大柳塔煤矿12305工作面覆岩活动规律的相似模拟

为了研究薄基岩浅埋煤层开采过程中覆岩活动规律,利用相似材料模型法,对大柳塔煤矿12305工作面进行了相似模拟实验,得出了薄基岩浅埋煤层开采过程中覆岩活动特点.结果表明,薄基岩浅埋煤层开采的覆岩活动规律与常规开采顶板活动规律存在根本区别,应该有其自身的开采理论指导现场生产.     

榆树湾浅埋煤层保水开采三带发展规律研究

在分析陕西榆树湾煤矿浅埋煤层分层开采的水文及工程地质条件的基础上，对保水开采中覆岩破坏“三带”的发展规律进行了相似材料模拟实验研究．实验表明在基岩厚度较大的浅埋煤层开采中覆岩垮落不是整体切落，而是有“三带”存在；同时，实验揭示了其“三带”的高度、覆岩的下沉与采高的关系，表明在基岩厚度较大、隔水土层较厚的浅埋煤层中采用分层开采可实现保水开采，这为榆树湾煤矿保水开采提供了重要的科学依据．图3，表1，参8．     

厚土层薄基岩浅埋煤层"支架-围岩"关系实验研究

依据陕西南梁煤矿首个综采面煤层赋存特征及覆岩力学参数,对厚土层覆盖层下薄基岩浅埋煤层开采进行了大比例相似材料模拟实验研究,分析了额定工作阻力6 000 kN支架的运行特性,揭示了厚土层浅埋煤层开采上覆岩层的破坏规律及"支架-围岩"关系,研究认为厚土基浅埋煤层裂隙带高度比一般赋存条件下的煤层大,在实验支架初撑力频率分布与生产实际相似的情况下,实验得出的支架额定工作阻力比按一般赋存条件计算公式得出的支架阻力大许多,说明一般计算公式不适宜用于厚土层浅埋煤层.实验首次采用了力学特征与原型相似的恒阻模拟支架控制系统,研究为南梁煤矿综采面支架选型及开采提供了重要的科学依据.图5,表3,参8.     

浅埋深短长壁工作面矿压显现特征

掌握浅埋深短长壁工作面矿压显现特征,采用现场观测和数值模拟方法对荣达煤矿试采工作面进行矿压显现特征研究,分析了浅埋深短长壁工作面矿压显现规律及覆岩结构特征.研究结果表明:由于采高及工作面长度等开采参数较小,短长壁工作面开采后对顶板岩层的破坏程度有限,基岩层并未全部断裂至地表,上覆岩层中仍然可以形成稳定的承载结构.     

浅埋煤层开采中的溃沙灾害研究

分析了浅埋煤层开采的水文条件和工程地质条件，得出了浅埋煤层发生渍沙灾害必须具备的4个条件；根据浅埋煤层中组合关键层的一些参数分析了老顶破断岩块的运动规律，判断了浅埋煤层开采中岩块是否发生回转失稳，探讨了岩块回转触矸后发生滑落失稳的可能性，计算了断裂岩块端角接触面高度，得出了满足裂隙滤沙的合理端角接触面高度；大柳塔1203工作面开采只发生了涌水而未溃沙，这和理论计算的结论基本一致．参8．     

急倾斜煤层不同覆岩结构导水裂隙演化规律

基于龙湖煤矿南二采区急倾斜煤层的赋存和水文地质条件,采用离散元数值计算方法,分析了覆岩结构组合对急倾斜煤层开采导水裂隙演化规律的影响。结果表明:急倾斜煤层采场上覆岩层无关键层及覆岩结构组合为隔水-结构关键层时,导水裂隙分布呈"耳型"特征;采场上覆岩层存在结构关键层,直接顶为坚硬岩层和软弱的隔水关键层时,导水裂隙以平行于层面的离层裂隙为主;急倾斜煤层开采不同覆岩结构组合,导水裂隙发育高度均随煤层采厚的增加呈增大趋势,裂采比呈降低趋势。现场依据导水裂隙分布特征,设计了合理的防水煤柱尺寸和矸石充填注浆胶结顶板控制技术,确保了水体下急倾斜煤层的安全回采。     

沟谷区浅埋煤层覆岩破坏特征及地面裂缝发育规律

沟谷区浅埋煤层开采覆岩损害特征不仅受覆岩结构影响,同时受地形地貌特征影响。为进一步研究浅埋煤层过沟开采时覆岩运动及损害机理,以陕北浅埋煤层区某矿14210工作面为研究对象,通过建立物理相似材料模型,利用人工测量、变形监测、数据分析等方法,研究沟谷区浅埋煤层开采覆岩破坏规律及地表裂缝形成机理。结果表明:煤层覆岩沉降值曲线在垂向上具有向下继承性,顶板周期性垮落后沉降曲线呈"U"型,沉降值变化速率大的"U"型两侧区域纵向裂隙发育,周期性垮落体边界与自然平衡拱结构基本吻合,并周期性向前发展;地表裂缝可根据坡向与煤层采动方向的关系分为顺向坡推挤裂缝、逆向坡拉张裂缝和沟底隆起3种类型,不同类型裂缝具有不同的动态发育规律。研究成果为沟谷区浅埋煤层开采覆岩及地表损害预测提供了理论基础,对浅埋煤层过沟开采可能因覆岩及地表损害引起的矿井水害防治具有重要意义。     

密集建筑物下采煤覆岩关键层判定及应用

应用关键层理论指导密集建筑下急倾斜煤层的开采，分析了沛城密集建筑下覆岩关键层的判别方法，得出了覆岩各硬岩层的破断层，确定了覆岩中关键层的位置，为建筑物下急倾斜煤层的开采设计提供了理论依据。并成功地在密集建筑物下急倾斜煤层中进行了走向条带开采，取得了显著的经济效益和社会效益。     

采场覆岩的流固耦合损伤分析

在分析浅埋煤层中潜水渗流场与工程开挖应力场相互影响的基础上,建立了厚松散层富含潜水浅埋煤层组合关键层的岩体水力学模型;提出了流固耦合损伤因子,分析了采动覆岩中组合关键层在流固耦合损伤作用下的破坏规律。对浅埋煤层采场来压步距的计算公式进行了修正。以修正公式计算的大柳塔1203工作面的初次来压步距与实测非常接近。这证明该公式对于地表厚松散层浅埋煤层中的组合关键层的破断距计算具有一定的适应性。     

急倾斜煤层覆岩破断和裂隙演化的采厚效应

为了确保水体下急倾斜煤层的安全回采,基于龙湖煤矿南二采区急倾斜煤层的水文工程地质条件,采用相似材料物理模拟实验,分析了急倾斜煤层覆岩破断和裂隙演化的采厚效应.结果表明:急倾斜煤层开采顶板坚硬上覆岩层存在关键层时,顶板岩梁以层状破断为主,初次破断均形成“复合破断”;急倾斜煤层开采顶板岩梁初次破断后,覆岩裂隙向关键层及其上方岩层发育,不同采厚导水裂隙分布均呈“耳型”分布;随着急倾斜煤层采厚的增大,急倾斜煤层初次破断步距呈降低趋势,覆岩裂隙发育高度和初次破断厚度呈增大趋势.     

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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