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161.
Chyun-Chau Fuh 《Communications in Nonlinear Science & Numerical Simulation》2009,14(8):3424-3431
Chaos is undesirable in many engineering applications since it causes a serious degradation of the system performance and restricts the system’s operating range. Therefore, the problem of controlling chaos has attracted intense interest in recent years. This paper proposes an approach for optimizing the control of chaotic systems with input saturation using an input-state linearization scheme. In the proposed approach, the optimal system gains are identified using the Nelder–Mead simplex algorithm. This algorithm does not require the derivatives of the cost function (or the performance index) to be optimized, and is therefore particularly applicable to problems with undifferentiable elements or discontinuities. Two numerical simulations are performed to demonstrate the feasibility and effectiveness of the proposed method. 相似文献
162.
Titanium tetrachloride promoted Michael addition reactions of α-cyanoketene-S,S-acetals 1 with enones 2 have been developed. The polyfunctionalized 2-[1,3]dithiolan-2-ylidene-3-substituted-5-oxo-5-substituted-pentanenitriles 3 were obtained in good to high yields and the corresponding mechanism was also described. 相似文献
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KAN Wei ZHONG Hua YU Haitao FU Honggang & SUN Jiazhong . School of Chemistry Materials Science Heilongjiang University Harbin China . School of Chemistry Chemical Engineering Qiqihar University Qiqihar China . State Key Laboratory of Theoretical Computational Chemistry Institute of Theoretical Chemistry Jilin University Changchun China 《中国科学B辑(英文版)》2005,48(5):415-423
Interstellar species have been of interest to chemists because of their unusual structures and reactivities, such as CN, NP, CP, and SiN, which have been identi-fied in interstellar medium[1―4] and well characterized for the formation, structures, spectr… 相似文献
165.
从矩阵的特征问题入手,引出常系数线性齐次微分方程求解的特征方程方法;利用分离变量法求解热传导方程,引入拉普拉斯方程的特征问题,给出求解过程,并给出热方程的解的渐近稳定性. 相似文献
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The resonance effect of microcrystalline cellulose/castor oil electrorheological (ER) suspensions was studied in a compressed oscillatory squeeze flow under external electric fields. The resonance frequency first increases linearly with increasing external field, and then shift to high-field plateau. The amplitudes of resonance peak increase sharply with the applied fields in the range of 0.17-1.67 kV/mm. The phase difference of the reduced displacement relative to the excitation force inverses in the case of resonance. A viscoelasticity model of the ER suspensions, which offers both the equivalent stiffness and the viscous damping, should be responsible for the appearance of resonance. The influence of the electric field on the resonance frequency and the resonance hump is consistent qualitatively with the interpretation of our proposed model. Storage modulus G' was presented for the purpose of investigating this influence. 相似文献
170.