酸洗处理对NaEuTiO4的结构、形貌以及电化学性能影响

采用溶胶-凝胶法合成了具有层状钙钛矿结构的NaEuTiO_4(NETO),并利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、循环伏安(CV)和充放电循环测试等方法对用稀硝酸溶液酸洗处理后的NETO在结构、形貌和电化学性能方面的变化做了表征。研究结果表明,对于NETO而言,除了文献报道的Na+→Li+离子交换路径外,还存在着Na~+→H~+→Li~+的离子交换路径,即NETO中的Na~+可以跟稀酸中的H~+发生离子交换。交换后得到的化合物HEuTiO_4可以在电池中通过电化学反应的方式转化为LiEuTiO_4。通过这样的路径得到的LETO具有相同优异的电化学性能,其中酸洗12 h的NETO具有最佳的电化学性能,经过300次循环后,其可逆容量约为213.2 mAh·g~(-1),而且表现出良好的倍率性能。     

基于咪唑基配体的Mn(Ⅱ)配合物的水热合成及结构、理论计算和三阶非线性光学性质

在水热条件下用氯化锰和咪唑基配体合成了配合物Mn[（IPB）₂Cl₂]·4H₂O（IPB=4-（1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl）benzaldehyde）,并通过元素分析、红外光谱、紫外衍射、X射线单晶衍射法和Z-扫描技术对其结构和性质进行了表征。X射线单晶衍射结果表明,该化合物晶体属正交晶系,空间群Pnna。采用Z-扫描技术测量了该化合物的非线性光学特性,结果显示,以45 μJ的脉冲能量,在焦点处的透光率为93%,非线性吸收系数为-4.5×10^-11 m·W^-1,非线性折射率为1.0×10^-19 m²·W^-1。该化合物显示了自聚焦的性质。在紫外-可见光谱区,该化合物的最大吸收波长为282nm。     

The Morphology Evolution of Nickel Phosphite Hexagonal Polyhedrons and Their Primary Electrochemical Capacitor Applications

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).     

掺镱TeO2-Al2O3-Cs2O玻璃的光谱性质

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.     

Surface modification of pure titanium by hydroxyapatite-containing composite coatings

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.     

Dynamics of Quantum Discord of Two-Qubit Coupled with a Vacuum Cavity

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.     

Some Properties of Regular and α-Regular （LM）-Spaces

In this paper, we give some properties of regular (LM)-spaces and α-regular (LM)-spaces and investigate the relationship among them.     

Magnetostriction and magnetoresistance in nanocontacts

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.     

极值过程的跳时点过程的精致渐近性

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。