采场结构参数敏感性正交数值模拟试验研究

采用正交数值模拟试验方法研究采场结构参数对采场稳定性的影响;建立基于指标满意度的多指标正交数值模拟试验综合评价模型,选取采场宽度、采场长度、人工间柱宽度、再造结构体弹模等因素,进行4因素3水平的正交数值模拟试验;选取顶板沉降位移、底板臌起位移、最大压应力、最大拉应力、塑性区共5个指标进行基于指标满意度的多指标综合评价及敏感性分析;结合云南某矿进行了实例分析,采场宽度、采场长度、人工间柱宽度、再造结构体弹模对采场稳定性的敏感度分别为0.050,0.132,0.315和0.074.研究结果表明:人工间柱宽度是影响采场稳定性最敏感也是最重要的参数,随着人工间柱宽度加大,采场趋向不稳定;采场长度和再造结构体弹模对采场稳定性有显著影响;采场宽度对采场稳定性的影响较小.     

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.     

大规模采场三维探测及回采指标可视化计算

针对我国金属矿山大规模采场回采指标难以准确获取的现状,综合运用空区激光探测系统(CMS)和大型矿床三维软件Surpac等数字化工具,结合凡口铅锌矿N3-4采场实际,研究一种新颖的大规模采场回采指标可视化计算方法.采用CMS探测三维采场空区,以宅区实测数据为基础运用Surpac构建采空区三维可视化模型,获取采场空区的三维形态和实际边界;运用采场设计资料,建立采场回采设计模型及矿岩边界模型,通过模犁间的布尔运算,计算出采场存留矿量、回采总体积、采下废石量、采下充填体最、采下纯矿石量、回采总量及回采贫化率等,从而有效地实现了大规模采场回采指标的可视化计算.研究结果表明:采用该方法计算获得的采场回采指标可靠,可用于矿山实际生产管理和同采质量评估.     

高位钻孔瓦斯抽采参数测评与优化研究

瓦斯抽采是从根本上治理煤矿瓦斯灾害的主要手段,由于其高效和安全的特性,高位钻场瓦斯抽采模式在现场应用日益广泛,但对于抽采参数的测评和优化却没有统一标准。本文分析了采煤工作面围岩裂隙场的分布特性与瓦斯抽采设计参数的相互关系,以现场高位钻孔瓦斯抽采实测数据为基础,采用四种方法对设计参数和抽采效果进行关联性分析,结果表明钻孔垂距、钻孔平距和钻场间距是影响瓦斯抽采效果的主要参数,在其优化区间内,瓦斯抽采效果会大幅度提高。论文研究结果对优化瓦斯抽采设计、保障采煤工作面安全生产具有一定参考意义。     

岩爆倾向矿床采场结构参数优化方法

讨论了有岩爆倾向矿床的采场结构参数的优化问题,以平均能量释放率为优化目标,将数值模拟与数理统计方法相结合,提出了深埋岩爆倾向矿床采场结构参数优化的一般方法．并简要介绍了为此目的而开发的计算机程序．采用作者提出的优化方法与程序,对某深埋岩爆倾向矿床的采场结构参数进行了优化研究,为该矿床的开采设计推荐了较优的采场结构参数     

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。     

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。     

复杂应力扰动下围岩稳定性评价与采场参数优化

夏甸金矿采矿活动已经进入深部，临近崩落法与充填法影响区域的采场受到多重扰动应力的影响，该区域围岩稳定性与采场尺寸的合理选取对矿山安全生产至关重要.采用先进的数字摄影测量技术，获取试验采场周围岩体结构面参数;并从多角度对采场围岩稳定性进行评价;在此基础上，运用Mathews图表法与跨度经验公式对试验采场的参数进行优化;最后，通过数值模拟，对得到的试验采场参数合理性进行分析与验证.图表法优化的采场尺寸在矿山开采的成功应用，验证了图表法在复杂应力下采场尺寸设计的可行性.     

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.     

二次动压巷道支护设计与参数优化

采用正交数值试验和灰色理论中的关联度分析,进行阳泉矿区二次采场巷道的分析与支护参数优化决策.选择13因素3水平的正交试验方案,进行27次试验,分析了不同应力状态和支护参数的巷道稳定性与变形特征.在计算中采用巷道稳定性和变形收敛率等多种评价指标,进行了局部优化;考虑支护成本和施工难易等因素,采用灰色理论,进行最佳方案的关联度分析.该研究已应用于阳泉矿区二次采场巷道支护设计,并取得较满意的支护效果.     

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.     

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.     

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