共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
指纹是人体的一项生物特征,是指手指末端正面皮肤上凸凹不平产生的纹路。尽管指纹只是人体皮肤的一小部分,但是,它蕴涵大量的信息,每个人指纹的纹路在图案、断点和交叉点上是各不相同的。随着计算机技术的发展,大容量存储器和处理芯片的存在,使得指纹识别技术的可靠性得到较大提高,成本得到很大降低,这项技术的安全系数也较普通系统有了很大的提高。指纹IC卡,让你生活更便捷目前,我国在金融、电子商务中使用的基本上是智能IC卡,这类卡在 相似文献
4.
5.
随着信息技术的迅猛发展,新技术不断在图书馆中得到应用,图书馆业务管理和服务手段也与时俱进,呈现出智能化、现代化特点。近几年来,智能卡在全国各地域、各行业得到了广泛的应用和推广。图书馆作为服务机构,在经历了传统的读者证、读者卡时代之后,也逐步在向智能卡这个方向推进。图书馆智能卡的使用可以实现馆内的借书。实现馆内费用的结算和管理,读者进入馆内借阅的身份验证。 相似文献
6.
7.
本文介绍了一种计算机用IEEE-488接口卡的硬件和软件设计。硬件主要采用一块8255芯片,软件使用C语言。该接口实现了与数字万用表的连接,可以与任何具有IEEE-488接口的仪器相连接。 相似文献
9.
CF卡在单片机系统中的应用 总被引:3,自引:0,他引:3
Compact Flash Card卡是近年来发展迅速的一种非易失性存储器,其内部集成了微控制器、Flash Memory阵列和读写缓冲区,具有体积小、存储容量大、数据保存具有非易失性、接口标准统一、便于携带等优点。文章介绍了Compact Flash Card的结构、工作方式和磁盘文件管理系统及在Compact Flash Card上的应用。并给出了Compact FlashCard与单片机的接口电路和单片机读写Compact Flash Card的汇编语言源程序。 相似文献
10.
11.
12.
Virtual spectrum analyzer based on data acquisition card 总被引:9,自引:0,他引:9
A virtual spectrum analyzer based on a data acquisition card is presented. The implemented functions are described. The properties of the device were examined. Such features as accuracy and speed are considered. The virtual analyzer and an instrument equipped with a DSP are compared. The integrated programming package LabView was used to design the analyzer 相似文献
13.
The existing approach of radiation protection is largely based on the collective dose to the population with provisions for protection at an individual level through justification and optimisation. With the individual patient dose now exceeding the life-long occupational dose to a worker in a typical radiology practice, there is a need to establish approaches based on the protection of an individual patient. Radiation exposure tracking seems a way forward in this respect. Technological advances in recent years have provided opportunities for tracking to becoming a reality. The IAEA project on Smart Card/SmartRadTrack is described in this paper. The tracking is now a reality in a few dozen centres in many countries connected by picture archiving and communication systems, and there is hope that this will extend to cover other countries and continents. 相似文献
14.
15.
A high-speed card changeable permanent magnet twistor memory is described. High switching speeds at low drive current levels are obtained by inverting the twistor (using the twistor wire as the word line rather than the sense line as in previous designs). A 512-word, 24-bit memory having a cycle time capability of 250 ns has been constructed and evaluated. Bipolar drive currents of 600 mA produced switching times of 60 to 70 ns and signal levels of 12 to 16 mV. The characteristics of a 4096-word, 90-bit memory are predicted. Drive currents of 400 mA would produce outputs of 10 mV and a cycle time of less than 400 us. 相似文献
16.
采用传统的高温固相反应法制备了钙钛矿氧化物Eu1-xCaxMnO3(x=0,0.1,0.2,0.3,0.4,0.5)多晶体系样品。通过样品的XRD谱线、磁化强度随温度、外加磁场的变化曲线(M-T、M-H)等数据研究了Ca不同掺杂量对钙钛矿氧化物EuMnO3系列多晶样品的居里温度、磁熵变、磁相变等的影响。结果表明,Eu1-xCaxMnO3(x=0,0.1,0.2,0.3,0.4,0.5)系列陶瓷样品呈现良好的单相性,空间点群为Pnma。低浓度掺杂的样品存在一个TC,高浓度掺杂的样品出现两个磁转变点,且由于双交换相互作用,随着Ca的掺杂,TC逐渐增大,当掺杂量达到0.4时,低温下的TC却明显减小。根据-ΔSM和RCP值可知,Eu0.7Ca0.3MnO3是该组样品中比较适合做磁制冷的材料。通过对Loop曲线的分析可知该组样品经历了由一级相变向二级相变转变的过程。 相似文献
17.
18.
针对一般总线的数据采集设备都受到不支持热插拔、PC端口资源有限等因素的影响,使用起来很不方便的问题,设计了采用通用串行总线USB作为通讯总线的数据采集卡,系统采用具有在系统可编程(ISP)功能的微控制单元AT89S52和专用USB接口芯片PDIUSBD12,整个采集卡具有接口便捷、易扩展和低成本等特点。 相似文献