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广东南雄盆地上湖组介形类动物群及白垩-第三系界线 总被引:11,自引:0,他引:11
南雄盆地上湖组介形类可划分为2个性质不同的动物群及4个化石带:下部为 Porpocypris 动物群,是以中生代属种为主,中、新生代属种混生的过渡性动物群,时代为晚白垩世最晚期;上部为 Cypris 动物群,以 Cypris 属占优势, Sinocypris 属开始出现, Cypridea 等古老属种绝灭为主要特征,时代为早—中古新世.根据介形类演化发展阶段和白垩纪末生物绝灭事件,南雄盆地白垩系与第三系的界线应划在 Porpocypris 与 Cypris 动物群之间,即上湖组坪岭段与下惠段之间. 相似文献
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本文报道合浦盆地晚白垩世乌家组和古新世上洋组的介形类化石14属23种(描述1新种),可划分两个化石组合:(1)Rhombicypridea quadrata-Heterocypris hepuensis-Limnocythere sinuata组合,属于Talicypridea动物群,产于乌家组,时代为晚白垩世;(2)... 相似文献
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Mahdieh Hashemi Mahmood Hosseini Farzad N. Asger Mortensen Sanshui Xiao 《Plasmonics (Norwell, Mass.)》2013,8(2):1059-1064
Quantum efficiency of the silicon Schottky-barrier photodetector is limited by the weak interaction between the photons and electrons in the metal. By engineering the metal surfaces, metallic groove structures are proposed to achieve strong light absorption in the metal, where most of the energy is transferred into hot carriers near the Schottky barrier. The proposed broadband photodetector with a bi-grating metallic structure on the silicon substrate enables to absorb 76 % of the infrared light in the metal with a 200-nm bandwidth, while staying insensitive to the incident angle. These results pave a new promising way to attain high quantum efficiency silicon Schottky-barrier photodetectors. 相似文献
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