由大变小 meaning in Chinese

down

But how strange the change
*可当曲调由大变小*
The average of the equal - area - circle diameter was changed from long to short and then to long , to short at last , as a wave . the average of the roundness was changed from low to high and to low again , as para - curve
平均等积圆直径由大变小再变大再变小，呈波浪状变化；而晶粒平均球化度则由小变大再变小，呈抛物线状。
5 . based on the physical model , summarized the general mode of river development in excavated segment with its up and lower influence reach after dredging , it means that gradually deposit in dredging segment while wash out in up reach , and the change intensities are weakening as the time goes on
概括总结出了河段疏浚挖槽后，疏浚挖槽河段及其上下影响河段的河床演变及水面线变化的模式，即挖槽段逐渐回淤，挖槽上游段逐渐冲刷，并且其回淤及冲刷的强度随时间的推移由大变小。