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…     

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。     

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。     

TiO2-Al2O3复合载体的比较研究

对用混胶法和共沉淀法分别制备的ＴｉＯ２－Ａｌ２Ｏ３复合载体（ＴｉＯ２含量为０．０８ｇ／ｇγ－Ａｌ２Ｏ３）进行了对比研究，采用的表征方法有ＸＲＤ，ＸＲＳ，ＬＲＳ等，得出的结论如下：两种载体均保持了γ－Ａｌ２Ｏ３的骨架结构，但ＴｉＯ２的分散状态不尽相同，混胶样品中ＴｉＯ２主要以表面富集的形式分散在γ－Ａｌ２Ｏ３表面，这有利于集二者的优点于一体，共沉淀样品中ＴｉＯ２趋于整个体相均匀分散，这有利于相互作用     

Bifonazole-β-cyclodextrin Inclusion Complexes. Thermal analysis and X-ray powder diffraction study

The complexation of bifonazole, an antimycotic hydrophobic imidazole derivative, with β-cyclodextrin (β-CD) was investigated in solid phase, using the following complementary techniques: differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and X-ray powder diffractometry. The β-CD-bifonazole samples were prepared in both aqueous medium by coprecipitation and in solid state by kneading method and the β-CD-bifonazole binary diagrams were drawn. The experimental results demonstrate the formation of two binary compounds, β-CD-bifonazole and (β-CD)_x bifonazole (x =2 or 4). The first compound may be an inclusion compound and the second a crystallized compound, in which the bifonazole is not necessarily included in the cyclodextrin internal cavity. This revised version was published online in July 2006 with corrections to the Cover Date.