共查询到20条相似文献，搜索用时 31 毫秒
1.
The technique of real-time digital speckle pattern interferometry is proposed to study diffusion of surfactants in hydrogel.
The diffusion coefficient is simply and directly determined from the interferograms. An example of diffusion coefficient measurement
of surfactant in agarose gel demonstrates the usefulness of the method. The results obtained are compared with the theoretical
simulating values.
Project Supported by National Natural Science Foundation of China (No. 29904007), Zhejiang Provincial Natural Science Foundation
of China (No. 699031), and SRF for ROCS, SEM, China 相似文献
2.
In this paper, the axisymmetric general solutions of transversely isotropic magnetoelectroelastic media are expressed with
four harmonic displacement functions at first. Then, based on the solutions, the analytical three-dimensional solutions are
provided for a simply supported magnetoelectroelastic circular plate subjected to uniform loads. Finally, the example of circular
plate is presented.
Project supported by the National Natural Science Foundation of China (No. 10172075) and Ningbo Natural Science Foundation
for Young Scientist (No. 02J20102-13) 相似文献
3.
Stabilization for a class of second-order switched systems with saturation constrains 总被引：1，自引：0，他引：1
This paper proposes a global stabilization method for a class of planar switched systems with input saturation constrains
by using a state feedback and switching strategy. This method is proved to be effective by analyzing the characteristics of
the trajectory of second-order linear systems with input saturation.
Project supported by the China Postdoctoral Science Foundation (Grant No.20070420643), the National Natural Science Foundation
of China (Grant No.60774059), and the Innovation Program of the Shanghai Municipal Science and Technology Commission (Grant
No.08DZ2272400) 相似文献
4.
Nonlinear dynamics analysis of a new autonomous chaotic system 总被引：2，自引：0，他引：2
CHU Yan-dong LI Xian-feng ZHANG Jian-gang CHANG Ying-xiang 《浙江大学学报(A卷英文版)》2007,8(9):1408-1413
In this paper,a new nonlinear autonomous system introduced by Chlouverakis and Sprott is studied further,to present very rich and complex nonlinear dynamical behaviors. Some basic dynamical properties are studied either analytically or nu-merically,such as Poincaré map,Lyapunov exponents and Lyapunov dimension. Based on this flow,a new almost-Hamilton chaotic system with very high Lyapunov dimensions is constructed and investigated. Two new nonlinear autonomous systems can be changed into one another by adding or omitting some constant coefficients. 相似文献
5.
Unbalanced vibration in dual-rotor rotating machinery was studied with numerical simulations and experiments. A new method
is proposed to separate vibration signals of inner and outer rotors for a system with very little difference in rotating speeds.
Magnitudes and phase values of unbalance defects can be obtained directly by sampling the vibration signal synchronized with
reference signal. The balancing process is completed by the reciprocity influence coefficients of inner and outer rotors method.
Results showed the advantage of such method for a dual-rotor system as compared with conventional balancing.
Project supported by the National Natural Science Foundation of China (No. 59875078), and Zhejiang Provincial Natural Science
Foundation of China (No. 502092) 相似文献
6.
Based on the traditional theory of fracture, time-dependence of rock fracture is taken into account and the creep fracture
criteria are given. The effect of the microcrack zone on fracture toughness is analyzed. Finally, a model for time prediction
of rheological fracture is derived and its feasibility is proven.
Supported by the National Natural Science Foundation of China (59809005) and the Science Foundation of Shanghai Municipal
Commission of Science and Technology (96QF14009) 相似文献
7.
This paper presents a sliding mode (SM) based identifier to deal with the parameter identification problem for a class of
parameter uncertain nonlinear dynamic systems with input nonlinearity. A sliding mode controller (SMC) is used to ensure the
global reaching condition of the sliding mode for the nonlinear system; an identifier is designed to identify the uncertain
parameter of the nonlinear system. A numerical example is studied to show the feasibility of the SM controller and the asymptotical
convergence of the identifier.
Project supported by the National Natural Science Foundation of China(No. 69974035) and Zhejiang Provincial Natural Science
Key Foundation of China (ZD9905) 相似文献
8.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｉｎｅｃｏｌｏｇｙ ,ａｐｒｅｄａｔｏｒ ｐｒｅｙｉｎｔｅｒａｃｔｉｏｎｏｆｂｏｔｈｐｏｐｕ ｌａｔｉｏｎｓｉｎｏｎｅｄｉｍｅｎｓｉｏｎｉｓｄｅｓｃｒｉｂｅｄｂｙｔｈｅｆｏｌｌｏｗｉｎｇｓｙｓｔｅｍ[1] :ｕｔ(ｘ ,ｔ) =ｕｘｘ ｕＭ (ｕ ,ｖ) ,ｖｔ(ｘ ,ｔ) =βｖｘｘ ｖＮ(ｕ ,ｖ) ,(1)ｗｈｅｒｅβｉｓａｐｏｓｉｔｉｖｅｃｏｎｓｔａｎｔ,ｕａｎｄｖａｒｅｔｈｅｐｒｅｙａｎｄｐｒｅｄａｔｏｒｄｅｎｓｉｔｉｅｓｒｅｓｐｅｃｔｉｖｅｌｙ ,ａｎｄｔｈｅｆｕｎｃｔｉｏｎｓＭａｎｄＮａｒｅ… 相似文献
9.
n-soliton-like solutions of three non-isospectral equations, the non-isospectral mKdV equation, the non-isospectral sine-Gordon equation and the non-isospeetral nonlinear Schroedinger equation were obtained by using the Hirota method. 相似文献
10.
In this paper, dynamics in the oscillations of the relative atomic population in two periodically driven and weakly coupled Bose-Einstein eondensates (BECs) was qualitatively studied. Using the well-known Melnikov method, the conditions of existence of the periodic and chaotic coherent atomic tunnellings were given in the model. Our results indicate the typical route from bifurcation of the limited circles to chaos, and are in agreement with the previous numerical results. 相似文献
11.
The results of systemic behavior analysis of cantilever arched retaining structure reported in this paper have significant
value for guiding the design and application of such structure.
Project(59738160) supported by Natural Science Foundation of China(NSFC). 相似文献
12.
A new algorithm is presented that generates developable Bézier surfaces through a Bézier curve called a directrix. The algorithm
is based on differential geometry theory on necessary and sufficient conditions for a surface which is developable, and on
degree evaluation formula for parameter curves and linear independence for Bernstein basis. No nonlinear characteristic equations
have to be solved. Moreover the vertex for a cone and the edge of regression for a tangent surface can be obtained easily.
Aumann’s algorithm for developable surfaces is a special case of this paper.
Project supported by the National Basic Research Program (973) of China (No. 2004CB719400), the National Natural Science Foundation
of China (Nos. 60373033 and 60333010) and the National Natural Science Foundation for Innovative Research Groups (No. 60021201),
China 相似文献
13.
FANG You-tong YAO Ying-ying 《浙江大学学报(A卷英文版)》2007,8(3):412-415
In this paper, a modified transient finite element (FE) algorithm for the performance analysis of magnetically levitated vehicles of electromagnetic type is presented. The algorithm incorporates the external power system and vehicle’s movement equations into FE model of transient magnetic field computation directly. Sliding interface between stationary and moving region is used during the transient analysis. The periodic boundaries are implemented in an easy way to reduce the computation scale. It is proved that this method can be used for both electro-motional static and dynamic cases. The test of a transformer and an EMS-Maglev system reveals that the method generates reasonable results at very low computational costs comparing with the transient FE analysis. 相似文献
14.
A new optimization algorithm based on chaos 总被引：8，自引：0，他引：8
LU Hui-juan ZHANG Huo-ming MA Long-hua 《浙江大学学报(A卷英文版)》2006,7(4):539-542
INTRODUCTION Chaos (Wang et al., 2002) is a common nonlin- ear phenomenon, whose action is complex and similar to that of randomness. The characteristics of chaos being highly sensitive to the initial value of chaos make a world of differences due to the ergodic prop- erty of the phase space—chaos can go through all states in certain ranges without repetition; the inher- ent randomness of the system—means that chaos behavior is similar to randomness which is disorderly; but at the same t… 相似文献
15.
Based on variable structure control (VSC) and fuzzy local controller network (FLCN), a new design method of robust gain-scheduling
control is proposed in this paper. The proper sliding-modes and the tendency-rates for general operation-points are introduced
such that the system gets into the sliding-modes’ motion as soon as possible and has the desired performance. Its good performance
is due to the robustness of VSC. However, any local controller works well only in the local region of a specified operation-point.
In this paper functions similar to the fuzzy-attributed function in fuzzy-systems are introduced to form FLCN. The simulation
results showed that the presented method is feasible and acceptable.
Project supported by the Natural Science Foundation of China (NSFC: 69934030) and the Zhejiang Provincial Natural Science
Foundation of China (ZJPNSFC: ZD9905). 相似文献
16.
Youliang Cheng Ph. D. 《上海大学学报(英文版)》1997,1(2):130-134
By using perturbation methods, the evolution equation is derived for the second-order internal solitary waves in stratified
fluids of great depth, which is a kind of inhomogeneous linearized Benjamin-Ono equation.
Project supported by the National Natural Science Foundation of China.(19672035) 相似文献
17.
本文从完善同行评议．改善嘎目经费预算、改进科学基金丹络信息系统等方面,对国家自然科学基金管理特别是数学研究申请和经费支出提出了改进建议。 相似文献
18.
关于混沌洛伦兹系统和陈系统中的广义投影同步 总被引：1，自引：1，他引：1
1 Introduction Since Pecora and Carroll[1]showed that it is possibleto synchronize two identical chaotic systems , chaossynchronization has been intensively and extensivelystudied due to its potential applications in secure com-munication,ecological systems ,systemidentification,etc.(see [2] and a huge volume of references citedtherein) . Among all kinds of chaos synchronizations ,projec-tive synchronization is one of the most noticeableones .This kind of synchronization was first observedin … 相似文献
19.
INTRODUCTION Image fusion can be defined as the process by which several images, or some of their features, are combined together to form different modalities or instruments, and is of great importance in many ap- plications (Hall and Llinas, 1997; Zhou et al., 1998), such as object detection, ATR (Automatic Target Recognition), remote sensing, computer vision, and robotics. Recently some researchers recognized that it seems more meaningful to combine objects/regions rather than pixels… 相似文献
20.
For the non-conservative holonomic Hamiltonian systems in phase space, the definition and criteria of the form invariance of the generalized Hamilton canonical equations were given. The relations among the form invariance, Noether symmetry and Lie symmetry were studied. The theory of the form invariance for the conservative holonomical systems was worked out. An example was given to illustrate the results. 相似文献