密闭消解电感耦合等离子体质谱法测定铝土矿中锂、锶、镓、铌、钽、锆和铪

采用电感耦合等离子体质谱,硝酸-氢氟酸增压密闭消解样品,实现了铝土矿中锂、锶、镓、铌、钽、锆和铪的同时测定。实验中探讨了最佳的消解程序,选择适当的同位素,并用铑、铼做内标元素,有效地抑制了分析信号的漂移。各元素的检出限在0.02～1.00μg.g-1,相对标准偏差在0.63%～1.63%,Nb,Ta,Hf的回收率在99.2%～99.6%;该方法经国家标准物质（GBW07177,GBW07182,GBW07180）验证,各元素测试结果与真值很接近。     

五氧化二铌与二氧化硅作用下氧化铝晶粒的各向异性生长(英文)

研究了少量SiO2和Nb2O5掺杂对α-氧化铝晶粒生长的影响.单一掺杂1 500℃煅烧2h的样品均表现为晶粒的等轴状,且铌掺杂明显促进了氧化铝晶粒的生长.SiO2与Nb2O5的共掺杂则导致晶粒各向异性优势生长.高分辨透射电镜照片表明:在一些晶粒晶界出现0.8~4nm的无定形层,晶界处的液相同样影响晶界能,从而诱导各向异性生长.结果表明:在固定铌含量的基础上,少量二氧化硅使材料的断裂韧度提高42%,抗弯强度提高约80%.     

纳米、微米ZnO对PPESUK复合材料性能的影响

用热压成型法制备了纳米、微米ZnO填充联苯型聚醚砜酮(PPESUK)复合材料;考察了复合材料的显微硬度和弯曲强度;并研究了干摩擦条件下纳米、微米ZnO对复合材料摩擦磨损性能的影响。利用扫描电子显微镜观察分析PPESUK／ZnO复合材料磨损表面形貌及磨损机理。结果表明,在干摩擦条件下纳米ZnO填充PPESUK的转移膜不完整,致使对偶钢环对复合材料表面产生严重的犁削;而微米ZnO填充PPESUK的主要磨损机理是严重的磨粒磨损。     

表面修饰FeS纳米微粒的研究(Ⅱ)--摩擦学特性研究

用四球摩擦磨损试验机考察了二烷基二硫代磷酸（DDP）修饰FeS纳米微粒作为润滑油添加剂的摩擦学行为.结果表明,DDP修饰FeS纳米微粒在极低的添加量时即具有良好的抗磨效果,但不能降低基础油的摩擦因数;磨损表面分析表明钢球表面形成了边界润滑膜,使摩擦学性能得到明显改善.     

Y2O3:Eu3+纳米晶的制备及其光学性能研究

以NaOH,Y(NO3)3.6H2O和Eu(NO3)3.6H2O为前驱体,通过添加络合剂PEG-2000,采用水热法,成功地合成了Y2O3∶Eu3+纳米棒和纳米管,并采用先进的测试手段对其结构和性能进行了表征与测试。探讨了Y2O3∶Eu3+纳米棒和纳米管的生长机制,同时研究了Y2O3:Eu3+纳米晶的光致发光性能。研究结果表明,水热温度、反应时间、NaOH的添加量和PEG-2000对产物形貌有着非常重要的影响,所制备的材料具有Eu3+的特征红光发射,并在Eu3+的掺杂量为5%(摩尔分数)时样品发光最好。     

水热法油酸修饰纳微米硼酸锌的制备及摩擦学性能研究

以硼砂和硫酸锌为原料经水热法制得硼酸锌;通过场发射扫描电镜、X射线衍射、热重分析和红外分析表征硼酸锌的结构.结果表明,分散介质的变化对硼酸钙的形貌有一定的影响.将油酸修饰的硼酸锌分散于聚α-烯烃( PAO)中,利用SRV 1型微动摩擦磨损试验机考察其摩擦学性能,并分析摩擦机制.结果表明:在一定水热时间下制备的油酸修饰硼酸锌,能有效降低PAO润滑时45#钢的摩擦因数和磨损率;XPS分析显示,油酸修饰硼酸锌作为润滑添加剂时,在磨痕表面形成了含B、Zn和Fe的摩擦膜.     

Selective synthesis and growth mechanism of CeVO4 nanoparticals via hydrothermal method

Selective-controlled structure and shape of CeVO4 nanocrystals were successfully synthesized via a hydrothermal method from Na3VO4·12H2O and Ce(NO3)3·6H2O.The resulting products were characterized by X-ray powder diffraction (XRD),field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS).The influence of hydrothermal temperature,precursor solution concentration on the crystal and morphology of products were further studied.The results showed that the as-synthesized products exhibited pure single-crystal CeVO4 nanoparticles with tetragonal structure.The hydrothermal temperature and precursor solution concentration had important effects on the formation of CeVO4 nanoparticles.Furthermore,the growth mechanism of CeVO4 nanoparticles was explained with Ostwald ripening mechanism.     

Hydrothermal synthesis and luminescence properties of YW2O6（OH）3：Tb^3＋ green phosphors

YW2O6(OH)3:Tb3+ green phosphors were synthesized at different pH values via a facile hydrothermal method. The structure and optical properties of as-synthesized samples were studied by X-ray diffractometer (XRD), scanning electron microscopy (SEM), photolumi-nescence spectra and luminescence decay curve. The results showed that pure monoclinic YW2O6(OH)3:Tb3+ green phosphors could be ob-tained at pH 2-5. Uniform spherical micro-phosphors of ~5 μm in diameter with narrow size distribution could be prepared at pH 5. pH value had dramatic influence on morphologies, which could be ascribed to the various spatial configurations of different poly-tungstates existing at different pH values. The emission spectra under 261 nm excitation exhibited dominant green emission at 546 nm. The green emission inten-sity reached the maximum value at pH 5 due to the high packing density of the obtained phosphor.     

水热(溶剂热)法制备形貌可控的ZnS纳米材料的研究进展

综述了水热(溶剂热)法制备纳米材料的特点以及用此法制备ZnS纳米球、纳米线、纳米棒的研究进展,分析了纳米材料制备中表面活性剂对其形貌的重要作用,指出了水热(溶剂热)法制备纳米材料存在的问题和发展前景。     

填料对聚合物基复合材料摩擦学行为的影响

本文综述了用于聚合物填充增强改性的填料种类、对摩擦学性能的影响以及填料的作用机理 ,同时讨论了填料的表面改性以及填料的选择标准。提出了今后研究填料对聚合物改性研究应注意的问题 ,从而对研究、开发、应用性能优异的聚合物基复合材料具有指导意义