阶段嗣后充填采场结构参数的多目标多属性优化

为确定某金矿阶段嗣后充填采场最优开采参数,采用弹性厚板理论,分析不同跨度下顶柱厚度与最大拉应力的关系;结合矿山实际开采条件,通过中心复合试验设计及数值模拟计算得到不同结构参数下的力学响应;构建最大拉应力、最大压应力和最大竖向位移的二阶响应面模型,研究各响应量之间的关系;通过多目标优化及多属性决策的方法最终实现采场结构参数的综合优化。研究结果表明:顶柱最小厚度为4.00 m;矿柱跨度及顶柱厚度对采场力学响应产生显著影响,采场最优开采尺寸是矿房跨度为29.90m,矿柱跨度为31.40m,顶柱厚度为5.24 m。     

中深孔崩矿阶段嗣后充填法采场结构参数优化

为获得合理采场结构参数,实现山东莱州望儿山金矿中深孔阶段崩矿嗣后充填法的安全高效开采,采用弹性薄板理论,分析不同跨度下顶板应力与厚度的关系,确定合理的开采参数范围;结合矿山实际开采条件,通过中心复合试验设计,采用数值模拟计算得到不同结构参数下的力学响应;基于二阶响应面法建立最大拉应力、最大压应力和竖向最大位移的回归模型;将回归模型作为目标函数,采用遗传算法进行多目标优化,获得Pareto最优解集。研究结果表明:根据工程实际需要,矿房跨度为26.0 m、矿柱跨度为28.0 m及顶板厚度为6.7 m为开采最佳结构参数。     

无底柱深孔后退式崩矿法采场结构参数优化

为实现某铅锌矿山无底柱深孔后退式崩矿法安全高效开采,开展采场结构参数优化研究.实测-650 m中段原岩应力,运用Surpac-FLAC3D模型生成技术构建数值分析模型,进而采用多元应力回归方法反演初始地应力场.通过弹性力学小薄板理论分析得到顶板稳定性随采场结构参数的变化关系,结合实际采准条件,提出采场结构参数初选方案.基于反演地应力场,进行初选方案开采数值分析,获得各方案力学响应指标.引入多目标理想点法决策,考虑安全和经济指标,计算方案评价指标集与理想解的向量近似度,优化确定该矿无底柱深孔后退式崩矿法采场结构参数为矿房采场宽10 m,矿柱采场宽8 m.     

倾斜中厚矿体采场宽度优化

采用弹性力学分析得到顶板受力状态与采场宽度的关系,在计算所得采场安全开采最大宽度为12.1 m的基础上,结合矿山实际开采条件,提出采场结构参数初选方案;运用数值分析方法模拟获取不同结构参数下采场的力学响应特征;采用多目标决策理想点法综合考虑安全和经济两大因素,计算各方案评价指标集与理想解的向量相似度,得到各方案的优越度排序,最终实现采场结构参数的综合优化。研究结果表明:在开挖过程中,最大压(拉)应力与矿房宽度和矿柱宽度成正比,塑性区体积与矿房宽度成正比,安全率与矿房宽度成反比;矿房宽为12 m、矿柱宽为8 m的方案为综合考虑安全与经济因素的开采最佳结构参数方案。     

高含泥破碎矿体中基于预加固注浆的采场支撑体系优化

为解决汤丹铜矿4号矿体含泥量高、矿石回收率低及回采安全性差等问题,优选MP364化学树脂对其进行采前预加固注浆;首先,通过理论分析与现场注浆试验确定合理的注浆参数,并根据室内力学试验确定注浆后矿岩的力学参数;然后,对采场支撑体系进行研究并以矿柱宽度B与矿房宽度W为因素,基于正交设计确定9种采场结构参数;接着,分析不同方案的矿柱安全系数,并利用ANSYS与FLAC 3D等软件对地表岩移等指标进行数值模拟;最后,基于安全性考虑确定最佳的采场结构参数。研究结果表明:按推荐的注浆及采场结构参数开采的效果较好,放矿过程中矿石含泥量大大降低,矿石回收率与炮孔成孔率分别比矿山原有方案提高4.7%与20%,且注浆至今无发生空区垮塌或变形等情况。     

破碎围岩条件下采场留存矿柱稳定性分析

采用岩体分级方法(RMR法)、Q系统和地质强度(GSI)指标对矿岩进行了工程地质评价,并通过扩展后的Hoek--Brown节理强度准则进行岩体力学参数确定.根据白羊矿段矿柱布置形式,推导出矿柱荷载公式,并确定了矿柱强度计算参数.针对井下矿柱主要破坏形式分别进行失稳机理分析.将正交设计法引入采场结构参数优化分析中,对各开采方案进行了三维数值模拟.运用正交极差分析法对矿柱稳定性影响因素敏感度进行评价.实践结果表明:采场高度控制在3.5～4.5 m,矿房宽度取值不大于5 m,矿柱直径不小于3.5 m留存矿柱稳定性基本能得到保障.     

人工砼柱置换残留矿柱采场结构参数优化

为了安全经济地回收某矿山已充填采场中的残留矿柱,根据矿山特殊的地质条件和残矿资源赋存状况,提出人工砼柱置换残留矿柱的回采方案。运用三维有限元模拟软件MIDAS/GTS建立采矿模型,模拟采矿过程,分析在采矿作业扰动下不同结构参数采场顶板围岩、矿柱和人工砼柱的稳定性,结合经济因素对拟选的5组采场结构参数进行优化选择。研究结果表明,采场最大拉、压应力随人工砼柱尺寸的增大而减小;最大拉应力位于上盘围岩顶板中央,是影响采场整体稳定性的主要因素;模型4最大拉应力0.474 MPa,远小于其抗拉强度1.57 MPa,安全富裕系数大,经济合理。最终确定矿山置换残留矿柱的人工砼柱尺寸为3.5 m×3.5 m。     

大汉石膏矿开采技术改进研究

确定合理的矿柱尺寸直接关系到矿井的安全和高效生产,通过数值模拟分析软件UDEC4.0对矿层的开采方法进行优化分析,在采场围岩稳定的条件下,确定矿房宽6 m与矿柱宽6 m的方案为最优方案,采出率比现场实际方案提高12.9%.     

石人沟铁矿北区采场结构参数的优化

唐钢石人沟铁矿目前处于露天转地下开采过渡期,亟需确定合理的地下采场结构参数.本文首先在岩石力学试验的基础上估算了岩体力学参数,采用三维有限元数值模拟方法对采场结构进行了研究,得出了地下开采时不同采场结构参数下采场的应力和应变情况,并以此为依据对其稳定性进行了分析,最终确定了最优方案,确定了石人沟北区合理的采场结构参数.     

缓倾斜薄矿体采场伪倾斜布置及参数优化研究

为了实现高效低成本开采缓倾斜薄矿体的目标,基于对缓倾斜薄矿体开采方法以及铲运机运距的研究,利用数学方法定量分析了伪倾斜采场布置中的各个采场参数之间的关系,得到各采场参数之间的数学公式,为生产实践确定采场参数提供了理论参考标准。针对国内某矿山1～9号缓倾斜薄矿体,在伪倾斜布置理论分析的基础上,运用正交试验方法对矿山采场参数的确定进行优化定量研究,选出最优的采场参数布置方案以及各因素影响采场指标值(采矿生产能力和采场成本)的权重大小,确定最优方案为A2B2C1,即矿体伪倾斜布置方向与矿体倾向夹角为45°、采场宽度8 m、采场沿倾向长度50 m。改善了传统采场参数的定性确定,提供了科学、准确、定量的理论判定依据,使得采场的生产能力得到提升以及采准工程的布置成本减低。此优化方案可推广应用到类似矿山。     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has