DCS系统在造纸污液回收中的应用

本文介绍了利用DCS系统对碱回收车间中的燃烧工段过程控制中的重要参数实行检测,已达到实施有效控制,确保系统正常安全的运行,以达到造纸过程中产生黑夜的碱回收,减少污染的排放,实现资源可持续发展。     

DCS系统在核电站中的应用

针对目前核电站在控制方面采用模拟量控制存在的问题,建议在核电领域全面采用全数字的DCS控制系统.DCS系统(分散控制系统)具有模拟量控制系统无法比拟的优越性.随着DCS系统在核电站不断推广使用,以及相应的法律、法规的出台和良好的运行业绩,笔者建议在核电领域全面采用DCS系统.     

基于Profibus和PLC的碱回收燃烧工段控制系统

介绍了碱回收燃烧工段的工艺流程和Profibus现场总线的特点.根据燃烧工段的控制要求,设计了基于Profibus现场总线技术和PLC技术的控制系统的网络结构和软件设计.     

浅论DCS与PLC在实际工程中应用的区别

DCS是一种分散式控制系统,而PLC(可编程控制器)是一种控制装置,两者在结构、一定的区别.本文分析了DCS与PLC的区别及其在实际中的应用.     

DCS控制系统在硫磺回收项目中的应用及控制方案组态

介绍DCS控制系统在锦州石化公司硫磺回收项目中的具体应用情况,系统整体结构采用DCS控制系统中的JX-300XP控制系统,给出系统复杂控制方案及组态程序.经过多次试验,DCS控制系统能够长期稳定运行,同时还能够满足一系列的复杂控制,效果令人满意,生产率大大提高.     

燃气锅炉ABB自动控制系统分析

燃气锅炉的DCS自动控制可以对整个生产的过程进行优化控制,实现全过程自动化,提升蒸汽质量和锅炉的燃烧效率.本文从燃气锅炉的DCS控制系统的构成与特点、主回路的控制原理等方面进行分析探讨,以促进燃气锅炉的可靠、安全和经济运行.     

延迟焦化DCS电源供电系统的改造

DCS控制系统在延迟焦化装置中具有非常重要的地位,采用EMERSON公司的Delta V系统完成延迟焦化装置的生产监视、过程控制、操作画面、参数报警、数据记录及历史趋势等项的功能要求.DCS控制系统电源供电系统的稳定性与可靠性至关重要,主要阐述了原DCS电源供电系统的缺陷以及对DCS电源供电系统的改造,通过安装双电源切换开关(PULSAR STS16),实现市电和UPS双电源冗余供电,提高了DCS电源供电系统的可靠性,保证DCS控制系统以及延迟焦化装置长周期稳定运行.     

基于Jini技术的DCS系统体系结构改进

主要探讨了现有DCS设备联网的体系结构和Jini体系结构,分析两者的实现功能和提高系统动态可扩展性的方法.利用Jini技术的多虚拟机环境和嵌入式操作系统,对DCS的多子网结构进行了改进,并针对DCS中的异构设备,提出了4种提高设备的动态可扩展性的方法,支持各种DCS控制设备的动态网络化.     

DCS控制系统的安装与调试

DCS既不同于分散的仪表控制,又不同于集中式计算机控制系统,而是克服了二者的缺陷而集中了二者的优势.它具有通用性强、系统组态灵活、控制功能完善、数据处理方便、显示操作集中、人机界面友好、安装简单规范化、调试方便、运行安全可靠的特点,已经在工业控制领域得到广泛的应用.因为DCS系统的复杂性,其系统的安装和调试也具有一定的特殊性.     

基于OPC技术的DCS信息集成系统

介绍了OPC技术的原理和方法,及其在企业管控一体化信息集成中的功能及应用,并构建了一种基于OPC技术的DCS信息集成系统,以实现DCS与管理网的数据通讯.详细叙述了OPC客户端的具体实现技术以及数据上传技术.系统运行表明,基于OPC技术的DCS信息集成系统打破了管理网络和DCS控制网络的分离状况,使管理人员能够更及时地了解整个DCS系统的现场运行状况,并做出更加合理的决策.     

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.     

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.     

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.     

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.     

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.     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

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.