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101.
Liqun Zhou 《Nonlinear dynamics》2013,73(3):1895-1903
In this paper, the problem of dissipativity is investigated for cellular neural networks with proportional delays. Without assuming monotonicity, differentiability, and boundedness of activation functions, two new delay-independent criteria for checking the dissipativity of the addressed neural networks are established by using inner product properties and matrix theory. Two examples and their simulation results are given to show the effectiveness and less conservatism of the proposed criteria. 相似文献
102.
103.
Liqun Zhou 《Nonlinear dynamics》2014,77(1-2):41-47
Proportional delay, which is different from distributed delay, is a kind of unbounded delay. The proportional delay system as an important mathematical model often rises in some fields such as physics, biology systems, and control theory. In this paper, the uniqueness and the global asymptotic stability of equilibrium point of cellular neural networks with proportional delays are analyzed. By using matrix theory and constructing suitable Lyapunov functional, delay-dependent and delay-independent sufficient conditions are obtained for the global asymptotic stability of cellular neural networks with proportional delays. These results extend previous works on these issues for the delayed cellular neural networks. Two numerical examples and their simulation are given to illustrate the effectiveness of obtained results. 相似文献
104.
PingGu Wu DaJin Yang Liqun Zhang XiangHong Shen XiaoDong Pan LiYuan Wang Jing Zhang Ying Tan Liang Feng Ying Ying 《Journal of separation science》2012,35(21):2932-2939
A quantified method for the determination of 17 phthalate esters (PAEs) in edible vegetable oil by GC‐MS with the pretreatment of acetonitrile extraction and silica/N‐(n‐Propyl)ethylenediamine‐mixed SPE column was established. By the quantification of internal standard of D4‐di(2‐ethylhexyl) phthalate, a good linearity range of related 17 PAEs was observed. The correlation coefficient was ranged at 0.994~1.000, and the standard lowest quantified level was 0.05~0.15 mg/L. The spiking recoveries of 17 PAEs were 78.3~108.9% with the relative standard deviations of 4.3~12.1% (n = 6). The method detection limits were 0.1~0.2 mg/kg. Meanwhile, PAEs were determined in 30 plastic buckets of edible vegetable oil from supermarkets in Hangzhou city of China. The survey of 30 oil samples showed di(2‐ethylhexyl) phthalate (DEHP) had the 100% (30/30) detection rate. The levels of diisobutyl phthalate with 86.7% (26:30), di‐n‐butyl phthalate (DBP) with 70% (21:30) and diethyl phthalate with 10% (3:30) were detected. It was worth note that DBP with 16.7% (5:30) samples and DEHP with 10% (3:30) samples were beyond the regular migrating limit, which indicated that more attention should be paid to the PAEs in oil with plastic package. 相似文献
105.
Immanuel M. Bomze Chen Ling Liqun Qi Xinzhen Zhang 《Journal of Global Optimization》2012,52(4):663-687
A so-called Standard Bi-Quadratic Optimization Problem (StBQP) consists in minimizing a bi-quadratic form over the Cartesian
product of two simplices (so this is different from a Bi-Standard QP where a quadratic function is minimized over the same
set). An application example arises in portfolio selection. In this paper we present a bi-quartic formulation of StBQP, in
order to get rid of the sign constraints. We study the first- and second-order optimality conditions of the original StBQP
and the reformulated bi-quartic problem over the product of two Euclidean spheres. Furthermore, we discuss the one-to-one
correspondence between the global/local solutions of StBQP and the global/local solutions of the reformulation. We introduce
a continuously differentiable penalty function. Based upon this, the original problem is converted into the problem of locating
an unconstrained global minimizer of a (specially structured) polynomial of degree eight. 相似文献
106.
Xiaojiao Tong Liqun Qi Soon-Yi Wu Felix F. Wu 《Computational Optimization and Applications》2012,51(1):175-197
This paper investigates a new class of optimization problems arising from power systems, known as nonlinear programs with
stability constraints (NPSC), which is an extension of ordinary nonlinear programs. Since the stability constraint is described
generally by eigenvalues or norm of Jacobian matrices of systems, this results in the semismooth property of NPSC problems.
The optimal conditions of both NPSC and its smoothing problem are studied. A smoothing SQP algorithm is proposed for solving
such optimization problem. The global convergence of algorithm is established. A numerical example from optimal power flow
(OPF) is done. The computational results show efficiency of the new model and algorithm. 相似文献
107.
The paper presents the method of moments estimation for generalized linear measurement error models using the instrumental
variable approach. The measurement error has a parametric distribution that is not necessarily normal, while the distributions
of the unobserved covariates are nonparametric. We also propose simulation-based estimators for the situation where the closed
forms of the moments are not available. The proposed estimators are strongly consistent and asymptotically normally distributed
under some regularity conditions. Finite sample performances of the estimators are investigated through simulation studies. 相似文献
108.
Linping Zhang Xianlei Song Yanyan Song Zhanbo Sun Qian Li Xiaoping Song Liqun Wang 《Journal of Thermal Analysis and Calorimetry》2012,110(3):1153-1160
A method has been developed to estimate the Gibbs free energy $ \left( {G_{\text{S}}^{\text{NE}} } \right) $ of the non-equilibrium solid alloys with multicomponents based on differential scanning calorimetry (DSC) analysis. In this method, the DSC curves of the non-equilibrium and equilibrium alloys during heating up to fully melting and those of the alloys during solidifying were measured. Then the thermal effects of the solid phase transformations from non-equilibrium to equilibrium states and the equilibrium solidification could be calculated. By evolving the traditional equal-G curve principle to equal-G point, the Gibbs free energy of the equilibrium solid alloy with multicomponents could be obtained on condition that the free energy of the liquid alloy was known. Considering the thermal effects of the solid phase transformations from non-equilibrium to equilibrium states, the Gibbs free energy value of the non-equilibrium alloys with a given composition could be achieved although the phase constitution of the equilibrium solid alloys and the Gibbs free energy of each phase were not known, and the calculation errors could be reduced by dividing the alloys into many infinitesimal virtual pure metals. The Gibbs free energy of the non-equilibrium Al?CSi?CMn alloys was calculated by using this method, confirming the validity of this method. 相似文献
109.
Q Meng S Xiang K Zhang M Wang X Bu P Xue L Liu H Sun B Yang 《Journal of colloid and interface science》2012,384(1):22-28
We report here the fabrication of hollow silica particles with mesopores larger than 10 nm on their wall via a facile two-step etching method. Different from the conventional template method, the new method uses the silica particles as starting materials, which were synthesized using the well-known Stöber method. In the hollow silica preparation, first, we gently etch the silica particles with a NaOH solution without using template molecules to make them porous. Then, we coat the porous silica particles with poly-dimethyldiallylammonium chloride (PDDA) and treat the PDDA-coated porous silica with an ammonia solution to form the hollow silica nanospheres. In this study, we found that the NaOH dosage and ammonia concentration have significant impact on the morphology of the final products. Adsorption was also studied and results show that the hollow nanospheres can effectively uptake protein-based biomolecules (hemoglobin). 相似文献
110.
作为"大众力学丛书"的新书,刘延柱教授著述的《趣味刚体动力学》最近由高等教育出版社出版(图1)1。将刚体动力学这门历史悠久、应用广泛的力学分支学科用生动有趣、深入浅出的语言进行阐述,它的意义正如培根所说:"知识就是力量。知识的力量不仅取决于其本身价值的大小,更取决于它是否被传播以及传播的深度与广度。"... 相似文献