排序方式: 共有11条查询结果,搜索用时 578 毫秒
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研究了代数多项式导数的Bernstein不等式和Markov不等式.通过代数多项式导数的一个积分表示式,给出这两个著名不等式以及它们的离散形式的证明. 相似文献
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主要研究股票价格的变化及对其拟合的方法.在介绍了关于分形和遗传算法的要点后,首先从理论上说明了分块分形插值的逆问题,进而做了具体的数据分析,对大量股票价格数据进行模拟,得到了较为满意的结果,说明这种方法是可行的. 相似文献
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The molecular structure and radical scavenging activity of three novel antioxidants from Lespedeza Virgata, lespedezavirgatol, lespedezavirgatal, and lespedezacoumestan, have been studied using density functional theory with the B3LYP and BhandHLYP methods. The optimized geometries of neutral, radical cation, radical and anion forms were obtained at the B3LYP/6-31G(d) level, in which it was found that all the most stable conformations contain intramolecular hydrogen bonds. The same results were obtained from the MP2 method. The homolytic O-H bond dissociation enthalpy and the adiabatic ionization potential of neutral and anion forms for the three new antioxidants and adiabatic electron affinity and H-atom affinity for hydroxyl radical, superoxide anion radical, and hydrogen peroxide radical were determined both in gas phase and in aqueous solution using IEF-PCM and CPCM model with UAHF or Bondi cavity. The antioxidant activities and reactive oxygen species scavenging mechanisms were then discussed, and the results obtained from different methods are consistent. Furthermore, the antioxidant activities are consistent with the experimental findings of the compounds under investigation. 相似文献
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