通用可靠的串口/以太网网关设计

介绍了一种串口/以太网嵌入式网关的设计方案,详细讨论了串口可靠通信的实现方法,并在开源操作系统RT-Thread和微处理器S3C2440开发板的软硬件平台上实现。网关实际应用于一个无线传感器网络项目,实验表明该网关能实现可靠的数据通信。     

基于增量式PID算法的帆板控制系统的设计

基于STC12C5A60S2单片机与增量式PID算法,实现对帆板系统的控制。该系统主要由键盘模块、显示模块、风扇驱动模块、角度测量模块、报警模块组成。角度传感器测量帆板的角度并反馈回单片机,通过增量式PID算法计算,并由PWM方法控制风扇的转速,从而实现精确控制风扇风力与帆板角度。     

基于MCS-51系列单片机时间控制器软件的设计与实现

本文设计的基于MCS-51系列单片机时间控制器主要应用AT89C51作为控制核心,采用实时时钟芯片DSl302、EipROM24C02及动态数码显示相结合。具有硬件电路简单、软件功能完善、控制系统可靠、性价比较高等特点,具有一定的使用和参考价值。     

基于嵌入式技术的倾角传感器检测系统设计

介绍了加速度传感器MMA7260的工作原理、结构及功能,设计了一个基于ARM的实时嵌入式自动检测系统,使用μC/OS-II操作系统,构造一个具有角度测量、相关数据处理以及与上位机通信等功能的现场角度测量单元,上位机则主要完成系统监控和人机交互等功能。     

“项目式教学”在高职《C语言》课程中的应用

本文针对高职C语言课程教学中存在的内容安排不合理、教学方法与手段陈旧、学生厌学等问题,提出基于以以就业为导向、以学生为中心,以项目为载体,以工作任务为驱动,将理论与实践有机结合,使学生在完成任务的过程中掌握知识和技能。同时重视职业素养的养成,充分体现职教课程的特色。     

浅谈自增自减运算符在C语言中的应用

C语言的运算符,操作灵活,其中自增自减运算符的功能较为特别。合理的使用自增自减运算符可以提高程序执行的效率,但同时灵活使用自增自减运算符也是个难点。根据自增自减运算符的特点和不同使用形式,剖析自增自减运算符的使用规则,以便更好地帮助初学者学习和使用自增自减运算符。     

双参数Bézier曲线的升二次扩展

本文以二次Bernstein基函数为例,首次提出了含双参数基函数的新扩展——αβQ—Bern-stein基函数,此类基函数具有新的特点,即基函数的扩展次数一次性升高两次,且包含了二次多项式和带一个参数的三次多项式基函数的所有性质。基于这组基函数定义了αβQ—Bézier曲线,该曲线也含有参数,具有形状可调性,当α与β取某些值时曲线能达到C4连续或在某个端点处C0连续。最后与含两个参数的升一次Bézier曲线进行比较,该曲线具有调节范围广、灵活性更强的优势。     

纯电动汽车太阳能辅助空调控制系统的硬件设计

纯电动汽车车载动力电池是其唯一的动力源且很有限,辅助设备消耗的电能减少了纯电动汽车的续驶里程,尤其是空调,所以开发高效的纯电动汽车空调系统是纯电动汽车能够被市场接受的关键。将纯电动汽车顶盖布满太阳电池,可以使空调系统的制冷能力增强,同时还能增加纯电动汽车的行驶距离。对小型纯电动汽车的太阳能辅助空调系统进行研究,设计出适合该空调的自动控制系统,可为纯电动汽车创造出一个更加舒适的驾驶和乘座环境。     

Corrosion behaviour of Ni-Zr-Ti-Si-Sn amorphous plasma spray coating

Ni₅₉Zr₂₀Ti₁₆Si₂Sn₃ amorphous material was deposited by a vacuum plasma spraying technique onto steel and copper substrates in order to investigate their behaviour in a corrosive environment. For comparison, the same alloy was prepared as amorphous ribbons by melt spinning. The amorphous nature of the coatings and ribbons was characterized by XRD, DSC and TEM, while XPS and AES analyses were performed to understand the origin of passivation and mode of corrosion. The corrosion behaviour of the coating was studied in H₂SO₄ and HCl solutions open to air at room temperature. Potentiodynamic polarisation and galvanic coupling tests were carried out on the substrate and the coating. It was found that the formation of Zr-, Ti- and Si-rich passive oxide layers provide a high corrosion resistance in H₂SO₄ solution while the breakdown of the passive layer by chloride ion adsorption was responsible for pitting corrosion of the Ni₅₉Zr₂₀Ti₁₆Si₂Sn₃ amorphous ribbons in HCl solution. Galvanic corrosion was the dominant corrosion mechanism for the coating/copper hybrid structure, in contrast to the Ni₅₉Zr₂₀Ti₁₆Si₂Sn₃ amorphous coating, which efficiently protected the steel substrate in the corrosive environment.     

Effect of atmospheric pollutants on the corrosion of high power electrical conductors: Part 1. Aluminium and AA6201 alloy

The aim of this study was to evaluate the joint effect of marine and industrial pollutants on the atmospheric corrosion of aluminium and its AA6201 alloy. Weight loss was determined after 4, 11, 16 and 24 months exposure being morphology and attack intensity analysed through SEM-EDX. Both materials showed the most intense attack for the highest SO₂ contents. Good correlation among weight loss, attack depth and tensile strength to rupture with time and with pollutant contents was determined for both materials in most sites. The cause for low aggressiveness of the heaviest Cl⁻ polluted atmosphere on aluminium was electrochemically demonstrated.