废旧电池溶胶-凝胶法制备Mn-Zn铁氧体的研究

以硝酸溶解废旧碱性锌锰电池所得的溶液为原料,用溶胶-凝胶法制备出了具有尖晶石结构的Mn-Zn铁氧体.借助于XRD、IR和SEM技术,对制备过程进行跟踪检测并对纳米晶铁氧体的晶体形貌进行表征.研究表明:制备Mn-Zn铁氧体的适宜条件为:金属离子和柠檬酸的比例为1:1(mol),pH=5.0,干凝胶煅烧时间为2h,煅烧温度为650℃;所得产物基本为球形,具有粒径小,分散均匀的特点.     

Lund模型和极端相对论系统的量子能谱

讨论极端相对论量子系统的能谱问题.从给出一个典型的极端相对论系统(Lund模型)的精确解及证明一个新的维里定理这两方面来演示了动能形式对能谱的影响. 关键词：     

Multi-Band Absorption Properties and Near-Field Enhancement in Mid-Infrared Based on the Interference Theory

We numerically study the multi-band absorption properties and near-field enhancement inside the microcavity based on the interference theory. The compact single unit cell consists of a gold square patch placed on the top of a metallic ground plane, separated by a dielectric layer. At the normal incidence of electromagnetic radiation, four bands of a maximum absorption of 98% are accomplished by appropriate sizes of the square patch. Furthermore, we demonstrate that the four bands, which are corresponding to the fundamental mode and higher modes of the standing wave, can be readily tuned in the mid-infrared region and associated with the near-field enhancement in the cuboid mierocavity. Since chemical and biological fingerprints of the common functional groups can be found in the mid-infrared region, we may readily tune the multi-bands of interest in the mid-infrared range and identify the molecular stretches of groups. Moreover, the proposed structure is insensitive to the polarization of the incident wave due to the complete rotational symmetry （C4 symmetry）. The unique properties of the optical metamaterial indicate that this approach is a promising strategy for surface-enhanced infrared absorption spectroscopy and for the tracking of characteristic molecular vibrational modes