应用于全数字锁相环中的精度可调的时间数字转换器（英文）

本文提出了一种应用于全数字锁相环中的分辨率可调的两级时间数字转换器.第一级采用缓冲器延时链结构,运用可异步重置的触发器作为采样单元;第二级采用Vernier延时链结构以提高时间分辨率.和传统的单级结构相比,两级架构可以在更低的电路面积下实现相同的测量范围,并提供更好的分辨率.为了降低工艺、电压、温度对分辨率的影响,本设计采用了电压控制的延时单元,通过调整其延时来降低分辨率的变化.本设计通过65 nm工艺验证,总体面积0.06 mm2.仿真结果表明,在输入频率为1.2~1.8 GHz时,分辨率可达6.15 ps,动态范围1 260 ps,实现8 bits时间数字转换器,功耗仅2.5 mW.     

一种应用于全数字锁相环的时间数字转换器设计

设计了一个应用于全数字锁相环的时间数字转换器(TDC).该时间数字转换器具有两种工作模式——粗量化和细量化.为了提高细量化模式的测量范围,TDC采用1-bit decision-select结构和游标门控环形振荡器(Vernier GRO)构成其两级量化单元.通过在Vernier GRO中使用一种新型结构的比较器,消除了用SR触发器做比较器时对测量范围的制约,也提高了GRO设计的灵活性.在TSMC 0.13μm工艺,1.2 V电源电压和40MHz采样速率下,仿真结果表明本设计的TDC在粗量化模式下具有不小于25ns的测量范围,在细量化模式下有效分辨率和测量范围分别为30ps,1.8ns.     

0.18m CMOS中用于频率综合的时间数字转换器

该文提出一种应用于全数字锁相环高分辨率的时间数字转换器TDC。该TDC延时单元由两级特殊的反相器构成,其中第一个反相器只考虑上升沿,而第二个反相器只考虑下降沿,通过合理选择两级反相器的尺寸可使总延时小于传统延时单元的一半,从而提高了TDC的分辨率。针对这种只考虑单沿的延时单元,该文还提出了相应的TDC系统。实验结果表明,在0.18μm CMOS工艺下,该文提出TDC的分辨率能达到28 ps。     

0.18m CMOS中用于频率综合的时间数字转换器

该文提出一种应用于全数字锁相环高分辨率的时间数字转换器TDC。该TDC延时单元由两级特殊的反相器构成,其中第一个反相器只考虑上升沿,而第二个反相器只考虑下降沿,通过合理选择两级反相器的尺寸可使总延时小于传统延时单元的一半,从而提高了TDC的分辨率。针对这种只考虑单沿的延时单元,该文还提出了相应的TDC系统。实验结果表明,在0.18μmCMOS工艺下,该文提出TDC的分辨率能达到28ps。     

基于多级放大结构的高速低功耗时间数字转换器设计

提出一种多级放大时间数字转换器新型结构。该结构由粗测和细测组成, 粗测部分利用延时链得到小于一个延时单元的关键余量, 并设计了面积小、功耗低的关键余量选择逻辑。细测部分, 利用两倍时间放大器和过半判断器从高位到低位依次产生4位二进制码。在SMIC 65 nm工艺下仿真, 新型结构的分辨率为1.44 ps, 量程为736 ps, 转换速度可达470 MS/s, 在100 MHz频率下, 平均功耗仅为1.3 mW。对两倍时间放大器设计了校准电路, 提高了抵抗PVT的能力, 得到良好的积分非线性。     

一种采用标准数字单元实现的5bit 100MS/s全数字闪烁型模数转换器

设计了一种全数字实现的5bit闪烁型模数转换器,该设计的核心思想是通过差分延时链对,将输入的差分模拟信号转换为延时信号,再经过锁存器得到与相应参考电压的比较结果.该数字比较器的参考电压内置于差分延时链对,无需从外部输入.采样保持电路的开关和保持电容也使用数字库中的合适器件代替.该模数转换器完全采用标准数字单元库中的单元搭建而成,与传统实现方法相比,在功耗、面积及设计复杂度上均有了较大程度的改善.电路采用TSMC 65nm工艺设计,核心面积为0.02mm2,在采样频率为100MS/s的情况下,后仿真功耗低达0.6mW,SFDR为37.89dB,ENOB为4.55bit.     

基于数字延时锁相环的FPGA IO延时管理电路

本文提出了一种基于过采样量化器和换挡(Gear-Shift)控制机制的新颖的数字延时锁相环(DDLL),可以嵌入于FPGA芯片IO单元的延时管理系统,实现了IO单元数据通路延时的精确校正,分辨率达到78ps,可调节范围达4ns,满足FPGA芯片对高速串行接口协议复杂时序的兼容.DDLL使用独具特色的过采样量化器,仅使用1bit时间数字转换器(TDC)达到了98dB SNR,等效理论分辨率达16位,并引入了全新的Gear-Shift控制机制,对误差信息合理的加权实现快速精确的锁入,结合2阶巴特沃斯衰减的数字环路滤波器,实现全数字环路控制,较传统模拟延时锁相环,节省了芯片面积和功耗,同时对数字电路所产生的衬底噪声具有更好耐受.DDLL采用65nm数字工艺,嵌入复旦大学自主研发的FPGA芯片,经过后仿验证,锁定时间小于50cycles.     

75 ps精度GM-APD阵列像素读出电路设计（英文）

提出了1种用于激光3D成像的中等规模盖革模式雪崩光电二极管(GM-APD)阵列的像素读出电路.根据时间飞行(TOF)原理,像素读出电路主要由两部分组成:有源淬火电路(AQC)和时间数字转换器(TDC).所采用的TDC是两段式粗细结合的架构,成功实现了时钟频率和时间分辨率的折中.基于内插技术,动态范围提高到了19 bit,而时钟频率降低为预计的1/5,显著降低了设计和应用的难度.采用延时线技术实现的4 bit细TDC将精度提高到75 ps.电路采用SMIC 0.18μm工艺设计.后仿结果显示达到了75 ps的高精度时间分辨率,对应3 km测距范围内的距离分辨率为1.125 cm.另外,总功耗为1.08 m W,且电路面积小于95×95μm~2.     

一种改进的用于FPGA的快速数字锁相环电路设计

设计了一种可以用于FPGA的数字锁相环的集成电路结构.传统的快速逼近设计方法因仅采用单层次的设计架构,会面临延迟单元数目与精度的矛盾,从而需要消耗大量的逻辑资源及面积.新设计创新性地采用多层次延迟链的结构,分粗、细、微调3级逐次进行延迟补偿.近似于采用多位数(这里相当于3位八进制)代替单一位数来代表延迟大小,与传统的单层次数字锁相环技术相比大大地减少了延迟链数目及设计面积,仅相当于同样工艺和设计要求下传统数字锁相环技术延迟单元数目的1/10,及面积的1/2.该结构可实现20~200 MHz频率范围并且设计精度可达到100 ps.     

一种基于有源真时延的低复杂度波束形成器设计

基于0.18μm BiCMOS工艺,实现一种基于有源真时延技术的低复杂度波束形成架构设计.该波束形成架构适用于多路输出的宽带多天线系统,能够将输入到阵列中的信号进行空间滤波处理,抑制噪声和干扰,增强有用信号.相比于传统的波束形成架构,该架构通过真时延单元共享,实现了低复杂度(更少的延时单元数量),并采用改进的有源真时延单元,在保证稳定延时的同时,有效降低了芯片面积,相比同样功能的无源结构实现方案,面积节省了近80%.仿真结果表明,在0.3 G～1 GHz频带内,波束形成芯片能够同时实现对空间中四个不同方向的信号合成,最小延时分辨率是103 ps,最大延时是1030 ps,延时波动小于2.4%,电源电压为1.8 V,输入、输出端口回波损耗小于-13.8 dB,带内合成增益为25 dB,版图面积为3.8mm~2.     

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.     

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.     

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。     

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.     

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.