白垩纪

The Dabie Mountains are unique among ultrahigh pressure metamorphic terranes in having the most profound post collisional plutonism The Mesozoic shoshonitic and calc alkaline intrusive rocks can be divided into three groups with different isotopic ages, rock assemblages and chemical features Group I consists of late Triassic (~ 210 Ma) mafic monzodiorites It could have been generated by partial melting of enriched subcontinental lithosphere mantle due to slab breakoff Group II consists ma...

第 I组，主要由晚三叠世（约210 Ma）二长闪长岩辉长岩体组成，它可能是在板片断离过程中富集的大陆岩石圈地幔部分熔融的产物；第I I组，由中侏罗世－早白垩世（160～120 Ma）的角闪石英二长岩、黑云母二长花岗岩和正长花岗岩组成，主要是由幔源岩浆的分离结晶与地壳混染共同作用的产物；第II I组，以白垩纪（125～95 Ma）的花岗岩和花岗斑岩为代表，是在热穹窿作用过程中大别杂岩深熔作用和高度演化的产物。

Based on field survey and microstructure analysis the author considered that Yiwulvshan is a Cretaceous metamorphic core complex, and pointed out the time of Yiwulvshan granite is not early Yanshanian by the comprehensive analysis of the regional structures and isotopic dating, but a late Yanshanian granite.

在此基础上，作者经过野外宏观观测和室内显微分析，基本厘定医巫闾山是一个白垩纪形成的变质核杂岩。根据区域构造演化综合分析及同位素年龄测定，认为医巫闾山花岗岩体时代并非前人所定的早燕山期，而是晚燕山期岩体。

Recently polypod ferns have been demonstrated to undergo diversifications in the Cretaceous after the rise of angiosperms. To further test this proposal, an adaptive evolutionary analysis was performed on the rbeL gene sequences of Polypodiaceous ferns under models allowing w (nonsynonymous/synonymous rate ratio) to vary among sites.

为验证蕨类植物在白垩纪适应被子植物兴起而发生分化的观点，本研究以水龙骨科附生蕨类为对象，利用位点间可变ω（非同义替换率d和同义替换率d的比值）模型对其rbcL基因的适应性进化进行分析。

A praying mantis trapped in amber that was found in Japan in January 2008 dates back 87 million years, to the late Cretaceous period.

一只被困在琥珀中的螳螂于2008年1月在日本被发现，形成的年代可以追溯到8700万年前白垩纪晚期。

Quadrupedal armored herbivore of the Jurassic and Cretaceous.

侏罗纪和白垩纪的一种四足有甲食草动物。

Amphibious quadrupedal herbivorous dinosaur with a long thin neck and whiplike tail; of the Cretaceous mostly in the southern hemisphere.

两栖类四足食草恐龙，颈长而细，鞭形尾；白垩纪主要生活在南半球。

Small toothless saurischian dinosaurs; upper Cretaceous of Canada.

发现于加拿大上白垩纪的小的无齿蜥臀目恐龙。

Carnivorous saurischian dinosaurs with short forelimbs; Jurassic and Cretaceous.

前肢较短的蜥臀目食肉恐龙；生活于侏罗纪和白垩纪之间。

Sauropod dinosaurs of the genus Titanosaurus, common during the Cretaceous Period especially in South America.

雷龙一种泰坦龙，食草的水陆两栖蜥脚类恐龙，在白垩纪的南美尤为常见

Any of various plant - eating,amphibious sauropod dinosaur s of the genus Titanosaurus,common during the Cretaceous Period especially in South America.

雷龙一种泰坦龙，食草的水陆两栖蜥脚类恐龙，在白垩纪的南美尤为常见

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。