电容式传感器的设计方法探讨

研究者从间距变化型电容传感器的工作原理出发,从检测原理、参数分析和主要误差来源等方面对差分式电容传感器系统的设计方案进行了研究。分析结果表明差动式电容传感器的灵敏度比一般电容传感器提高了一倍,同时差动式电容传感器的非线性误差得到了明显的改善。电容传感器的主要误差来源于电路噪声和电容传感器的非线性。     

虚拟仪器技术在连杆综合参数测量系统中的应用

利用电容传感器和电容测微仪作为汽车连杆综合参数测量系统的信号采集机构和前置信号预处理 (SCXI)机构 .利用计算机插入数据采集卡采集电容传感器的电压模拟信号为数字信号 ,由计算机进行后续处理 .通过虚拟仪器面板技术 ,把硬件仪器面板“移植”到计算机上 ,形成友好的人机界面 .     

高速高精度模数转换器的数字后台校准算法

研究了模数转换器(ADC)的数字后台校准技术,提出了一种针对2.5 b/级高速高精度流水线ADC的数字后台校准算法.在2.5b/级电容翻转式余量增益电路(MDAC)中注入与输入信号相关的抖动信号,提取MDAC中由于电容失配和放大器增益有限性造成的非线性误差,并在最终的数字输出端对这些误差进行校准.文中提出的数字后台校准算法具有电路实现简单、不中断ADC正常工作、适合高速高精度流水线ADC等优点,能有效地降低电容失配和放大器有限增益等非理想因素对流水线ADC精度的影响.仿真结果表明,经校准后的ADC信号噪声失真比可从63.3dB提高到78.7dB,无杂散动态范围由63.9 dB提高到91.8 dB.     

应用于眼压信号检测的低噪声前置放大器设计

基于SMIC 180nm CMOS工艺,设计并实现了一款应用于眼压信号检测系统的低噪声前置放大器.该放大器使用二极管连接的MOS管实现GΩ级别的大电阻,在反馈回路中该伪电阻与反馈电容并联在低频段产生高通截止点以抑制直流失调电压和低频噪声,达到较好的噪声性能.后仿真结果显示:低噪声前置放大器的直流增益为40dB,有效带宽从0.25Hz到46kHz,在低频频率100Hz处的等效输入噪声为197.3nVrms,采用1.8V的电压供电,核心电路功耗为32.4μW,芯片面积为0.75mm×0.62mm.     

探空湿度传感器的信号调理电路设计

针对高空气象湿度测量对高精度和低噪声提出的需求,设计了一种基于电荷放大器原理用于探空湿度传感器的微弱电容检测电路。该电路由晶体振荡电路、电荷放大器电路、整流滤波、A?D转换、MCU等部分组成。实验结果表明：研制的检测电路具有较强的抗杂散电容性能,线性度良好,准确度优于0.04%,对于标称100 pF的待测电容,噪声引起的误差仅相当于待测电容的100 PPM（百万分之一）,约10 fF,能满足高空探测的要求。     

利用ECT信息改进EST图像重建

提出了基于电容层析成像(ECT)与静电层析成像(EST)的双模态传感器技术.该技术应用电容层析成像重建得到的介质分布结果作为先验信息,提高了静电层析成像的图像重建精度.针对静电荷对ECT测量值的干扰进行了探讨.理论分析表明,ECT采用交流法检测电容,在高频交流激励、带通滤波方式下,微小电容检测系统可以消除颗粒感生电荷噪声的低频干扰.针对电荷灵敏场受介质分布的影响进行了研究,数值仿真计算表明,采用ECT提供的介质分布信息可修正实际流型下的电荷灵敏度,降低EST电荷分布反演的不确定度.由于EST的相对图像误差、相对电荷余量等图像重建指标均有所减小,所以图像相关性更好.     

低噪声前置放大器集成电路的设计与研制

论述了用于传感器的低噪声前置放大器的线路设计、器件版图设计和利用标准p-n结隔离工艺研制的结果.通过输入级最佳电流的设计及在线路设计和版图设计上采取一系列措施,使该放大器具有低噪声、宽频带等特点。该放大器的平均等效输入噪声电压为2.9nV/Hz~(1/2),单位增益带宽为12MHz。     

浮子电容式石油密度传感器的研究

推导出浮式电容式石油密度传感器的数学模型,设计了机械,电路结构,进行了误差人析和误差修正,根据阿基米德浮力原理,采用不锈钢浮子及多层筒形电容,组成高精度石油密度传感器。     

车辆电容称重传感器静态标定

针对传统车辆称重装置存在的不足,开发了一种车辆电容称重传感器.文章中从结构设计、称重原理对车辆电容称重传感器作了介绍,重点讨论了静态标定过程,根据试验数据,从非线性、重复性、迟滞性等方面进行了误差分析,给出了补偿办法.     

开关电容模拟电路原理及其应用

以有源放大器为例,介绍了开关电容模拟电路技术;同时介绍了开关电容PSoC模块,并讨论该类PSoC芯片的一些典型实际应用.     

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