施密特触发器电路及其改进

论述了常用555定时器构成的施密特触发器电路的局限性,给出了施密特触发器的改进电路,并用理论和实验加以证明和验证.     

动态体效应CMOS施密特触发器

提出了一种利用MOS管的体偏置技术实现的低电压施密特触发器电路,利用动态体偏置实现的施密特触发器可以适用于深亚微米芯片,可广泛用于滤除芯片的输入噪声,提高输入信号的信噪比。     

SET-MOS混合结构的触发器设计及应用

基于SET-MOS混合结构的或非门构建了基本RS触发器和主从式D触发器,对所设计的新型触发器电路进行了分析研究,并将其应用到寄存器和移位寄存器电路.利用SPICE对所设计的触发器电路进行仿真验证,仿真结果表明电路运行良好.该新型触发器电路与SET实现的电路相比,具有更高的驱动能力;与传统CMOS电路相比,电路的功耗仅为10-10 W的数量级.     

一类适用于串行通信的高速包络检测电路

设计了一类新颖的高速包络检测电路,与传统包络检测器相比无需工艺、温度以及电源电压(PVT)校准电路,且正负阈值平均电压和回差电压可以独立设定,无直接关系.首先推导出适用于此结构的能抑制PVT变化的电路设计函数,在此函数指导下完成USB2.0的高速包络检测器.仿真结果表明工作温度从-40~125℃变化时,负向触发电压变化小于6mV,正向触发电压小于1mV,工作电压和工艺变化导致的触发电压变化小于14mV,完全符合USB2.0协议要求.可以推广到需要包络检测的串行通信系统中,或者其他需要施密特触发器的场合中.     

555定时器的功能模型及其应用

提出一种用简化模型的形式表示555定时器逻辑功能的方法,运用该方法分析基于555定时器的电路具有形象、直观和便于理解掌握的特点.文中给出了使用该方法分析由555定时器组成的单稳态触发器、多谐振荡器和施密特触发器等实例.     

基于容忍单粒子效应的集成电路加固方法研究

针对现有容忍单粒子效应的锁存器结构无法同时容忍单粒子翻转(SEU)、单粒子瞬态(SET),以及未考虑电荷共享导致的双节点翻转(DNU)问题,提出一种高可靠性的同时容忍SEU、SET和DNU的锁存器加固结构SRDT-SET。基于空间和时间冗余原理,该锁存器结构采用了多个输入分离的施密特触发器来构建高可靠性数据存储反馈环,同时内嵌多个施密特触发器。HSPICE仿真结果表明,SRDT-SET锁存器结构能够从SEU中在线自恢复,容忍的SET脉冲宽度更宽,并且能够有效容忍DNU,功耗-延迟综合开销不大,有效增强了SET脉冲的过滤能力。     

一种温度不敏感频率可调锯齿波振荡器的设计

设计一种以双比较器型施密特触发器为核心的锯齿波振荡器,并对各部分电路的工作原理进行阐述.该电路利用基准电流源产生的电流信号对电容进行充放电产生锯齿波,并可通过外部电阻调节振荡频率,振荡频率受电源电压及温度等环境影响较小,稳定性高.通过Hspice对电路进行仿真对其功能加以验证.     

由施密特触发器构成的三相移相触发器的设计

提出了由施密特触发器构成三相移相触发器的设计思路及方法,即在给定电压控制下,输出脉冲能在0~150°夹角范围内移相,其主要应用于调节全控整流桥电路的输出功率。     

一种简易的街灯控制器设计

针对城市街道路灯照明的特点,提出了一种新型的简易街灯控制器设计方法;方法利用光敏电阻和施密特触发器组成光控电路实现傍晚开灯,利用电容的充放电特性实现持续点亮时间控制;对控制器的总体框架、硬件电路、参数分析进行了介绍,并通过实验证明了其可行性;设计原理简单,维护方便,成本低廉,具有较高的推广价值.     

基于Mulitsim7的555定时器的应用

555定时器是一种多用途的数字模拟混合集成电路,利用它可以方便地构成施密特触发器、单稳态触发器和多谐振荡器。本文从教学的角度对它的一些基本应用进行了分析,并在Multisim7里进行了实验仿真。     

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。     

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.