具多滞量和正负系数中立型微分方程解的渐近性质

该文考虑多滞量和正负系数中立型方程[x(t)-sum from n=1 to l(1/n)C_A(t)x(t-r_n)] sum from i=1 to (1/i)P_i(t)x()t-τ_i)-sum from j=1 to n(1/j)Q_j(t)x(t-σ_j)=0,其中C_A(k=1,…,l),P_i(i=1,…,m),Q_j(j=1…,n)∈C([to,∞co),R~ ),0≤τ_l<…<τ_m,0≤σ_1<…<σ_n,0相似文献   

Asymptotic Behavior of Oscillatory Solutions of Forced Nonlinear Neutral Delay Differential Equations

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A NECESSARY AND SUFFICIENT CONDITION FOR THE OSCILLATION OF HIGHER-ORDER NEUTRAL EQUATIONS WITH SEVERAL DELAYS

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二阶非线性中立型时滞微分方程的振动性

考虑二阶非线性中立型时滞微分方程(x(t)-p(t)x(t-τ))″+∑ from i=1 to n (qi(t)fi(x(t-σi)))=0,t0,其中p,q_i∈C(R+,R+),τ,σ_i∈(0,∞),f_i∈C(R,R),i=1,2,…,n,分别得到了方程所有解振动和方程存在非振动解的充分条件,推广和改进了相关文献中的相关结果.     

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Periodicity in a Nonlinear Predator-prey System with State Dependent Delays

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多滞量非自治中立型泛函微分方程的(3)/(2)-渐近稳定性

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用系数有界限的广义多项式的L逼近

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SOLUTIONS TO A SECOND-ORDER MULTI-POINT BOUNDARY VALUE PROBLEM AT RESONANCE

This article deals with the following second-order multi-point boundary value problem x′′(t) = f(t,x(t),x′(t))+e(t),t ∈(0,1),x′(0)=(α_ix′(ξ_i) from i=1 to m,x(1)=(β_jx(ηj) from j=1 to n .Under the resonance conditions α_i from i=1 to m =1,β_j from j=1 to n=1,β_jηj from j=1 to n =1,by applying the coincidence degree theory,some existence results of the problem are established.The emphasis here is that the dimension of the linear operator is two.In this paper,we extend and improve some previously known results like the ones in the references.     

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一类高阶整函数系数微分方程解的增长级、下级与超级

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设P, Q为Hilbert空间H上的幂等算子, 关于算子$P$的广义幂等算子类ω(P)定义为ω(P)={A∈B}(H): A²=αA+βP, AP=PA=A,P²=P,∨α, β∈C}. 对任意A ∈ω(P), B∈ω(Q)使得A²=αA +βP, B²=mB+nQ,βn≠ 0, 得到了如下的结论: 值域R(PQ)是闭的充要条件是值域R(AB)是闭的; 如果P-Q是可逆的, 则A-B是可逆的.     

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A Functional Equation Of J.A. Baker Involving Integral Means

The functional equation $$f(x)={1\over 2}\int^{x+1}_{x-1}f(t)\ dt\ \ \ {\rm for}\ \ \ x\ \in\ {\rm R}$$ has the linear functions ?(x) = a + bx (a, b ∈ ?) as trivial solutions. It is shown that there are two kinds of nontrivial solutions, (i) ?(x) = eλ_i ^x (i = 1, 2, …), where the λ_i∈ ? are the fixed points of the map z ? sinh z, and (ii) C^∞-solutions ? for which the values in the interval [?1,1] can be prescribed arbitrarily, but with the provision that ?^(j)(? 1) = ?^(j)(0) = ?^(j)(1) = 0 for all j = 0, 1, 2 …     

关于一类微分方程周期解的存在性的注记

本文主要探讨下列周期系数微分方程dy/dt=(A₁(t)y+A₂(t)y²+A₃(t)y³)/(a₀(t)+a₁(t)y+a₂(t)y²)(**)的周期解个数问题，利用方程（**）解的差率法得到了方程（**）周期解的个数定理．本文仅在Ａ_i（ｔ），ａ_j（ｔ）（ｉ＝１，２，３，ｊ＝０，１，２）是连续周期函数的条件下得到这一结论，从而减弱了文［２］中相应定理的条件，即Ａ_i（ｔ），ａ_j（ｔ）均是连续可微的周期函数．     

Commutators of BMO functions and degenerate Schr?dinger operators with certain nonnegative potentials

Let Lf(x)=-\frac1w?_i,j ?_i(a_i,j(·)?_jf)(x)+V(x)f(x){\mathcal{L}f(x)=-\frac{1}{\omega}\sum_{i,j} \partial_i(a_{i,j}(\cdot)\partial_jf)(x)+V(x)f(x)} with the non-negative potential V belonging to reverse H?lder class with respect to the measure ω(x)dx, where ω(x) satisfies the A ₂ condition of Muckenhoupt and a _i,j (x) is a real symmetric matrix satisfying l^-1w(x)|x|² ￡ ?ⁿ_i,j=1a_i,j(x)x_ix_j ￡ lw(x)|x|².{\lambda^{-1}\omega(x)|\xi|^2\le \sum^n_{i,j=1}a_{i,j}(x)\xi_i\xi_j\le\lambda\omega(x)|\xi|^2. } We obtain some estimates for V^aL^-a{V^{\alpha}\mathcal{L}^{-\alpha}} on the weighted L ^p spaces and we study the weighted L ^p boundedness of the commutator [b, V^a L^-a]{[b, V^{\alpha} \mathcal{L}^{-\alpha}]} when b ? BMO_w{b\in BMO_\omega} and 0 < α ≤ 1.     

一个非线性色散波方程的惟一连续性

该文证明:和如下耦合色散系统相联系的初值问题的充分光滑的解$(u,v)=(u(x,t),v(x,t))$, 如果在两个时刻有半线支集那么它们全为零. {∂ _tu+∂³_x u+∂ _x(u^p v^p+1)=0, ∂ _tv+∂³_x v+∂_x(u^p+1v^p)=0,x∈R,t≥ 0     

无限簇非扩张非自映象公共不动点的黏性逼近法

设E是具有一致Gateaux可微范数的严格凸的自反的Banach空间,K是E的非空闭凸子集而且是E的sunny非扩张收缩核.设f:K→K是一压缩映象,P:E→K是一sunny非扩张保核收缩,{T_n}_n~∞1:K→E是一可数无限簇非扩张非自映象且■是[0,1]中的非负数列.考虑下列迭代序列■其中W_n是由P,T_n,T_(n-1),…,T_1和λ_n,λ_(n-1),…,λ_1,■n≥1生成的W-映象.该文在较弱条件下用黏性逼近方法证明了迭代序列{x_n}强收敛于p∈F且p是下列变分不等式〈(I-f)p,j(p-x~*)〉≤0,■x~*∈F的唯一解.