Original surface chemistry of sulphidesis altered upon contact with air, leading to ''oxidation'', which is accompanied by evolution of heat. Th
Because of the low grade, high oxidation rate and the accumulation of little associated metal sulfide ore in the molybdenum concentrate during flotation, the Qi
为了解决高校中任课教师课堂点名的考勤方式既浪费教学时间,又不能避免学生替点名现象发生的问题,本文设计了一套基于无线射频识别(RFID:Radio Frequency Identification)技术的课堂考勤系统。该系统能够实现阅读器显示学生的姓名、学号、班级等基本信息,并可在学生迟到、早退、违规刷卡时进行报警提示,同时可查询已到、未到人数等考勤情况的功能。实践证明,该系统运行情况良好。