覆岩结构类型与开采覆岩损害特征分析

煤层开采打破了上覆岩层原有的平衡,必然引起岩层的移动、破断,导致应力场和裂隙场的改变,工作面出现矿压显现。上覆岩层的岩性和组合结构对工作面开采覆岩损害特征分布影响显著,一般岩性越坚硬,上覆岩层应力集中程度越高,采动裂隙越发育,矿压显现也越明显;坚硬岩层尤其是关键层对覆岩的破断运动起控制作用,覆岩破断发展到一定层位后软弱岩层往往是抑制覆岩破断进一步向上发展的关键。当工作面上覆岩层同时存在远近场关键层时,近场关键层的周期性破断引起裂隙带范围内岩层的运动和工作面周期来压;而远场关键层的周期性破断导致地表裂缝或台阶下沉,工作面压力急剧上升,有时甚至导致煤矿动压灾害,尤其是远近场关键层同步破断时动力现象更明显。通过地面钻孔使远场关键层提前破断是防止此类动力灾害的关键。     

A UV-LEDs based photomicroreactor for mechanistic insights and kinetic studies in the norbornadiene photoisomerization

In this work, we report a simple and inexpensive UV-LEDs based photomicroreactor assembly constructed by commercially available components. The photoisomerization of norbornadiene to quadricyclane was selected to validate this novel photomicroreactor design. Mass transport limitation was eliminated and indicated by dimensionless numbers Fo and Da _II, and photons loss was evaluated considering the absorption and reflection of the microreactor walls. The solvents, photosensitizers, and light sources selections were optimized for achieving better photochemical performance and mechanistic insights. The detailed comparison between the high-pressure mercury arc lamp and the UV-LEDs strip revealed great potential of UV-LEDs as appealing light source for photochemical transformations. Moreover, the reaction mechanism was thoroughly discussed and illustrated by the Jablonski diagram indicating electronic states transitions. According to possible intermediate steps, a kinetic model was proposed with the reaction rate constant being correlated with the photon flux, which is valuable for process optimization and further understanding reaction mechanisms.     

Unsteady conjugate mass transfer of a 2D deformable droplet in a modest extensional flow in across-slot

This work aims to investigate the unsteady conjugate interphase mass transfer between a stationary deformed drop and the modest extensional flow in a cross-intersected 2D channel. It is very difficult to accurately quantify the transient mass transfer rate of solute in such a geometry. Therefore, we established a mathematical model on the basic of the Stokes equation and solved it by the boundary element method, which could deal precisely with a two-phase flow system with a deformable interface; meanwhile, the convection-diffusion equation was solved by the finite difference method to calculate the unsteady conjugate interphase mass transfer. The simulation results showed that the mass transfer rate, analyzed and characterized in terms of mean concentration variation and Sherwood number Sh, was affected by capillary number Ca, Peclet number Pe, viscosity ratio λ , interior-to-exterior diffusivity ratio K, distribution coefficient m, and wall effect factor W.     

Local analysis of Marangoni effects during and after droplet formation

The influence on the mass transfer in liquid-liquid extraction was investigated during droplet formation in a quiescent aqueous continuous phase for the two transition components, acetone and acetonitrile, in toluene. Both transition components have similar characteristics. However, an approximately eight times slower mass transfer of a droplet hanging on a capillary in relation to a rising droplet could be observed. The droplet formation time and the initial solute concentration are decisive for the mass transfer behaviour. A lower volumetric flow leads to slower droplet formation and a higher specific mass transfer area enhancing mass transfer, which is visualized via laser induced fluorescence (LIF). Additionally, as expected, higher initial solute concentrations promote Marangoni turbulences and thus mass transfer, which is measured via confocal Raman spectroscopy inside a fixed hanging droplet.     

Reasons for breaking of chemical bonds of gas molecules during movement of explosion products in cracks formed in rock mass

The purpose of this study was to develop a physico-mathematical model and technique for estimation of chemical bond stability depending on electric field intensity of an external point charge. A hypothesis for a possible physico-chemical mechanism of the formation of additional harmful gases in the rock destruction by blasting was proposed. The theoretical basis of the hypothesis is the method of theretical evaluation of bond energy depending on the distance to a point charge, the third Coulomb centre. The quantum-mechanical model for calculating the electronic terms of molecules makes it possible to solve problems associated with the determination of parameters of molecules under the action of various physical fields on the system under consideration. The model was approved for some diatomic molecules. The discrepancy between the experimental data and calculated data did not exceed 14%, which proves accuracy of the obtained results. The model can be used in the field of research into the causes of gas-dynamic phenomena in underground coal mines, in studies of the degree of stability of nanostructured components of coal under physical influences, and in the theoretical design of new compounds and structures in the field of nanomaterial science and nanotechnology.     

复杂松软岩层大断面马头门巷道破坏机理及组合支护技术研究

针对辛置矿马头门巷道断面较大，围岩应力分布复杂，易发生变形破坏的特点，根据现场实际情况，通过理论研究和数值模拟等方法分析了马头门发生破坏失稳的主要原因和锚杆索临时支护作用机理，提出采用主、被动组合支护方式对巷道全断面围岩进行加固和支护，使巷道顶板、两帮和底板加固的围岩形成整体加固拱，提高马头门围岩的承载能力。     

萃取塔数学模型及过程强化的若干研究进展

萃取塔因生产能力大、占地面积小、密闭性好等优点，在石油、化工、生物、医药和环境工程等多领域被广泛应用。本文从以下几个方面介绍了萃取塔近些年的研究进展：综述了传统萃取塔（脉冲萃取塔、转盘塔与Kühni塔等）的水力学、轴向扩散与传质模型的发展，分析比较了表面张力、传质方向、放大效应等因素对模型的影响；介绍了计算流体动力学（CFD）在萃取塔中单液滴、单相流模拟、液-液两相流模拟、外加能量模拟、与群体平衡模型（PBM）耦合模拟中的应用进展；介绍了国内外设计开发的新型萃取塔，包括改变传统塔的内构件和引入多种外场能量等方式来强化相间传质。研究表明，将先进实验研究方法、准确经验模型和可靠理论计算相结合，将会是萃取塔研究的重要手段和方向。     

便携式飞行时间质谱仪的研制及其在石化污水系统挥发性有机物监测中的应用

近年来，国内的大气污染问题越来越严重，挥发性有机物（VOCs）的排放是其中一个重要原因。VOCs是臭氧和气溶胶的前驱物之一，在大气化学反应过程中扮演着极其重要的角色。本实验自行研制了一台基于真空紫外（VUV）灯的高分辨光电离飞行时间质谱仪（TOF MS），建立了一种新的VOCs稀释采样方法，并将其应用于石化行业污水处理系统VOCs的采样与分析。结果表明：隔油系统的3个池子基本没有测到高浓度的挥发性有机物，其中溶气气浮甲苯物质的质量浓度最高，为50.41 mg/L，其余组分的质量浓度大多数在0.1~1.0 mg/L之间；1#加氢和2#加氢隔油池有着类似的组分浓度，以1#加氢隔油池为例，二甲苯物质的质量浓度为10.60 mg/L，乙苯为52.33 mg/L，苯为59.80 mg/L；由于罐区隔油池没有加盖，处于露天状态，挥发性有机物气体容易向大气中扩散，并没有检测出较高浓度组分。可以看出，新式采样方法可有效地稀释定量样品，操作简便，减少了样品因闪蒸过程造成的VOCs损失，检出物质更丰富；同时，使用自行研制的TOF MS仪器能够快速检测不同装置污水处理系统的VOCs种类，将该仪器用于实际样品检测，发现化工企业大多数密闭的池子都含有苯系物、醚类等，但不同工艺的污水处理系统VOCs存在明显差异。该质谱仪适用于石化企业污水系统VOCs监测。     

安徽省铜陵市铁山头铜矿床地质特征及找矿潜力

铁山头铜矿床处于铜陵矿集区的中东部，属于扬子陆块下扬子凹陷中的铜陵隆起。矿床位于凤凰山矿田北侧，成矿潜力较大。综合研究分析认为：①接触交代作用使得岩体接触带及附近变质形成矽卡岩矿化带；②区内凤凰山岩体（花岗闪长岩）系成矿母岩；③矿体主要赋存于花岗闪长岩与三叠系下统南陵湖组石灰岩接触带上；④矿床成因类型为高—中温热液交代矽卡岩型矿床。