程潮铁矿联合开采时回采顺序的数值模拟优化

程潮铁矿的矿体随着开采深度的增加而逐渐西移,导致选矿车间下保安矿柱所占矿量不断增多,故拟采用联合开采方法回收-430~-500m阶段矿体:充填法回收选矿车间下预留保安矿柱;无底柱分段崩落法开采保安矿柱以外的其他矿体。为了研究联合开采时回采顺序对地表稳定性的影响,采用数值模拟方法得到不同回采顺序下地表监测点的垂直位移,确定地表沉降最小且施工组织容易的回采顺序组合为最优方案,即充填法采用"中-左-右"以及无底柱分段崩落法采用"左-右-中"的回采顺序。模拟开采结果表明,在该回采顺序方案下,选矿车间区域的地表稳定性、充填采场及隔离矿柱的安全性均满足要求。     

大直径深孔高阶段采场稳定性及回采工艺技术分析与研究

翠宏山铁多金属矿采用大直径深孔高阶段采矿法回采矿房、矿柱，阶段高度120m。本文对矿区岩体特性、采矿方法进行了阐述，重点就采场结构参数、充填体稳定性等关键技术问题及相关回采技术措施进行分析。     

松散破碎矿体采矿方法探讨

在地表不允许崩落的情况下,松散破碎矿体回采,不能采用崩落法和空场法,而胶结充填成本又太高.文章以大宝山矿2#主井②矿体为例提出采用胶结充填回采矿柱、干式充填回采矿房,连续采矿、分步实施的采矿方法,就采矿工艺、充填方法、安全保障措施进行探讨,与传统方法相比,在安全、效率、成本、回采率、最低可采品位等多项安全、技术经济指标上取得了成效,具有一定的推广应用价值.     

深部回采矿柱稳定性影响因素分析及其应用

为研究深部回采过程中矿柱稳定性影响因素的敏感程度,在保证矿柱安全的前提下,科学设计合理的矿柱宽度至关重要。以黑良山磷矿为研究背景,分析深部回采矿柱承载机理、失稳形式和主要影响因素,运用普氏理论和BIENIAWSKI矿柱强度公式推导方形矿柱的安全系数计算公式。设计基于正交试验的极差分析法对矿柱稳定性影响因素的敏感性进行分析,并研究矿柱安全系数与主要影响因素之间的关系。结合黑良山磷矿工程实例,计算深部开采中矿柱的合理宽度。研究结果表明:对矿柱稳定性影响最显著的因素为矿柱宽度、矿房宽度和矿柱抗压强度;矿柱安全系数随矿柱宽度的增加呈幂函数递增,随矿房宽度的增加呈负指数递减,随矿柱抗压强度的增加呈线性函数递增;验证了所计算的深部开采中矿柱宽度的合理性,可为深部开采中矿柱合理宽度设计提供依据。     

深部厚大矿体回采顺序设计及优化研究

针对高应力环境下的深埋厚大矿体，开展安全高效回采顺序设计及优化研究，基于产能、技术和经济指标要求，提出了5种合理的矿房回采顺序和4种矿柱回收顺序，并利用FLAC3D进行数值计算分析.计算结果表明:在回采矿房的5种合理方案中，先开采1#，5#，9#，16#，12#矿房，后开采3#，7#，10#，14#，18#矿房的“大间隔分散布置”的方案，应力集中程度最低，位移变化最小，采场安全性最高，即为矿房的最优回采顺序；在回收矿柱的4种合理方案中，先回收2#，6#，11#，15#矿柱，后回收4#，8#，13#，17#矿柱的方案，应力集中程度最低，采场安全性最高，为最优回采顺序.比较不同方案的应力分布规律和顶板位移变化规律，可以看出，盘区内采场回采后，压应力向盘区中央的矿柱迁移，在盘区内间柱处产生应力集中区，易导致间柱内采准巷道发生变形及顶板垮落现象，需加强支护工作.     

挂帮矿充填法开采对高陡边坡及采场围岩稳定性的影响

以大冶铁矿高陡边坡下2#挂帮矿回采为工程背景,首先采用GEO--SLOPE软件对挂帮矿开采中边坡稳定性进行了分析;然后通过现场监测及模型相似实验相结合的手段,研究矿柱及围岩的应力及位移变化规律,探讨了挂帮矿充填法开采对采场围岩稳定性的影响.研究表明挂帮矿所在露天初始边坡经过扩帮及内部开采后,安全系数平均值由1.274下降至1.005,边坡稳定性较差;目前空区采场矿柱及围岩稳定性较好,但必须对现有采空区进行充填,改变空区及矿柱应力集中状态,才能进行矿柱及顶底板矿石回采.     

水泥尾砂充填体劈裂拉伸破坏的能量耗散特征

应用INSTRON刚性伺服试验机对不同灰砂比的充填体进行了劈拉试验,测得荷载-位移和应力-应变全曲线.结合测得的力学参数计算出相关能量耗散特征参数,分析了不同情况下破坏过程的能量耗散变化规律,并通过数据统计回归建立了各种能量耗散指标与其影响因素的函数关系.实验结果显示:充填体只需吸收极少能量即可满足拉伸破坏所需,拉伸破坏是影响充填体断裂性质的主导因素.为防止充填体处于受拉环境,在矿房回采时应采用边孔控制爆破和不耦合装药,优化爆轰波破岩途径,减少欠挖超挖,保证矿柱形态规整,使充填体处于非拉区域以改善其受力状况;同时在矿房充填时应对需布设工程或应力集中区域等关键部位适当加大灰砂比,以增强充填体吸收破坏能量的能力.     

基于ＦＬＡＣ３Ｄ数值模拟厚大矿体开采方案与采场稳定性研究

针对淮南某厚大铁矿-500 m中段采场回采,应用FLAC3D建模并进行开挖模拟.对不同开采方案中采场稳定性进行研究分析表明:采场开挖后,在采场四周角落处应力集中最大,易产生剪切破坏,在顶板中央发生位移变形最大,采场顶板容易垮塌;采场长宽为30 m×30 m时,采用两矿房或三矿房同时回采,采场保持稳定,最大应力集中系数为1.5,矿岩自身强度满足自稳要求;采场长宽为40 m×40 m,三矿房同时回采时,由于采空区暴露面积过大,集中系数达1.7,顶板受拉且充填体受压发生剪切破坏,矿岩不足以维持自稳状态.在大规模开采条件下,最终选定采场参数30 m×30 m三矿房同时回采为矿山开采方案.     

基于FLAC~(3D)数值模拟厚大矿体开采方案与采场稳定性研究

针对淮南某厚大铁矿-500 m中段采场回采,应用FLAC3D建模并进行开挖模拟.对不同开采方案中采场稳定性进行研究分析表明:采场开挖后,在采场四周角落处应力集中最大,易产生剪切破坏,在顶板中央发生位移变形最大,采场顶板容易垮塌;采场长宽为30 m×30 m时,采用两矿房或三矿房同时回采,采场保持稳定,最大应力集中系数为1.5,矿岩自身强度满足自稳要求;采场长宽为40 m×40 m,三矿房同时回采时,由于采空区暴露面积过大,集中系数达1.7,顶板受拉且充填体受压发生剪切破坏,矿岩不足以维持自稳状态.在大规模开采条件下,最终选定采场参数30 m×30 m三矿房同时回采为矿山开采方案.     

浅部采场地压的试验研究

本文根据龙头锰矿李家背矿段试验采场室内模拟试验结果,和现场试采了一个采场(上部),三个矿房(下部)的初步观察,分析研究了覆岩厚度六十余米时,开采缓倾斜(8°～12°)矿层采场围岩移动的特点和矿柱承压的性态。试验研究表明,采场顶板岩层的稳固性土要受岩层层面、节理、裂隙的制约;全面法采场中留下的不规则矿柱,承压大,且随顶板暴露面积和时间的增加而增加;在开采多层近距矿层时,上下对齐地留设矿柱,利于回采作业的安全。     

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。     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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     

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