Ground fissure development regularity and formation mechanism of shallow buried coal seam mining with Karst landform in Jiaozi coal mine: a case study

A comprehensive study was undertaken at Jiaozi coal mine to investigate the development regularity of ground fissures in shallow buried coal seam mining with Karst landform,shedding light on the development type,geographical distribution,dynamic development process,and failure mechanism of these ground fissures by employing field monitoring,numerical simulation,and theoretical analysis.The findings demonstrate that ground fissure development has an obvious feature of subregion,and its geographical distribution is significantly affected by topography.Tensile type,open type,and stepped type are three different categories of ground fissure.Ground fissures emerge dynamically as the panel advances,and they typically develop with a distance of less than periodic weighting step distance in advance of panel advancing position.Ground fissures present the dynamic development feature,temporary fissure has the ability of self-healing.The dynamic development process of ground fissure with closed-distance coal seam repeated mining is expounded,and the development scale is a dynamic development stage of“closure→expansion→stabilized”on the basis of the original development scale.From the perspective of topsoil deformation,the computation model considering two points movement vectors towards two directions of the gob and the ground surface is established,the development criterion considering the critical deformation value of topsoil is obtained.The mechanical model of hinged structure of inclined body is proposed to clarify the ground fissure development,and the interaction between slope activity and ground fissure development is expounded.These research results fulfill the gap of ground fissures about development regularity and formation mechanism,and can contribute to ground fissure prevention and treatment with Karst landform.

Study of the Conditions of Formation and Forecast of the Perspective Areas of Hydrogen-Sulfide Water of Surkhandarya Depression

Increase in requirement of hydrosulphuric water for improvement of the population set the task of identification of places of their possible congestion for hydrogeological service. Earlier detection of such congestions was accidental at well-drilling of different function. Therefore, development of new methodical approaches of search and allocation of perspective zones of their formation was required. It was for this purpose necessary to study in what conditions and what factors have an impact on formation of underground hydrosulphuric water. So far, definition of communication attempts only with separate geochemical signs was known. Results of studying of influence on formations of hydrosulphuric water of such factors as lithologic and facial in combination with oil-and-gas content, the geological and structural and hydrodynamic mode are given in this work. It is established that the main sign for formation of hydrosulphuric water is existence of evaporite thickness and hydrocarbon congestions. Besides, it is shown that small depth (up to 2 km) of their bedding has to be an indispensable condition and existence of explosive violation on which there has to be a water infiltration (a geological and structural factor). In the Surkhandarya region, the hydrodynamic mode caused by inclined bedding of aquifers was also one of essential factors. Active water is an exchange process with washing away (oxidation) sulfate of the containing thicknesses and subsequently, its restoration in interaction with hydrocarbons with formation of hydrosulphuric water is described. The technique is developed and the expected card of perspective zones of formation of hydrosulphuric water is constructed.

基于图和流体扰动算法的多无人车编队及避障研究

为解决多无人车编队在存在运动目标、移动威胁与突发威胁等多种情况的复杂环境中的避障问题,设计了一种基于刚性图论和流体扰动算法的多无人车编队避障控制算法。首先,针对编队控制问题,采用图论方法描述多无人车之间的协同关系,利用无人车之间的距离约束,基于反步控制理论设计领航-跟随编队控制器。李雅普诺夫分析表明,期望的编队形状是渐近稳定的。其次,针对复杂动态障碍物环境下的编队避障问题,设计了基于流体扰动算法的避障路径规划方法,由领航无人车规划出编队的行驶路径,实现编队的整体避障。最后,基于MATLAB的仿真结果验证了所提算法的有效性。

领导干部“能上不能下”制度困境的形成机理与破解之道

本文以83名领导干部的访谈内容为研究样本,运用扎根理论,识别出影响领导干部“能上不能下”的因素主要包含实施主体、实施对象、制度本身和运行环境四个维度。具体来说:实施主体在推进干部能上能下过程中出现执行乏力问题;实施对象受到趋利避害的个人偏好的驱动和影响;制度本身存在着操作性障碍;蕴含于特定政治生态环境中的消极因素也成为领导干部“能下”的阻力。相应地提出破解领导干部“能上不能下”制度困境的因应之策:着力提高组工干部队伍的专业化能力,解决好实施主体执行乏力问题;进一步提升广大领导干部的担当精神与大局意识,解决实施对象利己偏好的问题;完善长效化协同化的制度体系,解决制度操作性障碍的问题;不断引导全社会形成包容开放的文化氛围,解决运行环境压力渗透的问题。

2019年湖南攸县7·15大型岩溶地面塌陷的发育分布规律及形成机理

2019年7月15日,湖南株洲市攸县樟井村发生大规模岩溶地面塌陷,严重威胁当地人民群众的生命和财产安全。为查明7·15大型岩溶地面塌陷的形成机理,通过地球物理勘探、水文地质工程地质钻探、地下水监测、水化学分析等多种手段对岩溶地面塌陷区开展了详细的调查研究,分析了该岩溶地面塌陷的发育规律及致灾因素。结果表明:7·15大型岩溶地面塌陷是由降雨主导,在地表覆盖层软化减强、岩溶气爆和渗流潜蚀效应等多种不良因素共同作用诱发的自然塌陷;地面塌陷位于断层、褶皱等构造密集发育的可溶性碳酸盐岩区域,区内岩溶强烈,广泛发育的溶洞、落水洞、泉、地下暗河等岩溶形迹为地面塌陷的形成提供了条件;7·15大型岩溶地面塌陷的形成演化可分为降雨诱发的地表覆盖层土体软化减强和封盖增荷、降雨导致地下水水位上升引发的岩溶气爆、地下水渗流潜蚀加速顶板垮塌形成土洞、土洞扩大及顶板失稳4个阶段。该研究结果可为类似地质条件地区的岩溶地面塌陷预测预报与防治提供科学依据。

中国男足球员职业污名形成机制——基于扎根理论的探索性研究

该研究运用污名化、第三人效应和场域等理论,深度剖析了由“冯巩大战”引发的中国男足球员职业污名现象,构建了由热点事件、应激反应、公众楷模、社会认知等17个范畴以及负面刻板印象、媒体舆论导向、球员生存场域、社会化程度4个主范畴组成的中国男足球员职业污名形成机制理论模型。研究发现:原本就固化于公众心目中的中国男足球员负面刻板印象,经媒体对热点事件的炒作后再次得到加强,并使公众产生相应的负面情绪,当负面情绪遇到球员的“回怼”时,中国男足球员职业污名已不可避免,球员愈想正名愈发污名。研究认为:中国男足球员职业污名既反映了公众对球员的失望和愤怒,亦深层次折射了公众对中国足球理性认知的缺乏,更是当前中国足球社会化程度偏低的现实呈现。研究建议:球员应提升自身的竞技能力,展现拼搏精神,承担社会责任;加强自媒体监管和规范,提倡正向评论,避免夸大负面事件;确保球员权益和利益受到保障,鼓励球员-媒体共生,增强球员心理韧性;建立行业自律,惩戒违规行为,重视足球文化建设。

Atomistic understanding of capacity loss in LiNiO_(2)for high-nickel Li-ion batteries:First-principles study

Combining the first-principles calculations and structural enumeration with recognition,the delithiation process of LiNiO_(2)is investigated,where various supercell shapes are considered in order to obtain the formation energy of Li_(x)NiO_(2).Meanwhile,the voltage profile is simulated and the ordered phases of lithium vacancies corresponding to concentrations of 1/4,2/5,3/7,1/2,2/3,3/4,5/6,and 6/7 are predicted.To understand the capacity decay in the experiment during the charge/discharge cycles,deoxygenation and Li/Ni antisite defects are calculated,revealing that the chains of oxygen vacancies will be energetically preferrable.It can be inferred that in the absence of oxygen atom in high delithiate state,the diffusion of Ni atoms is facilitated and the formation of Li/Ni antisite is induced.

基于扎根理论的上海红色旅游形象感知影响因素与形成机理研究

以上海28个红色旅游景点为研究对象,基于游客在线评论数据,运用内容分析和扎根理论对红色旅游形象感知内容特征、影响因素、形成机理进行了系统性的研究。结果表明:扎根理论分析得到红色旅游形象感知影响因素包括媒体渠道、旅游经验、出游目的等24个要素,可归纳为信息来源、个体因素、核心吸引物等7个维度,并基于游前、游中、游后的时间线索提取出原生/引致形象、复合形象、评判形象3个层次,构建了红色旅游形象感知形成机理模型。依据研究结果,提出上海红色旅游形象分阶段塑造与传播的对策建议。

山东鲁西北地区馆陶组热储及流体化学特征

鲁西北地热区热储主要为层状热储,地温相对于其它地热区均匀,具有较高的热流值和富水性较强的含水层,是山东省地热资源开发潜力最大的地区。鲁西北地区的主要热储之一为新近系馆陶组孔隙裂隙热储层组。研究发现其上部地层发育细—中粒砂岩及泥岩与细粒砂岩互层夹粉砂岩;下部地层发育中细粒砂岩、中粒砂岩及砂砾岩夹泥岩;新近系馆陶组热储层具有顶底板埋深自南向北由浅变深、厚度由薄变厚,在凸起区埋藏浅、厚度薄,凹陷区埋藏深、厚度大等变化规律;地热水化学特征在水平方向具有以下分布特征:水化学类型由南部、东南部的SO_(4)·Cl-Na型向北、西北逐渐过渡为Cl·SO_(4)-Na型至Cl-Na。

基于鸽群优化改进动态窗的多无人车协同编队避障控制

在复杂未知的战场环境中,无人车集群较单台无人车可承担更为复杂的任务,无人车集群协同编队避障行驶是群体智能领域研究热点之一.针对未知环境下无人车集群在规避障碍物时容易出现动态位置与预期队形偏差较大问题,本文提出了一种基于改进动态窗的无人车编队协同避障控制方法,在基本动态窗路径评价函数的方位角评价因子、障碍物评价因子、速度评价因子基础上,增加了无人车编队的方向协同因子和队形保持因子.同时,基于变权重鸽群优化算法对改进动态窗的路径评价函数各系数进行优化.当无人车集群感知到障碍物时,通过改进动态窗算法进行相对位置及速度的自适应协同调整,更好地保证无人车编队避障行驶过程中队形位置的精确性.最后,以3台无人车构成三角形编队避障行驶为例进行仿真验证.仿真结果表明基于改进动态窗和变权重鸽群优化算法的无人车编队在规避障碍物时,队形位置偏差相对较小.可见,本文提出的改进算法能够使得无人车集群在规避障碍物过程中提高动态编队的稳定性和精确性.

执行器故障下无人机无人车异构编队控制

针对存在执行器故障的无人机无人车异构系统,研究了编队跟踪容错控制问题。首先,异构系统采用有向图的拓扑结构,且并非所有无人机/车都能接收到参考信号,故在充分考虑无人机/车运动学模型存在较大差异的前提下,设计了一种针对两类系统都通用的分布式信号估计器来获取参考信号的信息。然后,基于参考信号估计值,利用鲁棒自适应控制理论,提出了形式统一的分布式容错控制协议。该协议无需获取精准故障信息,就能有效地补偿故障对异构系统性能的影响,确保异构系统在故障情况下仍能按照预先设定的编队构型跟踪上外界参考信号。最后,通过仿真试验验证了所提算法的有效性。

基于路网仿射模型的地面编队目标跟踪算法

针对地面多目标跟踪命题,文章首先给出编队目标定义,总结并比较现有编队目标的跟踪方法,在此基础上考虑地面编队目标在路网上编队慢速行进的特点,建立地面编队目标仿射模型,并采用非线性滤波算法对编队整体平移、旋转和缩放行为进行跟踪,从而实现对编队目标的状态估计,进而得到编队目标航迹情报。经数学仿真和实验验证,所提算法具备有效性。

Research on ground fissure origins and mechanisms in Hebei Plain,P.R.China

Ground fissure hazards frequently emerge in Hebei Plain, which damage roads, dams, buildings and farmland. The paper reviews and analyses current state of knowledge and research into ground fissure and geological environment in Hebei Plain. It is shown that the level of research and investigation is in some aspects insufficient. Knowledge is lacking in the use of corresponding geological concept models for specific ground fissures, three-dimensional numerical simulations of ground fissures caused by pumping through soil with pre-existing fractures, numerical simulations of ground fissures caused by dislocation in intersection faults, and the failure criterion and the constitutive relationship of rock and soil. Furthermore, we put forward geological concept models for ground fissure formation following the dislocation of a buried intersection fault, over-exploitation of groundwater and its compound origin mechanisms in order to provide scientific evidence for the quantitative analysis.

δ18O,δD and d-excess signatures of ground ice in permafrost in the Beiluhe Basin on the Qinghai-Tibet Plateau,China

In this paper, stable isotope （δ18O, δD） investigations were completed in ground ice from a deep borehole in the Beiluhe Basin on northern Qinghai-Tibet Plateau to unravel the isotopic variations of ground ice and their possible source water. The δ18O and δD of ground ice show distinctive characteristics compared with precipitation and surface water. The near-surface ground ice is highly enriched in heavier isotopes （δ18O and δD）, which were gradually depleted from top to bottom along the profile. It is suggestive of different origin and ice formation process. According to isotopic variations, the ice profile was divided into three sections： the near-surface ground ice at 2.5 m is frozen by the active-layer water which suffered evaporation. It is possible that ground ice between 3 and 4.2 m is recharged by the infiltration of snowmelt. From 5 to 6 m, the ground ice show complex origin and formation processes. Isotopic variations from 6 to 11.1 m and 20.55 m indicate different replenishment water. The calculated slope of freezing line （S=6.4） is larger than the experimental value （5.76）, and is suggestive of complex origin and formation process of ground ice.

组织韧性的概念结构与形成机制——基于扎根理论的研究

组织韧性作为应对危机的重要手段,其重要性受到学界和业界的关注,但是有关组织韧性的结构与形成机制亟待探讨。鉴于此,该研究在已有研究基础上提出了组织韧性的概念,并基于扎根理论研究方法,深入探究组织韧性的结构及形成机制。研究发现,组织韧性包含了资本韧性、战略韧性、文化韧性、关系韧性和学习韧性5个维度。在维度确立的基础上,构建了组织韧性的形成机制模型,发现组织韧性的形成过程主要存在5类影响因素:组织战略聚焦、组织资本稳健、组织关系互惠、组织文化塑造以及组织学习。最后,从愿景和使命、企业文化塑造、打造学习型组织等层面出发提出提升组织韧性的有效对策,可为未来研究提供借鉴。

空间多体绳系编队动力学与控制研究综述

针对空间多体绳系编队的构型进行了分类,分析了国内外对绳系编队动力学模型的研究现状,并总结了常用于绳系系统动力学模型建立的三种系绳模型。此外,对绳系编队全流程控制,包括绳系编队构型形成、构型稳定保持以及刚体姿态机动控制进行了梳理和分析,同时对现有的地面试验装置及方法进行了概括。最后针对目前绳系编队的动力学建模与控制、地面试验装置研究中存在的不足进行了总结,对未来的发展方向提出了建议。

致密砾岩油藏地层亏空区新井压裂参数优化设计

针对老井地层能量亏空对新井储层改造及生产存在影响的问题,在三维地质及地应力模型的基础上,建立油藏数值模型,结合生产资料研究老井应力场的动态变化规律,基于裂缝扩展模型预测新井裂缝形态特征,并优化压裂设计参数。研究表明:老井开发导致低应力区对邻井裂缝扩展有一定诱导作用,优化新井前置液比例,能够弥补地层能量亏空,避免新井人工裂缝向亏空方向过分延伸,储层改造更充分,压裂后产能更理想。玛湖砾岩油藏H1井组实例应用表明,优选簇间距为25~30 m,用液强度为18 m^(3)/m,单簇前置液量为400 m^(3),能够有效抑制低应力区对新井人工裂缝的诱导,提高支撑剂的铺置浓度。该研究对同类砾岩油藏开发具有重要指导意义。

基于地表位移控制的浅埋盾构管片壁后注浆压力确定方法

采用考虑卸载模量的硬化土小应变模型,模拟分析了不同埋深盾构隧道施工时地表竖向位移随管片壁后注浆压力的变化规律,并从盾构施工微扰动控制角度探讨了壁后注浆压力的确定方法。结果表明:随壁后注浆压力增大,不同埋深下地表竖向位移均可分为沉降敏感阶段、稳定阶段和隆起敏感阶段;壁后注浆压力应在隧道顶部上覆土自重应力的基础上进一步增大,以顶起上覆土,弥补超挖引起的地表沉降;当地层损失补偿率与地层损失率接近时,可达到盾构施工微扰动控制要求,据此提出一种综合考虑地表竖向位移、地层损失率、地层损失补偿率的壁后注浆压力范围确定方法。

面向中继通信的空地协同无人机编队控制算法设计与仿真

随着无人机(UAV)应用场景的不断丰富,近年来利用无人机编队实现空地协同的任务日益增多。根据现阶段的编队体系和控制方法,该文设计一种基于行为策略的空地协同无人机编队控制算法:通过引入空地协同思想,为地面移动用户提供中继通信服务,扩大了无人机编队的通信覆盖范围。为7架无人机组成的编队设计了4种无人机队形,推导相应的单位中心站位标准,并使用Unity软件对空地协同无人机编队控制算法进行仿真,测试使用该算法的无人机编队在理想环境下的转弯性能和模拟实际环境下的避障、中继通信以及队形变化能力。基于所提出的空地协同算法,设计了两种任务方案:区域搜索覆盖主任务方案和用户失联搜救应急方案。实验仿真证明了改进的空地协同无人机编队控制算法及两种方案具有可行性。

在线学习失信行为的驱动因素与形成机制研究——基于扎根理论

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