基于W78E58单片机的CAN总线适配卡设计

CAN（Control Area Network）总线是一种有效支持分布式控制和实时控制的总线式串行通讯网络。由于PC机一般不配备标准的CAN通讯模块,必须制作一块CAN通讯卡（CAN适配卡）。介绍了基于W78E58单片机进行设计的一种CAN总线适配卡的软、硬件设计思路。     

CAN现场总线在工业以太网远程监控系统中的应用

CAN是一种有效支持分布式控制和实时控制的串行通信网络。它具有传输速度快、自动解决总线竞争、实时性好、可靠性高、纠错能力强等特点，目前已成为一种国际总线标准。由CAN总线组成的局域网可以将很多底层测控设备连接起来，用工控机加接口卡已经实现了对底层设备进行真正意义上的远程控制，但存在着价格和接口卡带来的瓶颈等问题。本文以单片机、CAN器件和网络芯片为核心模块，实现CAN现场总线与以太网之间数据交换，完成对底层设备进行真正意义上的远程监控。这种方案降低了成本，避免了瓶颈。     

CAN总线接口模块的设计与实现

控制器局域网总线(CAN)是目前较流行的现场总线之一，是一种有效支持分布式控制或实时控制的串行通信网络。由于其高速、高可靠性及独立的设计，被广泛应用与工业现场控制系统中。本以单片机AT89C51和SJA1000控制器为核心组成CAN总线接口模块。介绍硬件原理图和SJA1000的初始化、发送和接收模块程序的设计方法。     

CAN总线在先进制造技术仿真教学系统中的应用

CAN总线是一种性能先进、价格低廉和保密性好的现场总线技术,能够有效支持分布式控制或实时控制串行通信网络;文章介绍了CAN总线技术应用在先进制造技术仿真教学系统的开发过程,说明了系统结构、通信协议及软硬件设计.     

基于CAN总线的汽车智能系统研究

提出了一种基于CAN现场总线的分布式汽车智能系统的设计方法,详细讨论了系统的设计方案、硬件搭建,通过CPLD控制外围硬件,把采集到的数据通过CAN总线传输到MCU进行处理,并通过软件仿真验证了该方案的可行性.     

基于CAN总线的铁路信号微机监测系统研究与设计

CAN（Controller Area Net）控制器局域网是主要用于各种过程检测和控制的一种现场总线网络。文章通过研究CAN现场总线在铁路信号微机监测系统中的应用原理,分析铁路信号微机监测系统的功能和特点,提出一种基于CAN总线的微机监测系统的设计方案以改进现有微机监测系统数据通信性能。     

星型CAN网络架构的研究与设计

局域控制总线CAN网络现已在分布式嵌入式系统中得到广泛使用.但是,由于CAN的总线型拓扑,即使网络中的普通故障,也会导致整个网络的瘫痪,使得其在高可靠性的应用领域中受到限制.文章研究了一种主动型星型网,解决了现有总线型CAN网络的缺陷,通过设计一种主动型的Hub,有效防止了故障在网络中的扩散,并且实现了与现有的CAN网络充分兼容.     

基于CAN总线的煤矿控制系统远距离传输的研究

控制器局域网(CAN)属于现场总线的范畴,它是一种有效支持分布式控制和实时控制的多主的异步串行通讯网络。文章以CAN总线在采矿行业中远距离传输为切入点,结合煤矿控制一体化系统具体项目,分析了影响CAN总线传输距离的3个因素,提出了相应的优化方法;介绍了国家煤矿安全标准120Ω双绞线的仿真导线的制作方法,并利用其与USNCAN-Ⅰ、Freescale MC9S08DZ60单片机为控制器的CAN节点,进行CAN总线远距离传输仿真实验,对实验结果进行了分析,在实际工程中有一定的借鉴意义。     

CAN总线技术在民用飞机中的应用

CAN全称为Controller Area Network,即控制器局域网。近年来随着CAN总线技术日趋成熟,CAN总线被逐渐应用到飞机的设计中来。本文结合CAN总线特点,通过CAN总线与常用的ARINC429总线和ARINC664总线的对比分析,得出CAN总线作为局部总线,在分布式控制中有明显的优势,并详细介绍了某机型飞行控制系统中CAN总线的具体应用,进一步阐述了CAN总线在民用航空机电系统发展中的应用前景。     

基于CAN总线的火灾报警系统设计

采用CAN总线设计方法,提出一种分布式智能火灾报警系统设计方案及系统实现方法。采用多CPU的并行处理方式和智能数据处理方法,实现了系统的实时、准确报警和可靠的联动控制。利用现场总线CAN实现控制器的联网。具有可靠性高、误报率低、人机界面友好的特点。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.