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On the Cauchy Problem for Certain System of Semilinear Parabolic Equations 被引量:6
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作者 Jian Huaiyu Chen Donggui Department of Applied Mathematics, Tsinghua University, Beijing 100084, China Yueying Teacher’s College, Hunan 414000, China 《Acta Mathematica Sinica,English Series》 SCIE CSCD 1998年第1期27-34,共8页
In this paper, we use the abstract theory of semilinear parabolic equations and a priori estimate techniques to prove the global existence and uniqueness of smooth solutions to the Cauchy problem for the following sys... In this paper, we use the abstract theory of semilinear parabolic equations and a priori estimate techniques to prove the global existence and uniqueness of smooth solutions to the Cauchy problem for the following system of parabolic equations. ψ<sub>t</sub>=-(σ-α)ψ-σθ<sub>x</sub>-αψ<sub>xx</sub> θ<sub>t</sub>=-(1-β)θ-vψ<sub>x</sub>(ψθ)-βθ<sub>xx</sub> 展开更多
关键词 System of parabolic equations NONLINEAR Global existence sectorial operator A priori estimate Fundamental solution
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Uniform dimension results for Gaussian random fields 被引量:6
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作者 WU DongSheng XIAO YiMin 《Science China Mathematics》 SCIE 2009年第7期1478-1496,共19页
Let X = {X(t), t ∈ ? N } be a Gaussian random field with values in ? d defined by (1) $$ X(t) = (X_1 (t),...,X_d (t)),\forall t \in \mathbb{R}^N . $$ . The properties of space and time anisotropy of X and their conne... Let X = {X(t), t ∈ ? N } be a Gaussian random field with values in ? d defined by (1) $$ X(t) = (X_1 (t),...,X_d (t)),\forall t \in \mathbb{R}^N . $$ . The properties of space and time anisotropy of X and their connections to uniform Hausdorff dimension results are discussed. It is shown that in general the uniform Hausdorff dimension result does not hold for the image sets of a space-anisotropic Gaussian random field X.When X is an (N, d)-Gaussian random field as in (1), where X 1,...,X d are independent copies of a real valued, centered Gaussian random field X 0 which is anisotropic in the time variable. We establish uniform Hausdorff dimension results for the image sets of X. These results extend the corresponding results on one-dimensional Brownian motion, fractional Brownian motion and the Brownian sheet. 展开更多
关键词 anisotropic Gaussian random fields sectorial local nondeterminism IMAGE Hausdorff dimension 60G15 60G17 60G60 42B10 43A46 28A80
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Dimension of Maximal Attractors for the m-dimensional Cahn Hilliard System 被引量:2
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作者 Wei Nian ZHANG(Weinian Zhang) 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2005年第6期1487-1494,共8页
On the basis of the existence of the maximal attractor of the m-dimensional Cahn-Hilliard system in the product spaces (L2(Ω))^m and (H2(Ω))^m, in this paper, its Hausdorff dimension is estimated by calculat... On the basis of the existence of the maximal attractor of the m-dimensional Cahn-Hilliard system in the product spaces (L2(Ω))^m and (H2(Ω))^m, in this paper, its Hausdorff dimension is estimated by calculating the orthogonal projection of the linear variational operator of the system. 展开更多
关键词 Cahn-Hilliard System sectorial operator Maximal attractor Hausdorff dimension
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ALMOST AUTOMORPHIC MILD SOLUTIONS TO SOME FRACTIONAL DELAY DIFFERENTIAL EQUATIONS 被引量:2
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作者 Xiliang Li 1,Fenglong Qu 2,Yuliang Han 1(1.College of Math.and Information Sciences,Shandong Institute of Business and Technology,Yantai 264005,Shandong 2.School of Math.and Informational Science,Yantai University,Yantai 264005,Shandong) 《Annals of Differential Equations》 2012年第4期412-416,共5页
In this paper,a new and general existence and uniqueness theorem of almost automorphic mild solutions is obtained for some fractional delay differential equations,using sectorial operators and the Banach contraction p... In this paper,a new and general existence and uniqueness theorem of almost automorphic mild solutions is obtained for some fractional delay differential equations,using sectorial operators and the Banach contraction principle. 展开更多
关键词 sectorial operator almost automorphy fractional delay differential equation
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Development of Measurement System for Flow and Shape Using Array Ultrasonic Sensors 被引量:2
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作者 Munkhbat Batsaikhan Zeliang Zhang +1 位作者 Hideharu Takahashi Hiroshige Kikura 《Journal of Flow Control, Measurement & Visualization》 2021年第3期45-72,共28页
In Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, the fuel debris formed in the Reactor Pressure Vessel (RPV) and Primary Containment Vessel (PCV) at Unit 1</span><span style="font-family:Verdan... In Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, the fuel debris formed in the Reactor Pressure Vessel (RPV) and Primary Containment Vessel (PCV) at Unit 1</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">3. To accelerate and decide further decommissioning steps of the FDNPP, it is crucial to obtain realistic information of the debris and localize contaminated water leakage from PCV. Due to high radiation and dark environment inside the PCV, investigating instruments and techniques should necessarily to meet specification of radiation resistance, waterproofness, dust resistance and so on. This study focuses on development of ultrasonic measurement system using a couple of sectorial array sensors to localize contaminated water leakage and visualize shape of object that repre</span><span style="font-family:Verdana;">- </span><span style="font-family:Verdana;">senting fuel debris, simultaneously. In this study, Total Focusing Method</span><span style="font-family:Verdana;"> (TFM) and Ultrasonic Velocity Profiler (UVP) methods are considered to visualize object shape and flow pattern around it, respectively. To demonstrate applicability and reliability of developed measurement system with sectorial array sensors, a mock-up experiment result</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">of simulated water leakage and fuel debris shape were discussed in this paper. 展开更多
关键词 Reactor Decommissioning sectorial Array Sensors Total Focusing Method (TFM) ULTRASOUND Ultrasonic Velocity Profiler (UVP) Vector Flow Mapping
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Visualisation of air–water bubbly column flow using array Ultrasonic Velocity Profiler 被引量:2
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作者 Munkhbat Batsaikhan Ari Hamdani Hiroshige Kikura 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2017年第6期379-385,共7页
In the present work, an experimental study of bubbly two-phase flow in a rectangular bubble column was performed using two ultrasonic array sensors, which can measure the instantaneous velocity of gas bubbles on multi... In the present work, an experimental study of bubbly two-phase flow in a rectangular bubble column was performed using two ultrasonic array sensors, which can measure the instantaneous velocity of gas bubbles on multiple measurement lines. After the sound pressure distribution of sensors had been evaluated with a needle hydrophone technique, the array sensors were applied to two-phase bubble col- umn, To assess the accuracy of the measurement system with array sensors for one and two-dimensional velocity, a simultaneous measurement was performed with an optical measurement technique called particle image velocimetry (PIV). Experimental results showed that accuracy of the measurement system with array sensors is under 10% for one-dimensional velocity profile measurement compared with PIV technique. The accuracy of the system was estimated to be under 20% along the mean flow direction in the case of two-dimensional vector mapping. 展开更多
关键词 Two-phase bubbly flow Bubble column Ultrasonic Velocity Profiler (UVP) sectorial array sensor
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General Stiffness Matrix for a Thin-Walled, Open-Section Beam Structure 被引量:1
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作者 Abdelraouf M. Sami Alsheikh D. W. A. Rees 《World Journal of Mechanics》 2021年第11期205-236,共32页
This paper is to review the theory of thin-walled beam structures of the open cross-section. There is scant information on the performance of structures made from thin-walled beam elements, particularly those of open ... This paper is to review the theory of thin-walled beam structures of the open cross-section. There is scant information on the performance of structures made from thin-walled beam elements, particularly those of open sections, where the behavior is considerably complicated by the coupling of tensile, bending and torsional loading modes. In the combined loading theory of thin-walled structures, it is useful to mention that for a thin-walled beam, the value of direct stress at a point on the cross-section depends on its position, the geometrical properties of the cross-section and the applied loading. This applies whether the thin-walled section is closed or open but this study will be directed primarily at the latter. Theoretical analyses of structures are fairly well established, considered in multi-various applications by many scientists. However, due to the present interest in lightweight structures, it is necessary to specify where the present theory lies. It does not, for example, deal with compression and the consequent failure modes under global and local buckling. Indeed, with the inclusion of strut buckling failure and any other unforeseen collapse modes, the need was perceived for further research into the subject. Presently, a survey of the published works has shown in the following: 1) The assumptions used in deriving the underlying theory of thin-walled beams are not clearly stated or easily understood;2) The transformations of a load system from arbitrary axis to those at the relevant centre of rotation are incomplete. Thus, an incorrect stress distribution may result in;3) Several methods are found in the recent literature for analyzing the behaviour of thin-walled open section beams under combined loading. These reveal the need appears for further study upon their torsion/flexural behaviour when referred to any arbitrary axis, a common case found in practice. This review covers the following areas: 1) Refinement to existing theory to clarify those observations made in 1 - 3 above;2) Derivation of a 展开更多
关键词 Thin-Walled Open Sections Shear Centre WARPING Bi-Moment sectorial Area Properties
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AREA INTEGRAL FUNCTIONS FOR SECTORIAL OPERATORS ON L^p SPACES 被引量:1
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作者 陈泽乾 孙牧 《Acta Mathematica Scientia》 SCIE CSCD 2014年第3期739-747,共9页
Area integral functions are introduced for sectorial operators on L^p-spaces. We establish the equivalence between the square and area integral functions for sectorial operators on L^p spaces. This follows that the re... Area integral functions are introduced for sectorial operators on L^p-spaces. We establish the equivalence between the square and area integral functions for sectorial operators on L^p spaces. This follows that the results of Cowling, Doust, McIntosh, Yagi, and Le Merdy on H^∞ functional calculus of seetorial operators on LP-spaces hold true when the square functions are replaced by the area integral functions. 展开更多
关键词 sectorial operator H^∞ Functional calculus area integral function square function L^p space
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On the Strongly Damped Wave Equations with Critical Nonlinearities
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作者 Qinghua Zhang 《Journal of Applied Mathematics and Physics》 2016年第4期697-705,共9页
We study the strongly damped wave equations with critical nonlinearities. By choosing suitable state spaces, we prove sectorial property of the operator matrix  together with its adjoint operator, investigate the... We study the strongly damped wave equations with critical nonlinearities. By choosing suitable state spaces, we prove sectorial property of the operator matrix  together with its adjoint operator, investigate the associated interpolation and extrapolation spaces, analysis the criticality of the nonlinearity with critical growth, and study the higher spatial regularity of the Y-regular solution by bootstrapping. 展开更多
关键词 Negative Laplacian Wave Equation Strong Damping sectorial Operator Fractional Power Global Attractor
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Feature Extraction of Sectorial Scan Image of Thick-Walled Electron Beam Welding Seam Based on Principal Component Analysis
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作者 Tie Gang Yilin Luan Chi Zhang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2017年第6期45-51,共7页
A feature extraction method was proposed to sectorial scan image of Ti-6Al-4V electron beam welding seam based on principal component analysis to solve problem of high-dimensional data resulting in timeconsuming in de... A feature extraction method was proposed to sectorial scan image of Ti-6Al-4V electron beam welding seam based on principal component analysis to solve problem of high-dimensional data resulting in timeconsuming in defect recognition. Seven features were extracted from the image and represented 87. 3% information of the original data. Both the extracted features and the original data were used to train support vector machine model to assess the feature extraction performance in two aspects: recognition accuracy and training time. The results show that using the extracted features the recognition accuracy of pore,crack,lack of fusion and lack of penetration are 93%,90.7%,94.7% and 89.3%,respectively,which is slightly higher than those using the original data. The training time of the models using the extracted features is extremely reduced comparing with those using the original data. 展开更多
关键词 electron beam welding phased array ultrasonic sectorial scan image feature extraction principal component analysis
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Transformation Matrix for Combined Loads Applied to Thin-Walled Structures
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作者 Abdelraouf M. Sami Alsheikh David William Alan Rees 《World Journal of Mechanics》 2022年第6期65-78,共14页
This paper transforms combined loads, applied at an arbitrary point of a thin-walled open section beam, to the shear centre of the cross-section of the beam. Therein, a generalized transformation matrix for loads with... This paper transforms combined loads, applied at an arbitrary point of a thin-walled open section beam, to the shear centre of the cross-section of the beam. Therein, a generalized transformation matrix for loads with respect to the shear centre is derived, this accounting for the bimoments that develop due to the way the combined loads are applied. This and the authors’ earlier paper (World Journal of Mechanics 2021, 11, 205-236) provide a full solution to the theory of thin-walled, open-section structures bearing combined loading. The earlier work identified arbitrary loading with the section’s area properties that are necessary to axial and shear stress calculations within the structure’s thin walls. In the previous paper attention is paid to the relevant axes of loading and to the transformations of loading required between axes for stress calculations arising from tension/compression, bending, torsion and shear. The derivation of the general transformation matrix applies to all types of loadings including, axial tensile and compression forces, transverse shear, longitudinal bending. One application, representing all these load cases, is given of a simple channel cantilever with an eccentrically located end load. 展开更多
关键词 Thin-Walled Structure Open Sections Transformation Matrix Load Transformation Combined Load Transformation Shear Centre WARPING BIMOMENT sectorial Area Properties
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SECTORIAL OSCILLATION THEORY OF LINEAR DIFFERENTIAL EQUATIONS
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作者 吴昭君 陈裕先 《Acta Mathematica Scientia》 SCIE CSCD 2013年第4期1177-1186,共10页
In this paper, the sectorial oscillation of the solutions of higher order homo- geneous linear differential equationswith infinite order entire function coefficients is studied. Results are obtained to extend some res... In this paper, the sectorial oscillation of the solutions of higher order homo- geneous linear differential equationswith infinite order entire function coefficients is studied. Results are obtained to extend some results in [19] and [18]. 展开更多
关键词 radial exponent of convergence iterated order sectorial oscillation Boreldirection
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AREA INTEGRAL FUNCTIONS AND H∞ FUNCTIONAL CALCULUS FOR SECTORIAL OPERATORS ON HILBERT SPACES
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作者 陈泽乾 孙牧 《Acta Mathematica Scientia》 SCIE CSCD 2013年第4期989-997,共9页
Area integral functions are introduced for sectorial operators on Hilbert spaces. We establish the equivalence relationship between the square and area integral functions. This immediately extends McIntosh/Yagi's res... Area integral functions are introduced for sectorial operators on Hilbert spaces. We establish the equivalence relationship between the square and area integral functions. This immediately extends McIntosh/Yagi's results on H∞ functional calculus of sectorial operators on Hilbert spaces to the case when the square functions are replaced by the area integral functions. 展开更多
关键词 sectorial operator H∞ functional calculus area integral function squarefunction Hilbert space
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Free Vibration Analysis of Sectorial Plates Using the Triangular Differential Quadrature Method
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作者 李欣 钟宏志 何玉红 《Tsinghua Science and Technology》 SCIE EI CAS 2004年第6期717-725,共9页
The triangular differential quadrature method was used to analyze the free vibrations of moderately thick sectorial plates. A triangular serendipity transformation was introduced to map the sectorial domain onto a uni... The triangular differential quadrature method was used to analyze the free vibrations of moderately thick sectorial plates. A triangular serendipity transformation was introduced to map the sectorial domain onto a unit isosceles right triangle. The first six non-dimensional frequencies of the sectorial plates were obtained for various combinations of clamped and simply supported boundary conditions. For sectorial plates with simply supported radial edges, the present results agree well with the available exact solutions and finite element solutions, demonstrating the effectiveness of the method. 展开更多
关键词 free vibration Mindlin plate sectorial plate triangular differential quadrature
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Gradient Observability for Semilinear Hyperbolic Systems: Sectorial Approach
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作者 Adil Khazari Ali Boutoulout 《Intelligent Control and Automation》 2014年第3期170-181,共12页
The aim of this work is to study the notion of the gradient observability on a subregion?ω of the evolution domain?Ω for a class of semilinear hyperbolic systems. We show, under some hypothesis, that the gradient re... The aim of this work is to study the notion of the gradient observability on a subregion?ω of the evolution domain?Ω for a class of semilinear hyperbolic systems. We show, under some hypothesis, that the gradient reconstruction is achieved following sectorial approach combined with fixed point techniques. The obtained results lead to an algorithm which can be implemented numerically. 展开更多
关键词 Distributed SYSTEMS HYPERBOLIC SYSTEMS GRADIENT Reconstruction Regional OBSERVABILITY Fixed Point sectorial OPERATOR
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Sectorial Approach of the Gradient Observability of the Hyperbolic Semilinear Systems Intern and Boundary Cases
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作者 Adil Khazari Ali Boutoulout 《Applied Mathematics》 2016年第12期1326-1339,共14页
The aim of this paper is to study the notion of the gradient observability on a subregion w of the evolution domain W and also we consider the case where the subregion of interest is a boundary part of the system evol... The aim of this paper is to study the notion of the gradient observability on a subregion w of the evolution domain W and also we consider the case where the subregion of interest is a boundary part of the system evolution domain for the class of semilinear hyperbolic systems. We show, under some hypotheses, that the flux reconstruction is guaranteed by means of the sectorial approach combined with fixed point techniques. This leads to several interesting results which are performed through numerical examples and simulations. 展开更多
关键词 Distributed Systems Semilinear Hyperbolic Systems Boundary Reconstruction Regional Boundary Gradient Observability Regional Gradient Observability Gradient Observability Fixed Point sectorial Operator
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Numerical study of hydraulic fracturing in the sectorial well-factory considering well interference and stress shadowing 被引量:1
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作者 Yu-Hao Liu Jin-Tao Zhang +2 位作者 Jie Bai Feng-Shou Zhang Ji-Zhou Tang 《Petroleum Science》 SCIE EI CAS CSCD 2023年第6期3567-3581,共15页
In the Changqing Oilfield in northwest China, when traditional petroleum exploitation encounters forestry reserves or water source protection areas, sectorial well-factory design is proposed. The most distinct feature... In the Changqing Oilfield in northwest China, when traditional petroleum exploitation encounters forestry reserves or water source protection areas, sectorial well-factory design is proposed. The most distinct feature of a sectorial well-factory is the deviation of the well from the minimum horizontal principal stress, resulting in hydraulic fracture deflection after the initiation, along with possible well interference (i.e., fracture hit) and fracture coalescence in the oblique wells. Four indexes describing well deflection are then proposed according to fracture morphology. Several fracturing designs, including stage arrangement, fracturing sequences, and fracturing techniques are applied to study the feasibility of the sectorial well-factory design. The results show that the “gradual” or “sparse” stage arrangement, large injection rate, and simultaneous multifracture treatment can help to optimize the fracture morphology and stimulation design. However, the subsequent stress shadowing effect usually adversely affects the fracturing of adjacent wells. With a small initial horizontal stress difference, large injection rate and staggered stage arrangement can achieve ideal stimulation performance. Our results can provide a guidance for optimizing stimulation design in unconventional well-factory while taking into account environmental protection. 展开更多
关键词 Hydraulic fracturing sectorial well-factory Fracture deflection Well interference Stress shadowing
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Existence of p-mean Almost Periodic Mild Solution for Fractional Stochastic Neutral Functional Differential Equation 被引量:1
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作者 Xiao-ke SUN Ping HE 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2021年第3期645-656,共12页
A class of fractional stochastic neutral functional differential equation is analyzed in this paper.With the utilization of the fractional calculations,semigroup theory,fixed point technique and stochastic analysis th... A class of fractional stochastic neutral functional differential equation is analyzed in this paper.With the utilization of the fractional calculations,semigroup theory,fixed point technique and stochastic analysis theory,a sufficient condition of the existence for p-mean almost periodic solution is obtained,which are supported by two examples. 展开更多
关键词 p-mean almost periodic solution fractional stochastic neutral functional differential equation fixed point theorem sectorial operator analytic semigroup
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Experimental Studies on Heat Transfer in the Tip Gap of a Sectorial Turbine Cascade
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作者 Li,Jie Yao,Yongqing 《Journal of Thermal Science》 SCIE EI CAS CSCD 1996年第1期16-18,共3页
Experiment using naphthalene sublimation mass transfer simulating heat transfer on the blade tip of a sectorial turbine cascade with tip clearance was performed.The effect of tip clearance,inlet Reynolds number and bl... Experiment using naphthalene sublimation mass transfer simulating heat transfer on the blade tip of a sectorial turbine cascade with tip clearance was performed.The effect of tip clearance,inlet Reynolds number and blade incidence on heat transfer has been studied. 展开更多
关键词 heat transfer sectorial cascade tip clearance.
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Free vibration of piezoelectric annular plate
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作者 王云 徐荣桥 丁皓江 《Journal of Zhejiang University Science》 EI CSCD 2003年第4期379-387,共9页
General solutions for coupled three dimensional equations of piezoelectric media were used in this work to obtain some analytical solutions for free vibration of piezoelectric annular plates. These solutions not only... General solutions for coupled three dimensional equations of piezoelectric media were used in this work to obtain some analytical solutions for free vibration of piezoelectric annular plates. These solutions not only satisfy the governing equations at every point in the concerned region but also satisfy the prescribed boundary conditions at every point on the boundaries. Therefore, they are three-dimensional exact. Numerical results are finally tabulated. 展开更多
关键词 Piezoelectric media sectorial annular plate Free vibration
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