| Historically, Ge has been considered to be a neutron-capture element. In this case, the r-process abundance of Ge is derived by subtracting the s-process abundance from the total abundance in the Solar system. However, the Ge abundance of the metal-poor star HD 108317 is lower than that of the scaled ‘residual r-process abundance’ in the Solar system, about 1.2dex.In this paper, based on a comparison of the Ge abundances of metal-poor stars and stellar yields, we find that the Ge abundances are not the result of the primary-like yields in massive stars and come mainly from the r-process. Based on the observed abundances of metal-poor stars, we derived the Ge abundances of the weak r-process and main r-process. The ontributed percentage of the neutron-capture process to Ge in the Solar system is about 59 per cent,which means that the contributed percentage of the Ge ‘residual abundance’ in the Solar system is about 41 per cent. We find that the Ge ‘residual abundance’ is produced as secondary-like yields in massive stars. This implies that the element Ge in the Solar system is not produced solely by the neutron-capture process.Unusual elemental abundances in globular cluster Palomar 1(Pal 1) could provide important information for us to study the relation between the globular cluster and our Galaxy.In this work, we study the abundances of α elements, Fe-peak elements, and neutron-capture elements in Pal 1. We found that the abundances of the SNe Ia and main s-process components of Pal 1 are larger than those of the disk stars and the abundances of the primary component of Pal 1 are smaller than those of the disk stars with similar metallicity. The Fe abundances of Pal 1 and the disk stars mainly originate from the SNe Ia and the primary component, respectively. Although the α abundances dominantly produced by the primary process for the disk stars and Pal 1, the contributions of the primary component to Pal 1 are smaller than the corresponding contributions to the disk stars. The Fe-peak elements V and Co mainly originate from the primary and secondary components for the disk stars and Pal 1, but the contributions of the massive stars to Pal 1 are lower than those of the massive stars to the disk stars. The Y abundances mainly originate from the weak r-component for the disk stars.However, the contributions of the main s-components and main r-components to Y are closeto those of the weak r-component for Pal 1. The Ba abundances of Pal 1 and the disk stars mainly originate from the main s-component and the main r-component, respectively. Our calculated results imply that the unusual abundances of Pal could be explained by the top-light IMF for Pal 1’s progenitor-system.Many works engaged to investigate the astrophysical origin of the neutron-capture elements in the metal-poor star HD 140283. However, no definite conclusions have been drawn. In this work, using the abundance-decomposed approach, we find that the metal-poor star HD 140283 is a weak r-process star. Although this star is a weak r-process star, its Ba abundance mainly originate from the main r-process. This is the reason that the ratio [Ba/Eu]=-0:58 ± 0:15 for HD 140283 is close to the ratio of the main r-process. Based on the comparison of the abundances in the six weak r-process stars, we find that their element abundances possess robust nature. Furthermore, we find that not only the abundances of the heavier neutron-capture elements but also the abundances of the lighter neutron-capture elements in the extreme main r-process stars([Eu/Fe]>1.5) possess robust nature. The abundance robustness of the two category r-process stars could be used as the constraint of the r-process theory and be used to investigate the astrophysical origins of the elemental abundances of the stars. |
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