大口径钢管高速检测系统

大口径钢管的质量关系到设备的安全运行,而我国目前还没有制定大口径钢管的检测方法和标准,也缺少管道的高速检测系统。合肥工业大学研究的大口径钢管高速检测系统,采用轴向、周向缺陷信号检测方法,对多路缺陷信号采用“时分复用”滑环传送技术,依靠计算机实现缺陷信号采集、处理、分析与缺陷类型识别;该系统已开始应用在工程中,达到API规范要求。     

材质分选技术与系统设计

不同材质的初始磁导率和饱和磁感强度不同,文章主要介绍一种利用饱和磁感应强度来区别不同铁磁性材料的新型材质分选系统;重点研究了检测线圈对比测量法,即当试件铁磁性材料和予置材料同时穿过2个完全相同的线圈时,如果材质有差别则饱和磁感强度不同,那么2个线圈的感应电压也不一样;对检测结果进行比较放大、滤波、A/D转换并送入到计算机中,由计算机实现可视化和图形识别。     

可编程和可记忆的炉温实时控制系统

本系统通过Z-80CPU中央微处理器及A/D、CTC等外围接口电路,利用热电偶进行温度检测,由毫伏放大环节及A/D转换器输入采样信号。微处理器将采样信号与给定温升曲线相比较,经过运算对炉温进行跟随控制,并随时显示现场炉温。 一、硬件设计 该系统灵活地利用具有定时和计数功能的CTC芯片来控制晶闸管导通角及采样周期,以直接产生晶闸管的触发脉冲信号,此外,对热电偶的微弱信号处理不是采用传统的温度变送器,而是利用精密运算放大器构成放大环节,以硬件处理方式将8位A/D转换精度     

船用电磁检测系统的研发

为了使船舶无损检测工作更加方便进行,以漏磁检测理论为基础,根据磁化方式的特点、磁化强度的要求以及局部磁化等,设计了以C8051F020单片机为核心的数据采集模块.利用C语言编写了检测系统的液晶显示、采集处理、通讯、按键和打印子程序.开发了阵列式电磁检测仪,能定性无损检测船舶设备的缺陷.通过对实验室钢板缺陷的测试,验证了本仪器的优越性     

轮对尺寸自动测量系统

轮对尺寸自动测量系统由机体、轮对自动进给、导向机构、轮对几何参数及缺陷测量机构、计算机与信号采集处理系统等5部分组成，完成对轴中央直径、轮径、轮缘厚、轮对内侧距、轮辋宽、踏面圆周磨耗、踏面擦伤及剥离等参数的自动测量与检测．     

单边激励电磁机构系统动态特性研究

对工作气隙很小的电磁机构进行磁路分析与计算，往往要做很多的假设和简化处理，但忽略磁阻及漏磁的影响将带来较大的误差。为此本文考虑这两方面的因素，运用辛浦生积分公式以及对磁性材料磁化曲线进行数学处理的方法进行磁路的分析与计算，建立了比较精确的系统状态方程，为计算机求解打下良好的基础。经计算机仿真验证，该方法得当，计算结果精度提高３１．６％左右。     

简介

轮对尺寸自动测量系统轮对尺寸自动测量系统由机体、轮对自动进给、导向机构、轮对几何参数及缺陷测量机构、计算机与信号采集处理系统等5部分组成,完成对轴中央直径、轮径、轮缘厚、轮对内侧距、轮辋宽、踏面圆周磨耗、踏面擦伤及剥离等参数的自动测量与检测.技术特点(1)采用通过式测量方式.测量系统实现轮对在车间线路上行走的条件下,对其几何参数及缺陷自动进行测量与检测,测量系统完全改变了既有技术需要复杂液压系统和转动机构的局面,从而使得整个测量系统具有机构简单、成本低、设备故障率低等优点,极大地缩短了测量周期.(2)采用具有…     

基于FDTD加速电磁传播可视化输出

空变环境中电波传输特性对于雷达等系统的设计和优化十分重要,针对目前电磁仿真系统存在的抽象、不直观等问题,为满足电磁传播并行计算及可视化输出需求,利用图形处理器、计算机图形学、人机交互等技术,在电大尺寸目标空变环境下,设计了电磁传播并行计算及可视化输出流程,并研发了软件模块。系统基于FDTD方法对电磁波传播过程进行建模和计算,然后使用CUDA与OpenGL交互技术进行可视化输出,具有灵活度高、渲染效率高等特点,可为电磁环境电波的传输研究提供重要支持。     

磁性参数测试中有关失真波形电压测量方法的研究

介绍了符合有关国际标准、数字与模拟技术相结合的、性能 /价格比较高的多功能磁性参数自动测试系统 .由于磁化曲线的非线性 ,系统中运用真有效值方法测量失真高频信号的有效值 ,在中速 A/ D转换的基础上利用内插采样技术等效提高数字化速率的方法测量失真波形的峰值和平均值 .文中阐述了磁性参数的测试方法、系统结构、失真波形电压的测量方案以及实验结果     

磁致伸缩超声导波的包覆层轻烃管道检测试验分析

采用磁致伸缩传感器(Ms S)超声导波检测系统,对带包覆层轻烃管道进行在线检测。研究了不同检测频率、管道直径对管道缺陷检测定位精度的影响,并分析了带有黏弹性包覆层环氧树脂对超声导波信号的影响。对114 mm和80 mm两类管道,以三通、弯头等近似为缺陷,分别使用32 k Hz和64 k Hz探头进行检测。检测结果表明:不同检测频率时管道缺陷检测精度不同,频率越高,定位精度越高。管道的直径对导波信号缺陷检测精度有重要影响,采用32 k Hz频率对80 mm管道的定位精度为9.3 cm,远高于114 mm管道的定位精度(17.6 cm)。黏弹性包覆层对检测信号有强烈的衰减,平均衰减速率约为1 d B/m。     

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