火星存在生命的证据？_英语科普

火星存在生命的证据？

文章来源：未知文章作者：enread 发布时间：2014-12-09 06:14 字体： [大中小]　进入论坛

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In 2012 the Mars Science Laboratory landed in the fascinating Gale¹ crater². The Gale crater is of such great interest because of the 5.5 km high mountain of layered materials in the middle. This material tells an intricate story of the history of Mars, perhaps spanning much of the existence of this mysterious planet. Once positioned, the Curiosity rover began field studies on its drive toward Aeolis Mons (also unofficially known as Mount Sharp), the central peak within the crater. Curiosity has travelled more than 9.4 km so far and during its trip up the mountain, Curiosity has begun taking samples of the mountain's lower slopes.

CheMin is one of ten instruments on or inside Curiosity, all designed to provide detailed³ information on the rocks, soils and atmosphere. CheMin is actually a miniaturised X-ray diffraction/X-ray fluorescence (XRD/XRF) instrument, approximately the size of a shoebox, that uses transmission geometry with an energy-discriminating CCD detector⁴ to obtain unparalleled results in quite challenging conditions.

Five samples have been analysed by CheMin so far, namely a soil sample, three samples drilled from mudstones and a sample drilled from a sandstone. Rietveld and full-pattern analysis of the XRD data have revealed a complex mineralogy, with contributions from parent igneous⁵ rocks, amorphous⁶ components⁸ and several minerals relating to aqueous alteration⁹, for example clay minerals and hydrated sulphates. In addition to quantitative¹⁰ mineralogy, Rietveld refinements¹¹ also provide unit-cell parameters¹² for the major phases, which can be used to infer the chemical compositions of individual minerals and, by difference, the composition of the amorphous component⁷. Coincidentally CheMin's first XRD analysis on Mars coincided with the 100th anniversary of the discovery of XRD by von Laue.

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收听单词发音

1 gale
n.大风，强风，一阵闹声（尤指笑声等）
参考例句：
We got our roof blown off in the gale last night.昨夜的大风把我们的房顶给掀掉了。 According to the weather forecast,there will be a gale tomorrow.据气象台预报，明天有大风。

2 crater
n.火山口，弹坑
参考例句：
With a telescope you can see the huge crater of Ve-suvius.用望远镜你能看到巨大的维苏威火山口。 They came to the lip of a dead crater.他们来到了一个死火山口。

3 detailed
adj.详细的，详尽的，极注意细节的，完全的
参考例句：
He had made a detailed study of the terrain.他对地形作了缜密的研究。 A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。

4 detector
n.发觉者，探测器
参考例句：
The detector is housed in a streamlined cylindrical container.探测器安装在流线型圆柱形容器内。 Please walk through the metal detector.请走过金属检测器。

5 igneous
adj.火的，火绒的
参考例句：
Igneous rocks do not contain fossils.火成岩不含化石。 The rocks here are igneous and do not fracture along predictable lines.这儿的石头都是火成岩，石头的裂缝极不规则。

6 amorphous
adj.无定形的
参考例句：
There was a weakening of the intermolecular bonds,primarily in the amorphous region of the polymer.分子间键合减弱，尤其在聚合物的无定形区内更为明显。 It is an amorphous colorless or white powder.它是一种无定形的无色或白色粉末。

7 component
n.组成部分，成分，元件；adj.组成的，合成的
参考例句：
Each component is carefully checked before assembly.每个零件在装配前都经过仔细检查。 Blade and handle are the component parts of a knife.刀身和刀柄是一把刀的组成部分。

8 components
（机器、设备等的）构成要素，零件，成分；成分( component的名词复数 )； [物理化学]组分； [数学]分量；（混合物的）组成部分
参考例句：
the components of a machine 机器部件 Our chemistry teacher often reduces a compound to its components in lab. 在实验室中化学老师常把化合物分解为各种成分。

9 alteration
n.变更，改变；蚀变
参考例句：
The shirt needs alteration.这件衬衣需要改一改。 He easily perceived there was an alteration in my countenance.他立刻看出我的脸色和往常有些不同。

10 quantitative
adj.数量的，定量的
参考例句：
He said it was only a quantitative difference.他说这仅仅是数量上的差别。 We need to do some quantitative analysis of the drugs.我们对药物要进行定量分析。

11 refinements
n.（生活）风雅；精炼( refinement的名词复数 )；改良品；细微的改良；优雅或高贵的动作
参考例句：
The new model has electric windows and other refinements. 新型号有电动窗和其他改良装置。来自《简明英汉词典》 It is possible to add a few useful refinements to the basic system. 对基本系统进行一些有益的改良是可能的。来自《简明英汉词典》

12 parameters
因素，特征；界限；（限定性的）因素( parameter的名词复数 )；参量；参项；决定因素
参考例句：
We have to work within the parameters of time. 我们的工作受时间所限。 See parameters.cpp for a compilable example. This is part of the Spirit distribution. 可编译例子见parameters.cpp.这是Spirit分发包的组成部分。

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