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首先给出了Heisenberg李代数的两种定义形式,由这两种定义形式,我们得到了(2n 1)维Heisenberg李代数的自同构群Aut(H);此外,我们还给出Aut(H)的一些子群;并在低阶(n=0,1,2)情形下,讨论了Aut(H)与这些子群之间的关系. 相似文献
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An easy method is presented to fabricate monodisperse magnetic macroporous polymer beads(MMPBs). Waterin-oil high internal phase emulsion(HIPE) is prepared by emulsifying aqueous iron ions solution in an oil phase containing monomers. The HIPE is introduced into a simple microfluidic device to fabricate monodisperse(water-in-oil)-in-water double emulsion droplets. The droplets serve as microreactors to synthesize Fe3O4 nanoparticles and are on-line polymerized to form MMPBs. The prepared MMPBs display uniform size, interconnected porous structure, superparamagnetic behavior and uniform distribution of Fe3O4 in polymer matrix. The MMPBs are characterized by scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FTIR), X-ray diffraction(XRD), transmission electron microscopy(TEM), vibrating sample magnetometry(VSM). We believe that this method is a universal technique in preparing macroporous nanocomposite beads. 相似文献
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张海山 《首都师范大学学报(自然科学版)》1995,16(3):10-16
本文引入了根格Q的另一种表示方法和强正根格Q++的概念,构造了无穷点列Ⅰβ(β∈Q++)整数对集K,由此给出了判定不定型Kac-Moody代数IBn(a)(a≥5)的根格Q中的一个元素是正虚根的充分条件并确切描述了△^im+∩(-C^v)。 相似文献
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