密绕椭圆截面螺线管轴线上的磁场

应用数值模拟方法,求解密绕椭圆截面螺线管轴线上的磁场,并分析了磁场与长短轴、管内轴线上位置的关系.计算结果表明,其磁场分布与密绕圆截面螺线管电流的磁场分布相差很大,磁场在空间各个方向都有分量,长宽比越小,垂直于轴线方向的磁场分量越大;长宽比较大或距螺线管中心较近处,磁场几乎与密绕圆截面螺线管电流产生的磁场相当,可用密绕圆截面螺线管电流轴线上磁场的简单公式来近似.     

各向异性磁介质中载流直螺线管轴线上的磁场

利用毕奥－萨伐尔定律,并在磁导率μ１１＝μ３３的条件下,可求出各向异性磁介质中载流圆线圈轴线上的磁场,以及载流直螺线管内部的磁场,显然,其使用条件受到限制。为此,有必要导出在μ１１≠μ３３的更一般情况下,各向异性磁介质中载流圆线圈轴线上磁场和载流直螺线管内部的磁向异性磁介质中载流圆线圈轴线上的磁场,使其结果适用范围更广。     

载流疏绕有限长螺线管内轴线上的磁场

讨论了有限长载流疏绕螺线管内轴线上的磁场,并与载流密绕螺线管内轴线上的磁场作了比较．用此分析方法可以求得较完整的载流螺线管内的磁场分布．     

密绕椭圆截面螺线管电流的磁场分布

利用叠加原理和数值计算方法,求解密绕椭圆截面螺线管电流的磁场,分析磁场与长短轴之比、螺线管长短的变化关系.计算结果表明,长短轴之比越大,螺线管越短,磁场在垂直于螺线管轴线方向的分量越大,螺线管内匀强磁场的区域越小,但当长短轴比接近于1或螺线管较长时,磁场与密绕圆截面螺线管的磁场相似,螺线管内匀强磁场的区域较大,只在螺线管端口是非均匀磁场.     

用磁荷观点研究载流螺线管内磁场

用基于电流或分子电流的等效磁荷观点 ,计算载流螺线管或柱形永磁铁轴线上任一点的磁场强度H ,进而求出磁感强度B ,并画出螺线管内外的磁力线分布。     

无限长通电螺线管内磁场与其截面形状无关的证明

建立柱坐标系,利用毕奥—萨伐尔定律和矢量微积分,首先求出任意形状载流线圈任一点磁感应强度的一般表达式;然后在特定的条件下得出载流圆线圈轴线上的磁感应强度;最后利用场强叠加原理对任意形状载流线圈任一点磁感应强度的一般表达式进行矢量积分,得出截面为任意形状无限长通电螺线管内的磁感应强度与截面为圆形无限长通电螺线管内的磁感应强度具有相同的表达式,从而得出无限长通电螺线管内的磁场与其截面形状无关的结论.     

考虑螺距时有限长超导螺线管电流磁场的分布

应用数值模拟方法 ,分析了疏松型超导螺线管电流轴线外的磁场与螺距、长宽比、管内位置的变化关系 .计算结果表明 ,当螺距较大时 ,其磁场分布与密绕螺线管电流的磁场 (均匀磁场 )分布相差很大 ,磁场在空间各个方向都有分量 ,螺距越大 ,长宽比越小 ,垂直于轴线方向的磁场分量越大 ;但当螺距较小 ,长宽比较大或距螺线管中心较近处 ,磁场几乎与密绕螺线管电流产生的磁场相当 ,可用密绕螺线管电流轴线上磁场的简单公式来近似     

特种螺线管磁场分布及自感系数的研究

自感是电磁感应现象中的重要概念,关于自感系数的定义可归纳为静态法、动态法、磁能法三种。文章在讨论分析载流长直导线、载流螺线管全空间磁场分布的基础上,利用叠加原理,求解特种螺线管的空间磁场分布;利用磁能法,解析计算长直特种螺线管单位长度的自感系数。     

载流螺线管轴上磁场的讨论

本文通过对载流螺线管导线沿半线叠绕和导线沿轴线密绕情况下，求出轴上任意一点的磁感应强度，补充了一般教材的不足。     

无限长密绕载流螺线管外的磁场

螺线管是用一根长直导线绕成密集排列的螺旋线圈组成的,无限长密绕载流螺线管内的磁场可通过极限方法求出,但管外的磁场,教材却没有仔细讨论,本文着重分析关解决这个问题。     

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.     

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.     

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.     

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.     

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with