步进电动机可变细分驱动器

设计了一种新型的步进电动机驱动器,该驱动器用于驱动三相反应式步进电动机,低速运转时采用细分控制,低频振荡小;高速运转时不采用细分控制,电机动态响应快、加速特性好。该驱动器适合与普通单片机控制器配套使     

Win98环境下OMR阅读机编程接口的扩展与实现

OMR(Optieal Mark Reader)光学标记阅读机是一种先进的计算机数据录入外部设备,其自带的软件多为DOS系统下的,本文讨论了Win98环境下OMR读卡机编程接口的扩展与实现.     

High power pulsed lasers

Pulsed high power lasers can deliver sufficient energy on inertial fusion time scales (0.1–10 ns) to heat and compress DT fuel to fusion reaction conditions. Several laser systems have been examined for application to the fusion problem. Examples are Ndglass, CO₂, KrF, and I₂, etc. A great deal of developmental effort has been applied to the Ndglass laser and the CO₂ gas laser systems. These systems now deliver >10⁴ kJ and >20×10¹² W to inertial fusion targets. The Nova Ndglass laser is being constructed to provide >200 kJ and >200×10¹² W of 1 m radiation for fusion experimentation in the mid-1980s. For inertial fusion target gain, >100 times the laser input, it is expected that the laser must deliver 3–5 MJ of energy on the 10–20 ns time scale. This paper reviews the developments in laser technology and outlines approaches to construction of a 3–5 MJ driver.     

Hazard perception and driving experience among novice drivers

The crash risk of novice drivers decreases rapidly during the first few months of post-licensing driving, indicating that some important safety-relevant traffic skills are learnt during this period. The present study tested the hypothesis that the risk decrease is related to improved hazard perception skills. A video-based hazard perception/reaction test, measuring reaction times to 31 traffic scenes, was administered to three groups of drivers, having held a licence for 1, 5, and 9 months, respectively, and to a group of drivers who had held their licences for several years. Average reaction times tended to decrease with experience, but the decrease was not significant. There were some significant differences in the expected direction for individual test items, indicating a possible effect of experience. One half of the situations were presented together with a secondary task, in order to investigate effects of increased mental load on hazard perception. Male novice drivers had relatively longer reaction times with the secondary task, compared to both female novice drivers and male experienced drivers. It is concluded that hazard perception as tested here is probably only a minor factor in explaining the initial risk decrease among novice drivers.     

手机用TFT-LCD驱动芯片接口电路的研究与设计

接口电路是手机用单片集成TFT-LCD驱动芯片的重要组成部分,用于MPU与驱动芯片之间的数据通信。文章详细分析了目前占市场主导的176RGB×220分辨率、26万色的手机液晶显示驱动芯片中接口电路的功能,包括系统接口和外部高速接口的工作原理和动作时序,同时介绍了接口模式之间的转换。在此基础上提出了一种接口电路的设计方案,并且在0.18μm工艺下实现了该电路。仿真结果表明,此电路完全实现了芯片规格中要求的接口功能,可以完成18/16/9/8-bit并行接口、串行接口以及18/16/6-bit外部高速接口的可选择使用。DC综合结果显示,接口电路的面积约为4600多门,可以工作的频率达到12.5MHz。     

Clearing the mind: A working memory model of distraction from negative mood.

The present research examined whether and how loading working memory can attenuate negative mood. In three experiments, participants were exposed to neutral, weakly negative, or strongly negative pictures followed by a task and a mood scale. Working memory demands were varied by manipulating task presence (Study 1), complexity (Study 2), and predictability (Study 3). Participants in all three experiments reported less negative moods in negative trials with high compared to low working memory demand. Working memory demands did not affect mood in the neutral trials. When working memory demands were high, participants no longer reported more negative moods in response to strongly negative pictures than to weakly negative pictures. These findings suggest that loading working memory prevents mood-congruent processing, and thereby promotes distraction from negative moods. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

小型化牵动下的硬盘技术

逐一分析了硬盘中的磁头、盘片等主要构件以及飞行高度发展至今的小型化过程,从而显示出当今硬盘技术发展的概貌;分析讨论了超顺磁效应,指出硬盘小型化要想继续下去必须另辟新路。     

采用LinkSwitch-TN系列寓线转换器的非隔离恒流LED驱动器电路

LinkSwitch-TN系列离线转换器IC专门设计去取代所有线性和电容降压非隔离电源。仅需用非常少量的元件，即可组成恒流LED驱动器电路。文中在介绍LinkSwitch-TN结构与特点的基础上。给出了由其构筑的LED驱动电路。     

基于命名管道和异构通信机制的多应用场景下驱动升级策略

针对电化学遗留系统驱动不兼容新的操作系统的问题,本文提出一种基于命名管道和异构通信机制的驱动升级策略。使用命名管道和WinUSB作为中间件,来完成上位机与下位机的通信,从而减少设备对驱动的依赖,提高通信的灵活性。结果表明本文所述的方法与原驱动的实验数据相对误差在0.000~0.001之间,将升级后的系统结果与原驱动的实验值进行比较,两者数据在误差允许的范围内结果一致。本文所述的方法通过修改少量代码来解决驱动与新操作系统的兼容性问题,既方便了驱动不适应新的操作系统的用户,也方便了工程开发人员对遗留系统的维护工作,实现了系统的低耦合和代码复用,并在某电化学软件得到了应用。     

Teen driver crash risk and associations with smoking and drowsy driving

Motor vehicle crashes are the leading cause of death for young people in the United States. The goal of this study was to identify risk factor profiles of teen and young adult drivers involved in crashes. General demographic and behavioral as well as driving-related factors were considered. Analysis of a nationally representative telephone survey of U.S. young drivers ages 14 to 22 (N = 900) conducted in 2005 was restricted to 506 licensed drivers (learners excluded). Statistically significant univariate associations between factors of interest and the primary outcome, crash involvement (ever) as a driver, were identified and included within a multivariate logistic regression model, controlling for potential demographic confounders. Aside from length of licensure, only driving alone while drowsy and being a current smoker were associated with having been in a crash. Gaining a better understanding of these behaviors could enhance the development of more customized interventions for new drivers.