多位小数的分类逼近法

本人多位不数可以用一个分数来近似表示，即采用多位小数的分数逼近法，按一定的程序，可使误差越来越小，直至达到所需的精确度。文中应用此方法，发展了圆周率的分数近似，并发展了中国古代乐律学中三分佃律加黄钟律的问题。     

小数知识点点通

正一、认识小数1.小数的含义:小数是分母为10、100……的分数的另一种表示形式。一位小数表示十分之几,两位小数表示百分之几。如:0.8表示810,0.12表示12100。2.小数的读法和写法:读小数时,整数部分按整数的读法来读(整数部分是0的读作"零"),小数点"."读作"点",小数部分一般顺次读出每个数位上的数字。如:0.12读作零点一二。     

关于单位分数的一个猜想

证实了一个有关单位分数的十进制小数的猜想.     

分数阶控制器离散方法的评估策略研究

针对分数阶控制器数值计算和应用难的问题，提出了分数阶微积分算予数字实现方法的评估策略，分析了分数阶微积分算予的多种数值计算法的机理和实现步骤．引入一个位置控制系统作为分数阶控制对象，将Mittag-Leffler函数的全记忆长度分数阶控制系统作为评估基准，提出了一种离散算法的近似性能函数，通过时域误差分析以及近似性能分析，对比研究了分数阶微积分算子的数字实现方法．研究结果表明，幂级数直接离散法得到近似离散模型需要记忆长度为100方可获得较好的近似，而连分式直接离散法近似离散模型为10阶时就可以获得较好的近似，因此连分式直接离散法比较适合于分数阶控制算法的实际工程应用．     

以“无名”命“微数”——论中国十进制小数的起源与发展

探讨中国古代分数的起源情况及其发展成为十进制小数的历史过程.找出中国古代分数的不同起源,结合古代历法讨论分数的广泛使用与十进制小数发展.中国古代分数起源于比例关系、度量分割及整数除法,其应用十分广泛,且形成一整套关于分数的理论.中国的十进制思想早已有之,其真实意义在于以"无名"命"微数".但由于中算数学追求数值算法的高精度性,使得现代意义下的十进制小数直到宋元时才出现.     

浅谈近似值的取值方法

通常情况下求近似值的取值方法都是“四舍五人”法。如：125600省略万后面的尾数是13万，而124300省略万后面的尾数是12万。但值得注意的是求近似值必须按要求保留有效位数。如：2．9998保留三位小数是3．000，保留两位小数是3．00，保留一位小数是3．0，保留整数是3。又如：2．0004保留三位小数是2．000，保留两位小数是2．00，保留一位小数是2．0，保留整数是2。前面两个例子中的几个数值，表面上看是一样的，其实表示的意义不同，只是它们的近似值相等。[第一段]     

一类具有非局部条件的Sobolev型Hilfer分数阶发展方程的偏近似可控性

研究了Hilbert空间中具有非局部条件的Sobolev型Hilfer分数阶发展方程的偏近似可控性。 通过使用变分法和近似法，构造了控制系统的近似解算子并得到了近似解集的紧性。 在非局部函数不满足Lipschitz条件的情况下，得到了控制系统偏近似可控的充分条件。     

分数阶常微分方程初值问题的高阶近似

对于整数阶常微分方程的数值解法,如欧拉法、线性多步法等都已有较完善的理论.而对于分数阶微分方程数值方法和误差估计的理论研究相对较少.在这篇文章中,我们考虑最简单的分数阶常微分方程,引进了分数阶的线性多步法,导出了分数阶常微分方程初值问题的高阶近似,证明了其方法的相容性和收敛性,并且给出了稳定性分析.最后给出了一些数值例子,证实了这个分数阶线性多步法是解分数阶常微分方程的一个有效方法.     

同符号数相加“大数吃小数”的界限:数值试验

利用大量数值试验,得出机器单双精度下关于两同符号数相加时"大数吃小数"界限的数据.对试验数据进行分段线性拟合,给出"大数吃小数"界限的近似公式,与试验数据比较表明近似公式具有良好的估计效果,可为单双精度下避免"大数吃小数"现象提供可靠的依据.进一步,将机器单双精度的结果推广至任意机器精度,得到的结论可方便应用于实际的数值运算中.     

一类带有时滞的Sobolev型Hilfer分数阶非自治发展方程的近似可控性

研究了Hilbert空间中带有时滞的Sobolev型Hilfer分数阶非自治发展方程的近似可控性.在其对应的线性系统是近似可控的这一假设下,通过使用分数阶微积分理论、半群理论、不动点定理,得到了控制系统近似可控的充分条件.     

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