碲氢化钠还原亚胺的方法

本文报道一种还原亚胺的新方法。取代的芳基和脂肪基亚胺可以在较温和的条件下被碲氢化钠顺利地还原为相应的仲胺。     

贮氢合金材料电化学与表面性能的研究进展

贮氢合金材料电化学与表面性能的研究进展①杨勇李骏林祖赓（厦门大学化学系，固体表面物理化学国家重点实验室，厦门３６１００５）八十年代后期以来，人们对地球的环境保护提出了更高的要求，而便携式电器（如移动电话，摄像机与笔记本电脑等）对电池的需求也大量增加...     

Effect of BaBiO3 and Ba0.6K0.4BiO3 additives on the rechargeability of manganese oxide cathodes in alkaline cells

The effect of the incorporation of small amounts (1–5 wt%) of semiconducting BaBiO₃ and metallic Ba_0.6K_0.4BiO₃ additives on the rechargeability of electrolytic manganese dioxide (EMD) cathodes in alkaline cells in the one-electron regime has been investigated. Both the BaBiO₃ and Ba_0.6K_0.4BiO₃ additives lead to better cyclability compared to the previously known binary oxide additive Bi₂O₃. X-ray diffraction patterns recorded before and after 30 cycles as well as cyclic voltammograms recorded after first and 30 cycles reveal that the better cyclability in the presence of BaBiO₃ and Ba_0.6K_0.4BiO₃ additives is due to the suppression of the formation of unwanted, electrochemically inactive birnessite and hausmannite phases and a shifting of the second-electron capacity of Mn to higher potentials.     

磷脂液相二次离子质谱分析中的分子离子簇

对3种极性头不同的磷脂DMPG、DMPC、DMPE的液相二次离子质谱分析中出现 的分子离子簇现象进行了系统的研究。结果表明，虽然分子离子簇的形成与许多因素有关， 如PH值、离子强度等，但起决定作用的是样品在底物中的浓度，浓度增大有利于分子离子簇 的形成。研究还发现，由不同种类磷脂分子形成的分子离子簇峰明显高于由同种磷脂分子所 形成的分子离子簇峰，指出异种磷脂分子间的簇离子形成能力高于同种磷脂分子。此外还讨 论了磷脂分子在离子源条件下的稳定性、裂解规律及相互作用等。结果表明，本实验所选用 的磷脂分子在LSIMS条件下是稳定的，均能得到较强的分子离子峰，其主要碎片峰是磷酰键断裂而产生的碎片离子峰。     

球形钴酸锂的乳液法合成及其结构、性能研究

采用一种特殊乳液法, 制备了锂离子电池正极材料球形LiCoO₂. 分别研究了一次颗粒尺寸、烧结时间对于二次造粒的影响. 还对LiCoO₂球体内部的结构进行了SEM和HRTEM研究, 发现一次颗粒非常紧密地融合在一起, 晶体边界区域没有明显的非晶相区, 也没有纳米级别的孔洞、裂缝. 电化学性能研究表明, 在900 ℃烧结4 h的材料具有较高的首次放电容量(143 mAh•g^－1)和良好的循环性能     

Synthesis and transformations of metallacycles. 30. Aluminacyclopentanes in the synthesis of secondary and tertiary alcohols

A method for the synthesis of secondary and tertiary alcohols was developed. The method is based on cycloalumination of olefins with trialkylalanes in the presence of Zr-containing catalysts followed by the CuCl-catalyzed in situ reaction of the corresponding aluminacyclopentanes with aldehydes or ketones.     

La2O3,Y2O3-Mo次级发射材料研究

采用粉末冶金方法制备了La2O3，Y2O3-Mo次级发射材料，测试了各种材料的次级发射系数。结果表明在钼中加入稀土氧化物可以具有很好的次级发射性能。经过激活处理后，材料的最大次级发射系数均高于2．0，达到了材料使用要求的发射水平。应用扫描电镜(SEM)和光电能谱仪(XPS)研究了稀土元素在烧结体断口和发射前后在试样表面的分布情况。分析结果表明稀土元素易于在晶界处偏聚，且发射后试样表面稀土元素的相对浓度明显高于发射前的浓度。     

LiCoO_2 electrode/electrolyte interface of Li-ion batteries investigated by electrochemical impedance spectroscopy

The storage behavior and the first delithiation of LiCoO2 electrode in 1 mol/L LiPF6-EC:DMC:DEC elec- trolyte were investigated by electrochemical impedance spectroscopy (EIS). It has found that, along with the increase of storage time, the thickness of SEI film increases, and some organic carbonate lithium compounds are formed due to spontaneous reactions occurring between the LiCoO2 electrode and the electrolyte. When electrode potential is changed from 3.8 to 3.95 V, the reversible breakdown of the resistive SEI film occurs, which is attributed to the reversible dissolution of the SEI film component. With the increase of electrode potential, the thickness of SEI film increases rapidly above 4.2 V, due to overcharge reactions. The inductive loop observed in impedance spectra of the LiCoO2 electrode in Li/LiCoO2 cells is attributed to the formation of a Li1-xCoO2/LiCoO2 concentration cell. Moreover, it has been demonstrated that the lithium-ion insertion-deinsertion in LiCoO2 hosts can be well described by both Langmuir and Frumkin insertion isotherms, and the symmetry factor of charge transfer has been evaluated at 0.5.     

Classification of integral trees

A finite poset Q is called integral over a field k if there exists an ASL (algebra with straightening laws) domain on Q{–} over k. We classify all trees (rank one connected posets without cycles) which are integral over an infinite field.