断裂密集带对油气运移和聚集的制约研究——以王府凹陷为例

为弄清断裂密集带对油气运移、聚集的控制作用,选取构造特征典型、油源单一的王府凹陷为例,按断裂密集带平、剖面特征对其进行分类.将王府凹陷扶杨油层断裂密集带分为4种类型,即地堑-反向断阶组合、地堑-反向-顺向断阶组合、地堑-地垒反向断阶组合和地堑-地垒-顺向断阶组合.通过分析断裂密集带中油气显示情况,探讨断裂密集带对油气运聚的制约作用.结果表明:断裂密集带对油气二次运移具有横向遮挡、侧向输导作用,并制约油气聚集.当断裂密集带走向与地层倾向近平行时,其两侧地垒、反向断阶是油气聚集优势部位;当其走向与地层倾向近垂直时,靠近生烃凹陷一侧的地垒、反向断阶优先捕捉油气,断裂密集带交汇处是油气富集有利部位.     

Coal mine entry rating system: A case study

Coal mines are continuously seeking to determine the performance of entries with different ground control products and installation methods. There are many factors that impact how an entry will perform which include but are not limited to geology, overburden, bolting type and pattern, and mine design.At the National Institute for Occupational Safety and Health(NIOSH), research has been instituted to examine the relationship of the parts of a coal mine entry as a system and not as individual components.To study this relationship, the first step in this study was to create a numeric rating system that accurately reflects visual observations of the mine entry and is easy to implement. NIOSH researchers devised this rating system to improve upon previous ideas, offering increased flexibility which can be incorporated into an overall entry condition that offers different levels of confidence based on the user's time devoted to the inspection. This new entry rating system was implemented at three different mines over varying periods of time to evaluate the ground response to the geology, bolt installation pattern, stress changes by mining, overburden, and time dependency.     

刍议英语学习的种种误区

英语教学实践中体会到,由于缺乏适宜的学习英语的语言环境和按语言规律学习英语的科学方法,许多学习者陷入英语学习的重重误区中,他们对所学内容一知半解、望文生义,学习效果事倍功半,针对大学生存在的普遍问题,围绕阅读理解、翻译、口语交流及词汇应用等四个方面,着重探讨和研究如何引导学生走出英语学习的误区,力求收到事半功倍的学习效果,真正提高学习者的语言应用能力。     

Complexity analysis of blast-induced vibrations in underground mining: A case study

Blasting in geological bodies is an industrial process acting in an environment characterized by high uncertainties (natural joints, faults, voids, abrupt structural changes), which are transposed into the process parameters (e.g. energetic transfer to rock mass, hole deviations, misfires, vibrations, fly-rock, etc.). The approach to this problem searching for the “optimum” result can be ineffective. The geological environment is marked out by too many uncertainties, to have an “optimum” suitable to different applications. Researching for “Robustness” in a blast design gives rise to much more efficiency. Robustness is the capability of the system to behave constantly under varying conditions, without leading to unexpected results. Since the geology varies from site to site, setting a robust method can grant better results in varying environments, lowering the costs and increasing benefits and safety. Complexity Analysis (C.A.) is an innovative approach to systems. C.A. allows analyzing the Complexity of the Blast System and the criticality of each variable (drilling, charging and initiation parameters). The lower is the complexity, the more robust is the system, and the lower is the possibility of unexpected results. The paper presents the results obtained thanks to the C.A. approach in an underground gypsum quarry (Italy), exploited by conventional rooms and pillars method by drilling and blasting. The application of C.A. led to a reliable solution to reduce the charge per delay, hence reducing the impact of ground vibration on the surrounding structures. The analysis of the correlation degree between the variables allowed recognizing empirical laws as well.     

Complexity analysis of blast-induced vibrations in underground mining:A case study

Blasting in geological bodies is an industrial process acting in an environment characterized by high uncertainties (natural joints,faults,voids,abrupt structural changes),which are transposed into the...     

Deep cover bleeder entry performance and support loading: A case study

Several questions have emerged in relation to deep cover bleeder entry performance and support loading:how well do current modeling procedures calculate the rear abutment extent and loading? Does an improved understanding of the rear abutment extent warrant a change in standing support in bleeder entries? To help answer these questions and to determine the current utilization of standing support in bleeder entries, four bleeder entries at varying distances from the startup room were instrumented,observed, and numerically modeled.This paper details observations made by NIOSH researchers in the bleeder entries of a deep cover longwall panel—specifically data collected from instrumented pumpable cribs, observations of the conditions of the entries, and numerical modeling of the bleeder entries during longwall extraction.The primary focus was on the extent and magnitude of the abutment loading experienced by the standing support.As expected, the instrumentation of the standing supports showed very little loading relative to the capacity of the standing supports—less than 23 Mg load and 2.54 cm convergence.The Flac3D program was used to evaluate these four bleeder entries using previously defined modeling and input parameter estimation procedures.The results indicated only a minor increase in load during the extraction of the longwall panel.The model showed a much greater increase in stress due to the development of the gateroad and bleeder entries, with about 80% of the increase associated with development and 20% with longwall extraction.The Flac3D model showed very good correlation between expected gateroad loading during panel extraction and that expected based on previous studies.The results of this study showed that the rear abutment stress experienced by this bleeder entry design was minimal.The farther away from the startup room, the lower the applied load and smaller the convergence in the entry if all else is held constant.Finally, the numerical modeling method used in this study was capable of replicating the expected and measured results near seam.     

Coal rib response during bench mining: A case study

In 2016, room-and-pillar mining provided nearly 40% of underground coal production in the United States.Over the past decade, rib falls have resulted in 12 fatalities, representing 28% of the ground fall fatalities in U.S.underground coal mines.Nine of these 12 fatalities(75%) have occurred in room-andpillar mines.The objective of this research is to study the geomechanics of bench room-and-pillar mining and the associated response of high pillar ribs at overburden depths greater than 300 m.This paper provides a definition of the bench technique, the pillar response due to loading, observational data for a case history, a calibrated numerical model of the observed rib response, and application of this calibrated model to a second site.     

Designing regional pattern for ecosystem restoration: A case study

Designing regional pattern is challenging for ecosystem restoration both in theory and in practice. The present study proposed a new approach to design regional pattern for ecosystem restoration with a case in the arid valley of Upper Minjiang River, SW China. The procedures are: (1) Determine the regional pattern of main environmental factors based on the relationships between the important environmental factors and the main geographical factors generated from DEM data. (2) Overlay the maps of the main environmental factors. (3) Generate a lookup table according to the species selection rule we proposed to link the candidate restoration species to the main environmental factors. (4) Determine the regional pattern of ecosystem restoration by positioning the restoration species in the map of environmental factors according to the lookup table. The regional restoration pattern designed in this way would be applicable not only to restoring a region, but also to predicting the future landscape change.     

Designing regional pattern for ecosystem restoration:A case study

Designing regional pattern is challenging for ecosystem restoration both in theory and in practice. The present study proposed a new approach to design regional pattern for ecosystem restoration with a case in the arid valley of Upper Minjiang River, SW China. The procedures are: (1) Determine the regional pattern of main environmental factors based on the relationships between the important environmental factors and the main geographical factors generated from DEM data. (2) Overlay the maps of the main environmental factors. (3) Generate a lookup table according to the species selection rule we proposed to link the candidate restoration species to the main environmental factors. (4) Determine the regional pattern of ecosystem restoration by positioning the restoration species in the map of environmental factors according to the lookup table. The regional restoration pattern designed in this way would be applicable not only to restoring a region, but also to predicting the future landscape change.     

国家助学贷款校级管理现状与对策建议

国家助学贷款自1999年正式实施以来,使更多的贫困生有了接受高等教育的机会,并逐步成为我国高等教育资助体系中最重要的资助方式。对国家助学贷款校级管理现状以及存在问题的原因进行了系统地考察。在此基础上,为完善我国高校国家助学贷款管理工作提出了几点建议。     

甲醇汽油双燃料发动机的怠速性能试验

为了解决城市工况中混合动力用发动机频繁停机/再起动导致排放恶劣的问题,提出以甲醇作为混合动力用发动机快速起动的燃料,并对采用甲醇燃料的发动机快速起动性能进行试验研究.试验用发动机为点燃式进气道喷射自然吸气汽油机,加装一套甲醇喷射系统可作为甲醇发动机,再通过加装一台交流电机来模拟混合动力发动机快速起动过程,采用自主开发的电子控制单元对试验系统进行控制.试验结果表明,相比于采用汽油燃料,采用甲醇燃料时,发动机高转速快速起动阶段消耗燃料的比能耗降低,发动机的火焰发展期和快速燃烧期都有所缩短,起动过程中的碳氢、一氧化碳和氮氧化物排放都明显减少.

     

Prediction of rock-burst-threatened areas in an island coal face and its prevention:A case study

The island coal face arises in coal mines with the purpose of preventing gas explosion or maintaining the balance between mining and tunneling. However, its particular stress conditions in the surrounding rock may increase the difficulty of stress control in the coal face and in its mining roadways, especially when the coal seam, the roof, and the floor have rock-burst propensities. The high energy accumulated in the island coal face and in its roof and floor will intensify rock-burst propensity or even induce rock burst,which further result in great casualties and financial losses. Taking island coal face 2321 in Jinqiao coal mine as a case, we propose a method for the prediction of rock-burst-threatened areas in an island coal face with weak rock-burst propensity. Based on the analysis of the movement of the overlying roof and characteristics of stress distribution, this method combined numerical simulation with drilling bits to ensure the prediction accuracy. The effects of coal pillars with different widths on the mitigation of stress concentration in the coal face and on the prevention of rock burst are analyzed together with the mechanism behind. Finally, corresponding measures against the rock burst in the island coal face are proposed.     

A Review on Efficient Routing Mechanisms in Urban Scenario of Vehicular Ad-Hoc Networks

Efficient routing protocols are crucial for enabling secure communication among the highly mobile and self-configurable nodes in Vehicular Ad-Hoc Networks(VANETs). In this work, we present a performance evaluation of different routing protocols in VANETs based on the currently available research. Our study focuses on analyzing the strength and weaknesses of the routing protocols, namely, Ad-Hoc On-demand Distance Vector(AODV), Dynamic Source Routing(DSR), and Destination-Sequenced Distance-Vecto...     

滨河带重要视景空间节点选择研究

选取汉中滨河景观带进行实例研究,从滨河景观构成要素入手,概括出滨河带重要视景空间节点所具有的三大特征;以视景研究为基础,对滨河带视景空间进行剖析,筛选出多个滨河带重要视景空间节点,初步构建了节点组织模型,将多个节点组织形成一个视觉整体,起到提升汉中滨河带视觉品质的作用。     

Towards an optimization design of seepage control:A case study in dam engineering

High dams generally suffer from higher seepage risks in their foundations, and seepage control is an important technology for limiting the amount of leakage and improving the stability of the foundations. In this study, a procedure was proposed for optimization design of seepage control system in large-scale hydropower projects, which relies on sufficient characterization of site conditions and proper quantification of the performance of the seepage control system. The proposed procedure was applied to the design of seepage control system in the Mengdigou Hydropower Station consisting of a double-curvature arch dam201 m in height. An optimized layout of the seepage control system, including the extended length of grout curtain, the rows of grouting holes and the spacing of drainage holes, was suggested. The proposed procedure provides a guide with lower risk and higher confidence for performance assessment and optimization design of seepage control systems in high dam engineering.     

Large-scale destress blasting for seismicity control in hard rock mines: A case study

Destress blasting is a rockburst control technique where highly stressed rock is blasted to reduce the local stress and stiffness of the rock, thereby reducing its burst proneness. The technique is commonly practiced in deep hard rock mines in burst prone developments, as well as in sill or crown pillars which become burst-prone as the orebody is extracted. Large-scale destressing is a variant of destress blasting where panels are created parallel to the orebody strike with a longhole, fanning blast pattern from cross cut drifts situated in the host rock. The aim of panel destressing is to reduce the stress concentration in the ore blocks or pillars to be mined. This paper focuses on the large-scale destress blasting program conducted at Vale's Copper Cliff Mine(CCM) in Ontario, Canada. The merits of panel destressing are examined through field measurements of mining induced stress changes in the pillar. The destressing mechanism is simulated with a rock fragmentation factor(a) and stress reduction/dissipation factor(b). A 3D model is built and validated with measured induced stress changes. It is shown that the best correlation between the numerical model and field measurements is obtained when the combination of a and b indicates that the blast causes high fragmentation(a = 0.05) and high stress release(b = 0.95) in the destress panel. It is demonstrated that the burst proneness of the ore blocks in the panel stress shadow is reduced in terms of the brittle shear ratio(BSR) and the burst potential index(BPI).     

地质遗迹保护开发的实施步骤与模式优选--以新疆为例

我国地质遗迹保护的发展轨迹可划分为从属保护、独立保护、保护与开发协调3个阶段,反映出保护理念从单一保护到保护与开发相协调的演进.新疆是我国地质遗迹资源最丰富的省区之一,但地质遗迹的保护与开发较为滞后,其现状诊断为:从属保护、级别不高、数量较少、协调性较差.基于首次全疆地质遗迹资源系统调查,确定保护分类、保护形式、保护模式、保护级别、保护时序、保护分区六大保护开发实施步骤,提出地质公园、地质遗迹保护区及其他保护地相结合的复合型保护开发模式优选思路和5个优选模式.     

城市竞争力的测度与评价——以直辖市及省会城市为例

文章以我国直辖市及部分省会城市竞争力为研究对象,根据城市竞争力的有关理论,从经济综合实力、经济发展能力指标、经济结构与效率、科技创新与教育、物流集聚与信息化水平、居民福利与生活质量、基础设施与环境指标七个方面选取构建了指标体系,通过均方差赋权重法对各案例城市竞争力进行了评价,并对城市竞争力评价结果进行了分析研究.     

Optimization of post-classification processing of high-resolution satellite image:A case study

The application of remote sensing monitoring techniques plays a crucial role in evaluating and governing the vast amount of ecological construction projects in China. However, extracting information of ecological engineering target through high-resolution satellite image is arduous due to the unique topography and complicated spatial pattern on the Loess Plateau of China. As a result, enhancing classification accuracy is a huge challenge to high-resolution image processing techniques. Image processing techniques have a definitive effect on image properties and the selection of different parameters may change the final classification accuracy during post-classification processing. The common method of eliminating noise and smoothing image is majority filtering. However, the filter function may modify the original classified image and the final accuracy. The aim of this study is to develop an efficient and accurate post-processing technique for acquiring information of soil and water conservation engineering, on the Loess Plateau of China, using SPOT image with 2.5 m resolution. We argue that it is vital to optimize satellite image filtering parameters for special areas and purposes, which focus on monitoring ecological construction projects. We want to know how image filtering influences final classified results and which filtering kernel is optimum. The study design used a series of window sizes to filter the original classified image, and then assess the accuracy of each output map and image quality. We measured the relationship between filtering window size and classification accuracy, and optimized the post-processing techniques of SPOT5 satellite images. We conclude that (1) smoothing with the majority filter is sensitive to the information accuracy of soil and water conservation engineering, and (2) for SPOT5 2.5 m image, the 5×5 pixel majority filter is most suitable kernel for extracting information of ecological construction sites in the Loess Plateau of China.     

Optimization of post-classification processing of high-resolution satellite image: A case study

The application of remote sensing monitoring techniques plays a crucial role in evaluating and governing the vast amount of ecological construction projects in China. However, extracting information of ecological engineering target through high-resolution satellite image is arduous due to the unique topography and complicated spatial pattern on the Loess Plateau of China. As a result, enhancing classification accuracy is a huge challenge to high-resolution image processing techniques. Image processing techniques have a definitive effect on image properties and the selection of different parameters may change the final classification accuracy during post-classification processing. The common method of eliminating noise and smoothing image is majority filtering. However, the filter function may modify the original classified image and the final accuracy. The aim of this study is to develop an efficient and accurate post-processing technique for acquiring information of soil and water conservation engineering, on the Loess Plateau of China, using SPOT image with 2.5 m resolution. We argue that it is vital to optimize satellite image filtering parameters for special areas and purposes, which focus on monitoring ecological construction projects. We want to know how image filtering influences final classified results and which filtering kernel is optimum. The study design used a series of window sizes to filter the original classified image, and then assess the accuracy of each output map and image quality. We measured the relationship between filtering window size and classification accuracy, and optimized the post-processing techniques of SPOT5 satellite images. We conclude that (1) smoothing with the majority filter is sensitive to the information accuracy of soil and water conservation engineering, and (2) for SPOT5 2.5 m image, the 5×5 pixel majority filter is most suitable kernel for extracting information of ecological construction sites in the Loess Plateau of China.