Variations in air temperature during the last 100 years revealed by δ~(18)O in the Malanice core from the Tibetan Plateau

By comprehensive analyses,it was found that the variations in δ^18O recorded in Malan ice core from the Kekexili Region on the Tibetan Plateau could represent the changes in air temperature during the summer half year (from May to October) over the Kekexili Region and the northern margin of the Tibetan Plateau.The general increase trend in δ^18O in the ice core during the past century indicated climate warming,and it was estimated that air temperature during the summer half-year rose about 1.2℃ over there then.However,this ice core record documented that the study area has been cooling while most of the world has been dramatically warming since the late 1970s. A tele-connection was found between the variations in δ^18O in the Malan ice core and the North Atlantic Oscillation.Moreover,the variations in δ^18O in this ice core were similar to that in the summer half-year air temperature over the southern Tibetan Plateau on the centurial time scale,but opposite on the multidecadal time scale.     

二阶非线性微分方程的渐近性

利用Gronwall不等式研究了二阶非线性泛涵微分方程的非振动解及其一阶导数的有界性与渐近性 ,改进和推广一些已知文献中的相应结果 .     

一类二阶非线性泛函微分方程的振动性

讨论了非线性二阶泛函微分方程(r(T)φ(x(t))x′(t))′ P(t)x′(t) q(t)f(x(α(t)))=0的振动性，得到了该方程所有解振动的充分条件，推广了M．M．A．El-Sheikh和R.Sallam(Appl.Math．Comput．，2000，115：113-121)及H．J．Li(J．Math．Anal．Appl．，1995，194：217-234)等人的结果．     

二阶微分方程的振动性

建立了方程 p(t) y′α- 1 y′′ q(t) y a- 1 y=0振动的新准则 .这些准则不同于现有的许多结果 ,仅需 [t0 ,∞ )中一列子区间上的信息 ,而不是整个半直线 .根据斯图姆定理 ,我们的结果更自然并比先前的结果更“Sharp”,且能应用到∫∞t0q(t) dt=-∞的情形 .     

The perturbed solution of sea-air oscillator for ENSO model

A class of delayed oscillators and coupled systems to oscillation of El Nino-Southern Oscillation (ENSO) models are considered. Using the perturbed theory and other methods, the exact solution or asymptotic expansions of the solution for ENSO models is obtained and the asymptotic behavior of solution of corresponding problem is studied.     

线性抛物型时滞微分方程组解的振动性定理

本文研究线性抛物型时滞微分方程组(δU_i)/(δt)+∑sum from j=1 to m P_(ij)(x,t)U_i(x,t-τ(t))=a_i(t)ΔU_i+∑sum from j=1 to m_1 a_(ij)(t)ΔU_i(x,t-δ_j),i=1,2,…,m (1)解的振动性,其中(x,t)∈Ω×(0,∞),ΩR~n 是具有逐片光滑的边界的有界区域,U_i=U_i(x,t),ΔU_i=∑sum from j=1 to n (δ~2U_i(x,t))/(δ)x_j~2),获得了方程组(1)的所有解振动的充分条件,同时给出了应用这些充分条件的例子。     

丙氨酸—KBrO_3—MnSO_4—H_2SO_4体系的化学振荡反应研究

本文研究了DL—丙氨酸—KBrO_3—MnSO_4—H_2SO_4体系的振荡反应,对这一反应的机理、反应产物及影响因素作了初步分析。     

中立型抛物方程解的振动性

本文给出了中立型抛物方程的两类边值问题的一切解振动的充分条件。     

二阶非线性微分方程的振动性定理

本文给出二阶非线性微分方程(a(t)Ψ(x(t))x′(t))′+p(t)Ψ(x(t))x′(t)+q(t)f(x(t))=0的一些振动性判别准则,这些判别准则改进或推广了燕居让和Grace & Lalli的某些结果。