理学 >>> 数学 信息科学与系统科学 物理学 化学 天文学 地球科学总论 大气科学 地球物理学 地理学 地质学 水文学 海洋科学 生物学 科学技术史
搜索结果: 1-15 共查到理学 Sharks相关记录18条 . 查询时间(0.049 秒)
Blue sharks use large, swirling ocean currents known as eddies to fast-track their way to food in the twilight zone -- a layer of the sea between 200 and 1,000 meters deep, according to new research b...
Sharks have a reputation as ravenous hunters and apex predators, but new analysis of fossil records shows that some of the earliest sharks might have been filter feeders, taking in water through their...
Sharks, marine scientists say, are often misunderstood, described as ravenous man-eaters. But researchers have discovered that sharks are critically important to the health of the world's oceans.For m...
If there was a top-rated restaurant in a dangerous part of the city, chances are some brave souls would be willing to risk it all for a delicious meal. So it goes with coral reef fish dining on algae...
Sharks, skates, and rays can detect very weak electric fields produced by prey and other animals using an array of unusual organs known as the ampullae of Lorenzini. Exactly how these electrosensory o...
DNA sequences for the mitochondrial cytochrome b gene were determined for 13 species of sharks. Rates and patterns of amino acid replacement are compared for sharks and mammals. Absolute rates of ...
The truth about sharks     truth  sharks       2015/8/4
Danger: shark attack (or more properly, say scientists, shark bite). With sharks swimming ever closer to shore this summer--or seeming to--and crossing paths with surfers and bathers, what's going on?
It is widely recognized that the western North Atlantic has recently warmed very rapidly. Sea surface temperatures (SST) in 2012 were measured to be 1–3°C higher than the 1982–2011 average (Mills et a...
All marine scientists who work in the field have them—personal stories of amazement, discovery, awe, excitement, and even danger while conducting research. They are the stories we love to tell to frie...
A team of scientists have unmasked the intricacies of how sharks hunt prey — from the first whiff to the final chomp —in a new study about shark senses that was supported by the National Science Found...
Great white sharks—top predators throughout the world's ocean—grow much slower and live significantly longer than previously thought, according to a new study led by the Woods Hole Oceanographic Insti...
Fossil deep-sea selachians are rare and their diversity underestimated as a consequence of the scarcity of available outcrops of sediments containing them. Here we report a new fossil locality from th...
The early history of heterodontid sharks is documented mainly by isolated teeth. So far, three different heterodontid genera have been recorded from the Jurassic: Proheterodontus from theMiddle Jurass...
As many hybodont sharks are known solely from their teeth, this investigation approaches the phylogeny of the group with an emphasis on tooth morphology and dentitional patterns. The preliminary resul...
The affinities of the selachian genus Ptychodus is discussed and Hemiptychodus is here re-introduced as a subgenus characterized by unusual tooth ornamentation pattern.An overview ofAsian hybodont gen...

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...