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Gamma Ray Observatory to Open Soon in Mexico
American and Mexican scientists have completed construction of the world's largest gamma ray observatory, situated high in central Mexico’s Sierra Negra Mountain. The observatory's huge array of water-based detectors will soon start discovering secrets about black holes and supernovas.
Extreme cosmic events, such as explosions of stars, pulsars or black holes, emit huge bursts of highly-charged particles, called gamma rays, that under certain circumstances can travel faster than the speed of light.
Scientists say the rays are so powerful that some of them can be detected coming from distances up to 10 billion light years away.
Jordan Goodman, a physics professor at the University of Maryland, said, “They are [the] highest-energy light so they let us understand where the highest energy particles in the universe come from. So our idea is to build this observatory to give us a wide field view of the sky at the highest energies.”
Cosmic glow
When cosmic gamma rays hit a medium like water, they create a soft bluish glow called Cherenkov electromagnetic radiation, a glow that can also be seen at the cores of nuclear reactors.
Three hundred tightly-sealed water tanks at the High Altitude Water Cherenkov Experiment observatory, or HAWC for short, also contain sensors that detect and record Cherenkov radiation.
By measuring the angle and intensity at which gamma rays hit the sensors, scientists can calculate where they came from.
Volcanic site
Goodman said along with studying deep space, the new observatory also can study our own star.
“This technique is unusual because someone yesterday, at the conference we had, said, 'you know, we should look at gamma rays from the sun, very high energy.' No one who does a telescope can look at the sun but we can look at the sun because we don't use the daylight, we use the gamma rays,” said Goodman.
The site, at the bottom of an extinct volcano in central Mexico, was chosen for its favorable climate conditions.
After 10 years it will be dismantled and the site's environment will be returned to its original condition.
词汇解析
conservative
难度：3星常用词汇，属常用6000词
英汉解释
adj.保守的；守旧的
n.保守派(党)；保守的人
参考例句
用作形容词 (adj.)
The professor's a radical in politics but a conservative dresser.
教授在政治上是激进派,但衣着却很守旧。
用作名词 (n.)
He listed himself as a conservative.
他自称是一个保守主义者。
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aggressive
难度：4星核心词汇，属常用3000词
英汉解释
adj.侵略的；进攻性的；好斗的；有进取心的
参考例句
用作形容词 (adj.)
His style of argument in meetings is not so much aggressive as pertinacious.
他在会议上的辩论态度并非锋芒逼人而是坚持己见。
But what impresses most is that they are aggressive in their career and responsible to their families and respectful to females.
但最印象深刻的,上海男人在事业上有进取心,对家庭有很强的责任感,而且尊重女性。
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northeast
难度：2星扩展词汇，属常用10000词
英汉解释
n.东北
adj.东北的；向东北的；来自东北的
adv.向东北；来自东北
参考例句
用作名词 (n.)
At this point the road turns northeast.
路在这里转向东北。
用作形容词 (adj.)
Hereby he is presenting the fellows in Northeast China.
在这里他向我们呈现的是东北的父老乡亲。
用作副词 (adv.)
Another ocean current flows northeast along the steep continental shelf.
还有一股沿陡峭陆架坡向东北流动的海流。
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assemble
难度：3星常用词汇，属常用6000词
英汉解释
v.集合；收集；装配
参考例句
用作动词 (v.)
The students assembled in the school garden.
学生们在校园集合。
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yearly
难度：3星常用词汇，属常用6000词
英汉解释
adj.每年的
adv.每年地；一年一次地
参考例句
用作形容词 (adj.)
Many Greek cities had to send yearly tribute to Athens.
许多希腊城市不得不每年向雅典进贡。
用作副词 (adv.)
I get a physical examination yearly.
我一年做一次身体检查。
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craft
难度：3星常用词汇，属常用6000词
英汉解释
n.工艺；手艺；狡诈；船舶；航空器；行会成员
vt.手工制作；精心制作
参考例句
用作名词 (n.)
He graduated from a school of crafts and arts.
他毕业于一所工艺美术学校。
用作及物动词 (vt.)
He told us a carefully crafted story.
他给我们讲了一个精心编织的故事。
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marine
难度：4星核心词汇，属常用3000词
英汉解释
adj.海的；海事的；海生的；航海的
n.海运业；船舶；水兵
参考例句
用作形容词 (adj.)
His father is a marine biologist.
他父亲是位海洋生物学家。
用作名词 (n.)
He sought an officer's berth in the merchant marine.
他在商船上找了一个高级船员的职位。
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