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卢希 《数学的实践与认识》2014,(20)
利用亚纯函数的Nevanlinna值分布理论,研究代数体函数第二基本定理的扩展形式,将该定理推广到两列互异且次数不超过d的多项式的情况,拓展了熊庆来、MillouX H等人的结果. 相似文献
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A thick natural uranium target was bombarded with a 60 MeV/u 18O beam. The neutron-rich isotope 230Ra as the target residue was produced through the multinucleon transfer reaction(238U-4p-4n). The barium and radium fraction as BaCl2 precipitate were radiochemically separated first from the mixture of uranium and reaction products. Then, the radium fraction was separated from BaCl2 precipitate by using cation exchange technique. The γ-ray spectra of the Ra fraction were measured using an HPGe detector. The production cross sections of 230Ra were obtained by a combination of the radiochemical separation technique and off-line γ-ray spectroscopy. The cross section of 230Ra has been determined to be 66±20 μb. 相似文献