2.5 Gbit/s无电感高灵敏度宽动态范围前置放大器设计

基于0.18μm RF CMOS工艺设计一种应用于无源光网络光接收机的无电感型2.5 Gbit/s前置放大器。该前置放大器主要包括跨阻放大器、单端转差分运算放大器和输出级电路。跨阻放大器基于3级推挽反相器结构,具有高增益和低噪声的特点,提高前置放大器的灵敏度;分析零点补偿原理,设计位于反馈环路之中的虚零点,提高跨阻放大器的工作速率,增加稳定性。提出一种新的具有自适应功能的自动增益控制技术,使得跨阻放大器在不同光输入功率下保持带宽不变,环路稳定,具有宽动态范围特性。研究结果表明:在误码率为10-10,传输速率为2.5 Gbit/s时,该前置放大器的接收光灵敏度高达-29 d B·m,输入最大光功率为2 d B·m,动态范围达31 d B·m;在1.8 V的电源电压下,芯片功耗为30 m W,芯片总面积为1×0.7 mm2。     

一种用于光纤传输系统的10 Gbit/s SiGe HBT限幅放大器设计

作为光接收机前端的关键部分，限幅放大器要求具有高增益、足够带宽和大动态输入范围。利用IBM公司0．5μmSiGe BiCMOS HBT工艺设计了一种用于10Gbit／s光纤传输系统的限幅放大器。整个系统包括一个输入缓冲级、3个放大单元级、一个用于驱动50Ω传输线的输出缓冲级和一个失调电压补偿回路。模拟结果表明采用3．3V单电源供电时限幅放大器的功耗为200mW，S21小信号增益大于46dB，3dB带宽为8．5GHz，对于输入信号从10mV到1．5V的变化范围内输出信号幅值都可以恒定在800mVpp。     

宽带电流模形式PHEMT前置放大器设计

设计并实现了基于0.2 μm PHEMT工艺的宽带电流模形式前置放大器.前置放大器将光电二极管产生的电流信号放大并转换为差分电压信号.电路为共栅结构,输入电阻小,减小了光检测器寄生电容对电路带宽的影响.设计时采用了电容峰化技术,可获得比普通共栅结构更宽的带宽.后仿真结果为,在单电源5 V,输出负载50 Ω的条件下,该前置放大器的跨阻增益为1.73kΩ,带宽可达到10.6 GHz,同时具有低噪声和较宽的线性范围,芯片面积为607 μm×476 μm.测试结果表明,此前置放大器可以很好地工作在10 Gbit/s速率上.     

光接收机中前置跨阻放大器的设计

利用0.6μm CMOS工艺设计了一种用于光纤通信的跨阻前置放大器。电路采用推-挽反相器级联形式的结构,本身能够自偏压,不需设计偏压电路,减少了芯片面积,同时它的输出可以端到端地满摆幅工作,而且只要放大部分的2个MOS管都处在饱和区,就能得到最大的电压增益;利用SmartSpice软件对电路进行仿真,结果表明在 5 V电源电压作用下,该放大器的增益为78.9 dbΩ,3 db带宽为540 MHz。     

一种低电压低功耗Rail-to-Rail CMOS运算放大器的设计

基于2 μm CMOS工艺,设计实现了一种2.4 V低功耗带有恒跨导输入级的Rail-to-Rail CMOS运算放大器.采用尾电流溢出控制的互补差分输入级和对称AB类推挽结构的输出级,实现了满电源幅度的输入输出和恒输入跨导;运用折叠共源共栅结构作为中间增益级,实现电流求和放大.整个电路在2.4 V的单电源供电下进行仿真,直流开环增益为76.5 dB,相位裕度为67.6 ,单位增益带宽为1.85 MHz.     

10Gb/s CMOS工艺光接收机前端放大器的设计

本文采用TSMC 0.18μm CMOS工艺,设计了一种应用于SDH系统STM-64(10Gb/s)光接收机的前端放大器。在跨阻放大器中,在共栅前馈结构的基础上加入有源电感,设计了一种宽带的跨阻输入级;跨阻放大器的增益级和限幅放大器核心单元采用三阶交叉有源反馈结构来扩展带宽。     

2.5Gb/s低噪声差分交叉耦合跨阻放大器的设计与实现

本文基于UMC 0.18 μm CMOS工艺,设计了一款低噪声交叉耦合结构的跨阻放大器.该电路由优化的调节型共源共栅(RGC)结构和输出缓冲级构成,其中采用两级共源放大器作为RGC结构的辅助放大器,用于提升电路的等效跨导和带宽.此外,通过优化电路参数以及在输入端引入阶梯型无源匹配网络来进一步拓展带宽和降低电路噪声.测试结果表明,在探测器等效电容为300pF时,所设计跨阻放大器芯片的-3d B带宽为2.2GHz,跨阻增益为61.8d B?,平均等效输入噪声电流谱密度仅为9 pA/(Hz)~(1/2),成功实现了2.5Gb/s的传输速率.在1.8V电源电压下,芯片功耗为43m W,包括焊盘在内的芯片总面积为1×1mm~2.     

带共模反馈的CMOS折叠式高增益运算放大器

提出了一种单电源5V供电的带共模反馈的两级折叠式运算放大器结构.折叠式运算放大器的输入共模反馈结构使输出共模电平维持在2.5 V左右,增益可达到90 dB以上,相位裕度为45°,同时增益带宽为33 MHz.     

2.5V/0.25um Rail-to-Rail运算放大器

本文采用0.25um CMOS工艺,设计了一种rail-to-rail运算放大器,该放大器用2.5V单电源供电,其输入共模范围和输出信号摆幅可以达到零电源电压,单位增益带宽为320MHz,相位裕度为60°.     

一种低电压低功耗Rail-to-Rail CMOS运算放大器的设计

基于2 μm CMOS工艺!设计实现了一种2.4 V低功耗带有恒跨导输入级的RailtoRail CMOS运算放大 器。采用尾电流溢出控制的互补差分输入级和对称56类推挽结构的输出级，实现了满电源幅度的输入输出和恒 输入跨导；运用折叠共源共栅结构作为中间增益级，实现电流求和放大。整个电路在2.4 V的单电源供电下进行 仿真，直流开环增益为76.5 dB,相位裕度为67.6,单位增益带宽为1.85 MHz。     

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.     

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.     

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.     

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.     

The Analects and the Moment in Peking——The influence of a Confucian education system on the personality formation,the way of thinking and the fate of the main characters

0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation＇s behavior in their social life throughout the long history is beyond list.