THEORETICAL RESULTS ON THE EXISTENCE,REGULARITY AND ASYMPTOTIC STABILITY OF ENHANCED PULLBACK ATTRACTORS:APPLICATIONS TO 3D PRIMITIVE EQUATIONS

Several new concepts of enhanced pullback attractors for nonautonomous dynamical systems are introduced here by uniformly enhancing the compactness and attraction of the usual pullback attractors over an infinite forward time-interval under strong and weak topologies.Then we provide some theoretical results for the existence,regularity and asymptotic stability of these enhanced pullback attractors under general theoretical frameworks which can be applied to a large class of PDEs.The existence of these enhanced attractors is harder to obtain than the backward case[33],since it is difficult to uniformly control the long-time pullback behavior of the systems over the forward time-interval.As applications of our theoretical results,we consider the famous 3D primitive equations modelling the large-scale ocean and atmosphere dynamics,and prove the existence,regularity and asymptotic stability of the enhanced pullback attractors in V×V and H^(2)×H^(2) for the time-dependent forces which satisfy some weak conditions.

共享缓存分组交换系统中的最佳阈值Pushout策略

提出了一种用于共享缓存分组交换设备的最佳阈值Pushout的缓存管理策略(OTP)。在这个策略中,缓存区采用共享的方式,而每个输出端口分组调度采用Pushout策略。OTP策略的主要思想是将输出端口按照其队列长度分为活跃和非活跃端口,根据队列长度与端口的活跃程度决定分组的接纳或丢弃。仿真结果表明,OTP策略在多个输出队列的情况下具有较好的公平性和鲁棒性,同时在丢包率方面,OTP策略的分组丢失率接近于SP(Selection Pushout)策略。

奇异扰动的分数阶随机反应扩散方程的吸引子

研究了定义在光滑有界域O■R^(n)上、带乘性噪声和奇异扰动的分数阶随机反应扩散方程在L^(2)(O)上的随机拉回吸引子的存在性。由于奇异扰动和分数阶算子对系统的作用,无法用正则估计得到系统的紧性问题,因此利用Aubin紧性定理获得了由方程生成的随机动力系统的渐近紧性。

模糊集范畴中的拉回

运用模糊理论的方法和原理,首先给出了模糊集范畴Set(L)的定义,并证明了范畴Set(L)中存在拉回.其次研究了范畴Set(L)双拉回的性质和单态射的性质.最后对于三类特殊的拉回进行了探讨.

带时滞的发展方程时间依赖拉回吸引子的存在性

考虑一类带时滞的非自治二阶发展方程.首先,利用Faedo-Galerkin逼近法得到其在C_(H_(t))上解的存在性和唯一性;其次,借助算子分解验证过程{U(t,τ)}t≥τ在C_(H_(t))上的D_(C_(H_(t)))-拉回渐近紧性,从而证明带时滞的发展方程时间依赖拉回吸引子的存在性.

具有非局部结构阻尼的非自治梁方程的时间依赖拉回吸引子

利用时间依赖空间上的过程理论,研究具有非局部结构阻尼的非自治梁方程解的长时间动力学行为.首先,用Faedo-Galerkin逼近方法得到解的适定性;其次,利用能量估计得到该动力系统在相应解空间中拉回吸收集的存在性;最后,用共圈技术和收缩函数的方法证明时间依赖拉回吸引子的存在性.

近距离采空区下综放工作面安全高效回撤工艺研究

综放工作面由于设备多、设备型号大,末采期间工作面顶板管理较综采工作面复杂,对于采空区下综放工作面,在回撤期间对顶板要求更高,国内外没有可以借鉴的经验。内蒙古福城矿业有限公司1502N为近距离采空区下放顶煤工作面,通过对工作面停采位置、层位、工作面顶板支护方案等方面进行全面论证,保证工作面末采及回撤期间的顶板安全。

模糊集范畴L-F中的拉回

文章研究了模糊集范畴L-F中拉回的问题.首先,给出了范畴L-F中拉回的定义,在已知函子F保持态射上单满结构的情况下,讨论了范畴L-F中拉回的存在性;其次,引入了切片范畴的定义,在已知范畴L-F存在拉回的情况下,证明了范畴L-F的切片范畴L-F/(P,Q,LP)存在拉回;最后,引入了一般范畴存在特殊拉回的例子,在已知范畴L-F存在特殊拉回的情况下,探讨了特殊拉回与单态射之间的关系.

非自治时滞抛物方程的pullback吸引子

研究一类具有平移指数增长函数的非自治时滞抛物型偏微分方程,证明了由方程解生成的非自治无穷维动力系统在L2(Ω)×C([-r,0];L2(Ω))空间中存在pullback吸引子。

PULLBACK ATTRACTORS FOR THE NON-AUTONOMOUS BENJAMIN-BONA-MAHONY EQUATIONS IN H^2

In this paper, we prove the existence of the pullback attractor for the nonautonomous Benjamin-Bona-Mahony equations in H2 by establishing the pullback uniformly asymptotical compactness.

Pullback的Nielsen数乘积公式

作者推广了自己以前的工作,在此基础上改进了P.

EQUI-ATTRACTION AND BACKWARD COMPACTNESS OF PULLBACK ATTRACTORS FOR POINT-DISSIPATIVE GINZBURG-LANDAU EQUATIONS

A new concept of an equi-attractor is introduced, and defined by the minimal compact set that attracts bounded sets uniformly in the past, for a non-autonomous dynam- ical system. It is shown that the compact equi-attraction implies the backward compactness of a pullback attractor. Also, an eventually equi-continuous and strongly bounded process has an equi-attractor if and only if it is strongly point dissipative and strongly asymptotically compact. Those results primely strengthen the known existence result of a backward bounded pullback attractor in the literature. Finally, the theoretical criteria are applied to prove the existence of both equi-attractor and backward compact attractor for a Ginzburg-Landau equation with some varying coefficients and a backward tempered external force.

The Global and Pullback Attractors for a Strongly Damped Wave Equation with Delays

In this paper, we study the global and pullback attractors for a strongly damped wave equation with delays when the force term belongs to different space. The results following from the solution generate a compact set.

Pullback Attractors for Semi-uniformly Dissipative Dynamical Systems

The existence of pullback attractors for semi-uniformly dissipative dynamical systems under some asymptotic compactness assumptions is considered.A sufficient condition for the existence of pullback attractors is presented.Then,the results are applied to non-autonomous 2D Navier-Stokes equations.

Assistant pullback technique for main span closure of Sutong Bridge

Sutong Bridge is a cable-stayed steel box girder bridge with a main span of 1 088 m. The erection of upper structure adopts geometry control method and requires no change to the unit＇ s size and the structure＇ s none-stress geometry. Before main span closure, the cantilever of girder reaches 540.8 m, the structure state is noticeably influenced by extemal circumstances, the main span closure face great difficulty. By abstracting the advantage of the pullback method abroad and the domestic temperature-cutting method, a new assistant pullback method have put forward and bring into practice actually. In this paper, the analysis key point of practice conditions, key parameter of practice, main measures of the method and the performance is introduced.

Pullback attractor of 2D non-autonomous g-Navier-Stokes equations on some bounded domains

The existence of the pullback attractor for the 2D non-autonomous g-Navier- Stokes equations on some bounded domains is investigated under the general assumptions of pullback asymptotic compactness. A new method to prove the existence of the pullback attractor for the 2D g-Navier-Stokes eauations is given.

Pullback attractor of 2D nonautonomous g-Navier-Stokes equations with linear dampness

The pullback attractors for the 2D nonautonomous g-Navier-Stokes equations with linear dampness axe investigated on some unbounded domains. The existence of the pullback attractors is proved by verifying the existence of pullback D-absorbing sets with cocycle and obtaining the pullback ：D-asymptotic compactness. Furthermore, the estimation of the fractal dimensions for the 2D g-Navier-Stokes equations is given.

PULLBACK EXPONENTIAL ATTRACTORS FOR THE NON-AUTONOMOUS MICROPOLAR FLUID FLOWS

This paper investigates the pullback asymptotic behaviors for the non-autonomous micropolar fluid flows in 2D bounded domains. We use the energy method, combining with some important properties of the generated processes, to prove the existence of pullback exponential attractors and global pullback attractors and show that they both with finite fractal dimension. Further, we give the relationship between global pullback attractors and pullback exponential attractors.

Pullback Attractor of a Non-autonomous Model for Epitaxial Growth

In this paper, we consider a non-autonomous model for epitaxial growth. It is shown that a pullback attractor of the model exists when the external force has exponential growth.

Pullback Exponential Attractors for Nonautonomous Reaction Diffusion Equations in H₀<sup style="margin-left:-6px;">1</sup>

Under the assumption that ?g(t) is translation bounded in , and using the method developed in [3], we prove the existence of pullback exponential attractors in ?for nonlinear reaction diffusion equation with polynomial growth nonlinearity(?is arbitrary).