>>> 哲学 经济学 法学 教育学 文学 历史学 理学 工学 农学 医学 军事学 管理学 旅游学 文化学 特色库
搜索结果: 1-15 共查到6.5 million years相关记录34条 . 查询时间(0.078 秒)
or plants, acclimation to low temperatures is fundamental to survival. This process involves the modification of lipids to maintain membrane fluidity. We previously identified a new cold-induced putat...
New research demonstrates that a decline in the concentration of atmospheric CO2 played a major role in driving Earth's climate from a warm greenhouse into a cold icehouse world around 34 million year...
The pressing concern posed by rising sea levels has created a need for scientists to predict how quickly the oceans will rise in coming centuries, researchers say. To gain insight into future ice shee...
For decades, scientists have gathered ancient sediment samples from below the seafloor to better understand past climates, plate tectonics and the deep marine ecosystem. In a new study published in...
A team of researchers led by Arizona State University geoscientist Linda Elkins-Tanton has provided the first direct evidence that extensive coal burning in Siberia was a cause of the Permo-...
Comparative analyses by scientists at the Swiss Institute of Bioinformatics and other institutions of 76 arthropod species spanning 500 million years of evolution reveal genomic changes that point to ...
A 550-million-year-old fossilized digestive tract found in the Nevada desert could be a key to understanding the early history of animals on Earth.More than a half-billion years ago, life on Earth con...
Some 250 million years ago, simultaneous mass extinctions of marine and terrestrial life occurred in an event known as the End-Permian. Or so scientists believed.New research led by Colby College geol...
Six million years ago, grass-eating mammals became more diverse in South America. Shifts in tropical atmospheric circulation known as Hadley circulation led to changes in climate and vegetation, espec...
Researchers have for the first time traced the roots of crabs, lobsters and shrimp to create the family tree of crustaceans people love to eat.The tree shows the 450-million-year evolution of these 10...
When the landmass that today is the Indian subcontinent slammed into Asia some 50 million years ago, the collision changed the configuration of the continents and altered global climate.Now a team of ...
At Northern Illinois University, Dan Gebo opens a cabinet and pulls out a drawer full of thin plastic cases filled with clear gelatin capsules. Inside each numbered capsule is a tiny fossil—some are s...
Millions of years before humans discovered agriculture, vast farming systems were thriving beneath the surface of the Earth. The subterranean farms, which produced various types of fungi, were cultiva...
Walking through a grassy field or forest take a moment to consider what lies beneath the surface. A web of plant roots interacts symbiotically with arbuscular mycorrhizal (AM) fungi that extend their ...
EVANSTON - A provocative new Northwestern University and Claremont McKenna, Scripps and Pitzer colleges study suggests it was the power of the eyes and not the limbs that first led our ancient aquatic...

中国研究生教育排行榜-

正在加载...

中国学术期刊排行榜-

正在加载...

世界大学科研机构排行榜-

正在加载...

中国大学排行榜-

正在加载...

人 物-

正在加载...

课 件-

正在加载...

视听资料-

正在加载...

研招资料 -

正在加载...

知识要闻-

正在加载...

国际动态-

正在加载...

会议中心-

正在加载...

学术指南-

正在加载...

学术站点-

正在加载...