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1.
This paper is dedicated to studying the following Schrödinger–Poisson system Δ u + V ( x ) u K ( x ) ϕ | u | 3 u = a ( x ) f ( u ) , x 3 , Δ ϕ = K ( x ) | u | 5 , x 3 . Under some different assumptions on functions V(x), K(x), a(x) and f(u), by using the variational approach, we establish the existence of positive ground state solutions.  相似文献   
2.
In this paper, we review some results over the last 10-15 years on elliptic and parabolic equations with discontinuous coefficients. We begin with an approach given by N. V. Krylov to parabolic equations in the whole space with $\rm{VMO}_x$ coefficients. We then discuss some subsequent development including elliptic and parabolic equations with coefficients which are allowed to be merely measurable in one or two space directions, weighted $L_p$estimates with Muckenhoupt ($A_p$) weights, non-local elliptic and parabolic equations, as well as fully nonlinear elliptic and parabolic equations.  相似文献   
3.
In this paper we consider an initial boundary value problem for a reaction-diffusion equation under nonlinear and nonlocal Robin type boundary condition. Assuming the existence of an ordered pair of upper and lower solutions we establish a generalized quasilinearization method for the problem under consideration whose characteristic feature consists in the construction of monotone sequences converging to the unique solution within the interval of upper and lower solutions, and whose convergence rate is quadratic. Thus this method provides an efficient iteration technique that produces not only improved approximations due to the monotonicity of its iterates, but yields also a measure of the convergence rate.  相似文献   
4.
本文对三层BP神经网络中带有惩罚项的在线梯度学习算法的收敛性问题进行了研究,在网络训练每一轮开始执行之前,对训练样本随机进行重排,以使网络学习更容易跳出局部极小,文中给出了误差函数的单调性定理以及该算法的弱收敛和强收敛性定理。  相似文献   
5.
In this paper, we are concerned with a class of nonlinear second-order differential equations with a nonlinear damping term. Passage to more general class of equations allows us to remove a restrictive condition usually imposed on the nonlinearity, and, as a consequence, our results apply to wider classes of nonlinear differential equations. Two illustrative examples are considered.  相似文献   
6.
本文得到了极大算子的几个不等式,并从这些结果推广了函数f∈L_(loc)~1(R,dx)属于VMO(R,dx)的一个必要条件。  相似文献   
7.
High-resolution Fourier transform spectra of CH3OH have been investigated in the infrared region from 930 to 1450 cm−1 in order to map the torsion-rotation energy manifolds associated with the ν7 in-plane CH3 rock, the ν11 out-of-plane CH3 rock, and the ν6 OH bend. Upper-state term values have been determined from the assigned spectral subbands, and have been fitted to power-series expansions to obtain substate origins and effective B-values for the three modes. The substate origins have been grouped into related families according to systematic trends observed in the torsion-vibration energy map, but there are substantial differences from the traditional torsional patterns. There appears to be significant torsion-mediated spectral mixing, and a variety of “forbidden” torsional combination subbands with |Δυt|>1 have been observed, where υt denotes the torsional quantum number (equivalent to υ12). For example, coupling of the (υ6,υt)=(1,0) OH bend to nearby torsionally excited (υ7,υt)=(1,1) CH3-rock and (υ8,υt)=(1,1) CO-stretch states introduces (υ6,υt)=(1,0)←(0,1) subbands into the spectrum and makes the ν7+ν12ν12 torsional hot band stronger than the ν7 fundamental. The results suggest a picture of strong coupling among the OH-bending, CH3-rocking, and CO-stretching modes that significantly modifies the traditional energy structure and raises interesting and provocative questions about the torsion-vibration identity of a number of the observed states.  相似文献   
8.
尹福其  李永昆  刘萍 《数学研究》2003,36(4):394-400
研究如下的具强迫项的高阶非线性时滞差分方程△^my(n) u(n)l↑∑i=1 gi(y(n-τ))=v(n)其中,m≥1,u,v:N→R,gi:R→R且τ∈{0,1,2,3,…),i=1,2,…,l,得到了使该方程的解具有某种渐近性态的充分条件。  相似文献   
9.
ASYMPTOTIC BEHAVIOR OF THE DRIFT-DIFFUSION SEMICONDUCTOR EQUATIONS   总被引:4,自引:1,他引:3  
This paper is devoted to the long time behavior for the Drift-diffusion semi-conductor equations. It is proved that the dynamical system has a compact, connected and maximal attractor when the mobilities are constants and generation-recombination term is the Auger model; as well as the semigroup S(t) defined by the solutions map is differential. Moreover the upper bound of Hausdorff dimension for the attractor is given.  相似文献   
10.
AClassofCauchyProblemforQuasilinearHyperbolicSystemswiththeWeaklyDissipativeTerms¥LiuFagui;YangQiao(NorthChinaInstituteofWate...  相似文献   
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