiO_(3)ceramics are consistent with Curie-Weiss *** Pyroelectric properties were also *** high pyroelectric coe±cients andfigure of merits indicate that the SPT ceramics are potential materials for pyroelectric sensors.

关键词： (Sr_(1-x)Pbx)TiO_(3)(SPT)ceramics dielectric properties Curie temperature CurieWeiss law pyroelectric properties

Anomalous open orbits in Hofstadter spectrum of Chern insulator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第3期Mechanics & Astronomy) .卷 143-148页

作者： Haijiao Ji Peng Zhou Noah F.q.Yuan Hua Jiang Haiwen liu x.C.xie Center for Advanced quantum Studies Department of Physics Beijing Normal University Tsung-Dao Lee Institute Shanghai Jiao Tong University Department of Mathematics UC Berkeley Institute for Nanoelectronic Devices and quantum Computing Fudan University International Center for quantum Materials School of Physics Peking University Hefei National Laboratory

The nontrivial band topology of Chern insulator can enrich the content of its Hofstadter butterfly spectra, which is closely related to recent experiments in twisted bilayer graphene and cold atom systems. We investigate the Hofstadter spectrum for various models of Chern insulators under a rational flux φ0/q, here φ0=h/e and q being an integer. We find the number of splitting subbands is |q-C| with C denoting the Chern number of parent band. Importantly, anomalous open-orbital subbands with Chern numbers q-1 and-q-1 emerge unexpectedly, which are beyond the parameter window（-q/2, q/2） of the Diophantine equation studied by Thouless-Kohmoto-Nightingale-den Nijs [Phys. Rev. Lett. 49, 405（1982）]. The emergence of anomalous open orbits can be traced by analyzing the evolution of the Hofstadter spectrum, identifying as a new type of topological phase transition. These novel findings not only pinpoint the peculiar Hofstadter spectrum of Chern insulator, but also provide routes to study exotic characteristics beyond the Landau level physics.

关键词： Hofstadter spectrum topological phase transition open orbit

维普期刊数据库

同方期刊数据库

[Skin mechanomedicine]

在线全文

学校读者我要写书评

暂无评论

Zhonghua yi xue za zhi 2025年第7期105卷 489-496页

作者： S M Geng J H Hu q Zhao Y q Feng x Wang H liu F xu Department of Dermatology Second Affiliated Hospital of Xi'an Jiaotong University Xi'an 710004 China Center for Dermatology Disease Precision Medical Institute Xi'an 710115 China. Bioinspired Engineering and Biomechanics Center (BEBC) School of Life Science and Technology Xi'an Jiaotong University Xi'an 710049 China Ministry of Education Key Laboratory of Biomedical Information Engineering School of Life Science and Technology Xi'an Jiaotong University Xi'an 710049 China.

Traditional research on skin diseases has mainly focused on biological characteristics for a long time. Recently, the integration of biomechanics and mechanobiology has introduced mechanical factors into skin disease research. The interaction between mechanical factors and skin's physiological and pathological changes has gradually been transformed in clinical diagnosis and treatment. The two emerging fields, mechanodiagnostics and mechanotherapy, have been developed to address clinical needs. However, clinicians often lack a comprehensive understanding of skin mechanical characteristics and the mechanobiological mechanisms in dermatology. Thus, we propose the concept of "skin mechanomedicine". By summarizing relevant research at home and abroad, this paper systematically elucidates the multiscale mechanical characteristics of skin diseases and their impact on biological behavior from four perspectives: skin biomechanics, skin mechanobiology, skin mechanodiagnostics, and skin mechanotherapy. Meanwhile, in-depth exploration was conducted on the potential application of mechanical factors in the diagnosis and treatment of skin diseases, aiming to provide new research perspectives and solutions for the diagnosis and treatment of skin diseases.

关键词：皮肤皮肤生物力学皮肤力生物学皮肤力诊断学皮肤力治疗学

Estimating Transient Stability Regions of Large-scale Power Systems Part Ⅱ: Reduced-order Stability Region with Computational Efficiency

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2025年第1期11卷 38-50页

作者： Yuqing Lin Tianhao Wen Lei Chen Yang liu q. H. Wu School of Electric Power Engineering South China University of TechnologyGuangzhou510640China

Part Ⅱ of this paper presents a reduced-order stability region (ROSR) based method to estimate the full-order stability region (FOSR) of a large-scale power system. First, we introduce the definitions of FOSR and ROSR, followed by a comprehensive theory that reveals the relationships between them. Since the full-order system can be rewritten as a standard two timescale model and the reduced-order system is regarded as the slow subsystem of it, the proposed theory is derived based on the idea of singular perturbation. With rigorous mathematical proof, the properties of FOSR and ROSR are revealed. Moreover, a modified Energy Augmented Dynamic (EAD) algorithm and a constrained equidistant projection (CEP) approach are employed to estimate the ROSR and FOSR, respectively. The modified EAD algorithm and CEP form a so-called reduced-order stability region mapping (ROSRM) method. Finally, the proposed ROSRM method is applied to the IEEE 10-machine-39-bus power system, and simulation studies confirm its superiority to the traditional energy function method in terms of computational speed and reliability of results.

关键词： Large-scale power system singular perturbation theory stability region sum of squares transient stability

Estimating Transient Stability Regions of Large-Scale Power Systems Part I: Koopman Operator and Reduced-Order Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2025年第1期11卷 24-37页

作者： Yuqing Lin Tianhao Wen Lei Chen q. H. Wu Yang liu School of Electric Power Engineering South China University of Technology Guangzhou China

This paper presents an estimation of transient stability regions for large-scale power systems. In Part I, a Koopman operator based model reduction (KOMR) method is proposed to derive a low-order dynamical model with reasonable accuracy for transient stability analysis of large-scale power systems. Unlike traditional reduction methods based on linearized models, the proposed method does not require linearization, but captures dominant modes of the original nonlinear dynamics by employing a Koopman operator defined in an infinite-dimensional observable space. Combined with the Galerkin projection, the obtained dominant Koopman eigenvalues and modes produce a reduced-order nonlinear model. To approximate the Koopman operator with sufficient accuracy, we introduce a Polynomial-based Multi-trajectory Kernel Dynamic Mode Decomposition (PMK-DMD) algorithm, which outperforms traditional DMD in various scenarios. In the end, the proposed method is applied to the IEEE 10-machine-39-bus power system and IEEE 16-machine-68-bus power system, which demonstrates that our method is significantly superior to the modal analysis method in both qualitative and quantitative aspects.

关键词： Power system stability Reduced order systems Nonlinear dynamical systems Eigenvalues and eigenfunctions Power system dynamics Kernel Transient analysis Analytical models Accuracy Modal analysis

Deep view of composite SNR CTA1 with LHAASO in γ-rays up to 300 TeV

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年

作者： Zhen Cao F.Aharonian Axikegu Y.x.Bai Y.W.Bao D.Bastieri x.J.Bi Y.J.Bi W.Bian A.V.Bukevich q.Cao W.Y.Cao Zhe Cao J.Chang J.F.Chang A.M.Chen E.S.Chen H.x.Chen Liang Chen Lin Chen Long Chen M.J.Chen M.L.Chen q.H.Chen S.Chen S.H.Chen S.Z.Chen T.L.Chen Y.Chen N.Cheng Y.D.Cheng M.C.Chu M.Y.Cui S.W.Cui x.H.Cui Y.D.Cui B.Z.Dai H.L.Dai Z.G.Dai Danzengluobu x.q.Dong K.K.Duan J.H.Fan Y.Z.Fan J.Fang J.H.Fang K.Fang C.F.Feng H.Feng L.Feng S.H.Feng x.T.Feng Y.Feng Y.L.Feng S.Gabici B.Gao C.D.Gao q.Gao W.Gao W.K.Gao M.M.Ge T.T.Ge L.S.Geng G.Giacinti G.H.Gong q.B.Gou M.H.Gu F.L.Guo J.Guo x.L.Guo Y.q.Guo Y.Y.Guo Y.A.Han O.A.Hannuksela M.Hasan H.H.He H.N.He J.Y.He Y.He Y.K.Hor B.W.Hou C.Hou x.Hou H.B.Hu q.Hu S.C.Hu C.Huang D.H.Huang T.q.Huang W.J.Huang x.T.Huang x.Y.Huang Y.Huang Y.Y.Huang x.L.Ji H.Y.Jia K.Jia H.B.Jiang K.Jiang x.W.Jiang Z.J.Jiang M.Jin M.M.Kang I.Karpikov D.Khangulyan D.Kuleshov K.Kurinov B.B.Li C.M.Li Cheng Li Cong Li D.Li F.Li H.B.Li H.C.Li Jian Li Jie Li K.Li S.D.Li W.L.Li W.L.Li x.R.Li xin Li Y.Z.Li Zhe Li Zhuo Li E.W.Liang Y.F.Liang S.J.Lin B.liu C.liu D.liu D.B.liu H.liu H.D.liu J.liu J.L.liu M.Y.liu R.Y.liu S.M.liu W.liu Y.liu Y.N.liu q.Luo Y.Luo H.K.Lv B.q.Ma L.L.Ma x.H.Ma J.R.Mao Z.Min W.Mitthumsiri H.J.Mu Y.C.Nan A.Neronov K.C.Y.Ng L.J.Ou P.Pattarakijwanich Z.Y.Pei J.C.qi M.Y.qi B.q.qiao J.J.qin A.Raza D.Ruffolo A.Sáiz M.Saeed D.Semikoz L.Shao O.Shchegolev x.D.Sheng F.W.Shu H.C.Song Yu.V.Stenkin V.Stepanov Y.Su D.x.Sun q.N.Sun x.N.Sun Z.B.Sun J.Takata P.H.T.Tam q.W.Tang R.Tang Z.B.Tang W.W.Tian L.H.Wan C.Wang C.B.Wang G.W.Wang H.G.Wang H.H.Wang J.C.Wang Kai Wang Kai Wang L.P.Wang L.Y.Wang P.H.Wang R.Wang W.Wang x.G.Wang x.Y.Wang Y.Wang Y.D.Wang Y.J.Wang Z.H.Wang Z.x.Wang Zhen Wang Zheng Wang D.M.Wei J.J.Wei Y.J.Wei T.Wen C.Y.Wu H.R.Wu q.W.Wu S.Wu x.F.Wu Y.S.Wu S.q.xi J.xia G.M.xiang D.x.xiao G.xiao Y.L.xin Y.xing D.R.xiong Z.xiong D.L.xu R.F.xu R.x.xu W.L.xu L.xue D.H.Yan J.Z.Yan T.Yan C.W.Yang C.Y.Yang F.Yang F.F.Yang L.L.Yang M.J.Yang R.Z.Yang W.x.Yang Y.H.Yao Z.G.Yao L.q.Yin N.Yin x.H.You Z.Y.You Y.H Southwest Jiaotong University School of Astronomy and Space Science Nanjing University Center for Astrophysics Guangzhou University Tsung-Dao Lee Institute & School of Physics and Astronomy Shanghai Jiao Tong University Institute for Nuclear Research of Russian Academy of Sciences Hebei Normal University University of Science and Technology of China LHAASO Collaboration State Key Laboratory of Particle Detection and Electronics Key Laboratory of Dark Matter and Space Astronomy & Key Laboratory of Radio Astronomy Purple Mountain Observatory Chinese Academy of Sciences Research Center for Astronomical Computing Zhejiang Laboratory Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences School of Physics and Astronomy Key Laboratory of Particle Astrophysics & Experimental Physics Division & Computing Center Yunnan University Key Laboratory of Cosmic Rays (Tibet University) Ministry of Education Department of Physics The Chinese University of Hong Kong Key Laboratory of Radio Astronomy and Technology National Astronomical Observatories Chinese Academy of Sciences School of Physics and Astronomy (Zhuhai) & School of Physics (Guangzhou) & Sino-French Institute of Nuclear Engineering and Technology (Zhuhai) Sun Yat-sen University Institute of High Energy Physics Institute of Frontier and Interdisciplinary Science Shandong University APC Université Paris Cité CNRS/IN2P3 CEA/IRFU Observatoire de Paris Department of Engineering Physics & Department of Astronomy Tsinghua University School of Physics and Microelectronics Chinese Academy of Sciences Zhengzhou University Yunnan Observatories Chinese Academy of Sciences China Center of Advanced Science and Technology College of Physics Sichuan University School of Physics Peking University Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and Technology University of Chinese Academy of Sciences Guangxi University Department of Physics Faculty of Science Mahidol University Moscow Institute

The ultra-high-energy（UHE） gamma-ray source 1LHAASO J0007+7303u is positionally associated with the composite SNR CTA1 that is located at high Galactic Latitude b ≈ 10.5°. This provides a rare opportunity to spatially resolve the component of the pulsar wind nebula（PWN） and supernova remnant（SNR） at UHE. This paper conducted a dedicated data analysis of 1LHAASO J0007+7303u using the data collected from December 2019 to July 2023. This source is well detected with significances of 21σ and 17σ at 8-100 TeV and >100 TeV, respectively. The corresponding extensions are determined to be 0.23°±0.03°and 0.17°±0.03°. The emission is proposed to originate from the relativistic electrons accelerated within the PWN of PSR J0007+7303. The energy spectrum is well described by a power-law with an exponential cutoff function dN/dE =（42.4 ± 4.1）(E/（20 TeV）)-2.31±0.11exp(-E/（110±25 TeV）) TeV-1cm-2s-1in the energy range from 8 to 300 TeV, implying a steady-state parent electron spectrum dNe/dEe∝(Ee/（100 TeV）)-3.13±0.16exp[(-Ee/（373±70 TeV）)2] at energies above ≈ 50 TeV. The cutoff energy of the electron spectrum is roughly equal to the expected current maximum energy of particles accelerated at the PWN terminal shock. Combining the x-ray and gamma-ray emission, the current space-averaged magnetic field can be limited to≈ 4.5 μG. To satisfy the multi-wavelength spectrum and the γ-ray extensions, the transport of relativistic particles within the PWN is likely dominated by the advection process under the free-expansion phase assumption.

关键词：

LHAASO detection of very-high-energy γ-ray emission surrounding PSR J0248+6021

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年

We report the detection of an extended very-high-energy(VHE) γ-ray source coincident with the location of middle-aged(62.4 kyr) pulsar PSR J0248+6021, by using the LHAASO-WCDA data of live 796 d and LHAASO-KM2A data of live 1216d. A significant excess of γ-ray induced showers is observed both by WCDA in energy bands of 1-25 Te V and KM2A in energy bands of >25 TeV with 7.3σ and 13.5σ, respectively. The best-fit position derived through WCDA data is R.A. = 42.06°± 0.12°and Dec. = 60.24°± 0.13°with an extension of 0.69°±0.15°and that of the KM2A data is R.A.= 42.29°± 0.13°and Dec. =60.38°± 0.07°with an extension of 0.37°±0.07°. No clear extended multiwavelength counterpart of this LHAASO source has been found from the radio band to the GeV band. The most plausible explanation of the VHE γ-ray emission is the inverse Compton process of highly relativistic electrons and positrons injected by the pulsar. These electrons/positrons are hypothesized to be either confined within the pulsar wind nebula or to have already escaped into the interstellar medium, forming a pulsar halo.

关键词：

Observation of the γ-ray emission from W43 with LHAASO

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年

In this paper, we report the detection of the very-high-energy (VHE, 100 Ge V100 TeV) γ-ray emissions from the direction of the young star-forming region W43, observed by the Large High Altitude Air Shower Observation (LHAASO). The extended γ-ray source was detected with a significance of～16σby KM2A and～17σby WCDA, respectively. The angular extension of this γ-ray source is about 0.5 degrees, corresponding to a physical size of about 50pc. We discuss the origin of the γ-ray emission and possible cosmic ray acceleration in the W43 region using multi-wavelength data. Our findings suggest that W43 is likely another young star cluster capable of accelerating cosmic rays (CRs) to at least several hundred TeV.

关键词：