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反鸟的新发现与早期鸟类的辐射
反鸟 早白垩世 辐射
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2013/12/11
报道产于辽宁省朝阳地区早白垩世九佛堂组一新反鸟化石(Longipteryx chaoyangensis sp. nov.).根据该反鸟的肋骨具有钩突、前肢较后肢长、嘴长和第4蹠骨长于其余蹠骨等不同于其他已知反鸟的特征, 建立一新属种,推测: (1) 该鸟具有类似于现代鸟类的稳固的胸廓,供发达的肌肉附着和具有发达的主动呼吸功能;(2) 翼发达, 具有较强的飞行能力;(3) 嘴长, 适应水中捕食; (...
A Direct Procedure for Determining the Number of Plates in Tactoids of Smectites: The Na/Ca-Montmorillonite Case
Bentonite Conductivity Dispersion Hydraulic Smectite Tactoid
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2012/2/10
The dispersion of clays is of great importance in determining various soil properties such as hydraulic conductivity. A procedure which involves fixing followed by embedding of clay particles in an ep...