棒状钒酸锂的制备与电化学性能研究

采用水热法制备了锂离子电池正极材料LiV3O8,通过X射线衍射(XRD)、红外光谱(FT-IR)和扫描电子显微镜(SEM)表征研究了样品的结构和形貌特征;通过恒流充放电技术测试了样品的电化学性质.结果表明,水热法制备的LiV3O8样品由棒状颗粒组成,粒径约0.5μm,棒长约1-3μm.首次放电容量为276mAh/g.所制备LiV3O8材料具有较高的初始放电比容量和良好的循环性能.     

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.     

Copper vanadate minerals found in mediaeval mural paintings

Abstract

A yellowish copper vanadate mineral has been found in Swedish mural paintings from the fifteenth century. Small patches occur in malachite-green paint. Thirteen samples from five churches have been analyzed by optical and scanning electron microscopy with energy–dispersive X-ray spectrometry, transmission electron microscopy, X-ray powder diffraction, and polarized light microscopy. The substance is evidently the rather uncommon mineral volborthite, with the chemical formula Cu₃V₂O₇(OH)₂.2H₂O. Very small quantities have also been noted for another mineral, presumably calcio-volborthite, CaCu(VO₄)(OH), also named tangeite. The results show that the conservator should always be observant for pigments not earlier noticed or reported. There are some old mines in Central Europe, e.g. in Germany, which contain malachite as well as copper vanadate minerals, and this is probably the origin of the yellow patches in the paintings.     

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.     

磷铋钼蓝光度法测定磷含量的方法改进

对磷铋钼蓝光度测磷的方法进行了改进.改进后的方法不但快速、准确,且应用范围更广.     

洛赛克与胶体果胶铋联合治疗幽门螺杆菌相关性消化性溃疡的临床观察

目的:探索作为补救疗法的四联疗法能否作为常用疗法;洛赛克与胶体果胶铋再加二种抗生素的四联疗法对幽门螺杆菌(Hp)相关性消化性溃疡的疗效.方法:146例Hp阳性患者随机分成三组,A组用洛赛克、胶体果胶铋、克拉霉素、甲硝唑四联疗法,B组用胶体果胶铋、克拉霉素、甲硝唑三联疗法,C组用洛赛克、克拉霉素、甲硝唑三联疗法;疗程均为7d,比较Hp根除率、溃疡治愈率及药物的不良反应.结果:A组四联疗法根除率、溃疡治愈率均较B、C组的三联疗法好.且药物的不良反应明显低于三联疗法.结论:四联疗法在治疗Hp相关性消化性溃疡方面较三联疗法优,可用作常用疗法.     

方波溶出伏安法测定头发中锌的含量

在pH=6．00的乙二胺-盐酸缓冲溶液中，采用铋膜电极做工作电极，饱和甘汞电极为参比电极，铂为辅助电极，测定头发样品中的锌的含量．结果：方波溶出伏安法的灵敏度高，线性范围较宽，因此该方法是一种灵敏度和正确度较高的测定微量锌含量的方法，且操作方便快捷，仪器装置简单，价格低廉，适合测量人发中锌的微量含量．     

铋膜修饰碳纤电极测定盐酸氨溴索的研究

介绍了一种制备碳纤电极的新方法,并研究了盐酸氨溴索在铋膜修饰的碳纤电极上的电化学响应。实验表明,在0．5mol／LH2SO4底液中,用示差脉冲伏安法进行扫描时,发现盐酸氨溴索在1．10V（vs．SCE）处出现一阳极峰,且峰电流与盐酸氨溴索的浓度在6．26×10^-8～4．64×10^-5mol／L范围内呈良好的线性关系,该方法的检出下限为4．0×10^-8mol／L。用标准加入法测得回收率范围为92．8％-102％,RSD为2．9％。将此电极用于实际样品的测定,取得较好的结果。     

氢化物发生—原子荧光法同时测定绞股蓝中的痕量铋和砷

采用氢化物-原子荧光法测定绞股蓝中的痕量铋、砷,实验了酸介质和不同还原荆对测定的影响,考虑了金属离子的干扰.在最佳测定条件下,检出限分别为Bi:0.070μg/L、As:0.085 μg/L.线性范围分别为Bi:0.1～130μg/L、As:0～180μg/L,加标回收率在90.1%～109.4%之阃.结果表明本法具有快速、简便、准确等特点.     

INTERFACIAL TENSIONS OF SOLID COPPER/LIQUID LEAD AND SOLID COPPER/LIQUID BISMUTH

The solid-liquid interfacial tensions of Cu(solid)-Pb(liquid)andCu(solid)-Bi(liquid)binary systems have been determined by the dihedral angle method.The results show that at 850℃ the interfacial tensions are 368±55mN/m for Cu-Pb sys-tem and 336±35mN/m for Cu-Bi systa,respectively,the error ranges of which aremore narrow than those found in some papers published abroad.In addition,there is nodetective segregation of other solute atoms or compounds in the vicinity of the tip of cop-per grain boundary where dihedral angles formed.