Gelor lens system

In this paper, it has been proved that there is a corresponding state theorem for Berthelot system and the critical index of above system have also been calculated.

本文论证了伯塞洛脱系统存在一个对应态定理 ,并给出了该系统的临界指数 。

In this paper,for Berthelot gas,not only thermodynamic properties have been investigated but also thermodynamic processes have been analysed systematicall

研究了伯塞洛脱气体的热力学性质，分析了该气体的热力学过程。

The first era is from late 19th and early 20th century to the Great Depression;the second era begins with the subscription of the Bracero Program and ends with the termination of that program;The third era is from the 1965 Amendments to the Immigration and Nationality Act to mid-1980s.

墨西哥人移民美国的历程大致可以划分为四个阶段,与之对应的是四次移民浪潮:第一次浪潮从19世纪末20世纪初到1929年美国经济大萧条;第二次移民浪潮从1942年美墨双方签署《布拉塞洛计划》到1964年该计划终结;第三次浪潮从1965年移民法颁布到20世纪80年代中期,此间大量墨西哥无证件移民流入美国;第四次浪潮从《1986年移民改革与控制法》颁布至今。