(CoFe)Se2@NC超级电容器电极材料的制备及其电化学性能

金属-有机框架(MOF)衍生的过渡金属硒化物和多孔碳纳米复合材料具有巨大的储能优势,是应用于电化学储能的优良电极材料。采用共沉淀法制备CoFe类普鲁士蓝(CoFe-PBA)纳米立方,并通过静电组装在CoFe-PBA上包覆聚吡咯(PPy)得到CoFe-PBA@PPy;通过在400℃氮气中退火并硒化成功制备了氮掺杂的碳(NC)包覆(CoFe)Se₂的(CoFe)Se₂@NC纳米复合材料,并对其结构和形貌进行了表征。以(CoFe)Se₂@NC为电极制备了超级电容器,测试了其电化学性能,结果表明,在电流密度1 A/g时超级电容器的比电容达到1047.9 F/g,在电流密度5 A/g下1000次循环后具有良好的循环稳定性和96.55%的比电容保持率。由于其性能优越、无毒、成本低和易于制备,未来(CoFe)Se₂@NC纳米复合材料在超级电容器中具有非常大的应用潜力。     

煤的孔结构特征对水煤浆性质的影响

本文选用１７种不同变质程度的中国煤，详细研究了煤孔结构特征对煤浆性质的影响。发现煤孔体积通过影响煤在分散体系中的吸水性，从而影响煤之成浆性。但由于不同变质程度煤表面亲水性的显著差异，煤孔体积在影响煤成浆性的能力方面差别很大，这使得煤吸水性和浆体最高煤浓度与煤孔体积并不存在直接的相关性，而是取决于煤孔体积Ｖ和以煤－水接触角（θ）的余弦值表示的煤表面亲水性因子的乘积，即煤之有效孔体积：Ｖ×ｃｏｓ（θ／     

Synthesis and applications of photochromic fulgides in optical information storages

A pyrryl substituted photocbromic fulgide, (1-p-methoxyphenyl-2-methyl-5-phenyl)-3-pyrryl-ethylidene (isopropylidene) succinic anhydride, was synthesized. Its chemical structure was identified by IR, 1H NMR MS and elemental analysis. The title compound was used to prepare the optical disks by the spin coating method and the vacuum evaporation method. The results of the static state examination show that the optical disks prepared with this kind of molecules possess excellent thermal stability and fatigue resistance, i.e. over 450 writing-erasing recycles, the relative contrast between writing state and erasing state remains at 40%.     

The Study on the Thermal Stability of CLA in Egg Yolk

Conjugated linoleic acids (CLA) have been a subject of extensive investigation for their anticarcinogenic, hypolipidemic, antiatherosclerotic and immune-enhancing activities. Stability of CLA in foods has not received much attention by both academics and industry. Although CLA has shown many beneficial effects, its decomposition must be prevented when CLA in foods is processed, stored and transported. However, no study to date has addressed the stability of CLA in foods. The present study was carried out further to examine the stability of CLA in egg yolk during the storage and frying, using gas liquid chromatography (GLC) and silver ion high-performance liquid chromatography (Agt-HPLC). The eggs, containing 4.0% CLA per gramme of egg yolk, were 40s. Either storage for 6 months or frying for 40 s did not significantly change the composition of CLA in egg yolk. However, the degradation of CLA was statistically significant when the CLA components of egg yolk protected CLA from degradation. It is concluded that CLA is well preserved in egg before it is consumed.     

Hexagonal Ferrites from Melts and Aqueous Solutions,Magnetic Recording Materials

Owing to their particular crystallographic properties, ferrimagnetic hexagonal ferrites exhibit a far greater coercive force than the conventional magnetic pigments. They therefore appear to be suitable for use in magnetic information storage procedures, some of which are novel and are at the development stage. Thus, magnetic tapes of high coercive force containing barium ferrite could be used as master tapes for copying magnetic information or for producing forgery-proof magnetic cards, if magnetic heads having high-order write fields were successfully developed. Moreover, platelet-like ferrite pigments in which the preferred direction of magnetic orientation is perpendicular to the plane of the platelet are of great interest for perpendicular magnetic recording. In this progress report, the crystal structures, magnetic characteristics of hexagonal ferrites, and chemical processes for their production are discussed. In particular, reactions in salt melts or under hydrothermal conditions produce finely divided pigments whose particles have a pronounced hexagonal, plate-like habit, a narrow particle size distribution, and advantageous magnetic properties. The magnetic properties of the pigments crystallized from salt melts may be adjusted by cation exchange.     

温度对贮氢合金MlNi3.75Co0.65Mn0.4Al0.2动力学性能的影响

在-20℃～85℃的范围内系统地研究了温度对贮氢合金MINi3.75Co0.65Mn0.4Al0.2动力学性能的影响.结果表明:该贮氢合金电极的电化学反应电阻Rt,欧姆内阻Ro,阴极极化过电位,阳极极化过电位,阳极极化过程中的电化学反应过电位ηa和浓差极化过电位ηa均随温度的升高而减小,该电极的交换电流密度i0,对称因子β和电极中氢的扩散系数D随温度的升高而增大.当放电电流密度较低时,电化学反应是整个电极过程的速度控制步骤;当放电电流密度较高时,氢的扩散是整个电极过程的速度控制步骤;在中等放电电流密度下,电极过程由电化学过程和氢的扩散过程混合控制.该电极中电化学反应过程和氢扩散过程的活化能分别为28.1 kJ·mol-1和19.9 kJ·mol-1.     

LaCo13基金属间化合物的磁性能和储氢性能

对LaCo13基金属间化合物在磁致冷材料和储氢材料领域中的应用进行了综述,总结了该系化合物的成相规律、替换元素对相稳定性的影响,讨论了近期的研究进展及存在的问题。作为磁致冷材料应用时,LaCo13基金属间化合物在室温具有巨大磁熵变,而作为储氢合金时该系化合物表现出优异的高温电化学容量。虽然在磁致冷和储氢材料领域尚未对LaCo13基金属间化合物进行实用开发,但作为新型绿色能源材料已经展示出良好的应用前景。     

Nonisothermal Kinetics of Sub‐Solidus Phase Transitions in C10Zn,C16Zn and Their Binary System

Nonisothermal kinetics of the solid‐solid phase transition in (n‐C₁₀H₂₁NH₃)₂ZnCl₄(C₁₀Zn), (n‐C₁₆H₃₃NH₃)₂ZnCl₄(C₁₆Zn) and their binary system were determined by Kissinger and Ozawa methods from DSC measurements. The activation energy E_a of the binary system shows a waving dependence on W_C10Zn%, which is caused by not only an intermediate (C₁₀H₂₁NH₃)(n‐C₁₆H₃₃NH₃)ZnCl₄ but also three solid solution ranges (α, β, γ) in the phase diagram of C₁₀Zn‐C₁₆Zn. The variations of the layer d‐spacing are also convenient for the above result.     

低钴AB5型稀土系贮氢电极合金的研究

为了进一步降低AB5型混合稀土系贮氢合金的成本,采用Cr,Si,Cu替代Co和调节化学计量比的方法制备低钴AB5型贮氢合金。结果表明:3种取代元素在寿命方面的效果依次为Si>Cr>Cu,在放电容量和活化性能方面依次是Cu>Cr>Si。Cr,Cu,Si只有少量的替代才可能发挥其有利影响;通过非化学计量比的调节,低钴混合稀土系贮氢电极合金的放电容量、活化性能及倍率放电能力都能较好地达到实用要求,但是循环寿命有待提高。     

N,N-二甲基甲酰胺中电沉积制备镁镍储氢合金

采用恒电位沉积法, 选用适宜的添加剂和络合剂, 成功地从N,N-二甲基甲酰胺(DMF)中沉积出致密的黑色Mg-Ni储氢合金膜. 并初步探讨了其共沉积机理. XRD显示沉积层中含有非晶态Mg-Ni相和微晶态Mg相. SEM图及相应能谱图分析表明合金颗粒以团聚状态存在, 合金成分不是很均匀. AAS分析表明沉积合金中Mg的原子摩尔分数达27.3%. LAND电池测试系统测得所镀合金膜的放电比容量最高为172.4 mAh/g.