应用于可穿戴脉搏血氧检测的G_m-C低通滤波器

为了解决可穿戴脉搏血氧检测芯片滤波器面积大、功耗高的问题,改进设计了一个三阶巴特沃斯G_mC低通滤波器.线性跨导器采用源极负反馈结构来增大线性范围,并且输入管工作在亚阈值区降低了功耗,然后通过密勒效应放大电容来减小面积;同时,该滤波器通过开关电容调谐电路调制滤波器的截止频率,降低工艺偏差.仿真结果表明:在SMIC 0.18μm CMOS工艺,1.8V电源电压供电下,该低通滤波器的截止频率为7.9Hz,面积为0.14mm~2,功耗为6.7μW,相比其他的设计方案,在功耗和面积上都有大幅优化.     

一种适用于低压SC电路的体效应补偿开关

为了减少NMOS开关阈值电压变化引起的信号失真,设计了一种适用于低压开关电容电路的体效应补偿开关,并利用该电路实现了一阶非反相开关电容(SC)低通滤波器.基于0.5μm标准CMOS工艺(Vtno=0.7 V,Vtpo=1.0 V)的SPICE仿真和总谐波失真(THD)的仿真结果表明:该电路具有很好的线性特性,采用该电路能够达到更优越的性能.     

开关电容滤波器设计与仿真方法的研究

为解决开关电容滤波器不能直接应用传统的电路分析程序和仿真方法的设计问题,提出了将开关电容网络的时变拓扑,变换为时不变拓扑,再对时不变网络进行分析的方法.建立了开关电容模拟电阻的z域模型,应用电阻替代方法,设计了二阶开关电容滤波器电路.将二阶开关电容滤波器级联,给出了8阶切比雪夫低通开关电容滤波器的设计与仿真实例,并给出了实现低Q值开关电容滤波器模型的SPICE程序.仿真结果显示,开关电容滤波器与有源低通滤波器的输出特性曲线相一致,满足切比雪夫低通滤波器的设计要求.该滤波器设计方法原理简明,建立模型容易,给出的开关电容模拟电阻的SPICE模型也非常理想,适合于高通、带通、陷波等各种滤波器的设计与仿真.     

片上集成自动可调谐非对称带通滤波器

提出了具有3阶高通、2阶低通的带有自动调谐系统的有源电阻电容非对称带通滤波器结构.带通滤波器的中心频率为4.055 MHz,带宽为2.63 MHz.源阻抗为50Ω时,滤波器带内3阶交调量为18.489 dB.m.滤波器输入参考噪声为47.91×10-6Vrms(均方根电压).滤波器采用基于二进制搜索算法(BSA)的调谐方案,其调谐精度为(-1.65%,2.66%).调谐电路的芯片面积为0.282 mm×0.204 mm,不到主滤波器面积的1/5.调谐系统完成调谐功能后会自动关闭,降低了功耗和对主滤波器的串扰.在1.8 V电源电压下,滤波器消耗电流为1.96 mA.该滤波器已在IBM 0.18μm标准互补金属氧化物半导体(CMOS)工艺线流片成功.     

适用于均衡器系统的高速低失调限幅放大器

基于0.13,μmCMOS工艺,设计了一款适用于均衡器系统的高速低失调电压的限幅放大器.电路设计中采用有源负载电感效应技术来提高系统的带宽;同时,为了优化由器件间失配导致的失调电压,提出了一种改进的失调电压消除技术.通过在负反馈环路中使用18,pF的电容来构建低频滤波器,该技术可以实现22.8,kHz的高通截止频率.蒙特卡罗仿真结果表明,该放大器输出端的直流失调电压均值为78.48,μV,标准差为3.73,mV.工作在1.8,V电源电压下,限幅放大器的带宽为6.0,GHz,增益为24.2,dB,功耗为23.6,mW,版图面积为0.030,6,mm2(170,μm×180,μm).     

微弱信号调理电路的设计及研究

精确的信号调理技术是测控领域发展的重要方向。基于开关电容滤波器和程控放大器设计了一种新的信号调理电路,采用ATmega 128单片机自适应地调整开关电容的滤波参数和程控放大器的放大倍数。微音器微弱信号检测的实验结果表明,该电路能达到动态范围几微伏到几十毫伏、灵敏度1μV、响应时间优于1 ms的技术指标,具有性能稳定,可靠性高、灵活性强、可编程等特点。     

一种双采样38-μ W92-dB8-kHz带宽ΣΔ调制器

提出了一种应用于助听器的单环3阶开关电容ΣΔ调制器,采用双采样技术通过提高过采样率来改善调制器的性能,详细分析了双采样中电容失配的影响.为进一步降低功耗,OTA采用了class-AB结构,并对后级的运放进行了缩放.采用栅压自举技术消除了低压下CMOS开关的开通电阻由于栅源电压变化而引起的非线性问题.整个调制器过采样率128.后仿结果表明,在SMIC 0.13μm CMOS MIX Signal工艺下,输入信号为2 kHz时该调制器在8 kHz信号带宽内,达到了92 dB的信噪失真比.在1 V电源电压下功耗仅为38μW.核心版图面积为0.25 mm2.     

脉冲频率控制的开关电容型DC/DC转换器的设计以及性能优化

设计了一个脉冲频率控制(PFM)的开关电容型直流转换器,并用0.25μm 2.5/5 V工艺进行了仿真.系统控制模式简单,采用输入限流使输出电压纹波控制在50 mV以内,采用多种模式的开关电容阵列以及增益跳变提高传输效率,得到60%以上的平均效率,85%以上的峰值效率.系统对输入电压和负载变化的动态响应特性良好.输入电压范围为2.8~5 V,输出电压为1.8 V,负载电流最大为200 mA.     

宽调谐范围低相位噪声的小面积VCO设计与实现

为了解决压控振荡器的调谐范围、相位噪声、功耗和芯片面积等指标难以多重优化的问题,本文基于TSMC 40 nm CMOS工艺,通过设计改进型开关电容阵列、高Q值LC谐振电路和大滤波电容等结构,实现了一种宽调谐范围低相位噪声的小面积压控振荡器.采用NMOS型负阻结构,以适应于0.9 V的低电源电压电路.将改进型开关电容阵列...     

用于植入式医用芯片的低电压低功耗SAR ADC

为适应植入式医用芯片的使用要求,给出一低电压低功耗逐次逼近型模数转换器(SARADC)的设计。从降低功耗出发,提出了一种新的能量高效开关策略。与传统开关策略相比,电容阵列的平均开关能量减少了68%,电容阵列的面积仅为传统开关策略的50%;采用带校正的动态比较器,在提高精度的同时可以降低功耗;采用异步时钟,省略了高频时钟产生器,进一步降低了功耗。提出的5 Ms-111位SAR ADC采用SMIC 0.18μm CMOS混合信号工艺流片。供电电压低至1 V,功耗仅为0.236 mW,SNDR,SFDR分别达到55.1,68.38 dB。核心面积为650μm×1 000μm,符合植入式系统的要求。     

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