11 research outputs found

    The Alpha Magnetic Spectrometer (AMS) on the international space station: Part II — Results from the first seven years

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    The Alpha Magnetic Spectrometer (AMS) is a precision particle physics detector on the International Space Station (ISS) conducting a unique, long-duration mission of fundamental physics research in space. The physics objectives include the precise studies of the origin of dark matter, antimatter, and cosmic rays as well as the exploration of new phenomena. Following a 16-year period of construction and testing, and a precursor flight on the Space Shuttle, AMS was installed on the ISS on May 19, 2011. In this report we present results based on 120 billion charged cosmic ray events up to multi-TeV energies. This includes the fluxes of positrons, electrons, antiprotons, protons, and nuclei. These results provide unexpected information, which cannot be explained by the current theoretical models. The accuracy and characteristics of the data, simultaneously from many different types of cosmic rays, provide unique input to the understanding of origins, acceleration, and propagation of cosmic rays.</p

    哈萨克斯坦和中国哈萨克马的母系遗传研究[J]

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    哈萨克马属于古老地方马品种,仅分布在哈萨克斯坦和中国新疆境内。哈萨克斯坦的哈萨克马产肉产奶性能大大高于新疆地区哈萨克马。本研究目的为探讨长期的地域分割和不同的育种方式,对两国哈萨克马遗传结构的影响,揭示哈萨克斯坦和中国新疆地区哈萨克马的母系遗传关系。研究方法:分别将线粒体DNA(mtDNA)D-loop区和功能基因ATP6-Arg(nps 7 974-9 963)区序列进行序列测定和分子遗传学分析。结果显示,哈萨克马分布于13个单倍体型组(笔者称为世系,字母排序A到Q),其中分布频率大于5%的世系有7个,哈萨克马世系种类占世界家马世系种类的72%,表明哈萨克马丰富的母系遗传背景。比较两国哈萨克..
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