“两硬”条件下分层放顶煤开采矿压规律研究

针对“两硬”条件,下分层放顶煤开采的实际,系统总结了下分层放顶煤开采矿压显现规律,包括支架工作阻力、初撑力、来压步距,为放顶煤开采提供理论依据。     

生物浸出技术的发展及其电化学研究现状

微生物浸出技术具有可处理对象丰富、过程简单、能耗低、环境友好的优点,在未来矿物处理和环境污染治理等方面将扮演重要的角色。介绍了国内外微生物浸矿技术的发展历史和应用现状,总结了浸矿微生物的分类方法及不同种类微生物的特性,概述了混合菌在浸矿过程中的群落演替,简述了微生物浸矿电化学的研究现状,并对微生物浸出技术发展前景进行了展望。     

龙桥铁矿采空区顶板岩层移动及冒落规律研究

采用FLAC-3D对龙桥铁矿采空区顶板岩层移动及冒落规律进行了模拟研究,研究结果表明：整个采空区的顶板岩层移动比较平缓、稳定,矿区整体失稳的概率小;回采完-342.5分段3_5线矿体后,采空区顶板围岩的垂直下降变形及应力出现较为明显的变化,此时顶板围岩出现冒落迹象;0-2线附近矿体对采空区顶板岩层移动及冒落规律有着重要...     

The characteristics of the bacterial community structure and population dynamics for phosphorus removal in SBR activated sludge processes

The characteristics of the bacterial community structure and population dynamics for phosphorus removal in activated sludge were investigated using laboratory-scale sequencing batch reactor (SBR) activated sludge processes fed with four different carbon sources. Phosphorus removal activity, quinone profile of the activated sludge and isolated bacterial strains were monitored. An enhanced phosphorus removal activity was accompanied by the increase in ubiquinone-9 (Q-9). The relationships between phosphorus removal activity and Q-9 contents of the isolated bacterial strains were dependent neither on the organic substrates nor on the species of isolated bacterial strains. The enhanced phosphorus removal capability of activated sludge seemed to be due to the increase in the populations of bacteria with activity of phosphorus removal, i.e. species succession of bacteria in activated sludge ecosystems, rather than the increase in the phosphorus removal capability of phosphorus removal bacteria. Not only Acinetobacter but also Pseudomonas identified from isolated strains were regarded as representative polyphosphates-accumulating organisms and predominant species to the whole of bacterial population in activated sludge for phosphorus removal.     

大角度俯采覆岩运动规律数值模拟

针对大倾角煤层俯采过程中覆岩运动所引发的支架倾倒、输送机下滑和顶板破碎等安全事故,以霍州煤电辛置煤矿10 428C工作面为例,运用FLAC3D数值模拟软件,分析了顶板岩层沿工作面走向和倾向采动特征。结果表明：大倾角俯采煤层顶板岩层无论沿工作面走向或倾向方向上,垂直应力等值线和位移等值线均呈现非对称拱形态。工作面下方支承压力和位移值普遍大于上方,岩层运动范围在中上部扩展较快。工作面顶板塑性破坏区向顶板发展,工作面下方顶板破坏范围明显增大。     

高水材料巷旁充填沿空留巷技术应用研究

煤矿沿空留巷具有提高煤炭回采率、减少掘进巷道工程量和利于采掘接替等优势。常村煤矿为减少巷道成本,缓解采掘压力,采用高水材料巷旁充填技术替代小煤柱护巷,根据现场条件,高水材料水灰比为2∶1,巷旁充填宽度为1 m,并辅以巷道补强支护、超前加固技术保证沿空留巷效果,实施后,工作面实现无煤柱开采,减少巷道掘进量,一条沿空留巷就为矿井节约成本700余万元,为矿井高效生产提供了保障。     

Influence of eco‐hydrological factors on aquatic plant succession in a regulated river: a case study of the Petchburi River,Thailand

Monitoring of aquatic plant biomass in the Petchburi River, a regulated river system in Thailand, was carried out together with the examination of eco‐hydrological characters and the sedimentary organic content. The surveys were performed during May, August and November of 2010 and 2011. The results indicated temporal variation in water velocity (0.08–2.51 m/s) and medium to low organic levels (0.58–4.68%) of the benthic substrates. Dominant aquatic plants were Hydrilla verticillata (L.F.) Royle and Potamogeton malaianus Miq. with the highest biomass of 70.84 and 182.72 g/m², respectively. The biomass was substantially decreased during the flood‐induced discharge period. This study indicates that Potamogeton has more adaptive potential to high water velocities than Hydrilla, while Hydrilla prefers lower water velocities. Discharge velocities of less than 0.5 m/s could provide positive growth rates of such submerged plants. Approaching the discharge control from this ecological point of view can further contribute to river habitat conservation.     

基于顶极—格局假说的植被修复规划设计途径研究

植被修复是一个具有重要理论与实践价值的热点领域。但在既往研究中,对理论机制与实践应用间的关系描述尚少,植被修复一直未能形成系统的步骤和途径。本研究从植被修复的整体过程出发,首先对顶极—格局假说进行了研究,归纳出顶极—格局假说有8个理论要点;继而通过推导理论要点与植被修复的关系,整合现有的多种技术方法,最终提出了一套具有普适性的植被修复规划设计途径,包含5个步骤:植被修复场地分析、修复时间方案选择、生境修复措施选择、关键修复位置识别、修复监测与评价。     

广义项目管理与施工企业项目管理

“项目管理”这一概念或者提法、做法,自80年代初期进入中国大地,至今已在社会各行业得到广泛的应用,尤其是建筑施工企业更是把“项目管理”做为自己企业管理的基础管理和核心管理,然而广义的项目管理与施工企业的项目管理在管理的性质、任务、内容、范围、主体上是有很大区别的,广大施工管理人员应对这一点有深入的了解和明确的认识。     

高层结构抗震分析的连续化方法

提出一种采用连续化方法对高层结构在水平地震作用下内力和位移的简化计算方法。把高层结构看作一个竖向悬臂剪弯梁,得到前三阶振型和频率,按振型分解反应谱法基本原理,推导出高层结构内力和位移的计算公式和表格。文中还给出一个算例,并与底部剪力法对比分析以表明此方法的优越性,供设计人员参考。