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周期压力驱动下管壁局部不规则的圆管Poiseuille流感受性问题
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作者 王志亮 周哲玮 《应用数学和力学》 EI CSCD 北大核心 2004年第11期1101-1112,共12页
 采用渐近分析方法,建立了在周期压力驱动下,完全发展的圆管Poiseuille流当管壁存在局部不规则几何形状时的感受性问题模型· 通过特征函数的双正交系统,应用Chebyshev配点法进行数值求解· 通过算例计算,获得周期压力和矩...  采用渐近分析方法,建立了在周期压力驱动下,完全发展的圆管Poiseuille流当管壁存在局部不规则几何形状时的感受性问题模型· 通过特征函数的双正交系统,应用Chebyshev配点法进行数值求解· 通过算例计算,获得周期压力和矩形突起激发起的流体系统中的各种空间发展模态以及相应的感受性系数· 从计算和分析可以知道,在流场的不同发展阶段不同的模态起着主导作用。 展开更多
关键词 POISEUILLE流 双正交系统 特征函数 感受性
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Green Function and Perturbation Method for Dissipative Systems Based on Biorthogonal Basis
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作者 ZHANG Li GAO Yi-Bo WANG Cheng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第6期1017-1022,共6页
Based on the approach of biorthogonal basis, we carry out the quasinormal modes (QNMs) expansions for a class of open systems described by the wave equation with outgoing wave boundary conditions. For such a non-Her... Based on the approach of biorthogonal basis, we carry out the quasinormal modes (QNMs) expansions for a class of open systems described by the wave equation with outgoing wave boundary conditions. For such a non-Hermitian system, the eigenfunction perturbation expansions and Green function method, which are based on the orthogonal eigenvectors of the Hermitian Hamiltonian for the dosed quantum system, can be generalized in terms of the biorthogonal basis, the two sets of eigenfunctions of H and its adjointness H . The time-independent perturbation theory for the complex frequencies can be also developed. 展开更多
关键词 biorthogonal basis open system quasinormal mode
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Model Order Reduction Methods for Discrete Systems via Discrete Pulse Orthogonal Functions
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作者 XIE Zhen TANG Shengguo WANG Zhaohong 《新疆大学学报(自然科学版中英文)》 CAS 2024年第6期641-650,共10页
This paper explores model order reduction(MOR)methods for discrete linear and discrete bilinear systems via discrete pulse orthogonal functions(DPOFs).Firstly,the discrete linear systems and the discrete bilinear syst... This paper explores model order reduction(MOR)methods for discrete linear and discrete bilinear systems via discrete pulse orthogonal functions(DPOFs).Firstly,the discrete linear systems and the discrete bilinear systems are expanded in the space spanned by DPOFs,and two recurrence formulas for the expansion coefficients of the system’s state variables are obtained.Then,a modified Arnoldi process is applied to both recurrence formulas to construct the orthogonal projection matrices,by which the reduced-order systems are obtained.Theoretical analysis shows that the output variables of the reducedorder systems can match a certain number of the expansion coefficients of the original system’s output variables.Finally,two numerical examples illustrate the feasibility and effectiveness of the proposed methods. 展开更多
关键词 model order reduction discrete linear systems discrete bilinear systems discrete pulse orthogonal functions
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The separable Hamiltonian system and complete biorthogonal expansion method of Mindlin plate bending problems 被引量:5
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作者 HOU GuoLin QI GaoWa +1 位作者 XU YaNan CHEN Alatancang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第5期974-980,共7页
A separable Hamiltonian system of Mindlin plate bending problems is obtained. Using the equivalence between the differen form and integral form of the separable Hamiltonian system, the biorthogonal relationships of th... A separable Hamiltonian system of Mindlin plate bending problems is obtained. Using the equivalence between the differen form and integral form of the separable Hamiltonian system, the biorthogonal relationships of the eigenfunctions are presen! Based on the biorthogonal relationships, a novel complete biorthogonal expansion of the Mindlin plate bending problems x~ two opposite sides simply supported is proposed through the products of operator matrices. The exact solutions to deflections bending moments for the Mindlin plate with fully simply supported sides are obtained. A numerical example is illustrated to ve~ the accuracy and validity of the expansion method. 展开更多
关键词 separable Hamiltonian system mindlin plate bending biorthogonal expansion off-diagonal Hamiltonian operator
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A full-duplex optical access system with hybrid 64/16/4QAM-OFDM downlink 被引量:2
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作者 贺超 谭泽富 +5 位作者 邵宇丰 蔡黎 蒲鹤升 朱云乐 黄思斯 刘毓 《Optoelectronics Letters》 EI 2016年第5期361-365,共5页
A full-duplex optical passive access scheme is proposed and verified by simulation, in which hybrid 64/16/4-quadrature amplitude modulation(64/16/4QAM) orthogonal frequency division multiplexing(OFDM) optical signal i... A full-duplex optical passive access scheme is proposed and verified by simulation, in which hybrid 64/16/4-quadrature amplitude modulation(64/16/4QAM) orthogonal frequency division multiplexing(OFDM) optical signal is for downstream transmission and non-return-to-zero(NRZ) optical signal is for upstream transmission. In view of the transmitting and receiving process for downlink optical signal, in-phase/quadrature-phase(I/Q) modulation based on Mach-Zehnder modulator(MZM) and homodyne coherent detection technology are employed, respectively. The simulation results show that the bit error ratio(BER) less than hardware decision forward error correction(HD-FEC) threshold is successfully obtained over transmission path with 20-km-long standard single mode fiber(SSMF) for hybrid downlink modulation OFDM optical signal. In addition, by dividing the system bandwidth into several subchannels consisting of some continuous subcarriers, it is convenient for users to select different channels depending on requirements of communication. 展开更多
关键词 downlink duplex multiplexing quadrature transmitting modulator bandwidth correction transmitter hardware
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