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 共查询到20条相似文献，搜索用时 15 毫秒
1.
This paper is devoted to the study of the period function for a class of reversible quadratic system
$ \begin{gathered} \dot x = - 2xy, \hfill \\ \dot y = k - 1 - 2kx + \left( {k + 1} \right)x^2 - \tfrac{1} {2}y^2 . \hfill \\ \end{gathered} $ \begin{gathered} \dot x = - 2xy, \hfill \\ \dot y = k - 1 - 2kx + \left( {k + 1} \right)x^2 - \tfrac{1} {2}y^2 . \hfill \\ \end{gathered}   相似文献   

2.
In this paper we solve the equations
  相似文献   

3.
ＦＩＮＩＴＥＤＩＦＦＥＲＥＮＣＥＳＣＨＥＭＥＳＯＦＴＨＥＮＯＮＬＩＮＥＡＲＰＳＥＵＤＯ－ＰＡＲＡＢＯＬＩＣＳＹＳＴＥＭＤＵＭＩＮＧＳＨＥＮＧ（杜明笙）（ＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉｅｄＰｈｙｓｉｃｓａｎｄＣｏｍｐｕｔａｔｉｏｎａｌＭａｔｈｅｍａｔ...  相似文献   

4.
An algorithm for constructing the operator OMn({kx}; x, y) with the properties
n, \hfill \\ \frac{{\partial ^n O_{Mn} (\{ \varphi _{ks} \} ;x,y)}}{{\partial v_a^p }}|_{\Gamma _a } = \varphi _{ap} (x,y)|_{\Gamma _Q '} q = \overline {1, M} ; p = \overline {0, n,} \hfill \\ \end{gathered} $$ " align="middle" vspace="20%" border="0">  相似文献   

5.
The modified Bernstein-Durrmeyer operators discussed in this paper are given byM_nf≡M_n(f,x)=(n+2)P_(n,k)∫_0~1p_n+1.k(t)f(t)dt,whereWe will show,for 0<α<1 and 1≤p≤∞  相似文献   

6.
The combinatorial identity
is established with the help of the differentiation of the convolution of some function with the sine function. Bibliography: 5 titles. __________ Translated from Problemy Matematicheskogo Analiza, No. 36, 2007, pp. 65–67.  相似文献   

7.
We study nonnegative solutions of the initial value problem for a weakly coupled system
  相似文献   

8.
We consider the three dimensional Cauchy problem for the Laplace equation uxx(x,y,z)+ uyy(x,y,z)+ uzz(x,y,z) = 0, x ∈ R,y ∈ R,0 z ≤ 1, u(x,y,0) = g(x,y), x ∈ R,y ∈ R, uz(x,y,0) = 0, x ∈ R,y ∈ R, where the data is given at z = 0 and a solution is sought in the region x,y ∈ R,0 z 1. The problem is ill-posed, the solution (if it exists) doesn't depend continuously on the initial data. Using Galerkin method and Meyer wavelets, we get the uniform stable wavelet approximate solution. Furthermore, we shall give a recipe for choosing the coarse level resolution.  相似文献   

9.
Extensions of some inequalities   总被引：2，自引：0，他引：2  
Abstract. By using a simple analytic method the following inequalities are proved:  相似文献   

10.
具有脉冲的二阶三点边值问题存在性定理   总被引：2，自引：0，他引：2  
In this paper, two existence theorems are given concerning the following 3-point boundary value problem of second order differential systems with impulses  相似文献   

11.
We consider the system
$\begin{gathered} x_{k + 1} = A_k x_k + b_k u_k , \hfill \\ u_{k + 1} = m_k^* x_k ,k = 1,2,..., \hfill \\ \end{gathered} $\begin{gathered} x_{k + 1} = A_k x_k + b_k u_k , \hfill \\ u_{k + 1} = m_k^* x_k ,k = 1,2,..., \hfill \\ \end{gathered}   相似文献   

12.
We construct new families of symmetric (v, k, )-designs with parameters
  相似文献   

13.
This paper deals with the periodic boundary value problem for nonlinear impulsive functional differential equation
$ \left\{ \begin{gathered} x'(t) = f(t,x(t),x(\alpha _1 (t)),...,x(\alpha _n (t)))fora.e.t \in [0,T], \hfill \\ \Delta x(t_k ) = I_k (x(t_k )),k = 1,...,m, \hfill \\ x(0) = x(T). \hfill \\ \end{gathered} \right. $ \left\{ \begin{gathered} x'(t) = f(t,x(t),x(\alpha _1 (t)),...,x(\alpha _n (t)))fora.e.t \in [0,T], \hfill \\ \Delta x(t_k ) = I_k (x(t_k )),k = 1,...,m, \hfill \\ x(0) = x(T). \hfill \\ \end{gathered} \right.   相似文献   

14.
A semilinear parabolic system in a bounded domain   总被引：1，自引：0，他引：1  
Consider the system
0, x \in \Omega \} , \hfill \\ v_t - \Delta v = u^q , in Q , \hfill \\ u(0, x) = u_0 (x) v(0, x) = v_0 (x) in \Omega , \hfill \\ u(t, x) = v(t, x) = 0 , when t \geqslant 0, x \in \partial \Omega , \hfill \\ \end{gathered} \right.$$ " align="middle" vspace="20%" border="0">  相似文献   

15.
The existence of at least one solution of the following multi-point boundary value problem
$ \left\{ \begin{gathered} [\varphi (x'(t))]' = f(t,x(t),x'(t)),t \in (0,1), \hfill \\ x(0) - \sum\limits_{i = 1}^m {\alpha _i x'(\xi _i ) = 0,} \hfill \\ x'(1) - \sum\limits_{i = 1}^m {\beta _i x(\xi _i ) = 0} \hfill \\ \end{gathered} \right. $ \left\{ \begin{gathered} [\varphi (x'(t))]' = f(t,x(t),x'(t)),t \in (0,1), \hfill \\ x(0) - \sum\limits_{i = 1}^m {\alpha _i x'(\xi _i ) = 0,} \hfill \\ x'(1) - \sum\limits_{i = 1}^m {\beta _i x(\xi _i ) = 0} \hfill \\ \end{gathered} \right.   相似文献   

16.
Global convergence result for conjugate gradient methods   总被引：2，自引：0，他引：2  
Conjugate gradient optimization algorithms depend on the search directions,
  相似文献   

17.
The purpose of this paper is to study the existence of periodic solutions for the non-autonomous second order Hamiltonian system
$ \left\{ \begin{gathered} \ddot u(t) = \nabla F(t,u(t)),a.e.t \in [0,T], \hfill \\ u(0) - u(T) = \dot u(0) - \dot u(T) = 0 \hfill \\ \end{gathered} \right. $ \left\{ \begin{gathered} \ddot u(t) = \nabla F(t,u(t)),a.e.t \in [0,T], \hfill \\ u(0) - u(T) = \dot u(0) - \dot u(T) = 0 \hfill \\ \end{gathered} \right.   相似文献   

18.
Continuous dependence for integrodifferential equation with infinite delay $$\begin{gathered} \dot x = h(t,x) + \int_{ \sim \infty }^t {q(t,s,x(s))ds} + F(t,x(t),Sx(t))t \geqslant 0 \hfill \\ x(t) = \Phi (t) \hfill \\ \end{gathered} $$ where \(Sx(t) = \int_{ \sim \infty }^t {k(t,s,x(s))} ds\) is studied under the assumption of existence of unique solution.  相似文献   

19.
In this paper, we analyse qualitatively a cubic Kolmogorov system: which is one of the mathematical models in ecology describing the interaction between Predator-Prey of two populations; and give the conditions of nonexistence, existence and uniqueness of limit cycles for three different cases.Fulfilled during engagement in advanced studies at the Institute of Mathematics, Academia Sinica.  相似文献   

20.
Conditions for the oscillation of all solutions and for the existence of nonoscillatory solutions with polynomial growth at infinity are given for the system of differential-functional equations of neutral type
  相似文献   

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