几种测控技术对比研究

为满足信息自动化多样性的要求,该文通过对Ethernet、Lab VIEW和Datasocket协议测控系统的方法原理和应用,分析了网络测控技术的工作特点和应用领域。结果表明,Ethernet测控系统利用8/16位嵌入系统和高档嵌入系统,在视频服务中应用效果良好;Lab VIEW测控系统能实现多任务实时测控,广泛应用于航空、通信和信息自动化等领域;Datasocket协议测控系统具有良好的兼容性,提高了粮仓温度监测的效率和质量。因此合理选择网络测控技术,能有效提高测控的效率和可靠性。     

pH过程测控系统可用性研究

文章是针对pH过程测控系统的可用性问题而提出的,从技术角度分析何为pH过程测控系统的可用性,如何设计pH过程测控系统的可用性,及如何测试与评估pH过程测控系统的可用性,从而为pH过程测控系统的可用性设计和测试提供方法理论支撑,设计出适合大多数用户使用的pH过程测控系统,促进pH过程测控系统的推广与应用。     

远程测控系统设计

网络化测控是测控系统的一个重要发展方向。本文采用工业以太网、总线网关和Internet技术来研究远程网络化测控系统的实现;介绍了远程测控系统的结构及其硬件设计和软件设计系统的实现。     

煤矿安全关键测控系统的抗干扰问题研究

煤矿安全关键测控系统能否可靠工作是测控系统应用、开发领域工作者十分关心的问题。对各种影响测控系统稳定工作的干扰进行了分析,并详细阐述了抗干扰措施,为煤矿现场测控系统应用和开发的工程技术人员提供了参考。     

飞机机务模拟器嵌入式测控系统的设计

某型飞机机务模拟器测控系统,包括九种类型的测控卡,可以检测模拟器训练场所的开关量、模拟量,驱动指示灯、继电器、数码管、步进电机、单色／彩色液晶屏。测控系统为分布式嵌入系统,具有单卡独立工作的能力,相对现行的PCI、VXI、PC104等总线产品,具有测控通道多,模块化强等优势,为模拟器硬件测控提供了良好的平台,本文阐述了测控卡的设计方案及功能。     

基于DSP的智能化测控系统设计

本文首先分析了嵌入式测控系统的系统结构和特点,结合嵌入式测控系统的发展要求分析了基于DSP的嵌入式测控系统的应用需求,并在此基础上提出了基于DSP的嵌入式测控系统结构,设计了基于DSP测控系统的硬件系统设计。     

环境对计量器具测控系统的干扰及解决方法

随着计量器具测控系统数字化、电子化,外部环境对测控系统采集、分析数据都存在着干扰,影响计量器具的准确性。本文就环境对计量器具测控系统的干扰的常见现象举例分析,并对干扰源及解决办法进行探讨。     

试论单片机在温度测控方面的应用

温度测控在工业领域具有广泛的应用,随着传感器技术、微电子技术、单片机技术的不断发展,为智能温度测控系统测控功能的完善、测控精度的提高和抗干扰能力的增强等提供了条件。由于单片机具有集成度高、功能强、体积小、价格低、抗干扰能力等优于一般CPU的优点,因此,在要求较高的控制精度和较低成本的工业测控系统中,往往采用单片机作为数字控制器取代模拟控制器。本文将介绍一种基于AT89C52和AT89C2051双MCU的注塑成型温度测控系统,及其硬、软件的设计方法和系统的原理框图等。     

智能变电站测控系统可靠性评估

文章基于智能变电站单套测控装置跨接双网结构,提出新的测控系统可靠性模型,采用蒙特卡罗和故障树混合算法求解。根据测控系统功能实现效果,引入运行状态概率评估模型。算例分析对比测控系统和保护系统的可靠性指标,获得测控系统各运行状态的概率。研究结果对智能变电站测控系统的规划设计和运行维护具有借鉴意义。     

多通信方式的远程测控系统的研究

远程测控技术的广泛应用,对通信系统的可靠性、准确性、及时性,以及如何扩大通信距离,都有着越来越高的要求。多通信方式的远程测控系统向我们展示了集成多种通信网络的思想,它突破以往测控系统通信网络单一的束缚,从很大程度上能够解决目前测控领域的远程通信面临的一系列问题。     

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.     

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.     

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.     

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.     

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.     

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that