正弦交流电路中的相位实验研究初探

正弦交流电路中电压和电流的相位关系是交流电的基础内容,通过使用Multisim仿真软件分析了RC串联电路、RL串联电路以及RLC串联电路中电压和电流的相位关系,并给出了电路中各电压的相量图。说明了Muhisim仿真软件对实验教学有重要的辅助意义,提高了学生的学习效率。     

Multisim在三相交流电路实验仿真中的应用

将EDA仿真软件Multisim应用于三相交流电路实验的仿真方法为：建立三相交流电路，按要求设置电路所需的参数，调用软件所提供的测试仪表进行仿真，根据仿真观测到的现象或数据进行三相交流电路特性的分析。本文运用Multisim对几个电路实例进行了仿真，三相电路的特性分析一目了然，有很好的现实效果。     

RLC电路并联谐振理论与仿真分析

本文对RLC并联谐振电路进行了理论研究,包括理想RLC并联电路、实际RL-C并联电路的电压电流特性与相量图、电容电感无功功率关系、品质因数Q的推导计算及其对谐振特性的影响,并采用Multisim软件对两类并联谐振电路进行了仿真分析,结果不仅能很好地验证理论分析的正确性,同时可以快捷准确观测并联谐振电路的幅频与相频特性曲线,简化了实验操作,弥补了设备不足。     

基于Multisim 10的RC桥式正弦波振荡电路仿真分析

本文基于探索RC桥式正弦波振荡电路工作特性的目的,运用Multisim 10软件对RC桥式振荡电路进行了虚拟仿真实验,给出了Multisim仿真实验方案,仿真了电路从起振到稳幅输出的工作过程,测试了电路的电压放大倍数、反馈系数及自激振荡条件等技术指标,通过改变电路元件参数进行对比观察了电路的输出幅度变化、非线性失真等特性,虚拟仿真实验结果与理论分析计算结果相一致.结论是仿真实验可直观形象地描述电路的工作特性,有利于系统地研究电路的构成及电路元件参数的选择.     

基于Multisim7的半波整流滤波电路频域分析及仿真

从频域的角度对RLC半波整流滤波电路进行了分析,在Multisim7里对该电路整流和滤波后的电压波形分别进行了仿真,需要克服半波整流滤波电路效率低且给电源带来谐波。     

倍压整流电路的广义忆阻特性

研究旨在证明二倍压整流电路具有广义忆阻特性,为挖掘倍压整流电路的新功能及新应用提供理论依据.首先,根据电路理论求得二倍压整流电路在电压源激励下输入端口伏安关系式以及电路中电容电压的状态方程;其次,由理论分析所得关系式,选取电路元件参数,施加正弦激励电压,由Matlab软件对端口伏安关系进行数值仿真分析;最后,通过Multisim软件进行虚拟实验以及物理实验进行验证.结果表明理论分析符合广义忆阻器数学定义,数值仿真、虚拟实验及硬件实验3者结果基本吻合,验证了输入端口呈现出忆阻器的3个本质特征,从而证实了二倍压整流电路在取适当电路元件参数时具有广义忆阻特性.     

谈通用电工实验台中串联谐振参数的改进

大中专、职高通用电工实验台在验证电路原理方面确实体现了理论与实践相统一的原则，但“金无足赤”。笔者在做正弦交流电路中的RLC串联谐振时发现它有瑕疵。例如在RLC串联谐振实验中，它设置了一组参数：     

RLC组合正弦交流电路谐振分析

该文对RLC组合正弦交流电路各个组态作详细分析,通过相关电路的串并联计算,得到各个组成电路复阻抗的解析解;进一步通过电路复阻抗相量的谐振分析要求,计算了该系列电路在谐振状态时所取的RLC参数值.将对应的阻抗解析解与所取谐振状态参数值进行对比分析,我们得到所有RLC组成电路谐振的产生条件、产生原因以及结果,并对其进行了全面的归纳总结,得到一系列简单而便于理解的结果,该结果将对相关电路的根本理解与基础设计有重要作用.     

单相正弦交流电路的实验研究

单相正弦交流电路实验目的在于研究R、L、C元件在正弦波交流稳态电路中的基本特性及验证相量形式的基尔霍夫电流定律KCL和电压定律KVL,理解正弦交流电量中用相量形式表达的相位关系。     

基于Muhisim技术的电路实验

电路实验是电类专业学生的重要基础实验课程,但由于受到传统实验条件以及学时的限制,实验项目和实验内容都无法全面、深入的展开。文章简要介绍了Multisim仿真软件的电路仿真步骤,并以RLC二阶电路为例详细阐述了利用Multisim对其动态过程进行仿真分析的方法,使学生能够直观、全面地了解不同阻值对二阶电路动态过程的影响,从而加深对动态电路的认识。     

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.