The biostratigraphy of calcareous nannofossils of the Cretaceous is investigated in the boundary between Abderaz and Kal......

聚偏二氯乙烯——PVDC是当今世界上塑料包装中综合阻隔性能最好的一种包装材料。PVDC涂覆膜是在选定的薄膜表面上涂一层薄薄的、连......