泄漏辐射模显微镜测量薄膜的局域双折射率

介质双折射率的传统测量方法有偏振光椭圆率测量仪和光学相干断层扫描等.提出一种新型的介质双折射率测量方法--切向偏振光照明的泄漏辐射模显微镜激励波导模共振,通过对物镜后焦面的傅里叶光谱信息进行成像,测量介质的双折射率.分析了利用切向偏振光照明的泄漏辐射模显微镜测量介质双折射率的原理并测量了双折射率差为△n≈0.005的偶...     

Photonic Crystal Fibre SERS Sensors Based on Silver Nanoparticle Colloid

A photonic crystal fibre （PCF） surface enhanced Raman scattering （SERS） sensor is developed based on silver nanoparticle colloid. Analyte solution and silver nanoparticles are injected into the air holes of PCF by a simple modified syringe to overcome mass-transport constraints, allowing more silver nanoparticles involved in SERS activity. This sensor offers significant benefit over the conventional SERS sensor with high flexibility, easy manufacture. We demonstrate the detection of 4-mercaptobenzoic acid （4-MBA ） molecules with the injecting way and the common dipping measurement. The injecting way shows obviously better results than the dipping one. Theoretical analysis indicates that this PCF SERS substrate offers enhancement of about 7 orders of magnitude in SERS active area.     

锂离子电池正极材料LiCoO2的制备新方法

利用电解金属制得Co(OH)2-2xRx(其中R为有机酸和无机酸根离子)中间产物,然后根据钴含量与LiOH.H2O固相反应制得了LiCoO2.通过X光衍射,扫描电镜以及激光粒度测试表明,所得的锂离子正极材料LiCoO2结构纯正,粒度分布集中,比表面积较大;对其进行充放电实验表明,放电容量比较高,首次放电容量达到146mAh/g,循环10次后容量仍保持在142 mAh/g.该法可大大降低制备LiCoO2的生产成本,具有十分广阔的应用前景.     

Lu2O3对球形Ni(OH)2高温充放电性能的影响

为了改善镍电极的高温充电效率，采用机械混合的方式将球形Ni(OH)2与不同比例的Lu2O3混合后制成粘结式镍正极。充放电测试、循环伏安和XRD等实验结果表明，掺杂Lu2O3后镍电极的析氧过电位明显提高，高温充电效率得到了很大改善，在充电后的电极中β-NiOOH生成；而且Lu2O3的掺杂比例对镍电极的高温性能在不同的充放电倍率下有不同程度的影响，3．5％是最好的掺杂比例，掺杂对高温小电流充电效率的改善作用要大于高温大电流充电。     

LaNi4Fe催化合成氨反应性能的研究

用冶金法、还原扩散法、共沉淀法制得了LaNiFe,并对其催化合成氨反应性能进行了研究。实验结果表明:还原扩散法,共沉淀法制得的LaNi_4Fe催化活性均比冶金法好。X—射线分析指出LaNi_4Fe在合成氨反应过程中变为Ni_4Fe和LaN。     

Y掺杂对氢氧化镍电极高温性能的影响

合成了内掺稀土元素Y的β-Ni(OH)2和α-Ni(OH)2材料, 并通过XRD、TEM、CV 和充放电测试等方法研究了Y元素对这两种晶型活性材料的结构、形貌以及高温电化学性能方面的影响, 发现Y元素可显著提高β-Ni(OH)2和α-Ni(OH)2材料的高温性能, 且作用机理相同, 均是通过提高析氧过电位来改善镍电极的高温充电效率. 但是α-Ni(OH)2在高温下的相稳定性仍有待提高.     

微波法制备掺碳LiFePO4正极材料

Cathode material LiFePO₄ of lithium-ion battery was synthesized by microwave heating. The “carbon-included” LiFePO₄ with improved conductivity was synthesized by the addition of graphite. And the influence of microwave-heating time on structure, morphology and charge/discharge performance of the products was discussed. The results of XRD, SEM, XPS, CV and charge/discharge testing measurements showed that the LiFePO₄ product after 9 min in microwave oven had more advantages than other products.     

锂离子二次电池正极材料LiVPO4F的制备及其电化学性能的研究

A new cathode material, LiVPO₄F, has been synthesized through two steps of solid-state reactions. In the first step, vanadium pentoxide, ammonium dihydrogen phosphate, and a high surface area carbon were pre-heated at 300 ℃ and reacted at 750 ℃ under an inert atmosphere to yield the trivalent vanadium phosphate VPO₄. In the second step, the product LiVPO₄F was synthesized by the reaction with VPO₄ and LiF. The LiVPO₄F was characterized by X-ray diffraction, scanning electron microscopy, cyclic voltammetry and charge/discharge testing measurements. The LiVPO₄F is triclinic crystalline system. At 0.1 C rate, the first charge/discharge capacities were 150.1 mAh·g^-1 and 132.6 mAh·g^-1; At 0.2 C rate, the first charge/discharge capacities were 142.9 mAh·g^-1 and 125.2 mAh·g^-1. The LiVPO₄F from this work has higher charge/discharge voltage 4.3 V and 4.1 V, respectively.     

核壳结构的锂离子电池材料

核壳结构材料可以实现核与壳功能的复合与互补,近年来核壳结构的设计理念也被引入到锂离子电池材料中。本文综述了纳米/亚微米核壳结构锂离子电池材料的制备方法、电化学性能和结构稳定性等方面的最新研究进展,评述了该类材料存在的问题并展望了其发展前景。商业化的锂离子电池材料还不能满足高能量密度和安全性等多方面的要求,通过合成核与壳功能互补的材料,可望提高材料的综合性能.     

不同气氛退火对Tl2Ba2CaCu2Ox超导电性的影响

本研究了Ａｒ气和Ｈ２／Ａｒ混合气体退火对Ｔｌ２Ｂａ２ＣａＣｕ２Ｏｘ（２２１２）超导体超导电性的影响。实验表明，在Ａｒ气中４００℃退火１至１２小时后Ｔｌ２Ｂａ２ＣａＣｕ２Ｏｘ的Ｔｃ（Ｒ＝０）随退火时间的增长明显降低。Ｘ－光衍射分析证实，在Ａｒ气或Ｈ２／Ａｒ混合气体中退火前后，Ｔｌ２Ｂａ２ＣａＣｕ２Ｏｘ超导体的结构没有发生变化。