应用分离变量法和Karamata正规变化理论,先得到了φ在0处的渐近行为,其中,φ表示 ∫0^φ(t)dv/g(v)=v,v〉0 的唯一解.从而在g满足适当的结构条件下,得到了一类一阶非线性微分方程终值问题 -v(t)=b(t)g(v(t)),v(t)〉0,t〉0,v(∞)=limt→∞v(t)=0 唯一解在无穷远处的精确渐近行为.其中,所给的结构条件隐含了g在0处以指数p(p〈1)正规变化,b∈C((0,∞),(0,∞)),并且任意a〉0,∫a^∞b(s)ds〈∞.
Under the new structure conditions on nonlinear term g, by Karamata regular variation theory and the separated variable method, we derive the exact asymptotic behavior of the unique solution at infinity to a class of terminal value problems for first order differential equations - v( t ) = b (t) g ( v (t) ), v (t) 〉 0, t 〉 0, v ( ∞ ) = lim v (t) = 0, where the new structure conditions imply that g is regularly varying at zero with index p(p 〈 1 ), and b is non-negative non-trivial on (0, ∞ ) and ∫a^∞b(s)ds〈∞,arbitary a〉0.The solution can be determined in terms of the solution φ to the following first order problem ∫0^φ(t)dv/g(v)=v,v〉0.