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Na3La2(BO3)3的晶体结构 总被引:1,自引:1,他引:0
以Na2CO3-H3BO3-NaF为助熔剂,使用顶部籽晶法生长出Na3La2(BO3)3透明单晶.测定了Na3La2(BO3)3的晶体结构,该晶体属正交晶系,空间群:mm2(No.38),晶胞参数为a=0.51580(10)nm,b=1.1350(2)nm,c=0.73230(15)nm,α=β=γ=90°,V=0.42871(15)nm3,密度:.053g/cm3.晶体结构中的硼氧基团是平面的BO3基团,BO3基团相互独立,且与Na(1)O6、Na(2)O8、Na(3)O6和La(1)O9配位多面体连结形成三维网络骨架结构.讨论了Na3La2(BO3)3的晶体结构与倍频效应的关系. 相似文献
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为了克服现有的WSN节点故障诊断方法所具有的难以实现在线诊断和诊断精度仍然不够高的缺点,设计了一种基于Sarsa算法和改进蚁群算法的WSN节点在线故障诊断方法。首先,建立了监测区域的网络模型和WSN节点故障诊断模型,然后,采用主成分分析法对节点故障样本数据进行降维,从而提高诊断效率,将样本数据作为层次,将故障诊断类作为各层节点建立层次树,采用改进的Sarsa算法求取各层节点的Q值,并将其用于初始化蚁群算法中路径的信息素,最后,提出了一种改进的蚁群算法求取从第一层出发的蚁群到各层节点之间的路径,将各层中信息素最大的节点作为最终的故障诊断类别。在Matlab环境下进行仿真实验,结果证明文中方法能有效实现WSN节点故障诊断,且与其它方法相比,具有故障诊断精确度高且能在线故障的优点,是一种有效的节点故障诊断方法。 相似文献
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Effects of Contact Atomic Structure on Electronic Transport in Molecular Junction 总被引:1,自引:0,他引:1 下载免费PDF全文
Based on nonequilibrium Green's function and first-principles calculations, we investigate the change in molecular conductance caused by different adsorption sites with the presence of additional Au atom around the metal- molecule contact in the system that benzene sandwiched between two Au(111) leads. The motivation is the variable situations that may arise in break junction experiments. Numerical results show that the enhancement of conductance induced by the presence of additional Au is dependent on the adsorption sites of anchoring atom. When molecule is located on top site with the presence of additional Au atoms, it can increase molecular conductance remarkably and present negative differential resistance under applied bias which cannot be found in bridge and hollow sites. Furthermore, the effects of different distance between additional Au and sulfur atoms in these three adsorption sites are also discussed. 相似文献
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