双运放高Q带通滤波器的研究

基于集成运放的主极点模型,首先导出了双运放高Q带通滤波器的环路增益和前向通道增益表达式,以此为依据,用梅森公式求出了滤波器的传输函数,讨论了理想和非理想两种情况下该滤波器极点频率和品质因数表达式,并给出了它们的相对误差公式,解释了该电路出现极点频率和品质因数减弱的原因.     

用平衡式对数域积分器实现连续小波变换

为满足低电压、低功耗及实时处理等应用要求的需要,提出了一种新的基于平衡式对数域积分器的连续小波变换实现方法.小波变换实现电路由冲激响应为高斯一阶导数小波的模拟滤波器构成,其传输函数用Levenbery-Marquardt非线性最小二乘法求得.滤波器以工作在甲乙类状态的平衡式对数域积分器为积木块进行设计,通过改变平衡式对数域积分器的偏置电流而实现不同尺度下的小波变换.计算机仿真结果表明了该方法的可行性.     

MOS器件失配对开关电流滤波器的影响

提出了一种ＭＯＳ器件失配时开关电流镜的简单模型，对开关电流（ＳＩ）非理想通用积分器进行了时域分析，以及积分器转移函数误差、Ｑ值及灵敏度的计算，并与开关电容（ＳＣ）原型做比较，文中还以ＳＩ非理想通用积分器模型为基块，导出了器件失配时双二次滤波电路的直流失调电流和转移函数表达式，为研究器件失配对ＳＩ滤波器的影响提供了一条有效的途径。     

低电压对数域滤波器的低功率性能分析

对线性Gm-C积分器和对数域积分器的功率性能进行了分析，表明对数域滤波器更适合于在低电源电压下的低功率信号处理。计算机仿真结果显示，对数域积分器比线性Gm－C积分器具有更低的失真度。因此，对数域电路适合于低电压低功率的高频率的低失真滤波器设计。     

基于傅里叶级数的多环反馈开关电流小波滤波器实现

提出一种基于傅里叶级数的多环反馈结构开关电流小波滤波器设计新方法。利用傅里叶级数法求取小波函数的时域小波逼近函数,以双输入多输出开关电流双线性积分器和单输入多输出电流镜作为基本单元设计相应的多环反馈结构小波滤波器,并通过调节开关电流滤波器的时钟频率获得不同尺度小波函数。对所设计的电路进行时域、频域和灵敏度分析,并研究元件非理想性对电路的影响。研究结果表明:该方法的小波逼近函数求取容易,滤波器电路具有设计简单、灵敏度低和受非理想性因素影响小的特点。     

基于MO-CCⅡ的通用有源电流模式二阶滤波器

提出了一种基于多输出电流传输器(MO-CCⅡ)的电流模式二阶通用滤波器,该滤波器具有3个输入端和1个输出端,通过选择不同的输入信号组合即能获得低通、高通、带通、带阻和全通5种滤波函数.电路结构简单,中心频率和品质因数独立可调,无源元件全部接地,滤波器特性参数对无源元件灵敏度低.理论分析和Spice仿真表明该电路设计方案正确可行.     

基于MO-CCII的通用有源电流模式二阶滤波器

提出了一种基于多输出电流传输器(MO-CCII)的电流模式二阶通用滤波器,该滤波器具有3个输入端和1个输出端,通过选择不同的输入信号组合即能获得低通、高通、带通、带阻和全通5种滤波函数.电路结构简单,中心频率和品质因数独立可调,无源元件全部接地,滤波器特性参数对无源元件灵敏度低.理论分析和Spice仿真表明该电路设计方案正确可行.     

线性相移有源带通滤波器的计算机辅助设计

本文介绍用计算机辅助设计求得各个全极点有源带通节的谐振频率和Ｑ值的方法，以获得窄带带通滤波器通带内理论上良好的幅频和相频特性。进一步分析了实现有源带通节时由于运算放大器非理想特性而产生的相对理论特性的偏离，给出并比较了多种有源带通节的幅频特性和群时延公式及曲线。最后以立体声附加信道调频广播中附加信道解码的中心频率为６７ｋＨｚ的带通滤波器为例进行讨论，给出了该滤波器在上述应用中的实际结果。     

一种中心频率可调节的高Q值微机械带通滤波器初探

设计制作了一种中心频率可调节的高Q值微机械带通滤波器，其核心部分是一个电热激励／压敏电桥拾振的硅／二氧化微桥谐振器或微桥谐振器阵列，通过调节施加在压敏电桥上的电压大小来改变桥的平均温度和轴向应变，可调节滤波器的中心频率，理论研究表明：中心频率与电桥电压的平方成线性关系，中心频率的可调节范围可通过减小梁的宽度和压敏电桥的电阻来扩展，所制作的滤波器其频率可调节范围达5．45％，品质因数达8000以上。     

基于BiCMOS的低电压全差分对数域积分器设计

分析一个由BiCOMS构成的单端对数域积分器的频率特性和存在的局限性。提出了一个工作在甲乙类状态的对数域全差分积分器,并采用跨导线性原理分析得到了其传递函数,分析了全差分积分器的频率特性和动态范围。PSpice仿真结果说明,全差分对数域积分器具有较宽的频率调谐范围,能在1－2V之间的低电压下工作,同时具有较大的动态范围,更适合于高频、低电压和大动态范围的滤波器设计。     

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.     

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。     

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.     

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.     

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.