以醋酸锂、醋酸锰、醋酸镁、正硅酸四乙酯为原料，采用溶胶—凝胶法制备Li2Mn1-xMgxSiO4／C正极材料。用X射线衍射和扫描电子显微镜表征材料的晶体结构和形貌。结果表明，掺杂10％Mg的Li2MnsiO4材料仍具有正交斜方结构。电化学测试结果表明：Mg掺杂能够提高Li2MnSi04材料的比容量，在16．65mA／g电流密度下，Li2Mn1-xMgxSiO/C（x=0．1）材料的首次放电比容量为212mA．h/g。用X射线衍射和X射线光电子能谱研究了硅酸锰锂正极材料的容量衰减机理，其主要是由硅酸锰锂晶体结构退化引起的。

Li2Mn1-xMgxSiO4/C cathode material for lithium-ion batteries was synthesized by a sol-gel method using LiCH3COO?2H2O, Mn(CH3COO)2?4H2O, Mg(CH3COO)2?4H2O, and Si(OC2H5)4 as starting materials under Ar/H2 atmosphere. The crystal structures and morphology of the as-prepared compounds were characterized by X-ray powder diffraction (XRD) and scanning electron mi-croscopy, respectively. The Li2MnSiO4 material maintains an orthorhombic structure with up to 10%(mass fraction) Mg doping on the Mn sites. The result obtained by electrochemical tests of the cathode materials reveals that Mg doping can improve the specific capacity of Li2MnSiO4. An initial specific discharge capacity of 212 mAh/g can be achieved for the Li2Mn1-xMgxSiO4/C (x=0.1) cathode material at a current density of 16.65 mA/g. The deterioration mechanism was also discussed based on the results determined by XRD and X-ray photoelectronic spectroscopy. The poor capacity retention is mainly caused by the deterioration of the silic

结合掺铈硅酸镥（ Ce：Lu2 SiO5）粉体的组成与性能特点、提拉法和焰熔法晶体生长工艺异同，讨论了目前使用提拉法生长掺铈硅酸镥单晶体存在的坩埚溶蚀、组分挥发、杂质浸入、闪烁性能不稳定等问题和原因，提出使用焰熔法生长Ce：Lu2 SiO5单晶体可以有效解决这些问题，给Ce：Lu2 SiO5单晶体的生长提供了一个新的研究方向。

Combined with the composition and properties of Ce:Lu2 SiO5 powder,by comparing the Czochralski meth-od with the flame fusion method,the main problems and causes were studied during the current used Czochralski growth of Ce:Lu2 SiO5 ,such as existing crucible erosion,components volatilization,other impurities intrusion and in-stable scintillation properties etc. The above problems can be solved effectively with the flame fusion method which can be as a new research direction for Ce:Lu2 SiO5 single crystal growth.

以四丙基氢氧化铵(TPAOH)为模板剂,正硅酸乙酯(TEOS)为硅源,钛酸四丁酯(TBOT)为钛源,采用水热合成结晶法在堇青石载体上结晶生长TS-1晶体.实验考察了在175,℃、结晶时间3,d的条件下,不同水与硅源比例(硅源质量分数)、模板剂质量分数对TS-1晶体在堇青石载体上生长及其粒径的影响;同时通过SEM、ATR-FTIR、XRD表征手段分析TS-1晶体颗粒在堇青石载体上生长机理.结果表明,TS-1合成前驱液中硅源和模板剂质量分数直接影响TS-1晶体在堇青石载体上结晶过程中的骨架胶团浓度和过饱和度,通过控制过饱和度可以调控堇青石载体上TS-1纳米晶体颗粒的大小.

Titanium silicalite-1(TS-1)membranes were prepared to grow on cordierite support under hydrothermal treat-ment,using TPAOH as template,TEOS as silicate source,and TBOT as titanium source. The effect of ratios of Si/H2O and concentrations of structure-directing agent(SDA) synthesized at 175,℃ for 72,h was studied throughout experiments. TS-1,nanocrystal growing on cordierite support was analyzed with scanning electron microscope(SEM),X-ray diffractome-ter(XRD)and ATR-FTIR. The result indicates that the mechanism of TS-1,growth on cordierite support is that the concentra-tion of skeleton micelle and supersaturation of TS-1 precursor in the process of hydrothermal crystallization directly control the growth of TS-1 nanocrystal on the cordierite support.

采用液体阴极辉光放电原子发射光谱（Solution-cathodeglowdischarge-atomicemissionspectrometry,SCGD-AES）法测定了硅酸钇镥（Lutetium-YttriumOrthosilicate,LYSO）闪烁晶体材料中痕量元素Ca,Fe,K,Li,Mg和Na。最佳实验条件是溶液pH为1的HNO3,直流电压为1080V,溶液流速为2.0mL/min。本方法对LYSO基体的耐盐量为10g/L。硅酸钇镥晶体使用HNO3,HF,HClO4溶解后经SCGD-AES分析测定,结果同电感耦合等离子体发射光谱（Inductivelycoupledplasma-atomicemissionspectroscopy,ICP-AES）和电感耦合等离子体质谱（Inductivelycoupledplasma-massspectroscopy,ICP-MS）分析结果比对,具有较好的一致性。在运用SCGD-AES对LYSO的测定中,未观察到Lu、Y元素的激发谱线,因此测定LYSO中痕量元素时测定的光谱干扰少,Ca,Fe,K,Li,Mg和Na的检出限分别为：1.0,3.0,0.02,0.01,0.02和1.0mg/kg。

TheLutetium-YttriumOrthosilicate(LYSO)isakindofscintillatingcrystalmaterialwiththebest comprehensive properties. In this work, the trace elements Ca, Fe, K, Li, Mg and Na in LYSO were determined by solution-cathode glow discharge-atomic emission spectrometry ( SCGS-AES ) . The optimal conditions included 0. 1 mol/L HNO3 sample solutions and operation at a voltage at 1080 V with a flow rate of 2. 0 mL/min. The LYSO matrix concentration tolerance of the SCGD source was determined to be 10 g/L. Sample solutions dissolving from several LYSO samples with HF, HNO3 and HClO4 were examined by SCGD-AES. For LYSO samples, the values obtained by SCGD-AES agree well with those obtained by axial inductively coupled plasma-atomic emission spectroscopy ( ICP-AES ) and inductively coupled plasma-mass spectroscopy (ICP-MS). The emissions of Lu and Y were not observed, so that the determination of trace elements in LYSO matrices could be conducted with little interference. The detection limits

采用溶胶凝胶法,以正硅酸乙酯(TEOS)作为硅源,分别以硝酸铝、氯化铝和硫酸铝作为铝源,制备干凝胶粉体。粉体通过碱激发转化成为粒径较为均一的微米级NaA分子筛晶体。通过X射线衍射(XRD)、红外(FT-IR)、扫描电镜(SEM)等分析手段对合成样品进行分析表征。结果表明,Al(NO3)3.9H2O作为铝源时晶化速率最快,Al2(SO4)3.18H2O次之。二者的晶化反应不易控制,导致终产物中同时包含有多相杂晶。而以AlCl3.6H2O作为铝源时反应较为平缓,能够制备出尺寸更均一且具有较高结晶度的NaA分子筛,是较为理想的铝源。

The dry gel powder was prepared by means of sol-gel method with tetraethyl orthosilicate ( TEOS ) as silicon source and different aluminum sources including aluminum nitrate , aluminum chloride and aluminum sulfate.Then the NaA zeolite with uniform size distribution was synthesized by the dry-gel conversion method ( DGC ).The final crystalline product was characterized by X-ray diffraction ( XRD) , Fourier transform infrared spectroscopy ( FT-IR) and scanning electron micros-copy ( SEM).The results showed that the crystallization rate was fastest when using aluminum nitrate as the aluminum source , followed by aluminum sulfate , which may cause the co-precipitation of several zeolite phases.However , the crystals with uniform size and high crystallinity could be synthe-sized with aluminum chloride , indicating that it is the ideal aluminum source .