The oil and gas resources in basin and mountain system emerge from the activity period of basalt magma under the effect of the mantle fluids. 盆-山系油气的产生始于地幔流体作用下形成的玄武岩浆活动时期，集中于富含地幔流体的中地壳塑性层变厚、上拱的断隆山及其上覆盖层，如中国大陆东部中、新生代盆-山系。
Freshmen and Sophomores: Your elections will be held today during Activity Period (not during retreats).Sophomores, you will meet where you met last week. 9和10年级同学班级干部的选举，将在今天的班会时间举行，请自备一篇竞选短讲谢谢配合!
The results have shown that two kinds of beach bars formed in shallower water environment in weak tectonic activity period and have high degree of compositional maturity and textural maturity. 结果表明,两种滩坝均发育在构造运动平缓时期的浅水地区,具有较高的成分成熟度和结构成熟度。砂质滩坝主要发育在陆源碎屑物质供应充分的沙三段上部并可进一步划分出五种微相。
In active period of SLE, patients in group HL had a significant higher positive incidence of ANA than those in group HH. 在疾病活动期,HL组患者的抗核抗体(ANA)阳性率明显高于HH组患者。
In a seismic zone, seismicity usually could be divided into relative active period and relative inactive period. 在同一个地震带内,地震活动常可分为相对活跃期和相对平静期。