吉林南部变质岩太古宙—元古宙分界时限的确定及过渡性构造演化

针对吉林南部古老岩石测年数据偏新和太古宙与元古宙之间分界时限的混乱,本文运用Sm-Nd等时线法和锆石U-Pb法将吉林南部变质岩系划分为4个年龄段:前阜平旋回(>2600Ma);阜平旋回第一幕(2600～2500Ma);阜平旋回第二幕(2500～2400Ma);阜平旋回第三幕(2400～2350Ma)。阜平旋回第三幕归入太古宙并作为太古宙—元古宙之间分界时限,吉林南部古陆构造环境由活动趋向于稳定,新、老板块沟、弧、盆系统交替,地壳隆起、剥蚀引起K-Ar年龄偏新。该过渡性构造环境和原2500～2350Ma间地质事件归入太古宙将有助于加深对该区地壳演化、板石沟绿岩带铁矿及夹皮沟剪切带金矿化形成的认识。

Research on Guaranteed Scheduling Algorithms

Guaranteed scheduling is necessary for hard real time systems, because each process of them must meet their deadline, or a serious consequence will result.In this paper we discuss two guaranteed schedule algorithms:backtracking and branch and bound,introduce the process to find the optimal solution by both methods,propose the concept of logical node and physical node.Through some experiments for different process sets,we have made comparisons between the two algorithms in branch nodes,comparing time,topology of the search tree,memory size needed,etc.