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1.
阐述了粮食熏蒸控制系统通信适配器的硬件、软件设计,该系统采用CAN总线结构,系统主要部分通信适配器。是上位管理机和现场测控节点之间通信接口.该适配器以8031单片机为处理器,以SJA1000为CAN总线控制器,软件采用模块化结构设计,由主程序、子程序、中断服务程序组成,完成数据缓冲、数据转发等功能.  相似文献   

2.
程丽宁 《科技信息》2012,(29):69+102-69,102
现场总线是在发展综合自动化的需要下产生的,它适应了工业控制系统向分散化、网络化和智能化发展的方向,CAN总线现已经形成国际标准,并已被公认为最有前途的现场总线之一。本文设计开发了电网监控系统的CAN总线智能通信节点硬件模块,它具有现场数据采集和控制及CAN总线通信的功能,可以通过CAN总线通信与其它CAN智能测控节点传送状态和各种参数,接收来自监控节点的命令和数据来调整和改变控制状态。  相似文献   

3.
根据汽车冷却液储液罐试验台测控系统的要求,设计了基于CAN总线的分布式测控系统.采用具有CAN总线接口的输入/输出模块实现了现场测控,监控室的工业控制计算机通过CAN适配卡与各模块进行通信,详细介绍了测控软件的设计方法.  相似文献   

4.
CAN总线网络节点的实现及应用   总被引:9,自引:0,他引:9  
为了安全传送现场采集的数据,选择了CAN总线作为现场总线.利用独立CAN控制器SJA1000及普通的单片机可以组成通用的CAN总线网络节点,其应用范围广泛,可以扩展成现场测控装置(开关量输入输出装置).该装置和上位机通信可以组成简单的集散控制系统.此网络节点方案已通过调试,可直接应用到其他系统中.  相似文献   

5.
介绍一种基于CAN总线的电力参数采集监控系统,系统由主控计算机、CAN总线适配卡和多个智能测控节点组成;各智能测控点则由80C196KC微控制器和电力参数采集专用芯片CS5460A构成现场测控电路。详细介绍了由新型独立CAN总线控制器SJA1000构成的CAN总线结口电路的组成和现场测控电路的硬件设计。实践表明:该系统能对5km配电范围的10个智能节点实行高精度的数据采集和有效监控。实现了配电系统参数的数字化采集和智能化管理.提高了配电系统运行的可靠件和效率.  相似文献   

6.
介绍一种基于CAN总线的电力参数采集监控系统,系统由主控计算机、CAN总线适配卡和多个智能测控节点组成;各智能测控点则由80C196KC微控制器和电力参数采集专用芯片CS5460A构成现场测控电路.详细介绍了由新型独立CAN总线控制器SJA1000构成的CAN总线结口电路的组成和现场测控电路的硬件设计.实践表明:该系统能对5km配电范围的10个智能节点实行高精度的数据采集和有效监控.实现了配电系统参数的数字化采集和智能化管理,提高了配电系统运行的可靠性和效率.  相似文献   

7.
介绍一种基于CAN总线的电力参数采集监控系统,系统由主控计算机、CAN总线适配卡和多个智能测控节点组成;各智能测控点则由80C196KC微控制器和电力参数采集专用芯片CS5460A构成现场测控电路。详细介绍了由新型独立CAN总线控制器SJA1000构成的CAN总线结口电路的组成和现场测控电路的硬件设计。实践表明:该系统能对5km配电范围的10个智能节点实行高精度的数据采集和有效监控。实现了配电系统参数的数字化采集和智能化管理,提高了配电系统运行的可靠性和效率。  相似文献   

8.
程英凯  樊超 《科技信息》2010,(3):324-325
为了实时测量电力系统参数,介绍一种基于CAN总线的电力参数采集监控系统,系统由主控计算机、CAN总线适配卡和多个智能测控节点组成;各智能测控点则由AT89C52微控制器和A/D采集芯片构成现场测控电路。详细介绍了由独立CAN总线控制器SJA1000构成的CAN总线结口电路的组成和现场测控电路的硬件设计。实践表明:使用该方法完全可以测量个配电站的电力参数就,该系统能对5km配电范围的智能节点实行高精度的数据采集和有效监控。实现了配电系统参数的数字化采集和智能化管理,提高了配电系统运行的可靠性和效率,具有较好的应用价值。  相似文献   

9.
研究了CAN总线智能变送器测控系统的通信实现,包括底层智能变送器与CAN总线接口软硬件设计及CAN总线与上位工业监控计算机之间接口卡设计两部分.采用单片机作为底层智能变送器的微处理器,设计了单片机与CAN总线的网络接口,使底层采集到的数据传输到CAN总线网络.再设计了PCI总线与CAN总线的接口通信卡进行通信,使采集的数据能够传输到工业计算机上完成对整个现场过程进行监视.  相似文献   

10.
CAN总线已被公认为是最有前途的现场总线之一,在汽车以及工业控制领域已得到了广泛应用。本文以集成有CAN总线的C8051F040微控制器为核心,设计了测控节点的软件和硬件。文中首先简要介绍了CAN总线测控系统构成,然后对C8051F040自带的CAN总线控制器进行了阐述,最后详细的说明了测控节点的软硬件设计方法。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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。  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
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.  相似文献   

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