危险性预先分析法在煤矿瓦斯事故中的应用

本文采用危险性预先分析法,统计出靖远煤业公司大水头煤矿东103综放工作面以往同类事故案例,分析工作面现状,辨识出瓦斯爆炸、瓦斯煤尘爆炸、瓦斯燃烧三类事故,提出相应预防措施.     

低瓦斯矿井综放工作面瓦斯治理研究实践

分析了U型通风方式综放工作面瓦斯分布特征和规律,给出了工作面、上隅角及其附近采空区等瓦斯积聚或超限原因,在此基础上,以3302综放工作面为研究对象,提出采用W通风方式来代替U型通风方式,并给出了W型通风方式下瓦斯情况,得出W型通风方式下3302工作面瓦斯控制更好,同时,提出采用吊挂风障和水射流风机来解决W型通风方式下风流汇集处瓦斯积聚问题。     

综放工作面高抽巷合理位置的研究

针对高抽巷抽采瓦斯条件下诱发采空区自燃发火问题,以某矿综放工作面实际开采的技术条件构建采空区气体渗流模型,结合实际高抽巷布置要求,利用Fluent数值模拟软件分析高抽巷不同平距和垂距条件下的采空区氧化带宽度,结果表明:当高抽巷垂距为35 m、平距为25 m时,采空区氧化带宽度最小。高抽巷合理位置的确定,在提高瓦斯抽采效率、减小煤自燃发火的危险性、保证综放工作面的绿色、安全、高效等方面具有实际的指导意义。     

关于放顶煤工作面瓦斯治理的技术研究

综采放顶煤开采技术已经成为我国煤矿实现高产高效的主要途径.由于工作面揭露煤层出现瓦斯异常涌出现象,加上放顶煤工作面一次采全高,产量集中,瓦斯的绝对涌出量将明显增加,在下作面后方采空区上部积聚的部分瓦斯随顶煤的冒落将涌人工作面,易导致瓦斯超限及潜在的瓦斯灾害.因此,瓦斯安全问题是综采放顶煤开采的主要研究课题之一,意叉重大.针对放顶煤工作面瓦斯偏高的情况,本文对工作面瓦斯涌出来源进行了分析,找出了采空区瓦斯分布规律,提出了瓦斯治理措施,以确保安全生产,带来更高的经济利益和社会效益.     

倾斜综放工作面停采期间支护技术研究

针对倾斜综放工作面停采期间,常常出现支架下滑、顶板冒落,片帮等问题,通过对停采线位置和末采期间采煤距离的确定,工作面停采支护方式,机道支护工艺等技术问题的研究,确保倾斜综放工作面安全高效进行停采支护,为下一步进行综放设备回撤提供了屏障。     

采空区高位钻孔瓦斯抽放的数值模拟

依据Darcy定律,在Navier-Stocks方程的基础上,对祁南煤矿综采工作面采空区瓦斯抽放问题作了计算分析,并进行了CFD数值模拟.从理论上模拟采空区瓦斯聚集过程,直观展示了瓦斯抽采时采空区流态、瓦斯分布变化.把抽放钻孔布置在顶板裂隙内,结合上隅角埋管实施瓦斯抽放,该抽放瓦斯技术起到了对开采工作面上隅角瓦斯的截流作用,现场管路测量显示,可抽出高浓度瓦斯达30%～80%(体积分数),工作面回风瓦斯的体积分数基本控制在0.3%以下.     

易自燃煤层综放工作面综合安全保障技术研究

综放开采具有产量高、效益显著等优点,但受开采方式影响采空区内遗煤量较大,采空区遗煤自燃发火危险性较高,如何避免采空遗煤自燃是综放工作面开采时需要重点解决的问题.采用综合安全保障技术是实现降低采空区遗煤自燃危险的重要举措.为此,对现阶段矿井常用的防灭火技术展开分析,并以5306综放工作面回采为工程实例,对综合安全保障技术...     

基于高精度微震监测的特厚煤层综放工作面顶板运动规律

采用高精度微地震监测技术,研究了微震事件的动态发展规律和分布规律,结合岩石力学和矿山压力与岩层运动理论,推断得到了特厚煤层综放工作面顶板岩层运动规律.随工作面的推进,微震事件先在高位岩层以低密度分布,后在低位岩层呈高密度分布.微震事件发生层位与其最大振幅能量和的对比研究表明,微震事件在高度和时间上具有周期性分布规律,根据矿山压力与岩层运动理论,进而推知特厚煤层综放工作面的顶板岩层运动规律.现场支架工作阻力宏观观测表明,研究得到的特厚煤层综放工作面顶板岩层的周期性运动规律是存在的.     

深部矿井冲击地压防控技术研究

针对131102综放工作面回采期间冲击地压危险性大、安全风险高等问题,在分析冲击地压主控因素及发生判据基础上,提出通过静载、动载卸压方式进行冲击地压防控,并进行工程应用。具体通过巷道底板大直径钻孔、巷帮大直径钻孔及巷帮爆破方式实现静载卸压;通过深孔爆破实现顶板坚硬砂岩预裂方式进行动载卸压。降低采空区顶板悬空面积及垮落时应力显现程度;依据131102综放工作面现场开采条件,对采取的冲击地压防控措施进行详细分析。工程应用后,131102综放工作面冲击地压危险性明显降低,现场取得较好应用效果。     

斜沟煤矿23103综采工作面控制风量防灭火技术研究

以西山晋兴公司斜沟矿23103综放工作面为案例,分析了该工作面在回采过程中采空区遗煤易自燃的问题,结合23103综放工作面的实际生产情况,在对采空区遗煤分布和漏风情况进行分析研究基础上,通过采取构筑隔离墙、注氮和降低供风量的综合防灭火措施,降低采空区遗煤自燃隐患,保证了工作面安全顺利回采及设备搬迁,实践取得显著的社会与经济效益,同时对矿井地质条件相类似的矿井易自燃厚煤层放顶煤开采具有借鉴意义。     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Comparison of the results of surgical and conservative treatment of fractures of the diaphysis of the tibia

In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.