分别在空气和N2中高温烧结得到了不同掺杂浓度的Fe3O4:Zn粉末.X射线衍射(XRD)结果表明,空气中烧结使得样品过氧化,生成大量的α-Fe2O3相,而N2环境下烧结可以获得较纯的ZnxFe3-xO4相.Zn2+在反尖晶石结构中A位的替位掺杂,影响到B位Fe阳离子的价态分布,电子输运依然保持了电子变程跳跃的传导机制.磁性测量结果显示低浓度的Zn2+掺杂对Fe阳离子之间的超交换耦合作用产生影响,也使负的磁致电阻的数值有所改善

7-1锁相环路概述 7-2锁相环路基本工作原理 7-3锁相环路分析 7-4锁相环路的应用 7-5频率合成

采用离子注入和高压电镜原位观察的方法,研究了氢对国产ODS铁素体钢辐照性能的影响.结果表明:室温注氢前后ODS铁素体钢的微观结构无明显变化;将其加热到500℃并电子辐照,未观察到辐照空洞,注氢与未注氢ODS铁素体钢室温电子辐照的结果表明:氢对点缺陷的迁移和聚集起着十分重要的作用

8.1 物流信息系统的内容与作用 8.2 自动识别系统及其应用 8.3 电子数据交换系统(EDI) 8.4 电子自动订货系统（EOS） 8.5 物流运输信息管理 8.6 销售时点信息系统（POS） 8.7 电子商务与物流信息系统

第八章局域网与国际互联网 8.1概述 8.2 Internet单机上网方式 8.3入网准备 8.4环球信息网WWW 8.5电子Email邮件 8.6远程登录 Telnet 8.7网上文件传输FTP 8.8电子公告牌BBS 8.9、8.10、8.11这三节为选修内容

Computer networks are geographically distributed collections of communication links and switching proces￾sors, the purpose of which is to transport data between computers, workstations, and terminals. In general the elements of a computer network must follow compatible rules of operation together to function effectively. These rules of operation are known as protocols

The term computer graphics refers to the generation,representation, manipulation, processing, and display of data by a computer. Computer-generated images may be real or imagined, animated or still, two-dimensional (2-D) or three-dimensional (3-D).Today most computers, particularly those in the PC,Macintosh, or workstation categories

The last decade has seen a revolution in software engineering tools and techniques. This revolution has been fueled by the ever-increasing complexity of the software component of delivered systems. Although the software component of delivered systems may not be the most expensive component, it is usually, however, “in series” with the hardware component; if the software doesn’t work, the hardware is useless

Input devices are those portions of computer, data processing, and information systems that perform the essential function of providing some means for entering commands and data into the system. Therefore, input devices are found in all such systems, but are treated here as a separate equipment group, independent of the

一、氧化还原反应的能量变化 化学反应:氧化还原反应和非氧化还原反应 电子 得失的角度) 氧化还原反应:因为伴随着微粒运动和电子得失而使微粒的 运动动能和微粒之间势能的改变,即伴随着能量的变化