普朗克常数测定的实验研究

对光电效应法测普朗克常数进行了理论分析,利用光电效应法测普朗克常数是一种简单有效的方法,在测量的过程中,传统的方法存在不小的误差,怎样尽量减小误差,解决传统方法无法克服的问题,是实验的关键。对实验数据进行处理,比较研究,探索测量的最佳条件。     

基于光电效应的普朗克常数的测定与分析

利用光电效应法测量普朗克常数是一种简单且有效的实验方法.在大学物理光电效应测量普朗克常数的近代实验中,采用PC-Ⅱ型普朗克常数测定仪对普朗克常数进行测定和分析.该文采用了上述仪器对普朗克常数进行了测量和理论分析,用"减速电位法"测遏止电压,应用数学中的斜率法进行分析,克服了传统实验的困难,实验操作可重复好.光电效应已经广泛地应用于各科技领域,利用光电效应制成的光电元件(如光电管、光电池)已成为生产和科研中不可缺少的器件.     

用光电效应测定普朗克常数的计算机辅助方法

分析了光电效应法测定普朗克常数的方法所存在的问题，给出了自动测定普朗克常数的计算机辅助方法。     

用光电效应测定谱朗克常数的计算机辅助方法

分析了光电效应法测定普朗克常数的方法所存在的问题，给出了自动测定普朗克常数的计算机辅助方法。     

Boltzmann方程的量子修正

讨论了经典玻尔兹曼分布函数的量子修正项及其满足的方程。我们将用于推导量子玻尔兹曼方程的梯度近似中的普朗克常数明显地写出，并且将量子Wigner分布函数用普朗克常数展开，经过推导就可以得到量子修正项所满足的方程。量子Wigner分布函数的普朗克常数展开式中的一阶和高阶项正好是量子修正项，它们可具有负值，而零阶项则具有正值。这样我们自然在量子Wigner分布函数中分离出正的分布函数，避免了用Husimi方法做粗粒平均取得正值的传统框架。另外我们也用量子Wigner分布函数普朗克常数展开的方法讨论了量子热力学熵的经典极限这一问题。     

一个奇妙的常数——h

综述性地分析讨论了普朗克常数－ｈ引入物理学领域的原因，指出ｈ虽然是在不同的物理学问题中出现，表面上看这些物理学问题好像没有什么必然联系，但大量事实揭示，任何物理问题的表达中，只要出现普朗常数－ｈ，就意味着这个问题的量子力学特征，若所研究的物理对象中普朗克数－ｈ可忽略，则这个问题便可以用经典物理理论来解决，那么微观领域中的物理问题为什么会与普朗常数有如此特殊的关系？它是否预示着更深层次的物理机制。     

外推法在光电效应实验中的应用与研究

在光电效应测量普朗克常数实验中,应用基于准爱因斯坦方程理论的外推法测量相应光电流接近于零时的"截止电压",并利用线性回归法计算直线斜率和普朗克常数。结果表明,普朗克常数测量值对应的相对误差平均值为0.6%,最小值可以达到0.10%。与零电流法相比,外推法能有效减少阳极电流的影响,从而获得更小的相对误差。     

普朗克函数的拐点光波长方程

基于普朗克公式,导出普朗克函数拐点光波长的普遍方程,并利用牛顿迭代法求出该光波长方程的2个根,找到普朗克公式中潜在的另外一个普适常数．     

用玻尔理论测量普朗克常数

提出用玻尔氢原子理论测量普朗克常数的原理和测量结果。     

基于热效应修正和指数函数拟合的光电效应法测量普朗克常数

光电效应法测量普朗克常数的理论依据是爱因斯坦光电方程,但该方程在绝对零度条件下才成立,而实验一般是在室温下进行。温度的影响必然会使计算结果存在一定的误差,为了减小这一误差,以金属阴极的光电效应为例,对普朗克常数测量原理进行热效应修正,引入了准爱因斯坦光电方程。理论推导得出一定温度下阴极光电流与反向电压呈指数函数关系,并在数据处理时采用指数函数拟合光电流-电压实验数据,再通过拐点法确定截止电压。计算结果表明,传统光电效应法的测量误差为14%,热效应修正后的测量误差为1.8%。     

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.     

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     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

正~~