The impact factor has been extensively used in the last years to assess journals visibility and prestige. While the impact factor is useful to compare journals, the specificities of subfields visibility in journals are overlooked whenever visibility is measured only at the journal level. In this paper, we analyze the subfields visibility in a subset of over 450,000 Physics papers. We show that the visibility of subfields is not regular in the considered dataset. In particular years, the variability in subfields impact factor in a journal reached 75% of the average subfields impact factor. We also found that the difference of subfields visibility in the same journal can be even higher than the difference of visibility between different journals. Our results show that subfields impact is an important factor accounting for journals visibility.

中文翻译：

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比较科学期刊中子领域的影响

影响因子在过去几年中被广泛用于评估期刊的知名度和声望。虽然影响因子对于比较期刊很有用，但只要仅在期刊级别衡量可见性，就会忽略期刊中子领域可见性的特殊性。在本文中，我们分析了超过 450,000 篇物理论文子集中的子领域可见性。我们表明子字段的可见性在所考虑的数据集中不规则。特别是几年，一个期刊子领域影响因子的变异性达到了平均子领域影响因子的75%。我们还发现，同一期刊中子领域可见度的差异甚至可以高于不同期刊之间的可见度差异。我们的结果表明，子领域的影响是影响期刊知名度的一个重要因素。