They form when two layers of air or liquid of different densities move past each other at different speeds , creating shearing at the boundary .
当两层不同密度的气体或液体以不同的速度擦肩而过时,会在边界处发生剪切,从而生成这种云。
Poor sanitation and high population densities provided an ideal breeding ground for disease in ancient cities .
恶劣的卫生条件和高人口密度为古代城市的疾病提供了一个理想的温床。
A great city needs a mix of neighborhoods and districts of varied heights and densities .
大城市需要结合不同高度和密度的社区和地区。
She 's overburdened with one of the world 's highest population densities , which makes for a seething mass of people , buildings and cacophonous traffic .
最为世界上人口密度最高的国家,埃及不堪重负,这些造就了这里复杂的人口、建筑以及嘈杂的交通环境。
The new findings may also help predict how the heliosphere varies in shape and size as it moves through the galaxy and encounters regions of space having different densities and magnetic field strengths .
To keep up speed on the way to the wall , the industry has begun building three-dimensionalchips by stacking circuits on topof one another to increase densities .
在冲向这堵墙的过程中,为了保持速度,通过把集成电路堆叠起来增加密度,闪存业已开始制造三维芯片。
Dubbed tres-4 the planet is about 1.7 times the size of jupiter and belongs to a small subclass of so-called puffy planets that have extremely low densities .
命名为tres-4的行星是木星的1.7倍大是被称为有极低密度的膨胀行星的一小部分。
They move much faster than those in traditional displays , though , because their densities are closer to those of the suspending media .
但是,因为密度接近悬浮介质,它们比传统的黑白颗粒移动得更快。
Dubbed tres-4 , the planet is about 1.7 times the size of jupiter and belongs to a small subclass of " puffy " planets that have extremely low densities .
这颗行星被称为“tres-4”,大小是木星的1.7倍,属于一类为数不多的“膨胀”行星,密度极低。
With these numbers in mind , renshaw and his associates from the university of utah brain institute , the veteran affairs salt lake city health system , and case western reserve university also turned to cdc data on gun ownership and population densities in the mountainous west region .