气相交换平衡技术在获得近化学计量比LiNbO3晶体中的应用

本文详细介绍了利用气相交换平衡（vapor transport equilibration:VTE)技术获得近化学计量比铌酸锂晶体薄片及其处理工艺。通过测量其OH^-红外吸收谱线宽及吸收边的位置，分析确定晶体薄片中的Li2O含量为49．9％，即[Li]/[Nb]=0.996，接近其化学计量比。     

温度及油酸钠复配对CTAB水溶液性质的影响

用滴体积法研究了温度及油酸钠（SO）的复配对十六烷基三甲基溴化铵（CTAB）水溶液的表面活性与胶团形成的影响。结果表明：在305－337K之间，CTAB的临界胶团浓度（Ccmc）随温度的升高而增大，形成胶团的过程是一个焓熵共同驱动的热力学自发过程；在CTAB－SO复配体系中，正负离子表面活性剂之间存在着强烈的相互作用，等摩尔混合体系（1：1）具有最高的表面活性，Ccmc，γcmc，β^m，β^s和pC20均具有最低值。     

40%野草净水基微乳剂麦田除草试验

田间试验表明，４０％野草净水基微乳剂防除小麦田中野燕麦和阔叶杂草较单用燕麦枯和２，４－Ｄ丁酯不仅效果好，而且省工、省时，在以野燕麦和以阔叶杂草为主的麦田使用剂量分别为１８００ｇ／ｈｍ２和９００～１２００ｇ／ｈｍ２。     

铁(Ⅲ)─苯基萤光酮─CTMAB多元络合物显色反应的研究

研究了在溴化十六烷基三甲按（CTMAB）存在下,铁与苯基萤光酮（PF）的显色反应,结果表明,在酸性条件下：Fe3+与PF和CTMAB形成紫红色的三元络合物,其摩尔吸光系数ε550=4.4×104L·mol-1·cm-1,铁在0～3.2μs／10mL服从比耳定律．用拟定方法进行的回收实验表明,该法的精密度和准确度都很高．关键词##4铁苯基萤光酮溴化十六烷基三甲铵     

Fast and accurate measurement of diffusion coefficient by Taylor’s dispersion analysis

This investigation aimed at improving the performance of Taylor's dispersion analysis for the fast and accurate measurement of diffusion coefficient of a minute solute in various solvents. The investigation was carried out on a capillary electrophoresis instrument by monitoring the UV absorption peak of a solute pulse and calculating the diffusion coefficient by peak efficiency. With L-phenylalanine as a main testing solute, some key factors were afterward disclosed including especially the capillary size, carrier flow velocity, injection volume and capillary conditioning. Peak tailing, large volume of sample injection and slow migration were found to underestimate the diffusion coefficient while very fast migration and high sample concentration caused overestimation. At a moderate flow velocity of 0.1―1 cm/s with a capillary of 72.44 μm I.D.×60 cm (50 cm effective) maintained at 25℃, the diffusion coefficient of aqueous L-phenylalanine was determined, giving a value of 7.02×10-6 cm2/s with error＜2% and relative standard deviation＜0.2% (n=3). The method was shown to be applicable to the measurement of various samples such as aqueous phenylalanine, acetone, phenol, toluene and benzene, and nonaqueous benzene (in ethanol or 1-butanol).     

锂离子电池锡基合金及其复合物负极研究进展

综述锡基合金及其复合物负极材料的研究现状,概述了锂离子电池负极材料的开发历程及其发展趋势,介绍了各种锡基合金的结构、电化学性能及其主要制备方法,分析了各类锡基合金的优势及存在的问题,最后指出纳米合金复合物与三维纳米多孔集流体的组合是当前合金负极实际应用的发展方向。     

溶胶-凝胶法制备层状LiMn_(0.5)Ni_(0.5)O_2锂离子电池正极材料及其电化学性能(英文)

以醋酸锂、醋酸锰和醋酸镍为原料,羟基乙二酸为螯合剂,通过溶胶-凝胶法制备层状LiMn0.5Ni0.5O2正极材料,得到的产物具有典型的α-NaFeO2层状结构,颗粒尺寸在300～400nm之间。对900℃下制得的层状LiMn0.5Ni0.5O2在2.5～4.3V之间进行充放电测试,电流密度为0.1mAcm-2,其首次放电容量达到了161.2mAhg-1。经过20次循环后,仍然保留了初始容量的88%。     

融盐包裹法合成球形正极材料LiNi_(0.7)Co_(0.2)Al_(0.1)O_2(英文)

以球形Ni(OH)2为核心原料,Al(NO3)3.9H2O、Co(NO3)2.6H2O和LiNO3为包裹原料,采用融盐包裹法在空气中煅烧合成了单相固溶体LiNi0.7Co0.2Al0.1O2。用XRD研究了合成产物的物相和结构,用SEM研究了合成产物的形貌,用电池性能测试仪研究了合成产物的电化学性能。实验结果表明,合成产物具有α-NaFeO2型层状有序结构、球状形貌和良好的电化学性能。     

Sol-gel Method Synthesized Polyhedron SnO_2 Anode Material for Lithium Ion Battery

1 Introduction Tin-based oxides will be promising anode materials for lithium ion batteries due to its high specific capacity, low potential platform, and safety[1]. Many methods have been applied to synthesize SnO2 materials of different morphologies, such as chemical vapor deposition, spray, sol-gel method[2]. Triblock copolymer poly (ethylene oxide)-block-poly (propylene oxide)-block-poly (ethane oxide) (P123) has been used as surfactant to prepare nano-crystalline tin oxide particles[3]. In this pap...     

Materials for Lithium Batteries Prepared via Mechanochemical Route

1 Results Nanostructured materials are currently of interest for lithium-ion batteries due to relevant demands for high-rate performance batteries and the aspect of structural stability (reversibility) under charge-discharge processes.Decreasing of particle size facilitates the reducing of diffuse paths for lithium ions as compared with micron-sized materials and the increasing of surface contact between electrode and electrolyte leading to acceleration of ionic transport and of charge-discharge process...