Study on a remote-control PWM drived mini car based on AT89C51

TX-2B编码的控制按键基带信号经ASK振幅键控后由30 MHz的载波发射,通过超再生接收电路再由RX-2B解码后,无线信号转化为数字脉冲信号并输入到AT89C51。从而控制单片机输出PWM信号,控制功率管驱动电路,配合直流电动机及现有玩具小车机械传动装置,实现遥控电动玩具车的前进、后退、加速、左右转等功能。The base-band signal,coded by TX-2B as the control key,is transmitted on 30 MHz carrier wave after being modulated with ASK.The wireless signal,after being decoded with RX-2B is transformed into digital signal and then sent to AT89C51 as the control signal.The PWM output from AT89C51 control the power driver of the DC motor,so the mini car,as the load of DC motor,can fulfill the functions such as forward or backward,left or right,even accelerate.福建省半导体及应用重点实验室开发课题基金资助项目(光子学研[2007]14号);; 福建省科技计划基金资助项目(2001I1021);; 厦门科技计划基金资助项目(3502Z20024006

纳米金刚石球晶的激光溅射产生

联系人：郑兰荪以脉冲激光束溅射浸入水中的单质碳样品.观察到产生一种外形完美且具有金刚石结构的纳米碳球.研究中考察了处于固/液界面的各种碳源在脉冲激光作用下发生的变化,初步探讨纳米碳球的形成原因.研究结果揭示:对于表面悬挂键为其他基团所饱和的纳米碳粒,金刚石与石墨结构的热力学稳定性相近,并且当熔融碳的尺寸小至纳米级时,其表面张力能产生较高的压力,因此使它同样有可能凝聚成金刚石的结构.国家杰出青年科学基金与国家教育委员会“跨世纪优秀人才计划”基金资助项

Diamond nanospherulite: A novel material produced at carbon-water interface by pulsed-laser ablation

地址: 1. XIAMEN UNIV, DEPT CHEM, STATE KEY LAB PHYS CHEM SOLID SURFACES, XIAMEN 361005, PEOPLES R CHINA 出版商: SCIENCE CHINA PRESS, 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINAFormation of carbon nanoparticles with perfectly spherical.shape and diamond structure (diamond nanospherulite) by laser-ablating a variety of carbon samples in water is reported for the first time The studies reveal that molten carbon nanoparticles generated by laser ablation are quenched directly by water and end up as diamond nanospherulites,possibly due to the high pressure arising from surface tension and the high stability resulting from termination of dangling bonds with hydrogen atoms.Project supported by the National Natural Science Foundation of China;;the State Education Commission of Chin