数学分析教学中的几个重要反例

反例在数学分析的教学中有其重要意义,构造反例是一种创造性的学习,运用反例可以加深学生对数学命题的正确理解.本文结合数学分析的具体教学实践,归纳了几个重要的反例,并探讨了这些反例在数学分析教学中的具体应用.     

数学应试的有力武器——反例法

数学中反例法与证明在解决问题时是同等重要的。介绍了反例的概念与类型、反例的作用,以及反例的构造方法三个方面并进行分析和探讨。     

浅谈数学反例

浅谈反例在数学 的作用及反例的构造，适当地和数学反例，在数学教学中会取得良好的效果。     

“反例”小角色大作用——反例教学的重要性

反例是数学学习中的重要内容,通过反例的辨析可以深刻理解相关的数学概念,分析问题解决中的问题,更好地掌握数学定理、公式,并灵活应用于新情境.本文通过理论分析和案例研究,探讨了反例在高考和竞赛中的应用、反例在课标中的地位及心理学的意义和反例在实际教学中的应用.     

浅谈数学反例

浅谈反例在数学教学中的作用及反例的构造,适当地使用数学反例,在数学教学中会取得良好的效果．     

高等数学中反例教学研究

本文对高等数学中的反例进行了探讨和研究，论述了反例的类型及构造，给出了高等数学中一些典型的反例，并进行了详细的分析，说明了反例在高等数学教学中的重要作用以及应注意的一些问题。     

反例在微积分教学中的作用

反例在微积分的教学中有着重要意义,通过列举反例可以有效加深学生对数学概念、公式、定理的正确理解和应用,构造反例是一种创造性的学习,对培养学生具有较好的数学素养和创新思维能力具有不可替代的作用,本文结合微积分学的教学实践,归纳了反例在微积分教学中的具体应用方法,探讨了构造反例的途径.     

基于克雷格插值的反例理解方法

针对错误原因提取效率低的问题, 提出一种利用克雷格插值对模型检测器产生的反例进行自动理解的方法. 该方法首先从反例失效状态出发推导出其最弱前置条件, 然后对初始状态与反例最弱前置条件进行不一致分析, 能在线性时间内提取克雷格插值作为反例失效原因, 产生的插值能直接用于定位错误事件. 实验结果表明, 基于克雷格插值的反例理解方法能显著提高反例理解速度, 提高软件的调试效率, 从而提升软件的可靠性和质量.     

反例在高等数学中的应用

在数学发展过程中,对于数学问题的探索,反例的作用往往是证明所无法替代的.因此,许多数学家从事于数学反例的研究.正确认识反例在高等数学中的作用,有利于人类更好地探索数学问题,认清数学问题的本质.本文详细阐述了反例在微积分、概率统计、线性代数以及解析几何这几个方面的应用,揭示了反例在高等数学中的重要性.     

哥德巴赫猜想成不成立均存在反例

本文证明了全序性成不成立均存在反例,许多猜想成不成立均存在反例（为不可证或存在悖论）.如哥德巴赫猜想成不成立均存在反例（为不可证或存在悖论）。奇完全数猜想成不成立均存在反例（为不可证或存在悖论）。     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the