温度与碱浓度对FeO_4~(2-)/FeO_2~-体系电化学行为的影响

研究了影响Fe(OH)3进行酸式电离反应的因素,在多种浓度和温度条件下的NaOH浓溶液中采用SnO2-Sb2O3/Ti电极,研究FeO42-/FeO2-体系的电化学氧化还原反应参数及其变化趋势,结果证实该体系发生电化学氧化还原反应的最佳碱溶液浓度范围为12~14 mol/L,最佳温度范围为295~315 K.阐明了在实验条件下FeO42-/FeO2-氧化还原体系中存在由FeO43-/FeO2-构成的氧化还原电对,而FeO42-不直接与FeO2-构成氧化还原电对;并给出了FeO42-/FeO2-氧化还原体系的Latim er图.     

纳米微晶TiO2合成Li4Ti5O12及其嵌锂行为

用溶胶-凝胶法并经热处理制备不同形态和晶体尺寸的TiO2，分别与Li2CO3高温固相反应生成锂钛复合氧化物，经电化学测试发现,用300 ℃热处理所得纳米微晶TiO2制备的Li4Ti5O12具有良好的嵌锂性能，其可逆比容量大于95 mA•h•g－1，充放电效率近100％，循环性能良好，电压平台平稳,在嵌锂至容量≥85％或脱锂至容量≥90％时均有明显的电压变化，可用作锂离子电池负极材料.     

催化剂Ni/Y2O3上低温乙醇水蒸气重整制氢研究——氢气预还原对催化剂性能的影响

用浸渍－热分解－氢还原法(IHDHR)和浸渍－热分解法(IHD)分别制备了两种纳米尺寸的Ni/Y2O3催化剂，并应用X-光电子能谱、X-射线衍射、BET比表面测试等分析技术对两种催化剂的结构进行了表征和比较。采用固定床反应器对两种催化剂的催化性能进行实验测试。结果表明，氢气预还原与否对该纳米Ni/Y2O3催化剂的催化性能有一定的影响，经过氢气预还原的催化剂对低温乙醇水蒸气重整反应表现出较高的活性和稳定性，250?℃时，乙醇的转化率达到81.9%；320 ℃时，乙醇的转化率达到95.3%，对氢气的选择性为53.6%。对经过氢预还原的Ni/Y2O3催化剂进行了60 h的稳定性测试。     

新贮氢材料——含微量锰的微晶镁粉

以气雾化冷凝法制备了含有微量Mn的微晶镁粉(Mg(Mn)). XRD表明，其主物相仍然是六方晶系的微晶镁，其粒径在100～500 nm之间.这种微晶镁粉(Mg(Mn))具有较高的储氢量(6.2％)，在280 ℃具有较快的放氢速度.     

Crystal growth and spectral properties of Tb:Lu_2O_3

The crystal growth,x-ray diffraction pattern,absorption spectrum,emission spectrum,and fluorescence lifetime of a Tb:Lu_2O_3 single crystal were studied.Excited at 483 nm,the peak absorption cross-section was calculated to be 3.5×10~(-22)cm~2,and the full width at half maximum was found to be 2.85 nm.The Judd-Ofelt(J-O)intensity parameters ?_2,?_4,and ?_6 were computed to be 3.79×10~(-20)cm~2,1.30×10~(-20)cm~2,and 1.08×10~(-20)cm~2,with a spectroscopic quality factor ?_4/?_6 being 1.20.The emission cross-sections of green emission around 543 nm and yellow emission around 584 nm were calculated to be 9.43×10~(-22)cm~2 and 1.32×10~(-22)cm~2,respectively.The fluorescence lifetimeτexp of ~5D_4 was fitted to be 1.13 ms.The data suggest that the Tb:Lu_2O_3 crystal could be a potential candidate for green and yellow laser operation.     

Ground-state energy of beryllium atom with parameter perturbation method

We present a perturbation study of the ground-state energy of the beryllium atom by incorporating double parameters in the atom's Hamiltonian. The eigenvalue of the Hamiltonian is then solved with a double-fold perturbation scheme,where the spin-spin interaction of electrons from different shells of the atom is also considered. Calculations show that the obtained ground-state energy is in satisfactory agreement with experiment. It is found that the Coulomb repulsion of the inner-shell electrons enhances the effective nuclear charge seen by the outer-shell electrons, and the shielding effect of the outer-shell electrons to the nucleus is also notable compared with that of the inner-shell electrons.     

量子化学方法在锂离子电池电解液研究中的应用

总结了近年来量子化学方法在锂离子电池电解液研究中的应用进展,阐述了量子化学方法在新型锂盐设计、功能添加剂作用机理分析和电极/电解液界面膜的形成过程研究中发挥的作用,对其用来设计锂离子电池电解液功能分子作出展望。     

ZSM-35沸石分子筛的晶化动力学研究

本文探讨了在不同条件下合成ZSM-35沸石分子筛的晶化动力学。在175℃、192℃、200℃温度下测得ZSM-35的成核活化能E_n=25.4kcal/mol,结晶活化能E_c=18.6kcal/mol。在200℃温度下,其成核反应级数a_n=2.5,结晶反应级数α_c=2。提出所有沸石结晶似均为二级自催化反应,并可用(dW_c/df)Τ=K[OH-]~2作为一种描述沸石结晶反应过程的一般形式。     

高氯酸锂-乙酰胺/乙烯脲体系的二元熔盐电解质

制备了高氯酸锂与乙酰胺和乙烯脲形成的二元低温熔盐电解质，采用差示扫描量热法、交流阻抗法和循环伏安法分别对其热学、电化学性质进行了研究.测试结果表明,高氯酸锂-乙酰胺体系具有较好的热稳定性和高的电导性，配比n（LiClO4）:n（Acetamide）=1.0:5.5的样品室温（25 ℃）电导率为1.25×10－3 S•cm－1，80 ℃电导率为1.15×10－2 S•cm－1;其电化学稳定电位窗近3 V左右.     

以Schiff碱为阳离子的新型离子液体的制备与表征

Two novel ionic liquids, N,N＇-disalicylideneethylenediaminium acetate and N,N＇-disalicylideneethylenediaminium trifluoroacetate, were prepared and characterized by IR, ^1H NMR, DTA-TG and elemental analysis. The experimental results indicate that the new ionic liquids possess lower melting point and higher electrical conductivity. It is noteworthy that the ionic liquids reported herein are the first member of the ionic liquid family with the Schiff base functional group in the cation.