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1.
In this part, the nonlinear wave speed formulas are discussed. Because the nonlinear wave speed formulas are relative to wave form, we introduce a non-dimensional quantity M, which describes the nonlinear wave pattern and qualitatively determines the nonlinear degree. It is called M criterion. The wave speed formulas of the nonlinear Rossby wave and the nonlinear inertial gravity wave are also discussed. The wave speed of the former decreases with the growth of the amplitude but that of the latter is on the opposite. Furthermore we have also discussed the problems which must be taken note of in applying the Taylor expansion as we solve the approximate solution of nonlinear waves.  相似文献   

2.
In this paper we discuss the problem of a nonlinear gravity inertial wave of twodimensions and the possibility of solitary wave's existence. First of all, the existingcondition and analytic solution expression of shallow water waves are obtained by theapplication of the qualitative method of O. D. Es. We find that when the problem is de-generated, some physical values produce the nonlinear solitary wave, while other physi-cal values will be unbounded, so we consider that the nonlinear solitary wave for thesystem does not exist. Then we introduce concepts of the generalized energy (i. e. pseu-do-energy): when the pseudo-energy produces the tiny change at acting on a special ex-ternal effect, there will be solitary waves in this system. Finally, we obtain the repre-sentative of the nonlinear solitary wave which is different from KdV equation.  相似文献   

3.
This paper deals with the nonlinear problems of the two-layer shallow water wave modelin the atmosphere by the multiple scale method and points out that a nonlinear Benjamin-Ono equation may be obtained if the meridional disturbance wind is weak. Furthermore, thealgebraic solitary waves and nonlinear periodic waves are also calculated and the breakup ofan algebraic solitary wave at the initial time into two is discussed. It is found that the waveform steepens in this process, which is similar to the triggering process of squall lines inthe atmosphere. On the other hand, we also point out that when the meridional disturbancewind is strong, we may obtain a modified Benjamin-Ono equation, i. e. the Benjamin-Ono-KDV equation.  相似文献   

4.
In this paper, two level quasi-geostrophic model is used to set up a simple nonlinear inter-action model including a near resonant forced wave component, a near baroclinically un-stable free wave and a zonal flow component. The dynamic mechanisms of the transition ofhigh and low index and index cycle are discussed. In the first part, the weak nonlinear problem with near baroclinic instability and nearresonant forcing are analysed. The simple periodic solution resulting from bifurcation ofHadley cell to Rossby transient wave and the more complicated solutions resulting from thebifurcation of the wave equilibria to mixed state with both forced stationary wave and tran-sient wave are discussed.  相似文献   

5.
In this paper, a baroclinic stable system with periodic forcing is used to discuss the dynamics of wave amplitude near the resonant forcing instability.In the first part, the linear resonant condition and weakly nonlinear resonant problem are analysed and two distinct periodic solutions with larger and smaller amplitudes are solved respectively for system without dissipation. When external forcing varies between the existence domains for these two kinds of periodic solution, nonperiodic oscillation appears, i.e. the so-called "chaos" phenomenon.  相似文献   

6.
In this paper, beginning with the shallow-water equations describing the geophysical fluid motion and by a method expanding the nonlinear terms in Taylor series near the equilibrium point, we find the analytic solutions of the finite amplitude nonlinear inertio-surface gravity waves and Rossby waves. We point out that (ⅰ) the finite amplitude nonlinear inertio-surface gravity waves and Rossby waves Satisfy all the KdV equations; (ⅱ) the solutions are all the enoidal functions, i. e. the enoidal waves which include the linear waves and form the solitary waves under certain conditions; (ⅲ) the dispersive relation including both the wave number and the amplitude is established; (ⅳ) the rotating transform method is given, and the two-dimensional nonlinear problem can be reduced to the one-dimensional one.  相似文献   

7.
In this paper, the existence of nonlinear non-dispersive wave solutions to the barotropic primitive equations is confirmed by using numerical experiments. The general characters of this family of waves are also investigated.  相似文献   

8.
By using the multiple-scale perturbation method a set of equations which describes two interacting nonlinear Rossby waves in the barotropic atmosphere is derived. The equations are used to study the collision of two envelope solitary Rossby waves. It is found that for a range of parameters, the collision interactions are envelope soliton-like in that the properties of the two envelope solitary waves change very little. For other parameters, new "inelastic" effects are observed, including speed changes, fission of envelope solitary waves and energy dispersion. It is also found that despite of the complexity of the interacting process, the energy of each wave is conserved.  相似文献   

9.
In this paper the KdV equation is derived from the three dimensional primitive equations for a class of finite amplitude waves in a stratified basic flow. The solitary wave solution is given for a simple case where a constant and uniformly stratified basic flow is confined in a region bounded by solid walls with rectangular cross section. The properties of the solitary wave solution can give a possible explanation for the preferential occurrence of a squall line or storm cell train at the left side of a low level jet and the concurrent fluctuation in the low level jet. For more general cases, i. e. sheared basic flow and nonuniform stratification, the qualitative response of the wave amplitude to the symmetric baroclinic stability of the basic flow is analysed. The results indicate that the vertical circulation in a solitary wave will possibly be dramatically intensified in a local area where the stability is weak or negative.  相似文献   

10.
In this paper, starting with the equations describing the atmospheric motion and by arelatively simple method, we find that, nearby the mechanical equilibrium point, all thefinite amplitude nonlinear inertia waves, internal gravity waves and Rossby waves in thedispersive atmosphere satisfy the KdV (Korteweg-de Vries) equation, its solution being thecnoidal waves and solitary waves. For the finite amplitude Rossby waves, we find the newdispersive relation which is different from the Rossby formula and contains the amplitudeparameter. It is shown that the larger the amplitude and width, the faster are the wavesfor the finite amplitude inertia waves and internal gravity waves, and the slower are thewaves for the Rossby solitary waves, to which perhaps the polar vortex and the blocking orcut-off systems belong. This treatise gives the nonlinear waves a new way and inspires usto study the nonlinear adjustment process and evolution process and the turbulence structure.  相似文献   

11.
In this paper, a new theory of blocking formation was proposed. The nonlinear Schrdinger equation satisfied by nonlear barotropic Rossby waves for the weak shear zonal flow was obtained by using the WKB method. It was pointed out that when the Rossby wavenumbers sarisfied the relation: k/3相似文献   

12.
In this paper, beginning with two-level quasi-geostrophie equations describing the baroclinic Rossby waves and using the bifurcation theory, a simple model of the stability for the baroclinic Rossby waves is set up. We find the linear and nonlinear control parameters and modify some classical conclusions of the stabilities.  相似文献   

13.
In this second part, the so-called "discontinuous vibration analysing" method is used to discuss the qualitative features of the solutions in the system set up in Part I. The system and the phase space are divided into two subsystems and two subspaces, which are corresponding to the slow and fast varying processes respectively. The qualitative vector field and trajectories for solutions are analysed and the mechanisms for the transition and nonuniform oscillation of high and low indexes are discussed.  相似文献   

14.
In this paper, a two--layer model with dispersive and dissipative effects but without Co-?iolis effect is investigated. It is proved that in the model, under certain parameter condi-tions, there exists monotone travelling wave as well as oscillation travelling wave in additionto the nonlinear periodic solution and solitary wave. The conditions for their existence areprovided. It is particularly pointed out that the pattern of the oscillation travelling wave issimilar to that of the pressure upwelling wave of a squall line which passes certain region.  相似文献   

15.
This paper presents chiefly a classification of the loess pores in the Loess Platcau according to their origin and size and deals with the characteristics of different sorts of pores and their distributional regularities in regions and loess layers of various ages. The relationship between various pores and collapsibility is also discussed in the paper. We come tto a conclusion that the supporting openings are one of the important factors causing the subsidence on wetting because of their looseness and unstability.  相似文献   

16.
In this paper, a new theoretical model of nonlinear wave propagations in arteries with surrounding tissues was put forward. The equations of motion for the blood vessels and their peripheral tissues as a system have been derived. These equations were expressed in terms of the stresses of the vessel wall and fluid, and the geometry of the blood vessel. They can be used to solve numerically the problems for the propagations of nonlinear pulse waves in arteries together with the momentum and continuity equations of incompressible-viscous flow, as well as the constitutive equations of fluid and vessel wall. The numerical solutions can involve pressure, velocities and flowrate of the blood flow, as well as displacements, velocities and stresses of the vessel wall. These physical variables of propagations of pulse waves in arteries are all of significance physiologically and clinically.  相似文献   

17.
郑建斌  张宏芳  高鸿 《中国化学》2005,23(8):1042-1046
The electrochemical behavior of chrysin in pH 2.0-9.0 Britton-Robinson (B-R) buffer solutions was studied by the means of linear sweep voltammetry and cyclic voltammetry at a static mercury drop electrode. In different pH range of B-R buffer solutions, chrysin could cause four reduction waves. In pH 2.0-5.8 B-R buffer solutions, wave P1 yielded by chrysin is a one-electron reduction wave, and wave P1 caused by further reduction of the products of wave P1 in pH〈3.0 B-R buffer solution is also a one-electron reduction wave. But in 3.0〈pH〈5.8 B-R buffer solution wave P1 was overlapped by the hydrogen wave. Between pH 5.8 and 9.0, chrysin could yield two reduction waves P2 and P3- The former is an irreversible adsorptive wave of ionized chrysin involving one electron and the latter is also an irreversible adsorptive wave of reduction intermediate radical of chrysin involving one electron and one proton. And a linear relationship between ip3 and the concentration of chrysin can be established from 1.0×10^-6 to 4.0×10^-5 mol·L^-1 (r=0.9924) with the detection limit of 5×10^-7 mol·L^-1. In addition, the antioxidant ability of chrysin was investigated by linear sweep voltammetry (LSV). The determination result of IC50 of chrysin showed that chrysin is a good antioxidant.  相似文献   

18.
This paper proposes a concept of "rhythmicity of heavy minerals", and points out that it is reflected by the percentage content of heavy fraction, stable mineral content and stability coefficient of heavy components. The three types of rhythmic curves exhibit synchronous or antisynchronous variation. Besides, the implications and constraints of the key horizon of "heavy minerals" are discussed. The approach to the paleoclimatic changes by using the "maturity of heavy mineral" and the "stability coefficient of heavy mineral" is also expounded.  相似文献   

19.
In this paper, the electronic spectra of hypocrellin A and B (HA and HB) are studied in detail. It has been proved that their three visible absorption bands come respectively from the ππ transition of their conjugated systems and intramolecular proton transfer. In dilute solutions, their fluorescence spectra consist of the fluorescence peak of the neutral monomolecule and that of the zwitter-ions that are formed through proton transfer of excited states. In concentrated solution, the longer wavelength emission band is composed of the overlapped fluorescence peaks of zwitter-ions and excimers. The fluorescence spectra of the crystalline hypocrellin A and B consist of the fluorescence peaks of zwitter-ions and excimers and the fluorescence of neutral monomolecules could not be observed. Their relative intensities are closely related to the excitation wavelength.  相似文献   

20.
The influence of basic horizontal current on the propagation of internal wave in the non-homogeneous ocean is studied in this paper. By means of pseudo-static hypothesis, the basic equation on propagation of internal wave in the non-homogeneous ocean is derived. By using geometric optics approximation the eikonal equation and transport equation are obtained, at the same time in a sort of fluid field, i. e. M= M(y)i+t-M(x)j, the extended Snell law and analytical solution of the rays are also obtained. The present work is an extension to the ray theory of internal wave in the static ocean.  相似文献   

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