normal grading meaning in Chinese

正弟变
正递变

In a way , the evolution to upward of distributary channel microlithofacies in shelf delta plain of later carboniferous epoch in this area is repeatedly and rapidly , and every time is a normal grading change from coarse to thin , at last it evolve into marshy deposit
应用马尔柯夫链分析方法得到的结果是，本区石炭统上段砾石质三角洲平原分支流河道的微岩相旋回的向上演化，是重复而迅速的，每次都是由粗到细的正旋回，最后演化为沼泽沉积。
Take the normal graded granularity for example , the curve function of the collaring rectangle was derived , which can provide a kind of mathematic model for drawing the lithologic frame of terrigenous elastic rocks in the second development of graphic software
为了弥补绘图软件的这些不足，提出用曲边矩形代替矩形来绘制陆源碎屑岩岩性框架，并以表示正粒序陆源碎屑岩岩性框架的曲边矩形为例，详细推导了其曲边的函数表达式，为绘图软件的二次开发提供了陆源碎屑岩岩性框架绘制的一种数学模型。