一种超低温漂的带隙基准电压源

为提高带隙基准电压源的温度特性,采用Buck电压转移单元产生的正温度系数对VBE的负温度系数进行高阶曲率补偿.同时使用共源共栅结构(Cascode)提高电源抑制比(PSRR).电路采用0.5 μm CMOS工艺实现,在5 V电源电压下,基准输出电压为996.72 mV,温度范围在-25~125 ℃时电路的温漂系数为1.514 ppm/℃;当电源电压在2.5~5.5 V变化时,电压调整率为0.4 mV/V,PSRR达到59.35 dB.     

无源标签中的全MOS电压基准源

为了解决传统基准源功耗和版图面积较大而无法适用于超高频射频识别技术中无源标签的设计,设计一无运放、全MOSFETs(metal oxide field-effect transistor)构成的低压低功耗基准电压源。提出的全MOS结构的基准核心电路,有良好的温度特性;加入了预稳压电路而摒弃传统的运放设计,提高电源抑制比。仿真结果表明,在1.5 V典型供电电压下,输出的基准电压为619 m V,静态功耗为1.8μW;1.5~5 V基准电压变化22μV,线性调整率为4.9μV/V;低频时电源抑制比高达-102 d B;-20~120°的温度系数为6.2×10~(-6)/℃。该设计尤其适用于要求低成本、低功耗的超高频射频识别标签芯片。     

一种超低功耗的低电压全金属氧化物半导体基准电压源

针对传统带隙基准电源电压高、功耗高和面积大的问题,提出了一种超低功耗的低电压全金属氧化物半导体(MOS)基准电压源。该基准源通过电压钳制使MOS管工作在深亚阈值区,利用亚阈值区MOS管的阈值电压差补偿热电势的温度特性,同时采用负反馈提高了电压源的线性度与电源抑制比。整个电压源电路采用SMIC 0.18μm互补金属氧化物半导体工艺设计,仿真结果表明:基准电压源的电源电压范围可达0.5~3.3V,线性调整率为0.428%V-1,功耗最低仅为0.41nW;在1.8V电源电压、-40~125℃温度范围内,温度系数为4.53×10-6℃-1,输出电压为230mV;1kHz下电源抑制比为-60dB,芯片版图面积为625μm2。该基准电压源可满足植入式医疗、可穿戴设备和物联网等系统对芯片的低压低功耗要求。     

一种BiCMOS带隙基准电压源的设计

设计了低温度系数、高电源抑制比BiCMOS带隙基准电压发生器电路.综合了带隙电压的双极型带隙基准电路和与电源电压无关的电流镜的优点.电流镜用作运放,它的输出作为驱动的同时还作为带隙基准电路的偏置电路.使用0.6μm双层多晶硅n-well BiCMOS工艺模型,利用Spectre工具对其仿真,结果显示当温度和电源电压变化范围分别为-45~85℃和4.5~5.5 V时,输出基准电压变化1 mV和0.6 mV;温度系数为16×10-6/℃;低频电源抑制比达到75 dB.电路在5 V电源电压下工作电流小于25μA.该电路适用于对精度要求高、温度系数低的锂离子电池充电器电路.     

一种高性能的BiCMOS带隙基准电压源

提出了一种新颖的利用负反馈环路以及RC滤波器提高电源抑制比的高精密CMOS带隙基准电压源．采用上海贝岭的1．2μm BiCMOS工艺进行设计和仿真,spectre模拟表明该电路具有较高的精度和稳定性,带隙基准的输出电压为1．254V,在2．7V-5．5V电源电压范围内基准随输人电压的最大偏移为0．012mV,基准的最大静态电流约为11．27μA;当温度-40℃-120℃范围内,基准温度系数为1mV;在电源电压为3．6V时,基准的总电流约为10．6μA,功耗约为38．16μW;并且基准在低频时具有100dB以上的电源电压抑制比（PSRR）,基准的输出启动时间约为39μs．     

一种电源抑制比增强的带隙基准电压源设计

本文介绍了一种适用于低功耗、高电源抑制比的低压差线性稳压器(LDO)低温漂、高电源抑制比带隙基准电路.该电路在原有传统的带隙基准电路的基础上,通过在误差放大器输出端与带隙基准电流镜之间添加结构简单的PSRR增强电路,使得本文设计的带隙基准较常见带隙基准的电源抑制比(PSRR)提高了近20 dB.本文基于CSMC 0.5 μm工艺Spectre仿真分析结果表明:在-25℃到85℃的温度范围内,输出电压变化值仅为0.3 mV,有较好的温度特性.在10 K处的电源抑制比为75dB,在60℃的条件下,输出电压在电源电压2.75～5 V的变化范围内,仅为90μV的波动,整个电路有较好的线性调整率.整体电路功耗小于20μA.     

一种无需运放的低温漂带隙基准源设计

文章依据带隙基准电压源的基本原理设计了一种低温漂的带隙基准源,与传统带隙基准相比,所设计的电压源未使用运放。该基准电源电路有较低的温度系数和较高的电源抑制比,此外还增加了启动电路,以保证电路工作点正常。仿真结果表明,低频时电源抑制比可达85 dB,在-20℃~100℃范围内输出变化仅为0.8 mV,温度系数仅为4.968×10-6,常温下输出电压为1.296 V,电源电压范围为3.9~5.5 V。     

基于硅带隙能量的1.2V基准电压源设计

基于0.35μm CSMC(central semiconductor manufacturing corporation)工艺设计,并流片了一款典型的带隙基准电压源芯片,可输出不随温度变化的高精度基准电压。电路包括核心电路、运算放大器和启动电路。芯片在3.3V供电电压,-40~80℃的温度范围内进行测试,结果显示输出电压波动范围为1.212 8~1.217 5V,温度系数为3.22×10-5/℃。电路的版图面积为135μm×236μm,芯片大小为1mm×1mm。     

一种带密勒补偿的带隙基准电压源

设计了一款宽温度范围并带有密勒补偿的带隙电压基准电路,基准输出可通过内接电阻调节.该电压源以带隙基准电路为基本电路,扩展预偏置电路和输出缓冲电路.此电路基于0.35μm CMOS工艺,利用Cadence仿真工具进行验证,结果表明该带隙基准的输入电压为2.3~4 V,可以输出受温度变化影响较小的高精度电压,低频时的电源抑制比为84 d B,基于以上性能优点,该基准电路可以应用于温度较宽的集成电路设计中.     

电流镜型二次曲率补偿的带隙基准源设计

为提高基准源的温度系数、电压调整率和电源抑制比,采用0.6μm标准CMOS工艺,设计一种采用电流镜复制技术的带隙基准源.仿真结果表明,电路具有结构简单、启动性能好、电压输出灵活稳定、温度范围宽等特点,能够满足模拟集成电路的要求.在3种工艺角模型,-50~+195℃温度变化范围内,其温度系数约为1.632×10-5℃-1,电源抑制比为-70 dB;而在4.5~6.5 V的电源范围内,其电压调整率为4.0×10-4.     

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.