重复采动覆岩裂隙网络演化分形特征

为研究重复采动下覆岩裂隙演化规律,以同煤集团煤峪口煤矿410盘区为地质原型,利用物理相似材料模拟实验模拟近距离煤层重复采动覆岩裂隙发育发展演化过程,运用分形几何理论研究重复采动条件下,覆岩裂隙网络分形特征.实验结果表明:随着开采宽度的增大,上层开采裂隙分形维数随之变大,其增幅随着宽度增加逐渐变小;而下层开采裂隙分形维数与开采宽度呈抛物线变化关系;开采采场覆岩裂隙上层煤分形维数与工作面前方支承压力峰值满足Freundlich方程,而与切眼附近支承压力峰值满足Langmuir方程,下层煤关系不明显;覆岩"三带"裂隙网络具有很好的自相似性,上层回采完裂隙带、冒落带分形维数比为1.0575:1;而下层煤为1.024:1.     

基于钻孔电阻率法动态监测的煤层覆岩瓦斯抽采层位确定——以李雅庄煤矿为例

高位水平钻孔瓦斯抽采技术是解决矿井瓦斯危害问题十分有效的工程技术手段.瓦斯抽采水平钻孔施工层位需要布置在覆岩采动裂隙带发育范围内,而复合顶板的采动裂隙带发育范围往往难以确定,导致钻孔施工层位不准确严重影响瓦斯抽采效率.为研究覆岩采动裂隙发育范围,精准确定水平钻孔布置层位,依据煤层开采覆岩变形破坏一般特征,采用钻孔电阻率法对李雅庄煤矿2607工作面开采覆岩裂隙发育特征进行动态监测,分析了不同采动时段的视电阻率响应特征和变化规律,得到覆岩裂隙发育分布的主要层位.研究表明:裂隙带主要发育范围位于煤层顶板26～47.5 m高度内的砂岩层,确定为瓦斯抽采的最佳层位,现场瓦斯抽采试验验证了该层位的准确性.钻孔电阻率法在覆岩裂隙动态监测方面具有较高的精度,为提高瓦斯抽采效率和降低瓦斯抽采成本提供了较重要的技术保障.     

采动覆岩破坏演化特征模型实验与分析

采动覆岩破坏演化特征研究对煤炭安全开采具有重要指导意义。以新疆哈密大南湖一矿1303工作面为研究对象,根据开采技术条件,构建采动覆岩破坏演化特征实验模型;分析覆岩运移特征与声发射监测信息,揭示了采动覆岩单次破裂及来压过程中多次破裂的能量耗散与演化特征,其历程分别为"释放-积聚-释放"与"裂隙扩展-破裂-垮落"。借助钻孔电视判定覆岩破坏演化高度,结果表明:工作面开挖后,覆岩破坏高度随模型开采持续增加,但受下方煤岩体碎胀效应影响,覆岩破坏高度增幅随来压次数增加而逐渐降低。工作面推进至246.4 m时,破裂岩块间形成稳定的挤压平衡结构,工作面达到充分采动状态,采动覆岩破坏高度峰值为96.0 m.相关研究成果为指导工程实践提供了定量依据。     

开采保护层覆岩裂隙演化规律模拟

为提高瓦斯抽采率和揭示保护层采动覆岩裂隙演化规律以及定量分析保护层卸压增透范围,将覆岩裂隙定义为具有开裂损伤功能的粘结单元,利用ABAQUS开发了粘结单元本构关系,建立了采动覆岩砌体结构内聚力模型,进行了粘结单元表征下的保护层采动裂隙演化数值模拟,通过粘结单元损伤程度分析采动裂隙发育状态,根据裂纹的连通状态界定采场覆岩损伤破坏区域,并得到了采动卸压范围及渗透率分布规律,采动裂隙演化规律模拟结果与实验一致,验证了覆岩砌体结构内聚力模型的精准性.     

覆岩采动裂隙演化形态的相似材料模拟实验

煤层开采后,覆岩采动裂隙演化规律及其形态特征与卸压瓦斯抽采密切相关。通过沿工作面走向及倾向相似材料模拟实验,得到覆岩采动破断裂隙的产生、发展为三阶段演化规律,形态呈"M"状。离层裂隙呈两大阶段、两个层位、三个区间的演化特征,即在主关键层触矸前,分布形态在垮落的最上位亚关键层上部,呈倒"V"状,下部呈"M"状;当主关键层触矸后,主关键层下部离层分布形态呈"M"状,上部少有离层发育。基于此,得到了覆岩采动裂隙演化形态与特征,提出了"采动裂隙圆角矩形梯台带"工程简化模型,为确定卸压瓦斯抽采钻孔参数提供了一定理论依据。     

基于声发射特征的覆岩采动裂隙演化规律研究

为研究覆岩采动裂隙演化过程能量释放规律,以构建的实验条件为基础,采用物理相似模拟、理论分析的方法,结合声发射技术,对覆岩采动裂隙演化过程中声发射特征进行了探讨。结果表明,采动裂隙演化过程是一个复杂的能量释放过程,模型开挖初期,覆岩损伤较小,声发射现象不明显,岩层移动变化较小,仅产生离层裂隙;在模型开挖中期,声发射现象越来越显著,即释放能量随来压次数显著升高,此时破断裂隙在纵向及横向不断发展;随着模型继续开挖,周期来压阶段内,声发射次数逐渐稳定,释放能量趋于稳定,此时破断裂隙纵向不再发展,仅随模型开挖在横向方向发展。     

综放工作面初采期煤与瓦斯共采试验研究

回采工作面初采期间瓦斯涌出异常,通常被称为困难时期。文中以余吾煤业N2105工作面为例,理论分析了工作面煤与瓦斯共采机理,采用数值模拟的手段,用走向模型分析初采期覆岩中裂隙演化规律,倾向模型判断覆岩卸压稳定后采动裂隙发育区分布。研究得出,初采期间,伴随顶板来压现象,覆岩采动裂隙逐步向高层位发育,采空区内冒落岩层被压实时,裂隙发育达到最高层位;距采空区上端头0~50m范围和煤层顶板上方30~50m范围空间交汇处,形成高浓度瓦斯富集区。工程试验表明,N2105工作面初采期间,覆岩采动裂隙逐渐发育,推进距达100~120m之间时,50#高位钻场瓦斯抽采量稳定在最高水平10m3/min,采动裂隙发育达到最高层位,并提出了高瓦斯工作面初采期定义,认为采空区内压实区形成时初采困难期结束。     

基于相似模拟实验的采动裂隙场演化规律研究

针对目前综放开采条件下对顶板岩移破坏时空演化规律研究不足的问题,采用相似模拟实验的方法对综放开采条件下覆岩移动和破坏机制以及采动裂隙分布规律和形态特征进行研究,结果表明:随工作面推进裂隙带逐渐地往上演化发展,而且当关键性岩层垮落断裂时,这种裂隙演化更为迅速;当工作面回采至240m时,离层裂隙趋于闭合,采动影响达到模型的顶部,裂隙带高度不再随着工作面推进距离的变化而改变。     

低瓦斯高强度开采综放工作面卸压瓦斯抽采关键技术

为研究低瓦斯高强度开采综放工作面采动覆岩裂隙演化过程中瓦斯的运移规律,提高矿井瓦斯治理能力,以王家岭矿12302工作面为例,研究了煤层开采后上覆岩层的垮落和位移特征,通过分形维数定量描述了裂隙的发育情况,得到了覆岩的三带高度、跨落角、裂隙区等参数,以此参数建立数值模型研究采动裂隙与瓦斯运移的耦合特性,将研究结果应用于现场的卸压瓦斯的抽采设计并进行了效果检验。结果表明:走向模型的冒落带为28.2 m,裂隙带为118.6 m,切眼处和停采线处的垮落角分别为59.5°和51.5°,倾向模型的冒落带为28.2 m,裂隙带为113.6 m,进刀端和停采线处的垮落角分别为62.5°和55.5°;随着工作面开采距离的增加,分形维数先增大后减小最后趋于平稳;采场卸压瓦斯整体上有向上、向采空区深部、向回风巷一侧运移的特性,采空区深部瓦斯浓度可达20%,上隅角瓦斯浓度接近1.5%,采动裂隙带瓦斯聚集区位于距回风巷20～50 m、高度距煤层顶板25～50 m范围内;采用高位定向长钻孔抽采采动裂隙带聚集瓦斯的抽采效果较好,上隅角和回风流瓦斯浓度均小于0.8%,保证了矿井的安全生产,为类似条件下的瓦斯治理提供参考。     

多煤层开采导水裂隙带发育与 覆岩破坏高度规律

为了进一步揭示多煤层开采过程中,采动裂隙带发育规律的影响因素与采空区水的变化特性,以公乌素煤矿为研究对象,分别研究了该矿区煤层的覆岩类型及其对覆岩破裂的影响,从理论和数值模拟的角度研究了多煤层开采对覆岩破坏高度的影响.研究结果表明:(1)煤层覆岩越坚硬,覆岩破裂带发育的高度较大,导水裂隙发育就越高,反之,则容易下沉,但不易产生开裂,最终表现为覆岩破坏高度降低;(2)煤层采动过程中,开采厚度、开采方法、工作面跨度、开采深度与导水裂隙带的高度变化呈正相关关系;(3)公乌素煤矿倾斜煤层回采的导水裂隙带的分布沿工作面的倾斜方向整体呈不对称“马鞍形”破坏特征,多煤层下行开采过程中,下部煤层开采可以有效地减小上覆岩层采动引起的应力集中现象,且采空区的卸压范围及高度也随之增加.相关研究成果可为同类型矿井安全开采提供参考依据.     

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.     

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.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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.