Both the transfer matrix approach and the Wentzel Kramers Brillouin(WKB) approximation are used to calculate the penetrability of
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decay for uranium isotopes. It is found that the penetrability obtained with WKB approximation is about 40% smaller than the accurate result obtained with the transfer matrix approach, and a parabolic relationship between this underestimation and the decay energy can be observed. Based on the cluster model, the half-lives of
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decay for uranium isotopes are calculated in which the transfer matrix approach is used to obtain the penetrability. In addition, the influences of potential depth
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, the diffuseness parameter
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, and the global quantum number
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on the calculated half-life are also investigated. Furthermore, with considering an isospin-dependent potential depth parameter, the
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decay half-lives of uranium isotopes can be fairly well reproduced by the cluster model.