forbot
所有国家
中国 蚌埠 预定 Dredge-up | 价值  ,中国 蚌埠 Dredge-up 的信息,ANHUI Province Dredge up Engineering Head co.. 土地工作 | Allbiz
汉语
    中国 蚌埠 预定 Dredge-up | 价值  ,中国 蚌埠 Dredge-up 的信息,ANHUI Province Dredge up Engineering Head co.. 土地工作 | Allbiz
    货币 (CNY)
    中国 蚌埠 预定 Dredge-up | 价值  ,中国 蚌埠 Dredge-up 的信息,ANHUI Province Dredge up Engineering Head co.. 土地工作 | Allbiz
    所有分类
    添加到收藏栏
    分享   ID: 47766:1613
    预定 Dredge-up
    介绍

    Dredge-up refers to a period in the evolution of a star where a surface convection zone extends down to the layers where material has undergone nuclear fusion. As a result, the fusion products are mixed into the outer layers of the stellar atmosphere and these nuclides can appear in the spectrum of the star.

    The first dredge-up occurs when a main sequence star enters the red giant branch (RGB). As a result of the convective mixing, the outer atmosphere will display the spectral signature of hydrogen fusion: the 12C/13C and C/N ratios are lowered, and the surface abundances of lithium and beryllium may be reduced.

    The names of the dredge-ups are set by the evolutionary and structural state of the star in which each occurs, not by the sequence experienced by the star. As a result, lower-mass stars experience the first and third dredge-ups in their evolution but not the second.
    照片
    • Dredge-up
    • more

      希望看到更多的图片?

      发消息
    购买 dredge-up
    预定
    Dredge-up
    定价
    或联系卖家
    Try to describe briefly the essence of your question to the seller (at least 20 symbols)
    返回上一级在部分中 "土地工作"
    参见 服务 分类 "土地工作, 地槽, 贮水池构造"

    就商品
    您消息不准少于20字符。消息不能超过2000字符。
    必填栏位不能为空
    栏位填写有误
    栏位填写有误
    比较0
    清除Selected items: 0