煤的渗透性研究

对南桐煤田的青年矿、鱼田堡矿和南桐矿煤样在不同应力状态下及不同电场下的渗透率进行了研究，得出了煤渗透率与有效应力和电场强度之间的关系。对了解煤的渗透特性、瓦斯涌出量预测具有一定参考价值。     

煤的渗透性实验研究

通过对南桐煤田煤样的渗透率进行实验研究，探讨了地应力、解吸瓦斯、温度、煤中水分对瓦斯渗透的影响。     

煤的结构模型及其电极化特征的研究

研究了采自四川鱼田堡、南桐和青年等三个煤太和的煤样的大分子结构，建立起了煤的结构模型。在此基础上对煤在外电场的极化特征进行了实验研究和理论分析，结果表明，转向极化和空间极化是引起通过煤样中的电流发生衰减的本质原因，且空间极化是煤极化的主要形式。     

注CO2对不同煤阶煤储层渗透率变化的影响

 研究CO₂注入煤层后与煤中不同矿物发生反应引起的渗透率变化规律,能够为提高煤储层导流能力提供实验支撑。通过对中、高煤阶煤样(屯兰矿、寺河矿)进行氮气吸附实验、矿物成分及渗透率的测试,探讨了注CO₂后,煤中不同矿物与其反应的渗透率变化规律以及渗透率改善效果;基于对初始渗透率、反应时间、改善后渗透率的非线性回归分析,建立渗透率变化模型。研究结果表明:注入CO₂后,由于发生CO₂-水-岩石相互作用,中、高煤阶煤渗透率均随注气时间增加呈现出先增大后减小的规律,寺河矿煤样先达到渗透率最大值,屯兰矿较滞后,寺河矿煤样渗透率改善效果比屯兰矿好。煤层中注入CO₂对初始渗透率过大或过小的煤层都不利于渗透率改善,只有渗透率在0.2×10^-3~0.4×10^-3 μm²的中等渗透率范围内,改善效果较好,渗透率变化模型经实验数据验证较可靠。     

CO_2对煤低温氧化反应过程的影响实验研究

为了深入研究CO2对煤低温氧化反应的影响,利用程序升温油浴实验装置,研究在不同CO2浓度下煤样的自燃特性。采集南屯矿煤样,破碎并筛分出混合平均粒径为4.18 mm的煤样,向试验管煤样中通入不同配比的混合气体,实验控制升温速度为0.3℃/min,供气量为190 mL/min.测定在6种不同浓度CO2气氛下的煤样低温氧化特性,实验结果表明:CO2浓度越高,煤样耗氧速率越小,CO产生率降低。在起始阶耗氧速率相差不大,煤氧复合作用以物理吸附和化学吸附为主,后期阶段以化学反应为主,变化明显。相比于空气气氛下,CO2气氛下煤样活化能有所提高,在40~100℃的温度范围内煤氧作用的活化能值由17.85 kJ/mol升高至22.71 kJ/mol,氧化反应速率降低,表明CO2的加入降低了煤的氧化反应速率,抑制了煤的氧化反应。     

煤的导电机理研究

本文用南桐煤田煤样研究了煤的导电性，并初步探讨了煤的导电性与煤大分子结构的关系．本文的研究结果对于煤的导电特性的研究及煤的气化均有一定的参考价值：图２，表３，参５。     

煤的瓦斯渗透性影响因素的探讨

对南桐煤田煤样的渗透率进行了实验室研究，探讨了瓦斯的解吸特性、温度、煤中水分对瓦斯渗透的影响，结果表明，在瓦斯无解吸的情况下，瓦斯压力降低，煤的渗透率也降低，然而在解析瓦斯压力作用下，煤对瓦斯的渗透率会增加，煤样瓦斯的渗透率的对数与温度成线性关系。含水煤样的渗透率明显低于干煤样的渗透率，随着含水量的增加，煤样瓦斯的渗透率减小。     

高温高压煤复电阻率各向异性实验研究

电阻率各向异性是影响煤储层电法勘探的重要因素,针对煤样复电阻率各向异性的参数评价,对焦作地区煤矿储层沿平行和垂直层理方向分别钻取了煤样,并在高温高压条件下测量得到了相应的复电阻率频谱。为了定量分析温度、压力对煤样复电阻率各向异性的影响,建立了煤样不同方向频散参数(界面极化频率、模值频散度、弛豫时间)与温度压力的对应关系,电阻率各向异性系数与温度、压力的对应关系。结果表明：平行层理方向频散参数均与温度、压力呈现良好的线性关系,垂直层理方向频散参数的线性关系不如平行层理方向好;任意方向煤样频散与温度、压力的响应关系都可以用弛豫时间来定量评价;随温度升高各向异性系数增大,随压力增大各向异性系数变化不明显。研究结果可为更精确地定量评价温度、压力对煤储层电各向异性的影响提供实验基础和理论参考。     

双鸭山集贤煤矿煤样自燃性程序升温实验研究

采用程序升温实验装置，研究双鸭山集贤矿不同粒度煤样在不同温度条件下与氧反应的特性。通过实验分析，得出双鸭山集贤矿煤自燃预测预报的主要指标气体为CO。通过计算得出不同粒度煤样的耗氧速度和CO，CO2，CH4等气体的产生速率，以及这些特性参数随煤温和粒度的变化规律。进而分析得出该矿煤样自燃的临界温度为65～75℃。为双鸭山集贤矿煤自然火灾的预测预报提供依据。     

大尺度冲击性煤体电阻率变化规律的实验研究

在未加载条件下对大尺度煤样的电阻率测试结果表明,在自然状态下煤样的电阻率较大;经过浸泡后其电阻率明显下降.在单轴压缩条件下的大尺度冲击性煤样电阻率实验表明,电阻率变化曲线整体上成不对称的"凹"型,基本符合二次曲线;煤样电阻率随压力增加逐渐减少,当达到一定的应力值时,电阻率达到最小值;继续加载,电阻率将升高,直到完全失稳.1#、3#和4#煤样单轴抗压强度与其受载过程中的视电阻率变化存在一定的正相关性;受载煤体的电阻率变化与其变形破裂过程中的裂隙分叉、发育、汇合贯通密不可分;兼有剪裂和拉裂特点的破坏类型可能是大尺度煤样较常见的破坏形式.     

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     

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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