用于片上多核互联的交叉开关方案

微处理器向多核发展是一种趋势,而且正在向许多核发展。连接结构的性能很大程度上决定着整个系统性能,因此有必要研究多核连接的高效机制。常用的总线在连接核心的数目比较多时,会因竞争而成为整个系统性能的瓶颈。而交叉开关竞争最少,是核间连接最高效的方法之一。文章设计一个用于核间连接的五级流水的交叉开关。它的输入和输出端均带有缓冲,并且为了有效和公平地得用带宽,使用了虚拟通道。数据流的控制用在端口的计数器来实现。

Localization of stationary pronuclei during conjugation of Paramecium as indicated by immunofluorescence staining

After the third prezygotic division during conjugation of Paramecium caudatum,migratory and stationary pronuclei are produced.The migratory pronuclei remain in the paroral region tightly against the conjugating boundaries;while the stationary pronuclei are located beside the migratory pronuclei.To date,however,it is not clear what causes this close side-by-side localization between migratory and stationary pronuclei.In the current study,immunofluorescence staining with monoclonal antibody of anti-α tubulin indicated that ＂U＂ or ＂V＂ shaped spindles connected the migratory and stationary pronuclei during the third prezygotic division.This observation accounts for the close localization between these two types of pronuclei.