High-low-blasting technology and its application in methane dynamic disaster prevention

The gas cooperative control model combined local pressure-relief with regional pressure-relief was established, based on the theory of multi-parameters cooperative. For the status of high gas contents, high in-situ stress and low-permeability of Ji-15 seam of No.12 coal mine in Pingmei Group. The law of detonation wave propagation and ground-stress change distribution were simulated by means of the finite element analysis software. The technology of high-low-blasting, composed of high blasting(deep crossing hole controlled hydraulic blasting) and low blasting (special roadway deep hole controlled blasting) were developed. The research shows that around control hole produce maximum tension fracture failure, and result in directional and controlled blasting, when the distance between control hole and blasting hole is 1.2 m. The theory makes blasting force and hydraulic force advantage superimpose, which raises the effect of pressure relief and permeability enhancements compared with general blasting. High blasting influence radius and low blasting influence radius superimposed with each other, that prevents methane dynamic disaster. The result of type approval test shows that the technology can increase gas permeability as high as 22.7∼36.2 ratio, decrease gas pressure from 2.85 MPa to 0.30 MPa, increase drilling influence radius to about 9 m. The technology realizes regional overall permeability improvement, that provides a new technical measure for methane dynamic disaster prevention.     

Model-based characterization of endogenous maintenance, cell death and predation processes of activated sludge in sequencing batch reactors

Maintenance, cell death and predation are endogenous processes of microorganisms and play an important role in governing the overall performance of biological wastewater treatment systems. However, in the previous studies on the activated sludge system, a widely used biological wastewater treatment process, the endogenous processes are summarized as a single process and the kinetics of all related processes are lumped into a single parameter set. In order to better understand the endogenous processes, efforts are made to quantify the maintenance, cell death and predation processes separately with both experimental and mathematical approaches in this work. A model-based analysis on endogenous processes of activated sludge is performed. Both oxygen uptake and biomass concentration gradually decrease with the increasing length of aerobic starvation. Model predictions are in accordance with experimental data. The active bacteria content is reduced to about 23% of the initial value after 10-day starvation, and the maintenance energy consumption rate under non-growth conditions is found to be about four times of that when the microbial growth is of its maximum level. The active microorganisms form the prey for the predator growth. The oxygen consumption related to the predation of active bacteria significantly contributes to the total oxygen consumption.     

用五氧化二钒防止酸性光亮镀锡液的氧化变质研究

向酸性光亮镀锡液加入0.05～0.1~g/l电化学活性物质(V_2O_6),便可完全终止Sn~(2+)在空气中的氧化,从而解决了该行业长期来存在的难题。此外,还对镀液变质及V_2O_5的作用机理进行了探讨。     

连通管配合瞄线法延设腰线的方法

介绍了用连通管配合瞄线法延设各类腰线的方法 ,并对几种主要影响腰线的误差作了分析。     

大口径埋地输水管道水泥砂浆内衬防腐蚀技术

本文介绍大口径埋地钢质输水管道水泥砂浆防腐蚀内衬的优良性能，报道该项技术在我国重要输水管道工程中的应用概况，总结了水泥砂浆内衬施工方法的特点以及近年来工程中的应用情况和效果。     

解读组织文化视野下的英语课堂教学

课堂也是一个组织,存在组织文化.主要从组织文化角度分析了英语课堂教学.英语课堂教学是课堂组织文化的载体,课堂组织文化可以分为操作(教学过程),理念(教学理念),假设(潜在的人生观,世界观),价值观三个层次.这三个层次互相影响,并影响着教学主体.揭示了组织文化三层次在英语课堂上的所在,阐释三层次的关系,以及其对英语教学和学习的影响,并对英语课堂组织文化管理提出建议.     

低分子聚酰胺热熔粘合剂的性能调节

为了适应不同聚酰胺热熔粘合剂用户的不同要求 ,避免改变合成条件带来的操作不便 ,探索了一条以本实验室合成的低分子聚酰胺热熔粘合剂为基本原料 ,用少量调节剂在局部范围内调节粘合剂性能的操作路线。从而进一步提高了产品的适应性     

路面钢纤维混凝土抗折强度偏低原因分析

从原材料、配合比和施工等方面，具体分析了导致某路面钢纤维混凝土抗折强度偏低的原因。指出采用振捣成型，施工过程中加水，不合适的砂率配比和水泥捩坟强度偏低是主要影响因素。