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641.
Sc2O@Td(19151)‐C76: Hindered Cluster Motion inside a Tetrahedral Carbon Cage Probed by Crystallographic and Computational Studies
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Ting Yang Yajuan Hao Laura Abella Qiangqiang Tang Prof. Dr. Xiaohong Li Yingbo Wan Dr. Antonio Rodríguez‐Fortea Prof. Dr. Josep M. Poblet Prof. Dr. Lai Feng Prof. Dr. Ning Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(31):11110-11117
A new cluster fullerene, Sc2O@Td(19151)‐C76, has been isolated and characterized by mass spectrometry, UV/Vis/NIR absorption, 45Sc NMR spectroscopy, cyclic voltammetry, and single‐crystal X‐ray diffraction. The crystallographic analysis unambiguously assigned the cage structure as Td(19151)‐C76, which is the first tetrahedral fullerene cage characterized by single‐crystal X‐ray diffraction. This study also demonstrated that the Sc2O cluster has a much smaller Sc?O?Sc angle than that of Sc2O@Cs(6)‐C82 and the Sc2O unit is fully ordered inside the Td(19151)‐C76 cage. Computational studies further revealed that the cluster motion of the Sc2O is more restrained in the Td(19151)‐C76 cage than that in the Cs(6)‐C82 cage. These results suggest that cage size affects not only the shapes but also the cluster motion inside fullerene cages. 相似文献
642.
Rui-Hua Xiao Zhan-Ying Guo Shi-Qun Zhu Jian-Xing Fang 《International Journal of Theoretical Physics》2013,52(6):1721-1728
The dynamical behaviors of quantum discord between two atoms coupled with a vacuum cavity are investigated. If the two qubits are initially prepared in two extended Werner-like states, the quantum discord and entanglement can be numerically calculated. There are remarkable differences between the time evolutions of the quantum discord and entanglement under the same conditions. These results imply that quantum discord is not zero for some unentangled states and in some regions entanglement can disappear completely. A large amount of quantum discord exists between the two-qubit. Thus, the quantum discord is more robust than entanglement for the quantum system exposed to the environment. The quantum discord shows sudden change and its existence depends on the initial state of the system. This property of quantum discord may have important implications for experimental characterization of quantum phase transitions. 相似文献
643.
Micro-arc oxidation (MAO) is commonly applied to modify the surface of titanium (Ti)-based medical implants with a bioactive and porous Ti oxide (TiO2) coating. The study reports a new method of incorporating hydroxyapatite (HA) within the TiO2 coating by MAO and alkali heat treatment (AHT) in the solution containing Ca ion and P ion. The morphology, composition and phase composition of the coatings were analyzed with scanning electron microscopy with energy-dispersive X-ray spectrometer and X-ray diffraction. Surface topography and roughness of the coatings were investigated by atomic force microscopy operated in the tapping mode. The results showed that TiO2-based coatings were obtained on pure Ti by MAO with an electrolyte containing Ca ion and P ion; the prepared MAO coatings were mainly composed of Ca, P, O and Ti. AHT transformed Ca and P to HA crystals. In conclusion, the TiO2/HA composite coatings can be obtained on the surface of pure Ti by MAO and AHT, and the addition of Ca ion and P ion to the AHT solution contributed to the formation of HA. 相似文献
644.
Huan Pang Zhenzhen Yan Yuanyuan Wei Xuexue Li Juan Li Li Zhang Jing Chen Jiangshan Zhang Honghe Zheng 《Particle & Particle Systems Characterization》2013,30(3):287-295
Nickel posphite (Ni11(HPO3)8(OH)6) hexagonal polyhedrons are successfully synthesized under hydrothermal conditions. The effect of surfactants on the growth mechanism of Ni11(HPO3)8(OH)6 are also explored. More importantly, Ni11(HPO3)8(OH)6 hexagonal polyhedrons are successfully applied as electrochemical supercapacitor electrode materials, which have a good specific capacitance (295 F g?1 at 0.625 A g?1), good rate capability, and cycling properties (maintained about 99.3% at 0.625 A g?1 after 1000 cycles). 相似文献
645.
采用熔融法制备了一种组分为80TeO2-10Al2O3-10Cs2O-xYb2O3(x=0~1.6)(mol%)的掺镱碲酸盐玻璃材料,测试了该玻璃材料的密度、热膨胀系数和折射率随波长的变化关系,分析了其吸收光谱、荧光光谱和荧光寿命随Yb3+浓度的变化性质.利用McCumber理论计算了该玻璃系统中Yb3+离子从2F5/2到2F7/2能级跃迁的受激发射截面.实验表明:当Yb2O3掺杂量为1mol%时,Yb3+在1 004nm波长处的发射截面为1.06×10-20 cm2,荧光有效线宽为89.6nm,荧光寿命达到最大值为0.80ms.激光性能评价结果表明,该掺镱碲酸盐玻璃是实现超短脉冲激光的候选材料之一. 相似文献
646.
In this paper, we give some properties of regular (LM)-spaces and α-regular (LM)-spaces and investigate the relationship among them. 相似文献
647.
Ni nanocontacts have been grown by electrodeposition using a self-terminating technique in a single electrolyte bath based on nickel sulfate, nickel chloride and boric acid. Resistance measurements performed on different samples presented two kinds of obviously different magnetoresistance effects. The analysis of the data sets showed that magnetostriction might play a key role in magnetoresistance of the electrodeposited Ni nanocontacts. 相似文献
648.
以统一的形式,得到了极值过程的跳时点过程的精致渐近性的一般结果,揭示了精致渐近性研究中拟权函数,边界函数,收敛速度以及极限状态之间的有机关系,从而可以给出许多新的具体结果。 相似文献
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