Numerical calculation for gas and strata movement law caused by protection layer mining

According to the problem during mining coal seam with high gas and its control, the theory numerical calculation of gas and strata movement law caused by protection layer mining was studied, with the background of Snake Mountain coal mine. First of all, the basic principle of fluid (gas)-solid coupling was briefly described, and a three dimensional model was established by FLAC software. Secondly, the calculation parameters of fluid-solid coupling were obtained based on the measured data, and the numerical calculation of sublevel mining was carried out in turn. Lastly, initial stress state, gas movement law, deformation law of pore pressure and movement characteristics of rock strata were studied, respectively. The results show that the gas and pressure were greatly reduced with the advance of 4 coal seam working surface, as well as the constant increase of area of goaf. Facilitating gas and the stress were gradually penetrated and released to goaf during the whole process of mining. The gas pressure, the aggregation degree and the surrounding rock pressure of the 1 coal seam and the 3 coal seam were greatly reduced.     

圆锥、圆柱正交相贯线最右点的准确求法

利用计算机辅助设计给出了一种新的圆锥、圆柱正变相贯线最右点的求解方法。原有的方法求解圆锥、圆柱正变相贡的最右点，常利用侧视图中圆柱的积聚性，过锥顶作积聚圆的切线，再求出该切点在V面的投影，但这一方法求出的并非准确的最右点。利用解析方法对新方法进行分析验证。     

T形、十字形截面柱翼缘对轴压比限值影响的讨论

从异形柱大、小偏心界限破坏条件出发,导出了T形、十字形截面柱轴压比设计值的计算公式,讨论了翼缘对轴压比限值的影响,并给出了T形、十字形柱轴压比设计值取值的建议。     

Exact algorithm for bin covering

This paper presents a new arc flow model for the one-dimensional bin covering problem and an algorithm to solve the problem exactly through a branch-and-bound procedure and the technique of column generation. The subproblems occuring in the procedure of branch-and-bound have the same structure and therefore can be solved by the same algorithm. In order to solve effectively the subproblems which are generally large scale, a column generation algorithm is employed. Many rules found in this paper can improve the performance of the methods. Project(19971078) supported by Natural Science Foundation of China (NSFC).     

特色栏目:创建知名学术期刊的奠基石

特色是期刊的亮点、迷人之处,是期刊的生命力所在,也是期刊入选名栏、名刊的重要基础。期刊特色的培养应从栏目入手。特色栏目的创建,除遵循栏目设置的一般规律外,主要通过特色定位、特色巩固两个步骤来完成。     

柱下交梁基础宽度计算的精确性探讨

对柱下交梁基础宽度按传统的刚度分配法计算的不足予以分析,提出用增大系数对其进行修k正,并给出值的求解方法。工程实践表明,修正后的方法简明实用,且计算的精确程度符合设计规范要k求。     

新集一矿推覆体夹片下150801工作面防水煤柱留设可行性研究

新集一矿150801工作面位于阜凤下夹片断层下,8煤顶板距离上覆下夹片断层46～88m,在局部地段,采动后的导水裂隙带有可能波及下夹片断层带,导致夹片断层带水及夹片灰岩水涌入矿坑,严重危及150801工作面的安全回采。通过对夹片灰岩的分布规律、赋水性、8煤顶板岩性特征的分析以及涌水量和最大导水裂隙带高度的计算,综合评价150801工作面防水岩柱留设的可靠性。     

综放工作面采向控制及辅助调整方法

介绍淮南谢桥矿综合机械化放顶煤采煤合理采向控制和辅助调整支架及刮板输送机状态的方法。该方法经多个综放面的实际应用证明是科学合理行之有效的,这为综放工作面的安全生产和高产高效奠定了坚实的技术管理基础。     

石油焦与煤在循环流化床中混合燃烧时SO2排放试验研究

在一热输入为0.6MW的循环流化床燃烧中试装置上进行了石油焦与煤混合燃烧和脱硫试验研究，得到燃料中石油焦与煤质量混合比、过量空气系数、床层温度、一次风率和钙硫摩尔比等参数对SO2排放的影响规律，结果表明，混合燃料中掺焦比例越大，混合燃料的硫含量越高，SO2排放浓度越高；纯烧石油焦时SO2排放浓度最高，对不同配比的混合燃料，随过量空气系数、一次风率和Ca／S摩尔比增大，SO2排放浓度降低，830-850℃的床温对脱硫最为有利，在燃用石油焦与煤质量混合比尺为1和3的混合燃料时可获得最低SO2排放。     

稳定采掘一线职工队伍初探

采掘一线职工队伍的现状艰苦且较不稳定。究其原因,一线职工社会地位低,经济地位亦不高。要改变职工队伍现状,必须创造良好的工作环境,提高职工综合素质,完善劳动分配制度,提高机关服务效能,以稳定采掘一线职工队伍。