Theory on single molecule-photon cryocooler

The micro mechanism of anti-Stokes fluorescent cooling was investigated on molecular or ionic scale. A new conception of single molecule-photon cryocooler (SMPC) was given, and the smallest cryocooler in the world was predicted. We described SMPC and its running principle in detail. The quantum transition processes of SMPC and the largest cooling coefficient that SMPC can get in an optical transition were given. Also we studied the random property of SMPC in cooling processes. The thermodynamic behavior of single Yb³⁺ ion as a photon cryocooler was imitated.     

Unbounded One-Dimensional Global Attractor for the Damped Sine-Gordon Equation

Summary. The dynamical behavior of the damped sine-Gordon equation with homogeneous Neumann boundary condition is studied. It is shown that the equation has an unbounded one-dimensional global attractor in a suitable functional space when the ``damping' and the ``diffusing' are not very small. Received March 16, 1999; accepted December 10, 1999     

Model investigation of non-thermal phase transition in high energy collisions

The non-thermal phase transition in high energy collisions is studied in detail in the framework of random cascade model. The relation between the characteristic parameter A_p, of phase transition and the rank q of moment is obtained using Monte Carlo simulation, and the existence of two phases in self-similar cascading multiparticle systems is shown. The relation between the critical point qc of phase transition on the fluctuation parameter a is obtained and compared with the experimental results from NA22. The same study is carried out also by analytical calculation under central limit approximation. The range of validity of the central limit approximation is discussed.     

EXISTENCE OF POSITIVE RADIAL SOLUTIONSFOR QUASILINEAR ELLIPTIC BOUNDARYVALUE PROBLEMS

1IntroductionInrecentyears,theexistenceandmultiplicityofsolutionsoftheproblemwerestudiedbynumerousauthors.WhereA>0,fiisasmoothdomaininR,N22.Thefundamentalquestionsaboveproblem(1.1)-(1.2):have.receivedrathersimpleanswers.Todoso,theauthorsalwaysusethenicepropertiesoftheoperatorA,forexample,thelinearity,maximumprinciple,strongmaximumprinciple,comparisonprincipleandsoon.Meanwhile,theexistenceandmultiplicityofpositiveradialsolutionsof(1.1)-(1.2)attractedmuchinterest,see[l,5-6,10,13-18]andtherefe…     

Uniform sliding states in the undamped Frenkel-Kontorova model

The uniform sliding states of the undamped Frenkel-Kontorova model are reduced to the periodic solutions of an advance-delay differential equation, the existence of which is investigated in this paper by employing variational methods.     

紧黎曼流形上的椭圆边界值问题

讨论一类非齐次非线性椭圆边界值问题.利用极大值原理证明了该问题解的梯度估计.作为它的应用得到了解的效率比估计.     

森林生态系统类自然保护区区域系统熵变模型构建及应用

基于熵理论,分析了森林生态系统类自然保护区区域系统的熵变机理,构建了该类保护区区域森林生态系统熵变状态转移模型,运用模型可以反映系统的发展状况并进一步确定影响其发展的关键协同因子.以云南省大围山国家级森林生态系统类自然保护区为例介绍了模型的具体运用,并证实了模型的合理性,从而为实现此类保护区的可持续发展提供新的战略思想.     

A two-grid discretization scheme for the Steklov eigenvalue problem

In the paper, a two-grid discretization scheme is discussed for the Steklov eigenvalue problem. With the scheme, the solution of the Steklov eigenvalue problem on a fine grid is reduced to the solution of the Steklov eigenvalue problem on a much coarser grid and the solution of a linear algebraic system on the fine grid. Using spectral approximation theory, it is shown theoretically that the two-scale scheme is efficient and the approximate solution obtained by the scheme maintains the asymptotically optimal accuracy. Finally, numerical experiments are carried out to confirm the considered theory.