REE characteristics of the coal in the Erlian Basin, Inner Mongolia, China, and its economic value

The rare earth elements(REE)content of the coal in the Erlian Basin was determined by inductively coupled plasma mass spectrometry(ICP-MS),and it turns out that the REE content from different geological age shows a significant difference:The REE content of the coal in the Jurassic Alatanheli Group is from 152.05×10^(−6) to 1416.21×10^(−6),with an average value of 397.31×10^(−6),and the relative concentration factor shows enriched;the REE content of the coal in Early Cretaceous Baiyanhua Group is from 20.65×10^(−6) to 102.53×10^(−6),the mean value is 49.06×10^(−6),and the relative concentration factor shows normally.The REE distribution patterns samples in Jurassic and Cretaceous shows the difference:The REE pattern in Jurassic coal mainly manifests as H-type distribution,with the Y,Lu positive anomaly,it is speculated that the fluid carried REE ions into the coal-bearing basin,and the heavy REE gather in the coal due to the different chemical properties of each REE.The REE occurrence mode is presumed to be mainly organic.Flat type is the REE main distribution pattern in Cretaceous coal.The REE patterns in clastic rocks of the roof,parting and floor of coal seam are similar to the REE patterns in the coal and the most possible reason is that the REE main source is from the clastic rock.It showed that the coal of the Early Jurassic,especially of Amugulen coalfield has resource value.

内蒙古8个群体女生月经初潮的月分布

作者调查了内蒙古自治区８个群体女学生月经初潮的月分布情况。调查结果显示８个群体初潮月分布曲线呈双峰特征，一个峰位于冬季（１２—２月），一个峰位于夏季（６—８月）。作者认为双峰特征产生的原因与女生的精神因素、体脂、光照变化有关。初潮的季节分布受遗传因素的影响，同一民族内不同群体冬、夏季高峰的峰顶所在的月份之间的差异与生活的环境因素有一定关系。