煤的燃烧热和氯离子含量测定

把燃烧热测定和氯离子含量测定两个实验结合起来,设计了一个物理化学综合实验．分别用氧弹燃烧法和氯离子选择电极法测定了无烟煤和烟煤两种煤样的燃烧热及氯离子含量．结果表明：无烟煤的燃烧热比烟煤高,而氯离子含量比烟煤略低．     

混凝土外加剂中氯离子和总碱量的测定

用氯离子选择电极法测定外加剂中氯离子含量,测定值与电位值之间的线性关系良好,回归系数高达0.9986;以FP-640火焰光度计测定总碱量,方法简便、迅速、测定结果准确,实用性强.     

混凝土渗透性影响因素的研究

以水泥混凝土的基本配制原理为基础,配制了不同水胶比的高性能混凝土及与其相对应的基准混凝土.采用ASTMC1202方法测定其28d龄期的氯离子渗透通过的电量和氯离子渗透系数,同时测定了表面涂刷有机硅防水涂料的相应对比组试件的氯离子渗透通过的电量和氯离子渗透系数.     

CODCr测定中氯离子的干扰及消除方法研究

通过实验研究氯离子对CODCr测定的干扰程度，采用硫酸汞掩蔽法，氯离子扣除法．稀释倍数法等方法去除氯离子的干扰，最终确定出处理的最佳方案是在不掩蔽氯离子条件下，对水样中氯离子产生的CODCr值进行扣除、且实验证明此种方法对实际水样同样适用。方法适用氯离子范围为0～8000mg/L。     

两种示踪物对配合饲料混合均匀度的影响

以配合饲料中氯离子和总磷为示踪物,通过对成都丰达饲料有限公司生产的仔猪配合饲料3批次(每批次10个样品)混合均匀度测定.测定结果显示:两种示踪物测得配合饲料混合均匀度的CV分别为1.22%、2.24%、2.40%和0.72%、2.20%、2.38%.符合国家对配合饲料混合均匀度CV≤10%的要求.配合饲料氯离子和总磷测定中所绘制标准曲线的相关系数R2为0.9982和0.9999,说明氯离子选择电极法和钒黄比色法测定均准确、可靠,且钒黄比色法较氯离子选择电极法具有相关系数更高、重现性更好、操作更简单和易于在生产实践中实施的优点.     

修补砂浆海水侵蚀性能试验研究

对处于氯离子和硫酸盐侵蚀环境下的水泥砂浆,由于环境介质中含有较多的氯离子和硫酸根离子,导致水泥砂浆极易受到氯离子和硫酸盐侵蚀而破坏,本章主要研究含有氯离子和硫酸盐的溶液对水泥砂浆的侵蚀,采取溶液浸泡的方法测定一定龄期后水泥砂浆的抗压、抗折强度的变化。     

快速测定水泥混凝土及其原材料的氯离子含量

水泥混凝土及其原材料中氯离子含量影响钢筋混凝土的耐久性能。采用标准滴定法测定水泥混凝土及其原材料中氯离子含量,步骤复杂繁琐,试验时间长;该文选择电极法,使用快速测定仪测定水泥混凝土及其原材料中氯离子含量,经与标准方法及标准溶液比对,该方法测试结果准确可靠,可以应用于生产和试验中,推荐编入试验规范。     

低浓度污水中CODcr测定的干扰因素和消除方法

CODcr的测定在水质监测中有重要意义,水体中氯离子及颗粒悬浮物对测定结果有很大干扰。氯离子的存在使CODcr值可偏高也可降低,颗粒悬浮物的存在使CODcr值明显偏高。在水样测定时分别采取加硫酸汞和静置法可使CODcr测定结果更准确。     

重铬酸盐指数法测定CODcr过程中氯离子干扰的疑问和探讨

本文对GB/T 11914-89《水质化学需氧量的测定重铬酸盐指数法》测定化学需氧量时在实验过程中把氯离子作为干扰进行掩蔽提出了疑问。根据GB/T 11914-89《水质化学需氧量的测定重铬酸盐指数法》的定义,氯离子不应成为干扰部分而掩蔽,相反氯离子作为在反应过程中消耗重铬酸盐的还原性物质,应该成为最后计算结果的一部分。因此,在整个测定过程硫酸银不适合作为催化剂,硫酸汞也无需作为掩蔽剂存在,它们会与氯离子产生反应降低计算结果。本文同时也对一些专家在催化剂的替代方面的研究成果进行了综述。     

屏蔽氯离子干扰高盐榨菜废水中COD的测定方法

高盐废水中氯离子的存在会严重干扰COD的测定,因此,如何屏蔽氯离子干扰准确测定其COD的难点之一。为研究高盐榨菜废水中更为准确的COD测定方法,实验中采用了2种屏蔽氯离子的方法：硫酸汞屏蔽法和硝酸银屏蔽法,屏蔽后再通过传统回流冷凝法来测定实验模拟配水水样中的COD,并比较两种方法的屏蔽效果。结果表明：硫酸汞屏蔽法的最佳HgSO4/Cl -值为40,此时误差最小,为1.43%,硝酸银滴定法的误差为0.21%,得出硝酸银屏蔽法的屏蔽效果较好;再分别用这两种方法屏蔽榨菜废水中的氯离子后测定其COD值,结果显示两种方法测定的COD相差了20 mg/L,而硫酸汞屏蔽法更适合于榨菜废水中COD的测定。综合以上2种方法的屏蔽特点,采用先用硝酸银滴定氯离子浓度,再添加少量的硫酸汞的联合方法测定榨菜废水中的COD值,结果表明此方法更可靠。     

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

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