基于磁致伸缩原理的液位传感器的设计

针对传统的液位测量技术在实际应用中的不足,提出了一种新型的液位传感器设计方案。该方案利用磁致伸缩原理,将液位信息的测量转化为对信号脉冲的精准计时。通过对磁致伸缩液位传感器的结构和工作原理的分析,对系统的构建、硬件电路设计和软件编程做了详细描述,尤其对磁致伸缩换能器与高精度时间测量方案给出了实现的基本框架和步骤。实验证明,这种基于磁致伸缩原理的液位传感器具有运行稳定、测量精度高、数字化等优点,具有一定的实用价值。     

高精度液位测量电路设计

目的 设计一种高精度液位测量电路.方法 利用磁致伸缩效应.结果 完成了脉冲发射电路、回波接收电路、脉冲转换电路以及脉冲计数电路的设计.结论 实验分析证明电路设计合理.     

基于磁致伸缩效应的液体密度在线测量方法

在分析磁致伸缩液位传感器工作原理基础上，针对磁致伸缩液位计不能进行密度测量的问题，提出多浮子相对位移测量法，在磁致伸缩液位计上实现了液体密度的在线高精度测量。同时分析了被测介质密度的变化对液位测量精度的影响，给出了液位测量的密度校正方法，进一步提高了磁致伸缩液位传感器的液位测量精度。     

基于DSP的磁致伸缩液位传感器的设计

基于当前国产磁致伸缩材料的前提,结合传统的设计方法,并且针对本课题前期完成的大量基础试验所发现的影响磁致伸缩液位传感器测量精度的因素,提出了采用数字信号处理技术提高测量精度的设计思路及方法.提高了国内磁致伸缩液位传感器测量精度,以满足多种工业液位参数的测量要求,结果表明本设计方法相比传统的设计方法测量精度有了较大的提高.     

海上平台磁致伸缩液位计变送器信号跳变故障分析与处理

磁致伸缩液位计精度高、可靠性强、安全性好,被广泛应用于石油化工、水力发电等行业进行液位测量和监控.某海上油田平台长期使用的磁致伸缩液位计出现液位跳变故障,给油田设备稳定运行带来了隐患.对出现跳变故障的液位计的信号进行收集和比较,通过分析液位计变送器的信号故障对关键参数配置进行合理调整,降低了磁致伸缩液位计跳变故障发生的...     

磁致伸缩液位计在油品储运系统中的应用

近年来石油储运行业引进并研制了多种油罐静态自动计量仪表，以实现油罐液位自动监测和自动计量。在由兰州到重庆的成品油管道输油系统中就将使用磁致伸缩液位计来测量和控制储罐中油品的液位，磁致伸缩液位计与其它液位测量系统相比，它能同时测量总液位和界位，测量精度高，可靠性好，在成品油管道输油系统中各个油库的油罐液位测量就采用了美国ＭＴＳ公司生产的Ｍ系列数字式软管磁致伸缩液位计。下面仅就Ｍ系列磁致伸缩液位计说明其特点、结构、原理及使用中出现的问题。１磁致伸缩液位计的特点磁致伸缩液位计的测量精度高，可达０．００５％或０．５０８ｍｍ；可靠性能好，一般情况下，有２３年的使用寿命；通用性好，最高承受压力可达６．８９Ｍｐａ，温度测量范围为－３４℃—＋１４９℃；具有先进的ＥＬＡ４８５总线结构，使现场能够任意地增加或减少液位检测点；防爆类型为隔爆型；抗干扰能力强；安装简单方便，操作简单，现场维护简单。２磁致伸缩液位计的结构及原理随着储罐内液位或界位的变化，磁性浮子在非磁性连通管内的位置同步改变，真空玻璃管内的橘黄色指示器也随之跟踪。在传感管内装有一根每秒发出１０个电脉冲信号的磁致伸缩线，由磁性浮子产生的磁场和电流脉冲间的耦合作用，在磁致...     

磁致伸缩液位计在油品储运系统中的应用

近年来石油储运行业引进并研制了多种油罐静态自动计量仪表，以实现油罐液位自动监测和自动计量。在由兰州到重庆的成品油管道输油系统中就将使用磁致伸缩液位计来测量和控制储罐中油品的液位，磁致伸缩液位计与其它液位测量系统相比，它能同时测量总液位和界位，测量精度高，可靠性好，在成品油管道输油系统中各个油库的油罐液位测量就采用了美国ＭＴＳ公司生产的Ｍ系列数字式软管磁致伸缩液位计。下面仅就Ｍ系列磁致伸缩液位计说明其特点、结构、原理及使用中出现的问题。１磁致伸缩液位计的特点磁致伸缩液位计的测量精度高，可达０．００５％或０．５０８ｍｍ；可靠性能好，一般情况下，有２３年的使用寿命；通用性好，最高承受压力可达６．８９Ｍｐａ，温度测量范围为－３４℃—＋１４９℃；具有先进的ＥＬＡ４８５总线结构，使现场能够任意地增加或减少液位检测点；防爆类型为隔爆型；抗干扰能力强；安装简单方便，操作简单，现场维护简单。２磁致伸缩液位计的结构及原理随着储罐内液位或界位的变化，磁性浮子在非磁性连通管内的位置同步改变，真空玻璃管内的橘黄色指示器也随之跟踪。在传感管内装有一根每秒发出１０个电脉冲信号的磁致伸缩线，由磁性浮子产生的磁场和电流脉冲间的耦合作用，在磁致...     

一种基于状态机的毛刺信号滤波方法

提出并实践了一种状态机的实时滤波方法,并成功应用于某军用车辆速度检测. 该方法以CPLD(FPGA)作为硬件,在高频时钟驱动下检测信号中瞬态脉冲宽度,滤除宽度短的脉冲,输出宽脉冲,从而实现脉冲干扰滤波功能. 阐述了该方法的原理和状态机实现方法,分析了该方法的滤波特性,并通过仿真计算其在方波毛刺信号上的应用,论证了该方法的可行性以及滤波宽度变化对该方法精度的影响.      

不锈钢护套对磁致伸缩导波桥梁缆索检测影响

针对带有不锈钢护套的桥梁缆索磁致伸缩导波现场检测中传感器的安装问题,基于磁致伸缩效应及其逆效应建立了有限元模型,并通过仿真分别研究了不锈钢护套对磁致伸缩导波激励与接收的影响,进而得到不锈钢护套对导波检测信号的影响.通过实验室和实桥实验进行了验证,结果表明:不锈钢护套对磁致伸缩导波的激励过程与接收过程均会造成衰减,激励端与接收端不锈钢厚度对信号衰减的影响趋势基本相同.根据仿真与实验结果得到了可以将磁致伸缩导波传感器安装于不锈钢护套上的激励频率及不锈钢护套厚度的范围,为现场安装提供了指导.     

基于频差倍增技术的陡脉冲上升时间测量系统

阐述了高速计数器测量陡（快）脉冲上升时间的原理,提出了基于频差倍增技术的计数方案,实现了由较低频率计数器进行较高频率计数,进而提高陡脉冲上升时间测量精度的目的。把高密度可编程逻辑器件（CPLD）的外接100MHz晶振作为系统低频时钟,利用D触发器组对时钟信号进行分频、倒相,经过二级倍频后混频器输出200MHz的脉冲作为计数脉冲,将计数精度提高至5ns左右,满足了测量要求且降低了测量成本,并可推广应用于测量脉冲的下降时间、脉冲宽度和周期等．     

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.