煤矿综采工作面粉尘分布及运移规律研究

煤矿综采工作面产尘强度大,是煤矿职业病危害的重大隐患。为了研究综采工作面粉尘的分布规律,降低工作面粉尘浓度,改善工作面劳动环境,文中采用了理论分析和现场实测相结合的方法,分析了综采工作面的产尘特点及影响因素,对董家河煤矿22518综采工作面进行了粉尘浓度的现场实测,分析不同工序及不同地点粉尘浓度的分布及运移规律,结果表明:采煤机割煤是工作面最主要的尘源,移架居第二;割煤、移架时产生粉尘的运动趋势基本相同,先迅速增大,达到最大值后再迅速减小,最后达到稳定;采煤机割煤时下风向10~50 m空间的粉尘浓度最大,需要重点防治。实验测得的数据及得出的结论可为综采工作面制定防尘技术措施提供依据。     

涡流风幕抽吸控尘系统数值模拟与应用

涡流风幕抽吸控尘系统可有效控制气载粉尘的扩散.为了解决综掘工作面粉尘浓度过大的难题,分析了涡流风幕的形成机制,并根据气固两相流理论和气体-粉尘颗粒两相流动的特性,建立求解综掘工作面祸流风幕抽吸控尘流场粉尘扩散规律的k-ε-θ-kp数学模型;采用基于同位网格的Simple算法,利用Fluent软件对综掘工作面粉尘浓度的空间分布规律进行了数值模拟,模拟结果显示,涡流风幕抽吸控尘流场能有效地将粉尘封闭在掘进头至掘进机司机前方0.5m的空间内.根据模拟结果和工作面现场的实际条件,设计了由附壁风简和抽尘净化装置构成的综掘工作面涡流风幕抽吸控尘系统,该系统在综掘工作面应用后,有效地降低了工作面现场的粉尘浓度.     

综放工作面粉尘产生及分布规律研究

本文采用现场实测的方法研究了综放工作面粉尘产生及分布规律,得出了有益的结论,为综放工作面制定防尘措施和测尘方法提供了依据。     

受料点密封负压袋式除尘机理分析

针对选煤厂输运皮带受料点处粉尘污染严重的问题,研究了密封负压袋式控尘机理.通过数值模拟和现场实测相结合的手段,采用颗粒运动方程理论,对各粒级粉尘颗粒分别受气流变化的运移轨迹进行研究.结果表明:粒子追踪技术可以实现除尘效率的量化分析,采取治理方案前后粉尘质量浓度的量化模拟数据和现场实际实测数据相一致,显示全尘和呼吸性粉尘质量浓度除尘效率分别达到95%和93%以上;密封负压袋式控尘方法能有效降低输运皮带受料点区域粉尘质量浓度,保障作业人员的健康.     

多径向涡形风控制岩巷综掘面粉尘污染分析

针对岩巷综掘面粉尘质量浓度高且难以控制的难题,利用数值模拟与现场测试相结合的手段分析了多径向涡形风控制岩巷综掘面粉尘污染规律.结果表明:多径向涡形风应用后,压风量、压抽比越小,越利于形成轴向指向迎头流动且风速均匀的控尘风幕;压风量越大,压抽比越小,50mg/m3以上粉尘扩散距离越小,并得出了随压风量、压抽比变化的函数关系;压抽比为0.75时,形成的控尘风幕较优,高质量浓度粉尘扩散距离为3.4m,掘进机司机处粉尘质量浓度为19.6mg/m3,且易于现场应用.现场测试与数值模拟结果基本一致,应用多径向涡形风且压抽比为0.75时,距迎头5.5m断面测点的粉尘质量浓度已降至18.9mg/m3以内.     

皮带运输巷道粉尘质量浓度分布规律的数值模拟

为了掌握皮带运输巷道粉尘质量浓度的分布规律,获取通风除尘设计的合理参数,以西石门铁矿提升车间系统40#皮带运输平巷为研究背景,依据气固两相流理论,运用计算流体力学的离散相模型对皮带运输巷道粉尘质量浓度进行数值模拟,并与现场实测的粉尘质量浓度分布情况进行对比分析,模拟结果与实测数据基本吻合.研究表明,运用欧拉--拉格朗日法对皮带运输巷道粉尘质量浓度分布规律进行模拟是可行的.在通风除尘设计中,当巷道风速为3 m.s-1时,排尘效果最好,粉尘质量浓度整体保持在3 mg.m-3以下;皮带运输速度为2.5 m.s-1时粉尘质量浓度较低;定期进行壁面洒水也能在一定程度上实现降尘目标.     

露天矿山运输路面复合抑尘剂的研究

针对露天矿山运输路面的扬尘问题,对复合抑尘剂进行了研究及现场应用.通过理论分析和实验,研制出两种性能优良的复合抑尘剂,并对这两种抑尘剂进行了性能测试和对比分析.采用FLUENT软件,对露天矿山运输路面的粉尘运移规律进行了数值模拟,确定了最佳粉尘监测点.现场实验表明,本文研制的复合抑尘剂能使粉尘质量浓度控制在4mg.m-3以下,有效抑尘时间为6 h.     

煤矿综掘工作面高效喷雾降尘系统

在煤矿生产过程中,粉尘是困扰着安全生产的重大灾害之一.对于煤矿综掘工作面粉尘防治工作,重点是针对截割产尘源.为了降低工作面粉尘浓度,改善工作面劳动环境,通过分析综掘工作面粉尘的主要来源和现场测试综掘巷道粉尘浓度的分布规律,在传统综掘工作面高压喷雾降尘的基础上,提出了2种改进的综掘工作面高效喷雾降尘方案.方案1使用增压水泵,设计一台体积小、重量轻的水泵泵组,安装在掘进机机身上,通过增压水泵的特定转换,获得高压水;方案2使用掘进机上的液压油,驱动一台以液压水泵为核心的增压泵,获得高压水.2种方案均克服了传统方法的缺点和不足,结合抑尘剂配比装置,在实际应用中取得了良好的降尘效果,降尘率最高达到了84%.     

综采割煤粉尘运移影响因素的数值模拟

为解决综采割煤粉尘质量浓度高的问题,获取粉尘控制的合理参数,改善作业环境,以邢东矿2225工作面为研究背景,依据气固两相流理论,运用Fluent软件对综采工作面割煤粉尘运动规律进行数值模拟,并与现场实测的粉尘质量浓度分布情况进行对比分析,模拟结果与实际数据基本一致.研究结果表明:工作面风速、采煤机滚筒转速、溜子速度以及壁面条件是影响综采工作面粉尘质量浓度分布的几个重要因素.当工作面平均风速在1.4m·s-1,滚筒转速不超过2.5rad·s-1,溜子速度不超过1.5m·s-1,防降尘效果最佳.同时洒水保持煤壁湿润也起到一定的捕尘作用.     

石棉筛分车间粉尘质量浓度分布规律的数值模拟

为了掌握石棉选矿厂筛分车间内部粉尘随时间和空间运移的规律,获取通风除尘优化的参数,以茫崖石棉矿第一选矿厂筛分车间为研究背景,依据气固两相流理论,采用计算机流体力学的离散相(DPM)模型对筛分车间粉尘浓度分布规律数值模拟,并与现场粉尘浓度实测数据比较分析,模拟结果和实测数据相吻合.研究结果表明:筛分设备附近粉尘浓度较高,以筛分设备为中心随着距离增加粉尘浓度降低;捕集边界下粉尘浓度比反弹边界较低,粉尘捕集效果更好;筛分车间进风风速控制在0.6m/s左右时,粉尘沉降效果较好;安装抽风集尘罩后,主抽风管风速为14 m/s时,平均控尘效率达到90%,石棉纤维浓度控制在2.52f/mL以下.     

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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