钡盐产品的研究开发和展望

介绍了国内外主要钡盐产品的研究开发现状和生产状况 ,并且阐述了主要的钡盐产品的应用前景和市场动态趋势     

利用铝矾土制备钛酸铝陶瓷

钛酸铝陶瓷是集低膨胀系数和高熔点为一体的新型陶瓷材料,传统钛酸铝的合成采用工业纯的氧化铝和二氧化钛为原料,生产成本较高。本文采用廉价的高铝矾土取代Al2O3制备钛酸铝陶瓷,实验分别取了三种铝钛比,通过性能测试,确定Al2O3:TiO2=1:0.90可制得综合性能较佳的Al2TiO5陶瓷,此时α=2.05×10-6℃-1,抗折强度σ=35Mpa,热震稳定性达到32次。     

First evidence of grass carp recruitment in the Great Lakes Basin

We use aging techniques, ploidy analysis, and otolith microchemistry to assess whether four grass carp Ctenopharyngodon idella captured from the Sandusky River, Ohio were the result of natural reproduction within the Lake Erie Basin. All four fish were of age 1 +. Multiple lines of evidence indicate that these fish were not aquaculture-reared and that they were most likely the result of successful reproduction in the Sandusky River. First, at least two of the fish were diploid; diploid grass carp cannot legally be released in the Great Lakes Basin. Second, strontium:calcium (Sr:Ca) ratios were elevated in all four grass carp from the Sandusky River, with elevated Sr:Ca ratios throughout the otolith transect, compared to grass carp from Missouri and Arkansas ponds. This reflects the high Sr:Ca ratio of the Sandusky River, and indicates that these fish lived in a high-strontium environment throughout their entire lives. Third, Sandusky River fish were higher in Sr:Ca ratio variability than fish from ponds, reflecting the high but spatially and temporally variable strontium concentrations of southwestern Lake Erie tributaries, and not the stable environment of pond aquaculture. Fourth, Sr:Ca ratios in the grass carp from the Sandusky River were lower in their 2011 growth increment (a high water year) than the 2012 growth increment (a low water year), reflecting the observed inverse relationship between discharge and strontium concentration in these rivers. We conclude that these four grass carp captured from the Sandusky River are most likely the result of natural reproduction within the Lake Erie Basin.     

CCTO掺杂对BaTiO3-Nb2O5-Co3O4陶瓷系统介电性能的影响

以BaTiO3-Nb2O5-Co3O4(BTNC)系统陶瓷为研究对象,研究了掺杂CaCu3Ti4O12(CCTO)对该系统陶瓷介电性能的影响.结果表明,在20～85℃温度范围内,BT系统中CC-TO掺杂量为3.0%时,体系平均介电常数>2 600,温度稳定性△C/C≤4.7%;在20～125℃温度范围内,BTNC系统中CCTO掺杂量为2.0%时,体系的平均介电常数>2 700,温度稳定性△C/C≤10%;CCTO掺杂量为4.0%时,平均介电常数>2 200,温度稳定性△C/C≤4.7%.     

钛酸锂作为锂离子电池负极材料的改性进展

钛酸锂因零应变特性已成为性能优异的锂离子电池负极材料,但导电性差和锂离子扩散率低等问题限制了其广泛应用.在介绍钛酸锂主要制备方法的基础上综述了国内外对于该材料作为锂离子电池负极材料的改性方法,包括体相内的金属离子掺杂、碳包覆和氮化处理等表面改性手段以及材料粒子的大小和形貌控制等.除了体相内锂位的掺杂对材料性能提升不明显外,导电层包覆和颗粒纳米化对材料性能都有较大的提高,因此对于钛酸锂体相内氧位或锂位的掺杂是比较有价值的研究方向.要同时提高材料的离子导电率和电子导电率必须从多个方面综合考虑和设计.     

微波水热法制备含氟钛酸铋系光催化剂及光催化性能研究

以Bi(NO3)3·5H2O和(NH4)2TiF6为原料,采用微波水热法在120℃~220℃反应1h得到了具有不同形貌的粉体.借助XRD、FE-SEM和EDS等分析手段对粉体的组成和形貌进行了表征,并以罗丹明B溶液为目标降解物,研究了200℃下所得粉体的光催化性能.结果表明:所得粉体是一种新型的F掺杂钛酸铋粉体,其中Bi、Ti、O、F的原子比例约为6∶11∶27∶8;随着反应温度的升高,粉体形貌从球形向六棱短柱状转变;紫外光照射下粉体具有较好的降解罗丹明B溶液的能力.     

均匀设计法筛选SBLC涂复料的化学配方

采用均匀设计法对ＳｒＴｉＯ３晶界层电容器（ＳＢＬＣ）的二次烧结涂复料配方进行筛选。研究了ＰｂＯ－Ｂｉ２Ｏ３－ＣＵＯ－Ｂ２Ｏ３四元体系不同配方涂复料对电容器的介电常数及损耗的影响。经回归分析得到涂复料的较优配方是：Ｐｂｏ：Ｂｉ２Ｏ３：ＣｕＯ：Ｂ２Ｏ３：８．３：５．６：１：６．３     

PbTiO3超微粉的介电性质

对于平均粒径２０～２００ｎｍ的ＰｂＴｉＯ３超微粉，首次通过它们的压块研究了介电性质。在粒径为３５ｎｍ左右时介电常数旦现峰值。     

氮化物添加对钛酸钡半导瓷电阻—温度曲线之影响

本文研究了氮化物添加对钛酸钡半导瓷电阻－温度曲线之影响，实验表明，除ＮＢ外ＴｉＮ、Ｓｉ３Ｎ４、ＡｌＮ也可以给出较平坦的电阻极大值，在适当的工艺条件下没有氮化物添加同样可以得到类似结果。     

Phase relations in the Barium Titanate—Titanium Oxide System

Phase relations in the BaTiO₃—TiO₂ system were studied at temperatures above 1300°C in air. Quenching experiments were performed with high-purity reagents, and a new equilibrium phase diagram was constructed. Results include redetermination of the liquidus boundaries, the eutectic temperature, the melting or decomposition temperatures of the stable compounds in the system, the cubic—hexagonal transition in BaTiO₃, and the solid solubility of TiO₂ in BaTiO₃.