例句與造句

1. Our yields increase with the mass of the progenitor main - sequence stars . massive stars ( i . e . 18m < m < 50m ) is the primary sites of the neclearsynthesis of the r - process and can explain the galaxy chemical evolution . 3 . we present formula to calculat the r - process galactic chemical evolution of ba peak elements . this formula contains metallicity abundance and point out the relation of the ba peak elements and disscuss the effect of various mass supersnova . besides , our formula can be confirmed by a lot of observations
   由此可以解釋以下觀測事實: ( l ) mg ， eu均產生于snh星，但質量范圍不同，在高質量( > 20 ) eu的產量高， mg的產量(相對于太陽) ，導致暈星中eu / mg > 0 ，而產生mg的質量范圍較大，致使在厚盤的晚期較小質量超新星也開始對mg有貢獻，而這些星對eu的貢獻很小，致使在厚盤星中eu / mg < 0 ，在厚盤中eu / fe隨金屬豐度的升高而降低，仁mg / fe隨金屬豐度的升高而不變
2. The dissertatation consists of two sections . the first one mainly intrduce the chemical evolution model and observational constrain , and the second mainly intrduce the ncleosyhthesis of r - process and the chemical evolution of ba peak elements the formation and evolution of the galaxy has long been a basic and important branch and one of the most active frontiers in the fields of astrophysics
   本文分二部分，第一部分重點介紹星系的化學演化模型和觀測約束，第二部分重點介紹r - process核合成和ba峰元素r - process的星系化學演化。
3. It's difficult to find r-process in a sentence. 用r-process造句挺難的