关于酸碱滴定常数和条件滴定常数

在酸碱滴定中，滴定常数(Kt)和条件滴定常数(K‘t)是一个教学难点。作者就酸碱滴定常数(Kt)和条件滴定常数(K‘t)谈谈教学体会。     

关于滴定过程的讨论：酸碱滴定

本文阐述了各种类型酸碱滴定过程中，滴定百分数与氢离子浓度之间的关系式，导出了滴定过程中计算ＰＨ值的数学表达式，并应用于实例计算滴定突跃ＰＨ值。     

混合酸中强酸直接准确滴定的判断

以林邦（Ｒｉｎｇｂｏｍ）误差公式为基础,讨论了滴定强酸与弱酸混合酸中的强酸时弱酸强度及两酸浓度比对滴定准确度的影响,得出了强酸直接准确滴定的简明易行的判断方法。     

EDTA配位滴定曲线方程式的推导及应用

本文推导了配位滴定中金属离子浓度计算的方程式。并通过具体计算，说明了在稀溶液中进行滴定时，金属离子浓度的计算不适于采用教材上三段式的方法。     

强酸弱碱滴定终点误差计算

从教学角度介绍了分布系数及质子条件，主要讨论了强酸滴定弱碱终点误差的计算法。     

酸碱滴定和氧化还原滴定中准确滴定条件的探讨

本文根据滴定分析的误差要求,以滴定曲线突跃范围为依据,对酸碱滴定和氧化还原滴定中,能准确滴定的条件进行了探讨。提出弱酸(碱)滴定的条件为CK≥10~(-8);多元酸(碱)分步滴定的条件为Ka_1Ka_2≥10~5,氧化还原滴定的条件为E_1~(0′)-E_2~(0′)≥0.56伏,并相应进行了有关公式的推导。     

对数图在沉淀滴定中的应用

本文应用对数图讨论了沉淀滴定中的滴定突跃、指示剂浓度、ＰＨ控制范围和终点误差。     

配位滴定中滴定条件的确定

从配位滴定终点误差公式出发,提出一种图解方法,能准确、快速地确定配位滴定的滴定条件。     

关于滴定过程的讨论：氧化还在滴定

论述了氧化还在滴定过程中滴定百分数ψ与氧化剂（或还原剂）浓度之间的关系。导出了滴定过程，体系电位Ｅ值变化与ψ之间的新的数学表达式。     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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