Has verse 34 of Surat An-Nisa, which permits a husband to gently strike his wife, been abrogated by the first twenty verses of Surat An-Nur, which discuss al-Li'an (mutual imprecation)?

The verse ("Men are in charge of women") is not abrogated; rather, it is definitive, and its ruling is firm. The proof for this is that the default for verses is non-abrogation, and the verses in Surat An-Nur, which speak about the punishment for the fornicator and mutual imprecation, have no relation to the disobedience of the wife mentioned in the verse from Surat An-Nisa. Furthermore, the Prophet's Sunnah affirmed the striking mentioned in the verse and interpreted it as a light, non-injurious striking. None of the scholars have ever said that this verse is abrogated. The striking in this verse is not recommended; rather, it is better not to use it, and if it is used, it has regulations and conditions. The Prophet, peace and blessings be upon him, disliked striking the wife when angry.