简单说，就是日本武士元服后的首次战役。一般说来在日本战国时期，武将们的元服多半在13岁到16岁之间，初阵和元服一般不会隔得太久。武将们对于元服往往会有若干程度的迷信，希望能够取胜，为自己一生的武运取得好兆头。有些实力强大的大名往往加派几个作战经验丰富的家臣参与继承人的初阵。
初等矩阵 [数] elementary matrix ; elementary reduction matrices ; elementary matrices
初基点阵 primitive lattice
初等阵 elementary matrix
矩阵的初等变换 elementary transformation of matrices ; Transformation of matrix ; elementary transformation ; elementary operations on matrix
初等矩阵代数 Elementary matrix algebra
分块初等矩阵 block elementary matrix
矩阵初等变换 Elementary matrix transformation
初始化磁盘阵列 mkraid
对矩阵作初等行变换 row operation
举个例子，有很多练习是取自上世纪初的剑桥大学的数学荣誉学位考试，它们绝对会让你忙上一阵。
For example, there are exercises coming from the Math Tripos examinations (at Cambridge) from early part of the last century, and they will definitely keep you busy for some time.
头顶上的喧嚣声戛然停止了，像初起时一样来得突然，像一阵狂风吹过似的；
The pandemonium above has ceased almost as suddenly as it arose, passed like a fierce gust of wind;
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