铋层状结构无铅压电陶瓷的研究进展

铋层状结构无铅压电陶瓷具有优良的铁电性能,适合应用于高温、高频领域以及疲劳特性好的铁电存储器领域.本文介绍了铋层状压电材料的结构特点,综述了铋层压电材料的改性研究;着重综述了铋层状结构压电陶瓷材料的掺杂改性研究进展,并对存在的问题和解决方法进行了分析,为制备出高性能的铋层状结构无铅压电陶瓷材料提供一定的参考价值,经过改性的材料可能应用在铁电显示器中.     

三元金属间化合物La3Cu3Bi4的合成、结构与性能研究

The new intermetallic compound La3Cu3Bi4 was synthesized by arc melting method followed by annealing.The crystal structure refined using the Rietveld method and X-ray powder diffraction data showed to be Y3Au3Sb4 structure type with space group I43D(No.220).The unit cell parameters were a = 0.997 797(7) nm and V = 0.993 41(2) nm3.The structure was characterized by covalent Cu-Bi4 tetrahedron, which formed three-dimensional network by sharing corners and La atoms separated in the space of Cu-Bi4 tetragon.The expansion of La3Cu3Bi4 studied by using low temperature X-ray di?raction showed to be positive expansion and diminished with the temperature rising.     

真空炉在锡精炼应用的探索

应用真空炉在除铅、铋的同时将大部分锑除去,可大幅度减少巨毒物料铝渣的产出,并大幅度提高锡精炼的直收率。     

[Bi(C_7H_5O_3)_2C_6H_4NO_2(H_2O)_2]·2H_2O配合物的合成及表征

以五水硝酸铋、水杨酸、维生素B3为原料,摩尔比为1:2:1合成了一种新型的三元配合物.通过元素分析、摩尔电导、紫外光谱、红外光谱、热重与差热分析对其结构进行了表征,确定其分子式为[Bi(C7H5O3)2C6H4NO2(H2O)2].2H2O.实验表明,水杨酸和烟酸均脱去羧基的质子形成羧酸根与Bi3+离子双齿配位.根据TG-DSC曲线可以看出,当温度为81oC时配合物开始分解,首先失去2个结晶H2O,接着失去2个水杨酸根,再失去1个烟酸根,最后残余物为Bi和Bi2O3的混合物.     

Large dipole moment induced efficient bismuth chromate photocatalysts for wide-spectrum driven water oxidation and complete mineralization of pollutants

Herein, a wide-spectrum (∼678 nm) responsive Bi₈(CrO₄)O₁₁ photocatalyst with a theoretical solar spectrum efficiency of 42.0% was successfully constructed. Bi₈(CrO₄)O₁₁ showed highly efficient and stable photocatalytic water oxidation activity with a notable apparent quantum efficiency of 2.87% (420 nm), superior to many reported wide-spectrum driven photocatalysts. Most remarkably, its strong oxidation ability also enables the simultaneous degradation and complete mineralization for phenol, and its excellent performance is about 23.0 and 2.9 times higher than CdS and P25-TiO₂, respectively. Its high activity is ascribed to the giant internal electric field induced by its large crystal dipole, which accelerates the rapid separation of photogenerated electron–hole pairs. Briefly, the discovery of wide-spectrum bismuth chromate and the mechanism of exponentially enhanced photocatalytic performance by increasing the crystal dipole throw light on improving solar energy conversion.     

钒酸铋黄色颜料的制备及其影响因素

以Bi(NO3)3.5H2O和NH4VO3为原料,利用化学沉淀法制备了BiVO4黄色颜料,并系统地研究了不同反应条件如:反应物初始浓度、溶液pH值、反应温度和反应时间对粒径和颜色的影响.采用扫描电子显微镜对产品进行了表征,得出如下结论:用化学沉淀法制备钒酸铋,粒子粒度较小,均匀性好.同时得到的钒酸铋是一种颜色鲜艳、无毒的高级无机黄色颜料.     

锡阳极泥中回收锡铋铜铅的工业试验

采用焙烧、碱浸、酸浸、水解、置换、结晶的工艺从锡阳极泥中回收锡、铋、铜、铅,工艺路线短、操作简便,收率可达80%以上.     

三元金属间化合物La3Cu3Bi4的合成、结构与性能研究

The new intermetallic compound La3Cu3Bi4 was synthesized by arc melting method followed by annealing. The crystal structure refined using the Rietveld method and X-ray powder diffraction data showed to be Y3Au3Sb4 structure type with space group I-^43D （No.220）. The unit cell parameters were a = 0.997 797（7） nm and V = 0.993 41（2） nm^3. The structure was characterized by covalent Cu-Bi4 tetrahedron, which formed three-dimensional network by sharing corners and La atoms separated in the space of Cu-Bi4 tetragon. The expansion of La3Cu3Bi4 studied by using low temperature X-ray diffraction showed to be positive expansion and diminished with the temperature rising.     

铅铋混合液连续测定中废液的回收与再生

通过对Bi3+、Pb2+混合液配制方法与测定结果的关系实验,确定了硝酸铋溶解时浓HNO3用量.连续测定后的废液可用硫化钠和CTMAB沉淀,用稀硝酸溶解,再次配成所需酸度和Bi3+、Pb2+浓度的混合液,供学生实验重复使用,实现了化学实验的绿色化.     

Bi_2O_3对低温燃烧合成堇青石粉性能的影响

采用X射线衍射、扫描电镜和EDS能谱分析等手段研究了Bi2O3对低温燃烧法制备的非化学计量组成的MgO-Al2O3-SiO2三元系堇青石基微晶玻璃的相变和烧结特性的影响.研究结果表明:添加Bi2O3能明显促进μ-堇青石向α-堇青石的相转变或促进α-堇青石相的直接析晶,使α-堇青石相的析出温度从1050°C降到900°C;Bi2O3的加入可促进玻璃粉体的烧结致密化;Bi2O3的添加量以5%(质量分数)左右为宜,加入量太大会阻止微晶玻璃的晶化.