共查询到20条相似文献,搜索用时 15 毫秒
1.
建立了一般增长区域上的反应扩散模型,并给出了定义在一种特殊的一维增长区域上的Lengyel-Epstein系统发生Truing不稳定的条件,结论表明如果区域增长速度的散度为零,那么这种变化对系统的稳定性没有影响. 相似文献
2.
We investigate the ground state of a uniaxial ferromagnetic plate with perpendicular easy axis and subject to an applied magnetic
field normal to the plate. Our interest is in the asymptotic behavior of the energy in macroscopically large samples near
the saturation field. We establish the scaling of the critical value of the applied field strength below saturation at which
the ground state changes from the uniform to a multidomain magnetization pattern and the leading order scaling behavior of
the minimal energy. Furthermore, we derive a reduced sharp interface energy, giving the precise asymptotic behavior of the
minimal energy in macroscopically large plates under a physically reasonable assumption of small deviations of the magnetization
from the easy axis away from domain walls. On the basis of the reduced energy and by a formal asymptotic analysis near the
transition, we derive the precise asymptotic values of the critical field strength at which non-trivial minimizers (either
local or global) emerge. The non-trivial minimal energy scaling is achieved by magnetization patterns consisting of long slender
needle-like domains of magnetization opposing the applied field. 相似文献
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气流雾化问题中的流动稳定性研究 总被引:6,自引:2,他引:4
运用流动稳定性理论研究气流雾化的机理问题并与有关实验进行比较,证明了界面波失稳引起的不稳定波增长是喷射雾化中液滴形成的主要原因.另外本文还研究了液滴粒径随各参数的变化规律,理论和实验的结果在一定程度上是符合的,因而它将对喷射成形工艺的研究起到一定的指导作用. 相似文献
6.
The Riesz–Sobolev inequality provides a sharp upper bound for a trilinear expression involving convolution of indicator functions of sets. Equality is known to hold only for indicator functions of appropriately situated intervals. We characterize ordered triples of subsets of R~1 that nearly realize equality, with quantitative bounds of power law form with the optimal exponent. 相似文献
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《应用数学年刊》2021,(3)
The Camassa–Holm–Kadomtsev–Petviashvili-I equation(CH-KP-I)is a two dimensional generalization of the Camassa–Holm equation(CH). In this paper, we prove transverse instability of the line solitary waves under periodic transverse perturbations. The proof is based on the framework of [18]. Due to the high nonlinearity, our proof requires necessary modification. Specifically, we first establish the linear instability of the line solitary waves. Then through an approximation procedure, we prove that the linear effect actually dominates the nonlinear behavior. 相似文献
10.
We show that spikes are unstable in a class of scalar reaction–diffusion equations coupled to a general conservation law. Our class includes the Keller–Segel model for chemotaxis, phase-field models and models for chemical reactions in closed chemical reactors. 相似文献
11.
We show that spikes are unstable in a class of scalar reaction–diffusion equations coupled to a general conservation law.
Our class includes the Keller–Segel model for chemotaxis, phase-field models and models for chemical reactions in closed chemical
reactors. 相似文献
12.
M. Shermatov P. M. Pakhomov V. E. Korsukov V. S. Kuksenko 《Mechanics of Composite Materials》1976,12(3):468-472
Large-angle x-ray diffraction and infrared spectroscopy have been used to investigate the behavior of the crystalline zones in oriented polymers under load. It is shown that under the influence of a load applied along the axis of orientation the crystallites are partially destroyed, the more so the greater the applied stress. For different polymers the destruction of the crystallites is the greater the weaker the intermolecular bonds. The stability of the crystallites is improved by orientation.A. F. Ioffe Physicotechnical Institute, Academy of Sciences of the USSR, Leningrad. Translated from Mekhanika Polimerov, No. 3, pp. 516–520, May–June, 1976. 相似文献
13.
《Journal of Applied Mathematics and Mechanics》2002,66(2):323-325
The concept of Krasovskii stability is introduced. The criterion of Krasovskii instability for time-dependent linearizations is obtained. This criterion is compared with Chetayev's theorem. 相似文献
14.
The problem of thermal instability in a fluid saturated porous spherical shell heated internally, due to uniform internal
heat sources and in equilibrium under its own radial gravitational field is studied theoretically. A general disturbance is
analysed into modes in terms of spherical harmonics of various orders,l, for different values of the thickness of the mantle and the criteria for the onset of convection for the first fifteen modes
is obtained in four different cases when the outer and inner bounding surfaces are either impermeable or permeable. It is
shown that as the thickness of the shell decreases, the pattern of convection which sets in at marginal stability shifts progressively
to harmonics of higher order for all the three cases except when both the bounding surfaces are permeable, in which case the
onset of convection occurs at a harmonic of order 1. A comparison of some representative results of these cases is made with
that of continuous fluid shell with rigid or free boundary surfaces. The neutral stability plots for various thickness of
the mantle, for five different models of the mantle, are plotted for the different types of boundary surfaces. 相似文献
15.
Matthew Andrews 《Journal of Algorithms in Cognition, Informatics and Logic》2004,50(2):232-245
We show that the First-In-First-Out (FIFO) scheduling discipline can be unstable in the (σ,ρ)-regulated session model for packet-switched networks. In this model packets are injected into the network in fixed sessions. The total size of the session-i packets injected during the time interval [x,y) is at most σi+ρi(y−x) for some burst parameter σi and rate ρi. The sum of the rates of sessions passing through a server is at most the server speed.Previous work on FIFO stability either allowed for dynamically changing session paths or else assumed that session-i packets are injected at a constant rate. Our result shows that FIFO can be unstable for static paths as long as the injections into a session can be temporarily suspended. 相似文献
16.
Josef Malik 《Applications of Mathematics》2005,50(6):503-525
In this paper the stability of two basic types of cable stayed bridges, suspended by one or two rows of cables, is studied.
Two linearized models of the center span describing the vertical and torsional oscillations are investigated. After the analysis
of these models, a stability criterion is formulated. The criterion expresses a relation between the eigenvalues of the vertical
and torsional oscillations of the center span. The continuous dependence of the eigenvalues on some data is studied and a
stability problem for the center span is formulated. The existence of a solution to the stability problem is proved. Some
other qualitative results concerning the stability/instability of oscillations are studied as well.
This work was supported by Grant ASCR K1019101. 相似文献
17.
Achill Schürmann 《Periodica Mathematica Hungarica》2006,53(1-2):257-264
Summary Let <InlineEquation ID=IE"1"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"2"><EquationSource Format="TEX"><![CDATA[<InlineEquation
ID=IE"3"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"4"><EquationSource Format="TEX"><![CDATA[<InlineEquation
ID=IE"5"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"6"><EquationSource Format="TEX"><![CDATA[<InlineEquation
ID=IE"7"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"8"><EquationSource Format="TEX"><![CDATA[<InlineEquation
ID=IE"9"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"10"><EquationSource Format="TEX"><![CDATA[<InlineEquation
ID=IE"11"><EquationSource Format="TEX"><![CDATA[$]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>X$
be a discrete subset of Euclidean $d$-space. We allow
subsequently continuous movements of single elements, whenever the minimum
distance to other elements does not decrease. We discuss the question, if it is
possible to move all elements of $X$ in this way, for example after removing a
finite subset $Y$ from $X$. Although it is not possible in general, we show the
existence of such finite subsets $Y$ for many discrete sets $X$, including all
lattices. We define the \textit{instability degree} of $X$ as the minimum
cardinality of such a subset $Y$ and show that the maximum instability degree
among lattices is attained by perfect lattices. Moreover, we discuss the
$3$-dimensional case in detail. 相似文献
18.
We investigate the onset of chaotic resonance (CR) behavior by studying the dynamics of chaotically driven bistable systems near the crisis bifurcation point. Our analysis reveals the existence and identification of a characteristic natural frequency associated with the dynamics of the system confirming that classical resonance is responsible for CR. We also classify the different routes via which CR can originate. The ability to manipulate the route to CR can be of importance in developing technological applications. 相似文献
19.
Masaaki Sugihara. 《Mathematics of Computation》2003,72(242):767-786
Near optimality of the sinc approximation is established in a variety of spaces of functions analytic in a strip region about the real axis, each space being characterized by the decay rate of their elements (functions) in the neighborhood of the infinity.
20.
In this paper we describe the instability of certain capacities in the Orlicz spaces. Our results generalize some of those obtained by Fernström in [6] and the Theorem 9 of Hedberg in [7] in the case of Lebesgue spaces. 相似文献