锰含量对LiNi_(0.85-x)Co_(0.15)Mn_xO_2结构及形貌的影响

采用共沉淀法先合成出氢氧化物前驱体Ni0.85-xCo0.15Mnx(OH)2,其中X=0、0.1、0.2和0.4,前驱体与Li2CO3在空气气氛中固相烧结制得正极材料LiNi0.85-xCo0.15MnxO2。用XRD、SEM研究了锰含量对材料结构和形貌的影响。研究发现,LiNi0.85Co0.15O2的X射线衍射图中存在微量第二相,而锰掺杂有利于减小反应过程中锂离子损失和镍离子占据锂位,容易形成有序层状结构材料。随着Mn离子替代Ni离子量的增加,晶胞参数a减小,晶胞参数c、c/a及I003/I104值增大。SEM结果表明前驱体和最终产物形貌均随锰含量增加颗粒均匀性增强,粒子尺寸变小,粒径分布变窄。

力学未来15年国际学术讨论会论文集

Investigation on nonradiative decay of the (Er3+I13/2)-I-4 -> I-4(15/2) transition in different tellurite glass matrix

Three kinds of Er3+-doped tellurite glasses with different hydroxyl groups are prepared by the conventional melt-quenching method. Infrared spectra are measured to estimate the exact content of OH- groups in samples. The maximum phonon energy in glasses are obtained by measuring the Raman scattering spectra. The strength parameters Omega(t) (t = 2, 4, 6) for all the samples are calculated and compared. The nonradiative decay rate of the Er3+ I-4(13/2) -> I-4(15/2) transition are calculated for the glass samples with different phonon energy and OH- group contents. Finally, the effect of OH- groups on fluorescence decay rate of Er3+ is analysed, the constant KOH-Er Of TWN, TZPL and TZL glasses are calculated to be 9.2 x 10(-19) cm(4)s(-1), 5.9 x 10(-19) cm(4)s(-1), and 3.5 x 10(-19) cm(4)s(-1), respectively.

Effect of hydroxyl groups on nonradiative decay of Er3+: I-4(13/2)-> I-4(15/2) transition in zinc tellurite glasses

A series of zinc tellurite glasses of 75TeO(2)-20ZnO-(5-x)La2O3-xEr(2)O(3) (x=0.02, 0.05, and 0.1 mol%) with the different hydroxl groups were prepared by the conventional melt-quenching method. Infrared spectra were measured in order to estimate the exact content of OH- groups in samples. The observed increase of the fluorescence lifetime with the oxygen bubbling time has been related to the reduction in the OH- content concentration as evidenced by IR transmission spectra. Various nonradiative decay rates from I-4(13/2) of Er3+ with. the change of OH content were determined from the fluorescence lifetime and radiative decay rates were calculated on the basis of Judd-Ofelt theory. (c) 2005 Elsevier B.V. All rights reserved.

Comparison of spectroscopic parameters of 15 at% Yb : YAlO3 and 15 at% Yb : Y3Al5O12

Yb: YAlO3 (YAP) (15 at %) and Yb: Y3Al5O12 (YAG)(15 at %) have been grown using the Czochralski method. Their absorption and fluorescence spectra were measured at room temperature and important spectroscopic parameters were calculated. Through the comparison of spectroscopic parameters of Yb:YAP and Yb: YAG, all results indicate that 15 at % Yb:YAP crystal is a potential candidate used for compact, efficient thin chip lasers when the laser output wavelength is 1012 or 103 8 nm. (C) 2004 Elsevier B.V. All rights reserved.

新疆紫草高产细胞系的筛选及其特性分析

本文在本实验室提供的愈伤组织高产系A1，的基础上，进行了单细胞水平的高产系筛选，并获得几个具有较高生长速率和色素含量的高产细胞系：对两种水平的筛选系进行了比较，结果表明在单细胞水平上筛选可以获得更加优良的细胞系。 愈伤组织系A1和A5在生长培养基中具有不同的性状。A1系为红色，而A5系则呈白色;二者同时显示出不同的PAL活性变化以及不同的可溶性蛋白质的种类和酯酶同工酶、过氧化物同工酶谱带。当转入生产培养基中，这种差异消失。 本文还报道了在固体和液体培养条件下，培养物在生长培养基中的生长动态，在生产培养基中的色素形成动态，并分析了不同种龄对色素形成的影响。结果表明，在固体培养基中第27天是最佳的由生长培养基转入生产培养基的时问，在液体悬浮培莽基中则第9天是最佳的转接时问。