用MC68332开发高性能双燃料发动机ECU

从系统设计的角度出发，使用MOTOROLA高性能的32位MCU（微控制器）MC68332开发发动机ECU（电控单元），阐述了ECU开发中硬件设计与软件设计的关键问题，提供了现代ECU开发的技术思路，以期开发出先进水平的ECU系统。     

车载ECU加密通信与身份认证机制研究

针对车载ECU使用明文通信,ECU固件易被篡改的安全问题提出了一种新的车载ECU加密通信与身份认证机制,该机制使用椭圆曲线加密算法(ECC)加密通信密钥,使用对称加密算法加密数据,采用哈希算法来验证ECU固件完整性.仿真实验分析表明,该机制具有计算快、安全性高、低成本等优点,能够保证ECU间的安全通信,解决ECU固件易被篡改的问题.     

柴油-CNG电控双燃料发动机的试验研究与开发

针对柴油-天然气双燃料汽车,设计了D6102柴油-CNG电控喷射双燃料发动机系统,并进行了性能试验.结果表明:D6102柴油-CNG电控喷射双燃料发动机具有良好的动力性、经济性和排放性能.标定功率和最大扭矩与原机相当,天然气替代率在70%～85%之间,发动机排放达到欧Ⅱ标准.     

发动机怠速控制系统分析

文章从怠速控制系统的原理出发,介绍了怠速控制系统的作用、组成与控制内容,以及步进电动机式怠速控制阀相关特性。     

双燃料发动机技术研究综述

气体燃料发动机的主要特点是缓解能源危机和降低有害物排放,按使用燃料的特点可分为单一燃料、两用燃料和双燃料发动机。双燃料发动机是气体燃料使用的主要方式,综述了国内外双燃料发动机技术的研究进展和现状。分析表明：研究生物制气-柴油双燃料发动机的燃烧和排放特性有重要的理论意义和实际价值。     

双燃料发动机燃烧模型研究综述

发动机燃烧模型的发展经历了零维模型,准维模型,多维模型三个阶段.双燃料发动机是气体燃料使用的主要方式,针对国内外双燃料发动机燃烧模型的研究进展和现状,介绍了气体-柴油双燃料发动机的三维燃烧模型应包含的子模型和计算方法.     

柴油天然气双燃料发动机的研究初探

本文通过对新疆天然气储量等现状的分析,阐述了新疆开展柴油天然气双燃料发动机研究的必要性。对柴油天然气双燃料系统方案进行了选择,设计了燃料供给系统的结构,并对天然气供给系统工作原理进行了阐述。     

浅论电子控制器及其在汽车发动机电子控制系统中的作用

随着汽车电子化程度的进一步提高和微电子技术的迅速发展,电子控制器(ECU)的控制功能得到了重大的发展,现在越来越多的控制系统都被以ECU为核心的电子控制系统所取代。本文主要介绍ECU及其在燃油喷射、点火和废弃再循环等三个重要的汽车发动机电子控制系统中的作用。     

用低等级粉煤灰开发绿色高性能混凝土

采用化学激发、水热激发与机械磨细相结合的三位一体的高效复合活化技术对低等级粉煤灰进行活化处理,可得到高活性粉煤灰. 综合运用该高活性粉煤灰的活性作用、高效减水剂的超塑化增强作用、复合早强剂的早强作用以及复合掺合料的超叠加作用,可保证用低等级粉煤灰配制绿色高性能混凝土的成功.     

天然气/柴油双燃料发动机电控技术研究

天然气作为燃料具有低排放、低消耗的优点,天然气/柴油双燃料发动机通过应用电控喷气技术,可以实现较高的发动机综合性能.本文系统介绍双燃料发动机电控系统的结构及特性等.     

发动机电子控制器的辐射骚扰测试研究

对发动机电子控制器的辐射骚扰测试方法进行分析,研究如何获得较理想的电磁场背景。介绍如何根据控制器的功能和电路特点来进行测试从而获得准确的测试数据。     

用VB绘制发动机实时数据动态曲线图

为使发动机监控系统中数据的显示和分析更直观，使用PictureBox控件和Timer控件，可以解决实时曲线显示问题，具体介绍了绘制实时监测曲线的程序设计方法．     

贮水水箱液位检测系统的开发与应用

设计能监控2m范围内的水位变化,测量精度1cm,测量时与被测液位无直接接触,能够清晰稳定地显示结果,在水位超出上、下限时发出声光报警,并能准确地控制水泵工作的控制及检测系统。     

机构陈列柜微机控制系统的设计

本文介绍了基于单片机实现多路开关量控制系统，用于机械原理实验室机构陈列柜演示系统，并用ISD 4004系列语音芯片构成语音解说系统。文中给出了硬件结构图和程序框图。     

一种无需同步的闪光测光系统的设计与实现

运用增强型51系列单片机 STC12C5A60S2内部集成的 A/D 转换器的高速采集功能,结合 ICL7650自稳零斩波集成运放,设计了一种硬件结构简单、性能较好的无需同步即可进行闪光测光的测光系统.给出了系统的软、硬件框架及部分关键代码,并对系统进行了实际评估测试,取得了较好的测光效果     

The challenges of a high-performance student athlete

To become a top athlete requires time, commitment and carefully planned training. Optimum adaptation to training requires the careful balancing of stress and recovery. The student athlete has to balance all these demands with the additional requirements of an academic programme. This can bring unique stresses and challenges. This research aims to investigate the challenges of combining high-level sport with academic demands. Nine elite student athletes (three females, six males) took part in semi-structured interviews around how the student athletes balanced their training and sporting demands with the academic demands of their course of study. The interviews were transcribed verbatim and analysed using grounded theory. The results suggested that the athletes had each developed their own distinct approach towards training management. Most of the subjects had experienced setback in their study and athletic performance due to overtraining or burnout. The findings highlight the need to empower and educate not only the athlete but also the coach on the impact of overtraining. Key findings from this study were the need for open coach–athlete communication, in-depth planning and the need for adequate recovery.     

Effect of a semi electro-mechanical engine valve on performance and emissions in a single cylinder spark ignited engine

In this study, an electro-mechanical valve （EMV） system for the intake valve ofa fottr stroke, single cylinder, overhead valve and spark ignition （SI） engine was designed and constructed. An engine with the EMV system and a standard engine were tested to observe the effects of the EMV on engine performance and emissions at different speeds under full load. The EMV engine showed improved engine power, engine torque and break specific fuel consumption （BSFC）. A 66% decrease in CO emissions was also obtained with the EMV system, but hydrocarbons （HC） and NOx emissions increased by 12% and 13% respectively.     

一种高性价比数字式直流信号源研制

利用8 bit单片机、2片8 bit D/A芯片构成16 bit D/A输出、专用键盘显示器电路8279、两级稳压电源、精密基准电源研制的数字式直流信号源,具有电路简单、操作方便、成本低廉、输出精度高等特点。数字式直流信号源设计包括电源及精密基准源电路、键盘显示电路、直流信号输出即16 bit D/A电路、直流电流输出电路。在实际现场测试结果表明,该信号源性能可靠,相对误差只有0.05%。     

高职学生职业能力培养存在问题与对策探讨

高职院校学生职业能力培养的效果如何,直接影响到毕业生的就业与创业。文章分析当前高职院校在学生职业能力培养方面的存在问题,并结合高职院校的实际,提出加强学生职业能力培养与实践的对策。     

Developing a Deeper Involvement with Science: Keith's Story

Much research in science education has focused on the conflicts that exist between individuals' ways of knowing the world and science. We have been left without an image of the compatibility or congruency that is necessary for science to occupy a fundamental position in a person's life. In this study we argue that Keith, a Jamaican American pre-service teacher, provides us with such an image. Using narrative, we trace the development of Keith's relationship with science over time and space in order to understand how Keith has constructed an identity through science amid the larger structures and contexts that comprise his life. We believe Keith's stories of practicing science in and out of the classroom illustrate how science, while taking an essential position in his lifeworld, extends and articulates Keith's subjective stances on experience. As part of his lifeworld, Keith finds a sense of value in science that turns it into a discipline that is part of the person he both is and wants to be and the world he wants to shape as a teacher. Richard Kozoll is an assistant professor of science education at the School of Education of DePaul University. His research interests include students' identity constructs as a means to understand engagement with and participation in science and inform inclusive science teaching practices. An additional line of research includes the use of narrative in science education research. Margery Osborne is an Associate Professor in the College of Education at the University of Illinois at Urbana-Champaign. She teaches early childhood and elementary science education courses. Her research interests, located within the intersections constructed between ideas of reflective practice and research on critical and feminist pedagogy, include exploring the dynamic and complex nature of teacher knowledge.