说明：  本文面向首次接触uC/OS-II的程序员，为他们介绍一下这个系统的一些基本特征和编程上的注意事项，并介绍几个值得了解的API。
(This article first contact for uC/OS-II of the programmers, for their introduction of this system, some of the basic features and programming on the note and introduce a few worthy of understanding API.)