铋镓共掺的高浓度掺铒石英基光纤中铒离子团簇率的实验研究

使用MCVD法结合溶液掺杂技术制作了铒铋镓共掺的石英基光纤.根据光纤吸收谱，得出其中铒离子浓度是5.24×10²⁵/m³.然后提出了一种新的利用透射率测定掺铒光纤的团簇率的实验方法，该方法相比于以前的方法更简单有效.利用该方法，测得了自制铒铋镓共掺光纤中团簇率.通过与前人的结果相比较，充分说明铋和镓的掺入大大提高了铒离子在石英基光纤中的溶解度，抑制了铒离子形成团簇.     

芪3在铅-锡-氟磷酸盐玻璃中的聚集及光谱特性

采用低温熔融法制备了有机染料芪3掺杂的不同浓度的铅-锡-氟磷酸盐玻璃,通过对掺杂玻璃激发光谱、发射光谱和吸收光谱的测试,研究了芪3在无机玻璃中的聚集状态和光谱性能。 结果表明,有机染料芪3以单体和二聚物的形式共存于无机玻璃中,和芪3单体分子的激发峰相比,二聚物的激发峰位于短波段,随掺杂浓度的增加,掺杂玻璃的发射峰发生红移,同时在荧光光谱中观察到浓度猝灭现象;芪3分子与无机玻璃通过亲水作用发生了键合,从而导致芪3在无机玻璃中的吸收光谱和发射光谱比在乙醇溶液中出现较大红移;与芪3在乙醇溶液中的荧光强度相比,芪3分子受无机玻璃的“笼”化作用有效的提高了其荧光强度。     

Geometries, stabilities, and electronic properties of gold-magnesium (AunMg) bimetallic clusters

The geometrical structures, relative stabilities, and electronic properties of bimetallic Au_nMg (n=1-8) clusters have been systematically investigated by means of first-principle density functional theory. The results show that the ground-state isomers have planar structures for n=1-7. Here, the calculated fragmentation energies, the second-order difference of energies, the highest occupied-lowest unoccupied molecular orbital energy gaps, and the hardness exhibit a pronounced odd-even alternation, manifesting that the clusters, especially Au₂Mg, with even-number gold atoms have a higher relative stability. On the basis of natural population analysis, the charge transfer and magnetic moment are also discussed.     

Structures, stabilities and magnetic properties of FeCon−1 (n≤16) clusters

Under GGA, size dependence of the geometrical structures, stabilities and magnetic properties of FeCo_n−1 clusters (n≤16) have been investigated together with the Co_n clusters for comparison using DFT within the PAW method implemented in VASP. The replaced Fe atom is favorable to occupy the surface position except for FeCo₁₃. The peaks appeared at n=6, 9 and 11 for FeCo_n−1 clusters and at n=6, 9 and 12 for Co_n clusters on the size dependence of second difference of total energy imply that these clusters possess relatively higher stability. The magnetic moment is strongly correlated with the effective hybridization, which is closely related to the average bond length 〈d〉 and average coordination number 〈n_c〉. A small change in the total charge of Fe atom in FeCo_n−1 clusters will lead to a relative large reverse change in the total magnetic moment of Fe atom.     

Controlled quantum state sharing of arbitrary two-qubit states with five-qubit cluster states

In this paper, we propose a controlled quantum state sharing scheme to share an arbitrary two-qubit state using a five-qubit cluster state and the Bell state measurement. In this scheme, the five-qubit cluster state is shared by a sender (Alice), a controller (Charlie), and a receiver (Bob), and the sender only needs to perform the Bell-state measurements on her particles during the quantum state sharing process, the controller performs a single-qubit projective measurement on his particles, then the receiver can reconstruct the arbitrary two-qubit state by performing some appropriate unitary transformations on his particles after he has known the measured results of the sender and the controller.     

酞菁铜成膜特性的多重分形谱

运用多重分形理论,研究了酞菁铜颗粒的团聚生长成膜特性.研究表明薄膜生长是远离平衡态过程,在团聚生长中,颗粒分布有很大随机性,存在大范围的非均匀区域,这些区域具有多重分形特征.测试了酞菁铜对二氧化氮的气敏特性,结果表明通气前后,涂膜通道的频率有明显移动.     

Structural, electronic and vibrational properties of indium oxide clusters

Geometric, electronic and vibrational properties of the most stable and energetically favourable configurations of indium oxide clusters In_mO_n (1≤m, n≤4) are investigated using density functional theory. The lowest energy geometries prefer the planar arrangement of the constituent atoms with a trend to maximize the number of ionic In-O bonds. Due to the charge transfer from In to O atoms, the electrostatic repulsion occurs between the atoms with the same kind of charge. The minimization of electrostatic repulsion and the maximization of In-O bond number compete between each other and determine the location of the isometric total energy. The most stable linear In-O-In-O structure of In₂O₂ cluster is attributed to the reduced electrostatic repulsive energy at the expense of In-O bond number, while the lowest energy rhombus-like structure of In₂O₃ cluster reflects the maximized number of In-O bonds. Furthermore, the vibrational frequencies of the lowest energy clusters are calculated and compared with the available experimental results. The energy gap and the charge density distribution for clusters with varying oxygen/indium ratio are also discussed.     

Remote preparation of a two-particle state using a four-qubit cluster state

We present a scheme of remote preparation of two-particle states using a particular four-qubit cluster state as the quantum channel. The probability of success regarding this preparation scheme is calculated in both general and some particular cases. Our results show that in general such remote state preparation can be realized with a probability of 1/4. But in several special cases, the probability of success can be improved to 1/2 or even 1.     

基于改进粒子群优化算法的氩原子团簇结构优化

采用改进粒子群优化算法(IPSO)结合Lennard-Jones势对氩原子团簇结构进行优化,得到了氩原子团簇的稳态结构能量。以氩原子团簇Arn（n = 2-14）为例,验证了该方法的有效性。结果表明,应用本文提出的方法可得到对称性良好的团簇结构。与基本粒子群优化算法(BPSO)及遗传算法(GA)相比,改进粒子群优化算法具有更好的收敛特性,能较快地得到氩原子团簇结构的最优解。     

Mn12-Ac磁性分子团簇单晶的热重-差热分析与结构转变

通过热重-差热分析(TG-DTA)，考察了Mn12-Ac磁性分子晶体从室温到270℃的热失重过程.结合x射线粉末衍射分析，认为在第一个失重阶段，即25—110℃，Mn12-Ac失去了处于团簇分子间隙的结晶乙酸和结晶水，同时失去了团簇分子中与4个Mn3+配位的4个H2O，Mn12-Ac单晶结构被破坏，但是团簇分子的基本结构依然存在；在第二个失重阶段，即180—230℃，Mn12-Ac转变为γ-Mn2O3，其中混有少量Mn3O4. 关键词： Mn12 分子团簇 热重-差热分析 x射线衍射