CD-ROM驱动器的原理、使用与维修

本文以我国图书情报界使用较多的 CDR- 1503S  CD- ROM光盘驱动器为例介绍了它的工作原理、使用和维修 ,以及光盘检索系统的安装问题。     

MD采访机数码录音笔闪存采访机——三种数字采访设备性能优劣比较

<正> 在广播电视领域全面迈向数字化的今天,信息的数字化进程得到了快速的发展,促进了信息以数据形式快速传递的方式实现,但在这个快速数据传输系统中,采访设备仍是一个薄弱的环节,因此,对采访设备的选择成了困扰众多电台的一项难题。 目前的采访设备以磁带采访机和MD采访机为主流,传统的磁带采访机以模拟录音技术为基础,它和数码录音技术为基础的数字采访机     

批处理在学生机管理中的应用

正作为信息技术学科教师,你是否会在上课的时候遇到以下问题:把桌面背景改得乱七八糟;用U盘复制游戏、MP3音乐;玩Windows自带的游戏、画图;随意改系统时间,随意删除文件(包括其他学生的作业)。我们如何应对课堂上出现的问题呢?大体思路是:在学生机的"启动"菜单中加入文件start.vbs(文件内容及解释见下文),再在教师机上建立一个文件start.bat(批处理文件),学生机开机后自动运行start.vbs,会从教师机下载start.bat,并运行这个文件,进而更改学生机的一些设置;在学生机上"映射网络驱动器",让每台电脑都有一个唯一的网络存储空     

王雨雷：找寻高功率激光技术的新突破

自1960年第一台激光器诞生之后,激光逐渐走进人们的生活,从小型的激光美容手术,到大型的工业设备,激光与人们的生活息息相关。我国较早地开展了高功率激光技术研究。科研工作者们通过自己的努力,不断地追求着更高的功率和更简单的装置,并在高功率激光驱动器的研究与应用方面取得了重要突破。     

磁力密封驱动器隔离套设计及涡流损失理论与实验技术研究

根据磁力密封驱动器的设计要求,完成了磁力密封驱动器整体结构设计;对隔离套的结构方式进行研究,完成了隔离套的设计;对磁力密封驱动器工作时的涡流损失进行了分析和计算,并将理论计算值与基于ANSYS的磁场分析计算结果进行了比较,结果显示:理论计算值与有限元分析的结果比较接近。     

Intel 710的兄弟：美光亦发25nm企业级固态硬盘

Intel推出SSD710系列企业级固态硬盘之后,做为在闪存事业上最亲密合作伙伴的关光也立刻发布了自己的新款产品“RealSSD P400e”,同样使用了25nm工艺的MLC NAND多层闪存芯片。     

Dynamics of installation way for the actuator of a two-stage active vibration-isolator

We investigated the behaviors of an active control system of two-stage vibration isolation with the actuator installed in parallel with either the upper passive mount or the lower passive isolation mount. We revealed the relationships between the active control force of the actuator and the parameters of the passive isolators by studying the dynamics of two-stage active vibration isolation for the actuator at the foregoing two positions in turn. With the actuator installed beside the upper mount, a small active force can achieve a very good isolating effect when the frequency of the stimulating force is much larger than the natural frequency of the upper mount; a larger active force is required in the low-frequency domain; and the active force equals the stimulating force when the upper mount works within the resonance region, suggesting an approach to reducing wobble and ensuring desirable installation accuracy by increasing the upper-mount stiffness. In either the low or the high frequency region far away from the resonance region, the active force is smaller when the actuator is beside the lower mount than beside the upper mount.     

EMC发布业务促进五大战略

前不久,EMC公司在京举行2009年业务战略发布会,提出了2009年促进业务发展的五大战略举措。 战略举措包括：第一,大力推广闪存驱动器、新一代Celerra NS系列统一存储、虚拟化等EMC创新存储技术,帮助客户提高效率、节约成本;     

Storage management strategy of flash-based platform

Storage management strategy can be expressed by a file system. Commercial file system for embedded application is generally complicated and resource wasted. In this paper, a specified file system adapted to embedded system with flash-based memory is developed. To guarantee the average usage of flash storage sectors, the strategy of wear leveling and adaptive damage management is introduced, in which a dynamic storage space management mode and the strategy of first in first out (FIFO) are adopted. Moreover, the strategy of redundancy design and fast-calculation and tracing is also adopted to extend the life of kernel sector, which can guarantee the reliable service of system booting. The practical application in an embedded CNC (computerized numerical control) platform proves that the file system has effective performance. Furthermore, the flash file system can be transplanted to different embedded platforms by changing a few bottom hardware parameters with universality.