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单羰基镧的键合异构现象 总被引:1,自引:0,他引:1
在过渡金属联基化合物中,谈基以碳端与金属原子结合,未发现由CO配位造成的键台异构现象山.稀土摄基化合物是一类新的金属联基化合物,迄今只有少数稀土元素的谈基化合物在低温下用基质隔离法合成出来和测定了红外光谱问,其结构和化学键的研究尚未见报导.稀土元素对氧有很强的化学余合力,当碳基与稀土元素结合时,CO是以碳端配位还是以氧端结合?为了回答这个问题,我们用高精度密度泛困理论方法问研究了单碳基润的结构和化学键合情况.结果表明、在稀土族基化合物中,谈基还是优先以碳端配位,但亦可以氧端与稀土元素结合,即可能存… 相似文献
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物流中心的分布对现代物流活动有很大的影响,物流中心合理的选址能够减少货物运输费用,大大降低运营成本,从而提高企业竞争力.本文在连续模糊有序加权算子的基础上,提出一种新的处理模糊数据信息方法,同时在专家权重无法确定的情况下,建立了一种新的基于离差最小的目标规划模型来集结专家群体的不同偏好,并将其运用在物流选址中,该方法避... 相似文献
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A new bipartite entangled state describing the parametric down-conversion process and its applications in quantum optics 下载免费PDF全文
We construct a new bipartite entangled state(NBES),which describes both the squeezing and the entanglement involved in the parametric down-conversion process and can be produced using a symmetric beam splitter.Constructing asymmetric ket-bra integrations based on the NBES leads to some new squeezing operators,which clearly exhibit the relationships between squeezing and entangled state transformations.Moreover,an entangled Wigner operator with a definite physical meaning is also presented. 相似文献
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Y.-H. Zhang 《International Journal of Theoretical Physics》2013,52(1):302-311
We investigate the quantum phase transition (QPT) and thermal entanglement in the two-qubit Ising model in an inhomogeneous magnetic field, and the DM interaction between the two lattices is considered. The results show the QPT highly relates to the magnetic intensity B and DM parameter D, by controlling the DM interaction D and external magnetic B we can change the positions of QPT points and the level spacing. Moreover, the QPT is closely related to thermal entanglement, when the QPT happens the ground state always changes between entanglement state and disentanglement state. The thermal entanglement highly depends on the system’s temperature T, DM intensity D and external magnetic field B. When T is lower, the entanglement can exhibit a platform-like region. By modulating the parameters D and B, the entanglement can be controlled and the entanglement switch can be realized. 相似文献
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利用高温固相法合成了Zn2GeO4∶Mn2+以及Zn2GeO4∶Mn2+,Yb3+绿色发射长余辉发光材料,对样品进行了X射线衍射分析、荧光光谱分析、色坐标、热释发光以及发光寿命测量。分析结果表明,在1 050℃下烧结3 h的Zn2GeO4为单相产物,所得Zn2GeO4∶Mn2+发光材料具有良好的发光性能,在紫外灯激发下发出最强发射位于528 nm的宽带发射并具有优良的长余辉发光特性,其色坐标值分别为x=0.145,y=0.773。Yb3+共掺杂对其长余辉发光性能提高明显。余辉发光在暗场环境下肉眼可观察的持续时间超过2 h。通过热释光谱对陷阱进行了分析。对Yb3+共掺杂的长余辉发光增强机理进行了讨论。 相似文献