煤矿掘进巷道冒顶事故原因分析及预防

掘进巷道冒顶是矿井最常见现象,严重地威胁着掘进工作面和作业人员的安全。从多方面详细阐述了掘进巷道冒顶事故发生的原因和机理,分析了巷道冒顶发生前发生的各项征兆。针对掘进巷道冒顶发生的原因,有针对性地提出了预防掘进巷道冒顶发生的措施,为巷道的掘进工作提供了一定的保障。     

巷道掘进支护中常见问题与应对措施分析

煤矿安全一直是国家和社会关心的重点,相较而言巷道掘进是事故发生的高发地点,因此对于巷道掘进支护 问题的研究具有十分重要的意义.分析了巷道掘进支护中常见问题及应对措施,并重点分析了锚杆支护在巷道掘进支护中的应用.     

煤矿巷道冒顶的防治与处理

巷道掘进工作面和巷道交岔处是煤矿巷道冒顶高发地带,通过了解和分析发生巷道冒顶的原因,提出一些主要的防治措施及处理措施,同时指出特殊环境下掘进巷道时采取的安全措施。     

煤矿掘进巷道顶板事故预防及断面优化设计

煤矿掘进巷道顶板事故是煤矿生产的主要灾害之一,分析了顶板事故的影响因素,并提出了断面优化和支护施工的方式,从而正确支护井巷、掘进巷道断面,预防顶板事故,保障煤矿工人的安全.     

冒顶片帮

冒顶片帮是指矿井、隧道、涵洞开挖、衬砌过程中因开挖或支护不当,顶部或侧壁大面积垮塌造成伤害的事故。矿井作业面、巷道侧壁在矿山压力作用下变形、破坏而脱落的现象称为片帮,顶部垮落称为冒顶,二者常同时发生。     

煤矿巷道掘进施工及顶板支护技术研究

煤矿巷道掘进施工和顶板支护技术对煤矿的安全生产起着重要的作用,是整个采煤的中心环节,一旦工作质量不达标,就会诱发顶板事故,给煤矿乃至社会带来不利影响,因此,做好巷道掘进施工与顶板支护工作至关重要。主要概述了煤矿巷道掘进施工与顶板支护技术,分析了其中存在的问题,并给出具有可行性、针对性的建议。     

冒顶片帮

<正>冒顶片帮是指矿井、隧道、涵洞开挖、衬砌过程中因开挖或支护不当,顶部或侧壁大面积垮塌造成伤害的事故。矿井作业面、巷道侧壁在矿山压力作用下变形、破坏而脱落的现象称为片帮,顶部垮落称为冒顶,二者常同时发生。两者常同时发生人身伤亡事     

运输巷道锚杆长度对锚固工程的影响研究

针对矿井20115运输巷道全锚索支护下大面积冒顶事故现象,对不同锚杆长度下围岩应力进行了数值模拟,从锚杆与围岩的协同作用和经济效益出发,确定了220 mm的锚杆长度.在加强支护方案下,围岩变形得到有效控制,保证了工作面的顺利回采.     

“钻楔”超前支护技术在破碎带及松软厚煤层掘进中的应用

阐述山贵崎矿山在巷道掘进中遇风化带、破碎带及松软厚煤层的超前支护方法,通过加工1寸焊接管和利用旧的1寸风水管"钻楔"超前支护控制顶板,有效防范顶板事故的发生,为复杂地质条件下掘进施工提供经验借鉴。     

ZLJ-10型机载临时支护装置在玉溪煤矿的应用

掘进工作面临时支护的安全问题是长期困扰煤矿企业的技术难题,由于巷道掘进后顶板未能及时得到有效的支护,经常会造成顶板掉矸、片帮伤人事故。中国煤矿目前普遍使用的临时支护形式有前探梁和单体液压支柱加横梁两种形式,但这两种方式都存在一定的缺陷,在安全方面存在薄弱环节,影响巷道掘进效率,不能从根本上解决安全问题。通过应用机载临时支护装置,不仅能确保掘进工作面空顶区域作业人员的人身安全,还能大大降低工人的劳动强度,提高巷道掘进效率。     

China and the relationship between the oil price and the dollar

We study cointegration and causality between the real price of oil and the real price of the dollar over the 1974–2004 period. Our results suggest that a 10% rise in the oil price coincides with a 4.3% appreciation of the dollar in the long run, and that the causality runs from oil to the dollar. Through the development of a theoretical model, we then investigate possible reasons why this relationship could be reversed in the future due to the emergence of China as a major player on both the oil and the foreign exchange markets.     

快速熔断器电阻值与电流、温度关系的研究

通过对单体和并联快速熔断器电阻值与电流的关系及并联快速熔断器的电阻值与温度的关系进行了模拟实验,给出了实验中有关数据。得出：快速熔断器的电阻值随电流增加和温度的上升而增加。对于设计大电流装置中如何安全选择快速熔断器提供了参考依据。     

无烟煤特性和无烟煤链条炉的燃烧调整与操作

针对无烟煤的特性,介绍了低挥发分无烟煤链条炉的燃烧调整与操作.     

谈科学技术进步与能源开发利用

本文论述了科学技术发展在不同阶段与能源消耗水平的关系。并指出在智能经济时代,只要合理开发利用能源的工作得到落实,能耗增长就会得到有效的控制,能源需求总量将缓慢下降;科学技术的进步将提供美好的能源前景;提出了合理开发和利用能源必须坚持的原则;对我国开发、利用能源的几个问题进行了探讨。     

Natural Convection Heat and Momentum Transfer in Rectangular Enclosures Heated at the Lower Portion of the Sidewalls and the Bottom Wall and Cooled at the Remaining Upper Portion of the Sidewalls and the Top Wall

Laminar natural convection inside air-filled, rectangular enclosures heated from below and cooled from above, with the lower portions of both sidewalls maintained at the temperature of the bottom wall, and the remaining upper portions of the sidewalls maintained at the temperature of the top wall, is studied numerically. A control volume formulation of the finite-difference method is used for the solution of the mass, momentum, and energy transfer governing equations. Simulations are performed for height-to-width aspect ratios of the cavity from 1 to 5, Rayleigh numbers based on the height of the cavity from 5 × 10² to 5 × 10⁶, and values of the heated fractions of both sidewalls from 0 to 1. It is found that when the heated portions of the two sidewalls are different in length, a steady-state solution is reached, with a basic three-cell flow pattern. In contrast, when the heated fractions of the sidewalls are the same, the asymptotic solution may be either stationary, with a flow field consisting of two pairs of superimposed roll cells, or periodic, with a flow pattern consisting of a primary cell and two secondary cells that pulsate about the center of the enclosure. Dimensionless heat transfer correlating equations are proposed.     

On the photovoltaic response of the J-domain and the JA-assembly

Photovoltaic devices based on poly-2′,5′-dioctyl-4,4′′-terphenylenecyanovinylene (J-domain) and 4-aza-4-(4′-(poly-2′,5′-dioctyl-4,4′′-terphenylene-1-cyanovinylene-2-yl)biphen-4-yl)-8,12-dioxa-4,8,12,12c-tetrahydrodibenzo[cd,mn]pyrenium tetrafluoroborate (JA-assembly) were prepared using indiumtinoxide (ITO) as the transparent electrode and aluminium as the second electrode. While the photovoltaic response of the J-domain exhibited low short circuit currents of −0.1 nA cm⁻², the corresponding short circuit current of the JA-assembly was observed to be +10 nA cm⁻². The 100-fold increase in magnitude was related to the known energy transfer from the J-domain to the A-domain in the JA-assembly, and the inversion of the sign of the photovoltaic response that implies that the electrodes have a reversed polarity was explained on the basis of the positions of the energy levels and involves the action of the A-domain as a blocking layer and a light operated charge pump that efficiently transfers electrons to the ITO electrode.     

企业能源统计的现状与分析

介绍了企业能源统计的现状,阐明企业能源统计是企业和政府进行节能管理的重要手段,能源统计是能源管理的基础.强调通过完善企业的能源统计管理工作,建立能源数据中心及能源信息化对当前的节能工作具有重要意义.     

浅谈农村环境污染及其保护

分析了农村环境的污染现状,指出了造成农村环境污染的几个主要原因,并根据中国农村发展规划,提出了相应的对策和保障措施。