CAN总线技术在光电编码器中的应用

介绍了采用CAN总线数据传输方式的系统中,光电编码器CAN总线接口的设计与应用。首先,设计了由单片机、独立CAN总线控制器SJA1000、CAN总线收发器TJA1050及高速光耦TLP113等构成的光电编码器CAN总线接口硬件电路;然后,介绍了光电编码器CAN总线接口的软件设计,包括初始化的设计、CAN总线报文接收及发送的设计;最后,通过周立功公司的“USBCAN1”型号CAN总线接口卡验证了该光电编码器CAN总线接口设计的可行性。实验中采用1米长的屏蔽双绞线作为传输介质,通信速率为800kbps;结果表明：带有CAN接口的光电编码器克服了传统的通信线路的缺点,具有更高的实时性、可靠性且通信速率高、传输距离长、抗干扰能力强,更加适用于自动化测量和控制系统。     

基于UWB定位系统硬件平台设计

为进一步研究基于UWB的无线定位技术,文中设计了一种基于UWB定位系统硬件平台。硬件平台基于模块式设计思路,选用STM32F405作为主控制器,通过SPI总线与DW1000射频芯片通信。UWB射频电路围绕DW1000设计布局,使用全向外置天线。硬件平台在通信方面设计使用GPRS无线通信模块并采用TOA定位方式,预留GPIO外设扩展接口。经制板测试,在视距空旷环境下最远通信距离为110m,在相同环境下100m测距均方根误差20.2cm,室内非视距环境中定位误差为20cm,满足室内高精度定位技术研究需求。     

On m-changes in atom-rigid-rotor collissions: influence of an initial rotation

Reorientation of the angular momentum of a diatomic molecule in collisions with atoms is investigated using classical mechanics. A factorisation formula for cross sections for rotational excitation is given. The factorisation allows the calculation of the state-specific cross section d σ (j′ m′ ← jm)/dΩ once the m-averaged cross sections d σ (j″← 0 )/dΩ for all possible j″ are known. The approach is applied to the Na₂-He system.     

Pretreatment studies with biological and environmental materials

Summary Pressure digestion units made from stainless steel, with up to 12 sample positions, are described. The sizes of the teflon digestion crucibles are 0.6 resp. 35 ml for sample weights (dry weights) from about 10 up to 1000 mg. The handling of the units and the digestion crucibles, the standard digestion program with nitric acid (needed time including cooling period about 3 h), its evaluation and the very important safety aspects are extensively discussed.Supported by research grant MT 405 g/AUT 03 from the German Federal Department of Research and Technology (BMFT), Bonn, FRG     

独立CAN总线控制器SJA1000

在对CAM总线进行简要介绍的基础上介绍了Philips公司新推出的独立CAN总线控制器SJA1000的特点、内部功能和引脚定义,并对其内部寄存器进行了说明,同时列出了SJA1000的新增功能,最后给出它的典型应用电路。     

基于AT89S52的CAN点对点通信的软硬件设计

随着人们对总线各方面要求的不断提高,总线上的系统数量越来越多,随之产生诸如电路复杂性增加、可靠性下降、生产成本增加等问题,为了解决上述问题,本文简单介绍了一种低成本的CAN总线通信接口的设计方案,在选型上采用了Philips公司的SJA1000作为外挂控制器,完成了基于AT89S52的CAN通信硬件设计,就平台的初始化、模块的发送、接收给出了设计分析,并且附上了部分C语言设计代码.最后通过连续的实验数据分析,通信速度满足设计要求,整个系统具有较高的实用性.     

HPR1000堆芯装载50%MOX组件的燃料管理方案

针对HPR1000压水堆堆芯,开展了应用MOX (混合氧化物燃料)组件的燃料管理方案初步研究。对MOX燃料组件进行设计,研究了MOX燃料成分及燃料棒在组件内的布置。在此基础上,开展了1/4堆芯年换料、18个月长周期换料,并装载50%MOX组件这两种燃料管理方案研究。通过与UO2堆芯的对比,分析了装载50%MOX组件堆芯的核特性。分析结果表明,两种50%堆芯装载MOX组件的燃料管理方案,其堆芯主要物理参数均满足核设计准则要求。     

TMS320C6416与CAN控制器的接口实现

分析了数字信号处理器TMS320C6416和CAN控制器SJA1000的接口时序。给出了基于复杂可编程逻辑器件EPM7512的DSP数字信号处理器和CAN控制器之间的接口电路,同时给出了详细的软硬件实现方法。     

基于CAN总线和无线技术的输液网络监控系统

为实现大中型医院静脉输液网络化与智能化,设计了一种利用CAN总线和无线技术的输液监控系统。该系统包括执行机节点、CAN总线网络、主节点、无线数据收发系统、控制主机等。无线通信模块采用2.4 G的nRF2401通信芯片,而CAN总线通信模块采用SJA1000和PCA82C250,通过单片机控制,实现与其他节点通信。试验表明所设计的CAN总线和无线通信系统均能正常工作,数据传输错误率为0%。     

Chemoenzymatic route to optically active dihydroxy cyclopenta[b]naphthalenones; precursors for decalin-based bioactive natural products

The development of an efficient chemoenzymatic route for the synthesis of optically active dihydroxy cyclopenta[b]naphthalenones; (+)-1,4a-dihydroxy-4a,5,6,7,8,8a,9,9a-octahydro-1H-cyclopenta[b]naphthalen-2(4H)-one (+)-10 and (+)-1,8a-dihydroxy-4a,5,6,7,8,8a,9,9a-octahydro-1H-cyclopenta[b]naphthalen-2(4H)-one (+)-11 is described. Different lipases and esterases were tested in the enzymatic hydrolysis of the corresponding acetates (±)-4a-hydroxy-2-oxo-2,4,4a,5,6,7,8,8a,9,9a-decahydro-1H-cyclopenta[b]naphthalen-1-yl acetate (±)-8, (±)-8a-hydroxy-2-oxo-2,4,4a,5,6,7,8,8a,9,9a-decahydro-1H-cyclopenta[b]naphthalen-1-yl acetate (±)-9, CRL (Candida Rugosa Lipase) and PLE (Pig Liver Esterase) were found to be the most effectual enzymes; for (?)-8 by 47% ee with the corresponding dihydroxy; (+)-10 by 98% ee in the presence of CRL; whereas, (?)-8 was obtained with 40% ee with the corresponding dihydroxy, (+)-10 with 58% ee in the PLE hydrolysis. It was concluded that CRL was the best biocatalyst for the substrate (±)-8. Moreover, enzymatic resolution in the presence of CRL yields, (?)-9 with 46% ee with the corresponding dihydroxy derivative; (+)-11 with 98% ee; however, in the presence of PLE, yields (?)-9 with 36% ee as well as the related dihydroxy derivative; (+)-11 with 49% ee respectively. The study concluded that CRL is the best biocatalyst for compounds (±)-8 and (±)-9.