添加剂对SnO2气敏材料敏感特性的影响

采用浸渍法和化学共沉淀法制备了十五种金属或金属氧化物掺杂的SnO_2气敏材料.用透射电子显微镜(TEM)、X射线衍射(XRD)和X光电子能谱研究了材料的陶瓷微结构和化学组成,用静态配气法测试了材料的气敏性能.结果表明:Ag,CuO和ZnO作为廉价的敏感添加剂,可用于制造可燃气体传感器;ZnO和Re_2O_3的掺杂可显著改善SnO_2对酒精的选择性;Sb_2O_3的掺杂能明显降低SnO_2的电阻;添加剂Ag和CeO_2与SnO_2之间存在一定的电子相互作用,对Sn3d的键合能(BE)有一定影响.     

富镍三元层状过渡金属氧化物正极材料的改性方法研究综述

富镍三元层状过渡金属氧化物正极材料因具有比容量高、价格低廉以及对环境友好等特性而备受关注,但受锂镍混排、相变反应、产气、微裂纹、过渡金属溶出、表面结构等影响,材料本身存在循环容量衰减等问题。针对正极材料循环容量衰减过快、高温性能不佳等问题,总结了近年来国内外关于富镍三元层状过渡金属氧化物正极材料的改性方法,包括表面包覆材料合成、元素掺杂材料制备、核壳结构材料开发、浓度梯度材料设计等优化方法,指出高镍层状过渡金属氧化物正极材料的应用需要从不断完善材料制备方法、改变材料性状、降低材料成本等方面入手,开发高能量密度的锂离子电池,使富镍三元层状过渡金属氧化物正极材料在动力电池领域尽早得到广泛应用。     

有色金属锡矿尾矿协同脱除活性污泥水分

针对水泥窑掺烧活性污泥的输送工艺和含水量要求、以及尾矿可协同掺烧的特点,本文研究了以有色金属锡矿尾矿协同脱除活性污泥水分,并以热重和红外等方法探讨了脱水机制。结果表明：常温下,污泥中掺入有色金属锡矿尾矿后可使污泥的物理挤压方法脱水效果得到显著的改善,使内部结合水容易脱除分离出来,可达到深度脱水。尾矿粉掺入量为污泥质量的50 %时可将污泥脱水率从物理挤压方法的60 %左右进一步提高到90%以上,脱水后污泥的含水率从74 %左右进一步下降到约40 %,脱水效果显著。脱水后污泥质量可得到大幅缩减,脱水压滤饼固体化程度较高,粉碎性好,污泥的粘附性得到了显著的降低,可为实现污泥和有色金属尾矿在水泥窑协同掺烧大量化处置提供更为简便和能耗小的工艺前提条件。     

Advanced materials for aqueous supercapacitors in the asymmetric design

Supercapacitors have been recognized as one of the promising energy storage devices in the future energy technology. In this perspective, rapid progress is made in the development of fundamental and applied aspects of supercapacitors. Various techniques have been developed specifically to estimate the specific capacitance. Numerous efforts have been made in the literature to increase the specific capacitance of electrode materials. Recently, researchers pay more attention on designing supercapacitors of asymmetric type with extending cell voltage and dissimilar materials with complementary working potentials. Researchers try to increase the specific energy of asymmetric supercapacitors (ASCs). Conversely, it is still a challenge to find a suitable operation conditions for ASCs in various designs, especially for the one with battery type electrode. In this review, we describe our recent research works and other reports on the preparation of various nanostructured electrode materials and the performances of both symmetric and asymmetric supercapacitors. Finally, we demonstrate effects of charge balance on the capacitive performances of ASCs which consist of one electrode material of the battery type and one capacitive material. We also demonstrate how to evaluate the charge capacities of both positive and negative electrode materials for this ASC application.     

Microstructure and oxygen storage capacity of Sr-modified Pt/CeO2-ZrO2 catalysts

Strontium was introduced into CeO2-ZrO2 mixed oxides (CZ) by doping and impregnation methods,and then Pt was impregnated on the Sr-modified CZ to obtain the catalysts.X-ray diffraction (XRD),X-photon s...     

ZnO 玻璃系压敏电阻配方研究

研究了 Zn O玻璃系压敏电阻的材料组成对其微观结构和电性能的影响 .发现玻璃料的添加量 w玻璃料 一般在 8.0 %～ 1 0 .0 %时效果最佳 .Sb2 O3的引入可生成 Zn7Sb2 O1 2 尖晶石相 ,抑制晶粒的生长 ,并使压敏场强E和非线性系数 α值增加 .Co和 Mn的添加使界面态密度增加 ,引起势垒升高 ,使非线性特性显著提高     

天然锡中子反应数据的评价和理论计算

对天然锡中子反应的实验数据进行评价，并用光学模型（ＯＰＭ）、带宽度涨落修正的豪泽－费许巴哈理论（ＷＨＦ）以及平衡前发射的蒸发模型（ＰＥＭ），计算了入射能量为１～２０ＭｅＶ的中子与锡核相互作用的反应数据．计算结果与评价实验值符合较好．     

合成偏苯三甲酸三(异)辛酯催化剂的研究

采用锡的氧化物及氢氧化物为主要组分的催化剂,进行偏苯三甲酸与2-乙基已醇的酯化反应,通过其终点酸值,考察所用催化剂的催化效果。实验结果表明,在210℃、反应3h 时,酯化酸值在0.2mgKOH/g 左右。     

Synthesis and characterization of Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>@SiO<Subscript>2</Subscript> magnetic composite nanoparticles by a one-pot process

Fe₃O₄@SiO₂ core–shell composite nanoparticles were successfully prepared by a one-pot process. Tetraethyl-orthosilicate was used as a surfactant to synthesize Fe₃O₄@SiO₂ core–shell structures from prepared Fe₃O₄ nanoparticles. The properties of the Fe₃O₄ and Fe₃O₄@SiO₂ composite nanoparticles were studied by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. The prepared Fe₃O₄ particles were approximately 12 nm in size, and the thickness of the SiO₂ coating was approximately 4 nm. The magnetic properties were studied by vibrating sample magnetometry. The results show that the maximum saturation magnetization of the Fe₃O₄@SiO₂ powder (34.85 A·m2·kg–1) was markedly lower than that of the Fe₃O₄ powder (79.55 A·m2·kg–1), which demonstrates that Fe₃O₄ was successfully wrapped by SiO₂. The Fe₃O₄@SiO₂ composite nanoparticles have broad prospects in biomedical applications; thus, our next study will apply them in magnetic resonance imaging.