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Single-particle resonance states of 122Zr are studied in the real stabilization method within the framework of relativistic mean field theory. Two efficient methods are adopted to extract the resonance energy and width of 122Zr. The results are compared with those obtained from the analytic continuation in the coupling approach and scattering phase-shift methods. 相似文献
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在具有伸缩子的QCD势模型中的重介子 总被引:1,自引:0,他引:1
从伸缩子–胶子有效耦合理论得到的重夸克–反夸克势模型出发,计算了重介子的自旋平均能谱及轻子衰变和辐射跃迁宽度,并与Cornell势模型所得到的相应结果作了比较.结果表明,新的重夸克势的计算结果与重介子的实验数据更好地符合,而且估计的伸缩子质量5?7MeV很好地位于有关伸缩子质量的其他理论途径所估计的范围之内. 相似文献
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钛酸酯催化碳酸二甲酯与苯酚酯交换反应 总被引:15,自引:0,他引:15
The transesterification of phenol and dimethyl carbonate (DMC) to diphenyl carbonate (DPC) was studied using tetrabutyl titanate and tetraphenyl titanate as catalysts. The main product was found to be methyl phenyl carbonate (MPC) which is an intermediate of the reaction. The selectivity for DPC was improved when increasing the phenol/DMC molar ratio or prolonging the reaction time. The phenol conversion, selectivity for MPC and DPC were 47 4%, 90 9% and 9 14%, respectively, when the transesterification reaction approached equilibrium under the conditions of 175 ℃, 25 h and DMC∶phenol∶ Ti(OBu) 4 molar ratio of 1 5∶1∶0 05. The selectivity for DPC could reach 12.2% when the reaction time was 30 h. The tetrabutyl titanate catalyst showed a higher catalytic activity than tetraphenyl titanate. 相似文献
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采用变分累积展开方法,研究了立方格点上磁性薄膜的热动力学性质.计算自发磁化强度、 内能和热容到了三级累积展开,并对每一级给出了这些物理量对薄膜原子层数的依赖关系. 虽然变分累积展开的收敛性还没有严格证明,但计算结果显示这些物理量的变分累积展开收 敛很快.三级计算结果足已表明:对低于某一临界厚度的薄膜,自发磁化强度随原子层数的 减少而减小;不论在临界温度以下,还是在临界温度以上,每单位格点的内能都随原子层数 的减少而增大;每单位格点的热容在临界温度以下随原子层数的减少而增大,但在临界温度 以上随原子层数的减
关键词:
磁性薄膜
热动力学性质
变分累积展开 相似文献
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离子选择性电极电位滴定法测定维生素B1的含量 总被引:4,自引:0,他引:4
1 引言 维生素B1化学名称为氯化4-甲基-3-[(2-甲基-4-氨基-5-嘧啶基)甲基]-5-(2-羟基乙基)噻唑盐酸盐,作为一种药物,可以维持正常糖代谢及神经消化系统功能,用于防治缺乏维生素B1所致的脚气病,也用于神经炎、消化不良等症的辅助治疗.目前我国药典法规定维生素B1注射液及其片剂中维生素B1含量采用分光光度法测定.国外有人研究采用银离子选择性电极,在0.5mol/L NaOH溶液中用电位滴定法测定维生素B1含量,而国内未见报道.本研究采用离子选择性电极,在水溶液中用电位滴定法测定维生素B1的含量. 相似文献
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介绍了量子场论中基于准势途径的一个相对论夸克模型,并使用这个相对论夸克模型计算了重夸克偶素的质量谱.显示这个相对论夸克模型可较好地拟合实验上肯定的质量谱数据. A relativistic quark model based on the quasipotential approach in quantum field theory is briefly introduced, and by using this model, heavy quarkonium mass spectra are calculated in detail. It is shown that such a model can give results which are in agreement with the observed experimental data on the mass spectra. 相似文献
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