高压水射流割缝揭穿煤层关键参数研究

针对高瓦斯低透气性煤层石门揭煤过程中瓦斯抽采难的现状,提出了高压水射流割缝提高煤层透气性方法。在理论分析射流轴向速度的分布规律基础上,得出射流冲击力与煤体力学性质耦合作用关系;通过分析煤体颗粒运动、受力状态,得出钻孔倾角、水量与煤体颗粒流速之间的关系;基于连续损伤力学分析出煤体产生损伤破坏的临界值,确定了高压水射流割缝煤体有效半径;并将该技术在平顶山某矿-380 mS4〖KG-*6〗石门进行现场试验,试验结果表明钻进工程量减少了38.2%,瓦斯预抽率提高了2.86倍,预抽时间缩短了57.1%,预抽面积增加     

近距离煤层群水射流割缝卸压石门快速揭煤技术分析

针对西南地区高瓦斯近距离突出煤层群层间距小于7 m时,石门揭煤工作面前方多层煤层需统一消突管理,常规超前钻孔工程量大,严重制约了煤矿安全生产和采掘工作面接替等问题,提出采用穿层钻孔水射流割缝防突技术,一次性对石门工作面前方煤层群统一卸压增透,快速安全揭煤的思路。以贵州雷公山煤矿为例,采用FLAC3D模拟了不同缝槽布置方式以及缝槽间距对煤层群卸压效果的影响。研究表明：多煤层煤孔中部均布置一个缝槽,同一煤层内缝槽间距为4 m,可使石门揭煤工作面前方控制范围内煤体整体卸压。现场应用证明：采用水射流割缝技术,预抽达标时间缩短约39 d,钻孔工程量减少610 m,钻孔数量减少30个,可实现快速安全揭煤。     

煤体水力割缝中瓦斯突出现象实验与机理研究

通过室内1：1大煤样水力割缝抽放瓦斯的实验研究,揭示了水力割缝过程中煤与瓦斯突出现象,依据煤体特性、应力状态、应力水平、水射流压力、瓦斯压力等实验结果,并结合数值模拟计算,分析了水力割缝中煤与瓦斯的突出机理。     

水射流促进煤基质收缩提高煤层透气性机理分析

高压脉冲水射流割缝是新型有效的增透技术,但增透机理尚未明确,制约了其在不同赋存条件煤层中的推广应用.文中从煤基质收缩提高煤层透气性角度出发,在分析高压水射流冲击煤体的动态效应基础上,得出冲击动态方程;理论分析了在高压脉冲水射流作用下煤基质的受力状态,得出了高压脉冲水射流能够促使煤基质收缩,并推导出射流冲击力-煤基质的关系方程,在此基础上采用P-M模型,得出射流作用下煤层内瓦斯渗流方程,为高压脉冲水射流割缝增透技术的推广应用提供了理论支撑.     

高瓦斯突出煤层石门揭煤防突措施的实践与应用

石门揭煤最容易发生煤与瓦斯突出,而且突出的强度较大,因此,在石门揭开有突出危险的煤层之前,必须对煤层采取防突措施,消除了局部范围内煤层的突出危险,确保了掘进期间的安全,为类似条件石门揭煤期间防防突治理提供了借鉴。     

涌山矿石门揭煤地应力数值模拟

针对煤矿石门揭煤突出强度大、破坏性强,对煤矿安全生产潜在威胁较大问题,以涌山矿五煤石门揭煤过程中巷道应力变化规律为研究对象,采用FLAC3D数值模拟的方法对石门揭煤过程中地应力的变化情况建立模拟模型,并对其工作面掘进过程进行数值模拟,分析得到研究成果,得出了揭煤过程中巷道周围应力分布的规律,有助于预防煤与瓦斯突出事故.     

深孔爆破增透瓦斯抽采技术在石门揭煤中的应用

为防止突出煤层在石门揭煤过程中发生煤与瓦斯突出,合理选择深孔爆破增透瓦斯抽采技术抽采待揭露煤层瓦斯,有效地消除了其突出危险性,加快了石门揭煤过程,保证了矿井的安全生产和正常接替。     

海孜矿三水平主石门揭煤防突设计

矿井的煤与瓦斯突出事故很多都发生在石门揭煤的过程中。由于石门揭开突出煤层的局部地点,首先打破了原始应力平衡状态,该处具有较大的煤岩弹性潜能和瓦斯内能：加以爆破揭开煤层．煤岩体中的潜能和瓦斯内能又有高速释放的较好条件,所以极容易造成较大强度的煤与瓦斯突出。本文就海孜矿三水平主石门揭煤进行了专项防突设计。     

煤与瓦斯突出预测指标及其临界值确定方法研究

为了避免突出的漏报,提高煤与瓦斯突出预测工作的有效性与准确率,在系统分析煤与瓦斯突出预测敏感指标以及各影响因素对突出的影响程度基础上,以显德汪矿为例提出了基于钻屑量S,Δh2和K1等3种预测指标的综合指标K值,并建立了综合指标的计算公式,实现了对煤与瓦斯突出预测的各项指标的综合考虑。基于该指标对显德汪矿进行了突出预测并确定了临界值。根据所确定的临界值,对分析结果进行验证,证明所选取的临界值符合要求。在此基础上对煤与瓦斯突出预测指标临界值的确定方法进行了推广,建立了具有普遍使用性的矿井瓦斯突出综合预测指标及其临界值确定方法,并提出将该综合预测指标与各单项预测指标结合应用。     

高压水射流自旋式割缝技术在柿花田煤矿的应用

瓦斯治理的根本措施是抽放,然而应用单一钻孔预抽瓦斯,钻孔直径是决定抽放效果的关键因素.孔径小,其自由面小,瓦斯的排放速度低,等待开采的时间较长,影响了矿井的生产效率,而孔径又不能太大,否则在煤层综合应力下,孔的形成和孔的稳定性会受到破坏,而且孔径大的钻孔钻进速度较慢,效率较低,而且钻孔的有效煤孔段往往只占整个钻孔的一小部分,完全没有必要施工孔径较大的钻孔.介绍了一种新型高压水射流自旋式割缝技术,该技术可以有效解决上述问题.高压水射流自旋式割缝设备主要由高压水泵、水箱、高压胶管、高压密封钻杆、旋转接头、力矩喷头和喷嘴组成,该技术是在瓦斯抽采钻孔完成后,利用钻机将切割钻具输送至孔内,采取后退切割的方式,对钻孔内煤体进行切割,形成若干个垂直于钻孔方向的圆盘状缝隙,使孔内煤体暴露面积增加,同时由于高压注水作用,缝隙周围裂隙增加使煤体的透气性增强,从而有效提高抽采效率.试验发现：该技术的割缝半径为0.6～0.7m,使用该技术切割后,瓦斯涌出量大幅增加,百米瓦斯自排量和瓦斯抽放量分别是非切割钻孔的5.6和4.5倍,且衰减系数有所增加.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that