文章来源:未知 文章作者:enread 发布时间:2012-12-18 06:37 字体: [ ]  进入论坛
Imagine riding in an airplane as the plane is jolted1 back and forth2 by gusts3 of wind that you can't prove exist but are there nonetheless(尽管如此). Similar turbulence4 exists in space, and a research team led by the University of Iowa reports to have directly measured it for the first time in the laboratory.
"Turbulence is not restricted to environments here on Earth, but also arises pervasively5 throughout the solar system and beyond, driving chaotic6 motions in the ionized gas, or plasma7, that fills the universe," says Gregory Howes, assistant professor of physics and astronomy at the UI and lead author of the paper to be published Dec. 17 in the online edition of Physical Review Letters, the journal of the American Physical Society. "It is thought to play a key role in heating the atmosphere of the sun, the solar corona8(日冕), to temperatures of a million degrees Celsius9, nearly a thousand times hotter than the surface of the sun."
He adds: "Turbulence also regulates the formation of the stars throughout the galaxy10, determines the radiation emitted from the super massive black hole at the center of our galaxy and mediates11 the effects that space weather has on the Earth."
One well-known source of gusty12 space winds are the violent emissions13 of charged particles from the sun, known as coronal mass ejections. These solar-powered winds can adversely14 affect satellite communications, air travel and the electric power grid15. On the positive side, solar storms also can also lead to mesmerizing16 auroras at the north and south poles on Earth.
Howes notes that unlike gusts of wind on the surface of Earth, turbulent motions in space and astrophysical systems are governed by Alfven waves, which are traveling disturbances17 of the plasma and magnetic field. Nonlinear interactions between Alfven waves traveling up and down the magnetic field -- such as two magnetic waves colliding to create a third wave -- are a fundamental building block of plasma turbulence, and modern theories of astrophysical turbulence are based on this underlying18 concept, he says. "We have presented the first experimental measurement in a laboratory plasma of the nonlinear interaction between counter-propagating Alfven waves, the fundamental building block of astrophysical(天体物理学的) turbulence," Howes says.
Contributing authors on the paper are D.J. Drake, K.D. Nielson, Craig Kletzing, and Fred Skiff, all of the University of Iowa, and T.A. Carter of the University of California, Los Angeles. The research, conducted at the Large Plasma Device at UCLA, was funded by a grant from the NSF/DOE Partnership19 in Basic Plasma Science and Engineering.


1 jolted 80f01236aafe424846e5be1e17f52ec9     
(使)摇动, (使)震惊( jolt的过去式和过去分词 )
  • The truck jolted and rattled over the rough ground. 卡车嘎吱嘎吱地在凹凸不平的地面上颠簸而行。
  • She was jolted out of her reverie as the door opened. 门一开就把她从幻想中惊醒。
2 forth Hzdz2     
  • The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
  • He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。
3 gusts 656c664e0ecfa47560efde859556ddfa     
一阵强风( gust的名词复数 ); (怒、笑等的)爆发; (感情的)迸发; 发作
  • Her profuse skirt bosomed out with the gusts. 她的宽大的裙子被风吹得鼓鼓的。
  • Turbulence is defined as a series of irregular gusts. 紊流定义为一组无规则的突风。
4 turbulence 8m9wZ     
  • The turbulence caused the plane to turn over.空气的激流导致飞机翻转。
  • The world advances amidst turbulence.世界在动荡中前进。
5 pervasively a7fba7749e7b7cb0af4a20d3e484c523     
  • The idea of Healthy, Brief, Fashion, Comfort, Leisure "accepted pervasively." “健康、简约、时尚、舒适、休闲”家居理念得到人们认同。 来自互联网
  • Knowledge is being used pervasively in the overall economic system. 知识与资讯正全面渗透到整个经济运作过程中去。 来自互联网
6 chaotic rUTyD     
  • Things have been getting chaotic in the office recently.最近办公室的情况越来越乱了。
  • The traffic in the city was chaotic.这城市的交通糟透了。
7 plasma z2xzC     
  • Keep some blood plasma back for the serious cases.留一些血浆给重病号。
  • The plasma is the liquid portion of blood that is free of cells .血浆是血液的液体部分,不包含各种细胞。
8 corona jY4z4     
  • The corona gains and loses energy continuously.日冕总是不断地获得能量和损失能量。
  • The corona is a brilliant,pearly white,filmy light,about as bright as the full moon.光环带是一种灿烂的珠白色朦胧光,几乎像满月一样明亮。
9 Celsius AXRzl     
  • The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
  • The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。
10 galaxy OhoxB     
  • The earth is one of the planets in the Galaxy.地球是银河系中的星球之一。
  • The company has a galaxy of talent.该公司拥有一批优秀的人才。
11 mediates 9cf5b4b4c1ee4c1361a2114028f23c30     
调停,调解,斡旋( mediate的第三人称单数 ); 居间促成; 影响…的发生; 使…可能发生
  • We therefore investigated whether hypercoagulability mediates a beneficial effect during denovo atherogenesis. 因此我们研究了高凝在原位动脉粥样硬化形成中是否介导了有益的作用。
  • Not happy when the mood that how mediates oneself? 不开心的时候怎样调解自己的情绪?
12 gusty B5uyu     
  • Weather forecasts predict more hot weather,gusty winds and lightning strikes.天气预报预测高温、大风和雷电天气将继续。
  • Why was Candlestick Park so windy and gusty? 埃德尔斯蒂克公园里为什么会有那么多的强劲阵风?
13 emissions 1a87f8769eb755734e056efecb5e2da9     
排放物( emission的名词复数 ); 散发物(尤指气体)
  • Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
  • Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。
14 adversely 6zEzi6     
  • We commented adversely upon the imbecility of that message of telegraphic style. 我们对着这条电报式的愚蠢的留言发泄了一通不满。
  • Widely fluctuating exchange rates may adversely affect international trade. 浮动幅度很大的汇率可能会对国际贸易产生有害的影响。
15 grid 5rPzpK     
  • In this application,the carrier is used to encapsulate the grid.在这种情况下,要用载体把格栅密封起来。
  • Modern gauges consist of metal foil in the form of a grid.现代应变仪则由网格形式的金属片组成。
16 mesmerizing 7b8d59e68de653b4d25887c4d54c07d2     
adj.有吸引力的,有魅力的v.使入迷( mesmerize的现在分词 )
  • I think you must be mesmerizing me, Charles. 查尔斯,我想你一定在对我施催眠术啦。 来自辞典例句
  • The attendant one-dimensional wave equation has mesmerizing harmonic properties. 伴生的一元波平衡具有迷人的和谐特性。 来自电影对白
17 disturbances a0726bd74d4516cd6fbe05e362bc74af     
n.骚乱( disturbance的名词复数 );打扰;困扰;障碍
  • The government has set up a commission of inquiry into the disturbances at the prison. 政府成立了一个委员会来调查监狱骚乱事件。
  • Extra police were called in to quell the disturbances. 已调集了增援警力来平定骚乱。
18 underlying 5fyz8c     
  • The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
  • This word has its underlying meaning.这个单词有它潜在的含义。
19 partnership NmfzPy     
  • The company has gone into partnership with Swiss Bank Corporation.这家公司已经和瑞士银行公司建立合作关系。
  • Martin has taken him into general partnership in his company.马丁已让他成为公司的普通合伙人。
TAG标签: wind space stars