导电剂形貌对富锂正极材料性能发挥的影响

研究了纳米颗粒状的Super P、气相生长的碳纤维(VGCF)、片状的KS6和石墨烯四种不同的导电剂对富锂正极材料Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_2(LR-MNC)的电化学性能发挥的影响。研究结果表明,当导电剂的添加量为10%(质量分数),以Super或VGCF的导电剂在活性材料的表面形成了完整的导电通路,电极的表面电阻最小,从而有利于电子的传输,因此,正极活性物质表现出优异的倍率放电性能和循环性能。其中,以Super P为导电剂的电极性能最优,3 C放电比容量为164.4 mAh/g,1 C循环100周,容量保持率为82.3%。而以片状的KS6或石墨烯单独作为导电剂,在电极中没有形成完整的导电通路,不利于正极活性物质的大倍率放电性能的发挥。     

Effect of MgF2-H3BO3 flux on the properties of (Ce,Tb)MgAl11O19 phosphor

The green-emitting(Ce,Tb)MgAl11O19(CTMA) phosphor was prepared by the conventional high temperature solid-state reaction method.The effect of fluxes on the crystal structure,particle morphology,size distribution and photoluminescence properties of CTMA phosphor was investigated by means of the X-ray powder diffraction,scanning electron microscopy and photoluminescence spectrum.The results showed that the addition of appropriate amount of MgF2-H3BO3 flux improved the phase purity of CTMA phosphor,and influen...     

Re-determination of the crystal structure of Ca2Y8Si6O26 and study on the luminescent properties of Ca2Y8Si6O26:Tb3+

The crystal structure of silicate oxyapatite Ca2Y8Si6O26 was indexed as hexagonal,space group P63/m,a=0.93515 nm,c=0.67872 nm,α=β=90°,γ=120°,V=0.5138692 nm3.Three strong peaks located at 32.079o,32.595o,and 50.104o with d=2.7903,2.74649,1.8194 was in accordance with,(112),and(213) planes.The optimum concentration of Tb3+ in Ca2Y8Si6O26 to yield highest photoluminescence intensity was 10 mol.% of Y3+.The corresponding excitation spectrum consisted of an intense broad band from 220 to 260 nm.The photoluminescence measurements showed that the green emission originated from 5D4-7F5 was predominant in the measured range with strong doublet lines at 543 and 549 nm.     

Preparation and luminescence properties of Eu2+-doped CASN-sinoite multiphase system for LED

A series of Eu2+-doped CASN-sinoite multiphase system with a formula of(CaAlSiN3)(1-x)-(Si2N2O)x were successfully synthesized by the high temperature solid-state method.The crystal structure and morphology of the phosphors and their photoluminescence(PL) were investigated.For the Eu2+-doped samples the PL intensity approached its maximum when the molar ratio of Si2N2O in the samples was about 0.15.With increase of the concentration of Si2N2O,the emission peak shifted from 645 to 605 nm.It was because the spectroscopic polarizability(αsp) became smaller with the increase of Si/Al ratio or the adding of O atoms,which caused the change of crystal field strength.In addition,the full width at half maximum(FWHM) widened with the increase of x value,which was favor of the improvement of the color rendering index.     

氢氧化物前驱体制备LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2的机理

用共沉淀法制备前驱体Ni0.5Co0.2Mn0.3(OH)2,焙烧前驱体与Li2CO3制备Li Ni0.5Co0.2Mn0.3O2。用XRD、SEM和DSCTGA分析焙烧中间产物的结构、形貌及变化,探索制备Li Ni0.5Co0.2Mn0.3O2的机理。随着焙烧温度的升高,前驱体分解成(Ni0.5Co0.2Mn0.3)3O4,随后Li2CO3参与反应,形成Li Ni0.5Co0.2Mn0.3O2。Li Ni0.5Co0.2Mn0.3O2的生成在650℃时结束,但层状结构在900℃时才趋于完美。     

Thermodynamic Analysis of Burning Resistivity of Ti-Cr-V-Mo Alloys

ＴｈｅｒｍｏｄｙｎａｍｉｃＡｎａｌｙｓｉｓｏｆＢｕｒｎｉｎｇＲｅｓｉｓｔｉｖｉｔｙｏｆＴｉＣｒＶＭｏＡｌｏｙｓ①ＬｉｕＹｕｑｉｎ，ＺｈｕａｎｇＷｅｉｄｏｎｇ，ＢａｉＫｅｗｕ，ＳｈｅｎＪｉａｎｙｕｎ②ａｎｄＺｈａｎｇＺｈｕ（刘玉芹）（庄卫东）（白...     

YCl_3－AECl_2（AE＝Mg，Ca，Sr，Ba）二元相图的研究

用差热分析法测定了ＹＣｌ_３一ＳｒＣｌ_２体系二元相图，并用Ｘ时线衍射法验证了该二元体系中新相的生成。使用ＣＡＬＰＨＡＤ技术评估和优化了ＹＣｌ_３一ＡＥＣｌ_２（ＡＥ＝Ｍｇ，Ｃａ，Ｓｒ，Ｂａ）系列四个二元相图和热力学性质，取得了热力学性质和相图自相一致的结果。     

副产醋酸水溶液回收利用工艺研究进展

化工生产副产大量的醋酸水溶液,将其中的醋酸分离并回收利用,是涉及化工资源利用和环境保护的重要课题。醋酸水溶液分离方法包括精馏、萃取、吸附法、膜分离等物理方法和直接酯化、反应精馏等化学方法,在对已见报道的分离方法进行综述的基础上,提出利用烯烃水合反应脱水将醋酸提浓的新思路,并简要介绍初步研究结果。     

我国温室环境的模糊控制技术应用现状

温室环境系统具有非线性、大滞后、强耦合的特点,难以建立精确的数学模型,采用基于模型的传统和现代控制方法无法对其实施精确的控制.随着模糊控制技术研究的不断深入,模糊控制以其所具有的强大优势,成为解决温室环境调控问题的主要技术手段.在回顾了近几年我国在温室环境模糊智能控制技术研究中所取得的成果基础上,分析了各控制方法的特点,探讨了目前在温室环境控制中存在的主要问题及今后可能发展的方向.     

陶瓷金卤灯用封接材料膨胀系数的研究

为了制造性能良好的陶瓷金卤灯，保证陶瓷放电管和金属电极引线之间形成牢固的气密性封接是一个关键，和石英管不同，陶瓷管无法在加热软化后通过挤压与金属电极引线粘合在一起，为了完成放电管和电极的密封，必须采用合适的封接材料将它们封接起来，因此对陶瓷金卤灯的关键材料Al2O3-Dy2O3-SiO2系封接材料膨胀系数进行了研究。