采用XTRl01的冲板流量计变送器

介绍了当前广泛应用的冲板流量计测量机理及传统变送器的基本结构,针对传统流量计变送器存在的弊端,设计了一种以4～20mA专用两线制U／I集成电路XTR101为核心的新型冲板流量计变送器,重点介绍了XTR101的工作原理以及计算方法,该变送器结构简单,信号适合远距离传送,各项性能指标优于传统流量计变送器。     

冲板流量计的改进设计方案

固体物料流量测量技术在各行各业中已得到广泛应用,并且要求的测量精度也越来越高.分析了目前广泛应用冲板式流量计的测量机理,提出了传统冲板流量计的基本结构和工作原理以及存在的问题,指出改进的必要性和具体方案,使其性能更加优越、适用性更强、智能化程度更高,并且很容易实现与上位计算机通讯.     

借创新基金东风 行自主创新方舟

<正>沈阳泰普自动化仪表有限公司成立于2001年6月,主导产品为复合一体化孔板、差压迭代流量积算仪、全系列抗震型涡街流量计、通用智能流量积算仪、全系列陶瓷压力变送器、全系列陶瓷投入式液位变送器、全系列智能数显表等。公司以复合孔板、迭代流量计、智能复合涡街流量计为特色,配套生产压力、差压变送器和各类指示、控制、记录仪表,已成为优势明显、门类齐全、在国内具有一定影响和规模的自动化仪表生产企业。     

在城镇燃气计量中内锥流量计与几种常用流量计的性能比对

<正>1概况及内锥流量计简介1.1概况比对测试项目为:(1)准确性(2)流量比(始动流量)(3)压力损失(4)阻流件影响等四项。分析比对项目为:城镇燃气计量中流量计的选用。测试流量以孔板为参照标准。事先对孔板环室节流装置进行了实流标定,不准确度为0.5%。其二次仪表,压力、差压的采集采用日本EJA系列变送器,温度的采集采用A级PT100铂电阻。数据采集采用了配置天然气孔板流量测量最新标准版本软件的工控机系统。参加比对试验的流量计为国内厂家生产的天然气计量常用的涡轮流量计、旋进旋涡流量计、罗茨流量计。1.2内锥流量计简介     

基于CFD的双锥形孔板浮子流量计的优化

孔板浮子流量计因其结构简单、加工方便,近年被广泛应用,但与锥管浮子流量计相比,线性度较差、压力损失较大,尤其是大口径孔板浮子流量计,这些问题尤为明显．文中提出了一种双锥形孔板浮子流量计结构,利用计算流体动力学方法确定了双锥形结构的优化参数,根据优化结果加工样机进行实流实验,得到了可参比的实验数据．实验结果表明,与常见的单锥形结构相比,DN100双锥形孔板浮子流量计的线性度提高了约50％,压力损失减小了8％左右,明显改善了孔板浮子流量计的性能,也验证了仿真结果的正确性．     

用孔板流量计测量脉动气流

基于脉动流对孔板流量计影响的基本原理,介绍了孔板流量计在脉动流测量中产生误差的原因及误差的分析方法。针对实际过程,实验研究了复杂脉动流对孔板流量计测量误差影响,得到复杂脉动流条件下孔板流量计计量误差的估计方法和应用时应注意的问题。     

浅谈我公司大口径管道煤气流量的测量

大口径管道煤气流量测量一直是流量仪表检测的难点,压力低、流速低、气体脏是其主要流体特点。传统测量方法多采用孔板测量,存在很多缺点。匀速管流量计、锥型流量计等新型流量计为煤气流量测量提供了新的测量方法。本文重点介绍德尔塔巴流量计对《陕化化肥股份有限公司》的半水煤气总管流量的测量实施过程。     

涡街流量计在我厂氧气计量中的应用

流量计量技术是一门综合性学科,它集流体力学、仪表技术、计算机技术、电子电路、通讯技术及现场工艺状况于一体,具有较深的理论研究价值,而流量计量是公司一项极其重要的工作,和生产操作、成本核算直接关联,可以说流量计量工作是影响我公司生产与效益的重要因素之一。在我厂动力量厂际流量计量中常用的流量计主要有以下几种:孔板(配差压变送器、流量计算仪)、涡街流量计、金属转子流量计、文丘里管、威力巴等。它们分别有着不同的测量原理及特点因而适用范围(对象)也有所不同。其中涡街流量计在我厂的氧气计量中取得了比较好的测量效果。下面结合实例阐述涡街流量计的使用方法及在使用中的注意事项。     

瓦斯抽放管路流量测量的多孔孔板流量计性能

针对标准孔板流量计对瓦斯抽放管路直管段长度要求严格、制作成本高的问题,基于多孔孔板的结构与原理,提出采用多孔孔板流量计测量瓦斯抽放管路流量的方法。实验表明,多孔孔板流量计对直管段长度要求低,量程范围宽,线性度高,可在煤矿企业推广应用。     

高精度热疗灌注机温度测量系统的设计与实现

介绍了一种高精度热疗灌注机温度测量系统的设计及实现方法.该系统以XTR105变送器芯片为核心,用Pt100铂电阻作为温度传感器,使用C8051F060单片机实现通道切换、A/D转换和系统误差自校正等功能.在15～50℃测量范围同内,测温精度达到±0.1℃.所论述的内容既可用于热疗灌注机、人工心肺机等医疗设备,也可应用于其它需要精确测量温度的领域.     

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.     

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     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with