纳米PbSnO3的制备及其燃烧催化性能的研究

Nanocomposite PbSnO₃was synthesized by coprecipitation method , and its phase evolution process was investigated. The particle size, crystal form, and phase of samples were determined with XRD, TEM and EDS. The catalytic actiyity of sample on the thermal decomposition of RDX was investigated by DSC. The results show that nanocomposite PbSnO₃with the diameter of 9 nm can be obtained by calcining at 600 ℃ for 2 h, which crystal is cubic (pyrochlore type). The catalytic actiyity of nanocomposite PbSnO₃on the thermal decomposition of RDX is much higher than that of normal PbSnO₃. The nanocomposite PbSnO₃can decrease the peak temperature of thermal decomposition of RDX from 240.1 ℃ to 236.5 ℃, and the decomposition enthalpy ΔH of RDX increases 722 J·g^-1 （about 70%）.     

LaNi4Fe催化合成氨反应性能的研究

用冶金法、还原扩散法、共沉淀法制得了LaNiFe,并对其催化合成氨反应性能进行了研究。实验结果表明:还原扩散法,共沉淀法制得的LaNi_4Fe催化活性均比冶金法好。X—射线分析指出LaNi_4Fe在合成氨反应过程中变为Ni_4Fe和LaN。     

沉淀法合成纳米晶长余辉材料Y2O2S∶Eu3+，Ti

The long-lasting phosphorescent materials, yttrium oxysulfides doped by Eu and Ti, were systhesized by coprecipitation with their subsequent thermal decomposition in the presence of sulphur. The products were characterized by XRD, TEM, phosphorescent spectra, and thermoluminescence. The XRD results indicate that the lowest synthesis temperature is 700 ℃. From the TEM, the average diameter of particles was in the range of 60～120 nm, and augmented with the increase of temperature. The materials under UV excitation presented well afterglow from the transition of ⁵D_0,1 → ⁷F_J of Eu³⁺, and the persistent time was about 2 h. The long-lasting afterglow mechanism was discussed, too.     

流动注射在线共沉淀预富集火焰原子吸收法测定痕量铜

研究了以Ｎｉ＾２＋－ＤＤＴＣ为共沉淀载体，流动注射在线共沉淀预富集－火焰原子吸收光谱法测定痕量铜的体系，在０．３ｍｏｌ．Ｌ＾－１的硝酸介质中，铜离子在编织反应器中与Ｎｉ＾２＋－ＤＤＴＣ（产生共沉淀，并被收集在编织器内壁上，用甲基异丁基酮（ＭＩＢＫ）在线洗脱沉积物并引入火争原子化器中测定。当富集时间为４０ｓ时，４０μｇ．Ｌ＾－１的铜１０次测定的相对标准偏差为３．０％，灵敏度提高６０倍，检出限（３σ）     

不同碳酸铵试剂对共沉淀法制备的GDC粉性状的影响

近年来工作温度在500￣700℃的中温固体氧化物燃料电池(IT-SOFC)受到广泛关注。稀土掺杂氧化铈尤其是钐、钆掺杂氧化铈在中温下的离子电导率远高于钇掺杂氧化锆(YSZ),是较为理想的IT-SOFC电解质材料。由于掺杂氧化铈难于烧结,不便于制备致密的电解质膜,通过提高掺杂氧化铈粉体细度来降低其烧结温度,是近年来该材料应用领域的一个研究热点。已有各种合成掺杂氧化铈纳米粉的报道,如采用共沉淀法、固态反应法、水热处理法、燃烧法、溶胶-凝胶法等等。其中碳酸盐共沉淀法由于具有成本低、设备简单以及合成粉体细度高等优点而倍受青睐。通…     

铁酸钴纳米微粒的共沉淀法制备和磁性质(英)

The cobalt ferrite nanoparticles were prepared by coprecipitation in the presence of poly (N-vinylpyrrolidone) (PVP) and characterized by XRD, TEM, EDX and magnetometry. XRD results suggest the formation of pure cobalt ferrite. The mean particle sizes of CoFe₂O₄ samples annealed at 400 ℃ and 600 ℃ were ca. 6 and 25 nm, respectively as obtained by transmission electron microscopy (TEM). The magnetic measurements indicated that nano-particles obtained at 400 ℃ were superparamagnetic while that prepared at 600 ℃ were ferrimagnetic.     

超细粉Pb0.75Ca0.25[(Ni1/3Nb2/3)0.08Ti0.912Mn0.008]O3的制备与表征

报道了用化学共沉淀法制备掺杂Ca、Ni、Nb、Mn钛酸铅超细陶瓷粉末的方法。制得的粉料化学式为:Pb_0.75Ca_0.25[(Ni_1/3Nb_2/3)_0.08Ti_0.912Mn_0.008]O₃,粒径小于0.1μm,所有的掺杂元素均能定量掺入。     

离线预富集电感耦合等离子体质谱法测定天然水体中溶解态硅

以Mg(OH)2共沉淀和阳离子交换树脂作为离线预富集方法,建立了天然水体中溶解态硅电感耦合等离子体质谱(ICP-MS)测定方法。实验采用NaOH作为Mg(OH)2沉淀引发剂,以共沉淀方式将溶解态硅元素从天然水体中分离富集,再利用阳离子交换树脂将基体Mg2 清除,并对洗脱液流速、共沉淀碱度等条件进行优化选择。结果显示:Mg(OH)2共沉淀步骤可定量回收溶解态硅,控制溶液通过阳离子交换树脂的速率可将硅元素与基体Mg2 完全分离而不会造成损失。不同基体的水样的加标回收率为99%~105%,方法检出限为4.5μg/L(3S,n=8),方法精密度RSD小于3%。     

用草酸胍制备钴酸盐尖晶石

本文采用先驱物法合成钴酸盐尖晶石MCo₂O₄(M=Zn,Ni,Cu,Mg,Cd,Mn)。以草酸胍作为沉淀剂，在溶液中以共沉淀的方法合成草酸盐先驱物。采用热分析(TG和DTA)、化学元素分析、红外光谱等手段对先驱物进行分析表征。通过红外光谱、X射线粉末衍射、扫描电镜对产物进行表征。产物的平均粒度范围在3.5～8.8 μm之间。