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近距离煤层回采巷道非对称性破坏机理与演化规律研究

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中国矿业大学学报 2021年第6期50卷 1029-1040,1050页

作者：赵洪宝程辉吉东亮王涛王伊阔蒋长宝中国矿业大学(北京)能源与矿业学院北京100083 重庆大学煤矿灾害动力学与控制国家重点实验室重庆400030 太原理工大学安全与应急管理工程学院山西太原030024

近距离煤层开采过程中,上位煤层的工作面回采与煤柱应力集中均会对下位煤层巷道围岩稳定性造成较大影响.本文以回坡底煤矿11^(#)煤层1021巷为工程背景,探究巷道在受到10^(#)煤层103工作面回采与煤柱应力集中情况下产生非对称性破坏的机... 详细信息

近距离煤层开采过程中,上位煤层的工作面回采与煤柱应力集中均会对下位煤层巷道围岩稳定性造成较大影响.本文以回坡底煤矿11^(#)煤层1021巷为工程背景,探究巷道在受到10^(#)煤层103工作面回采与煤柱应力集中情况下产生非对称性破坏的机理与演化规律.研究结果表明:受103工作面前方支承压力与煤柱应力集中影响的区域巷道处于拉-压偏应力场之中,此位置的巷道最容易发生破坏变形,而位于工作面后方与前方原岩应力处的区域巷道均处于压偏应力场中;不同位置处的巷道所受最大、最小主应力均发生一定角度的偏转,但应力偏转程度不同.考虑中间主应力作用时,侧压系数λ>1条件下,巷道顶底板不同深度处最大、最小偏应力呈"八"字形分布,两帮最大、最小偏应力呈"√"形分布,巷道围岩偏应力差整体呈倾斜的"8"字形分布.随着103工作面的回采,1021巷围岩塑性区由倾斜的"O"形分布向倾斜的"X"形分布演化,呈对角式发育,最大塑性区半径达到6 m;针对1021巷出现的非对称性破坏,在受103工作面前方支承压力与煤柱影响的区域巷道进行单体液压支柱与工字钢梁配合的补强支护;同时,基于1021巷原支护技术提出了合理的巷道支护优化设计方案.

关键词：近距离煤层非对称性破坏偏应力场塑性区演化合理支护

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煤层纳米孔隙结构对瓦斯运移特性的影响研究

采矿与安全工程学报 2022年第6期39卷 1256-1264,1271页

作者：赵洪宝秦逢缘李作泉程辉王伊阔中国矿业大学(北京)能源与矿业学院北京100083 甘肃靖远煤电股份有限公司甘肃白银730913

为探讨煤层纳米级孔隙结构对瓦斯运移特性影响机理,选取霍尔辛赫煤矿3号煤层煤样进行小角X射线散射试验,得出该煤层煤体纳米范围内孔隙结构参数及分布特征。基于试验所取得参数,并结合实际地温和储层压力条件进行数值模拟,引入运移通道... 详细信息

为探讨煤层纳米级孔隙结构对瓦斯运移特性影响机理,选取霍尔辛赫煤矿3号煤层煤样进行小角X射线散射试验,得出该煤层煤体纳米范围内孔隙结构参数及分布特征。基于试验所取得参数,并结合实际地温和储层压力条件进行数值模拟,引入运移通道可达性系数和运移时间定量表征瓦斯输运效率。结果表明:煤样纳米孔隙中瓦斯的主要运移方式为过渡流。孔隙通道内各初始条件对瓦斯运移特性影响不同,孔隙通道可达性系数随孔隙直径的增加而增加。受气体滑脱效应影响,15nm以下通道运移时间随尺度增大急剧衰减。通道内瓦斯运移受启动压力和浓度梯度共同作用,启动压力克服阻力,浓度梯度决定后续运移,运移时间受浓度增益和碰撞阻力效果共同作用。微孔内,运移通道变窄时,可达性系数及运移时间均与窄通道直径正相关;运移通道变宽时,可达性系数受窄通道长度与宽通道直径共同作用,运移时间与可达性系数存在最大差值区域。微孔内,可达性系数与通道几何参数有关,通过数据拟合,并引入太沙基有效应力得出煤层受应力作用下微孔通道瓦斯输运效率的表征公式,拟合效果良好。

关键词：孔隙结构瓦斯运移可达性系数运移时间

非等压应力场巷道围岩主应力差分布规律与稳定性分析

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采矿与安全工程学报 2021年第6期38卷 1111-1121页

作者：赵洪宝程辉刘绍强秦逢缘王伊阔中国矿业大学(北京)能源与矿业学院北京100083

采用理论分析、数值模拟方法对非等压应力场巷道围岩主应力差分布规律与稳定性进行研究,重点分析不同侧压系数下巷道顶底板与两帮的主应力差分布演化规律、塑性区形态和变形演化规律。研究结果表明:侧压系数λ1时,顶底板破坏范围大于两... 详细信息

采用理论分析、数值模拟方法对非等压应力场巷道围岩主应力差分布规律与稳定性进行研究,重点分析不同侧压系数下巷道顶底板与两帮的主应力差分布演化规律、塑性区形态和变形演化规律。研究结果表明:侧压系数λ1时,顶底板破坏范围大于两帮。基于数学拟合得到巷道围岩最大主应力差轨迹线方程,该式可计算出围岩破坏最严重区域。巷道在围岩四周会形成主应力差承载壳,λ增大过程中,承载壳形态演化过程为:水平的类"8"字形→扁平椭圆形→圆形→瘦高椭圆形→类"8"字形。顶底板主应力差峰值随着λ的增大而增大,并向围岩深部转移,两帮峰值随着λ的增大而减小,向围岩浅部转移。巷道围岩塑性区总是分布在主应力差承载壳内,其形态演化过程与主应力差承载壳保持一致。λ增大过程中,巷道顶底板位移曲线离散程度不断增大,两帮位移曲线离散程度先减小后增大。λ顶底板表面位移;λ>1时,顶底板表面位移>两帮表面位移。λ越接近1,巷道围岩稳定性越好。以回坡底煤矿11-1021巷为工程背景,研究发现巷道围岩主应力差呈倾斜的类"8"字形分布,理论分析结果与巷道实际破坏情况吻合,验证了理论的正确性。

关键词：非等压应力场侧压系数主应力差承载壳塑性区

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不透气夹矸层对煤层瓦斯运移特性影响研究

采矿与安全工程学报 2020年第4期37卷 852-860页

作者：赵洪宝李金雨刘一洪王伊阔王宏冰任朝鹏中国矿业大学(北京)能源与矿业学院北京100083 矿山地质灾害成灾机理与防控重点实验室陕西西安710054

为探究不透气夹矸层对煤层瓦斯运移特性的影响,利用自主研发的"一种恒压式煤岩体瓦斯渗流装置"对不同大小和位置形态的不透气夹矸层对煤层瓦斯运移特性的影响进行了系统研究,并对其影响机理进行了深入分析,最后提出了含夹矸煤层瓦斯运... 详细信息

为探究不透气夹矸层对煤层瓦斯运移特性的影响,利用自主研发的"一种恒压式煤岩体瓦斯渗流装置"对不同大小和位置形态的不透气夹矸层对煤层瓦斯运移特性的影响进行了系统研究,并对其影响机理进行了深入分析,最后提出了含夹矸煤层瓦斯运移的等效表征。研究表明:全煤试样、含夹矸试样的渗透因子随瓦斯吸附平衡压力的增加呈现"V"字形变化规律,存在一个渗透因子最低时的临界瓦斯压力点;随夹矸层面积的增加,煤层内有效渗流面积不断减小,导致其渗透系数呈负函数降低;夹矸层的位置直接影响着煤层内瓦斯压力分布规律,根据瓦斯压力分布特征可大致分为膨胀影响区、稳定渗流区和上下有效渗流区4个影响区域,且夹矸层越靠近瓦斯源位置,膨胀影响区越小,对瓦斯运移的抑制作用越大。

关键词：不透气夹矸夹矸大小与位置渗透特性等效表征

“两进一回”通风系统氧化带宽度影响因素分析

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煤矿安全 2022年第6期53卷 153-160页

作者：王宁邵嗣华李作泉权继业秦逢缘王伊阔甘肃靖远煤电股份有限公司魏家地煤矿甘肃白银730900 中国矿业大学(北京)能源与矿业学院北京100083 甘肃靖远煤电股份有限公司甘肃白银730900

为使“两进一回”通风系统应用效果最佳,降低采空区遗煤自燃危险性,基于理论分析结合COMSOL数值模拟软件,依托魏家地煤矿北1103工作面工程背景,针对第2进风巷不同布设位置、两进风巷风量配比、进风侧封堵墙宽度及工作面推进距离进行了研... 详细信息

为使“两进一回”通风系统应用效果最佳,降低采空区遗煤自燃危险性,基于理论分析结合COMSOL数值模拟软件,依托魏家地煤矿北1103工作面工程背景,针对第2进风巷不同布设位置、两进风巷风量配比、进风侧封堵墙宽度及工作面推进距离进行了研究,分析了不同工况下采空区氧气体积分数及氧化带范围。结果表明:第2进风巷位置对采空区氧化带范围影响较大,当通防巷位于进风巷右侧0.618D(D为工作面倾向长度)位置时,最大氧化带宽度为23 m;通过改变两进风巷风量配比可减小氧气影响区域,改变采空区氧化带范围;进风巷一侧封堵墙的存在可一定程度抑制采空区漏风,但存在最佳封堵范围;随工作面推进,120 m后采空区氧化带范围整体趋于稳定。

关键词： “两进一回”通风系统氧化带布设位置风量配比采空区

Swarm intention identification via dynamic distribution probability image

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Chinese Journal of Aeronautics 2024年第10期37卷 380-392页

作者： Yinhan wang Jiang wang Shaoming HE Fei wang Qi wang School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Institute of Computing Technology Chinese Academy of SciencesBeijing 100190China

In the realm of decision-making for defense and security applications,it is paramount to swiftly and accurately identify the intentions of incoming *** identification methods predominantly focus on single-target applications and overlook the perturbations introduced by measurement *** this study,we propose a novel concept:the Dynamic Distribution Probability(DDP)image,which is constructed using the estimated state and its covariance *** grayscale pixel value within the image signifies the probability of the presence of the agent within the *** proposed identification scheme integrates the use of Extended Kalman Filter(EKF),Convolutional Neural Network(CNN),Back Propagation(BP)network,and Gated Recurrent Unit(GRU)***,the DDP image is processed through a CNN to distill the formation characteristics,and the estimated swarm state from EKF is inputted into a BP network to deduce the kinematic *** outputs from both networks are summed and subsequently channeled into a GRU network to capture temporal *** numerical simulations and flight experiments are presented to demonstrate the robust anti-noise capability of the proposed scheme compared with conventional methods,as well as its superior training efficiency.

关键词： Intention Identification Kalman filters Convolutional neural networks Swarm intelligence

The reformation of catalyst:From a trial-and-error synthesis to rational design

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Nano Research 2024年第4期17卷 3261-3301页

作者： Ligang wang Jiabin Wu Shunwu wang Huan Liu Yao wang Dingsheng wang Department of Chemistry Tsinghua UniversityBeijing 100084China

The appropriate catalysts can accelerate the reaction rate and effectively boost the efficient conversion of various molecules,which is of great importance in the study of chemistry,chemical industry,energy,materials and environmental ***,efficient,environmentally friendly,and easy to operate synthesis methods have been used to prepare various types of *** previous studies have reported the synthesis and characterization of the aforementioned catalysts,more still remain in trial and error methods,without in-depth consideration and improvement of traditional synthesis ***,we comprehensively summarize and compare the preparation methods of the trial-and-error synthesis strategy,structure–activity relationships and density functional theory(DFT)guided catalysts rational design for nanomaterials and atomically dispersed *** also discuss in detail the utilization of the nanomaterials and single atom catalysts for converting small molecules(H_(2)O,O_(2),CO_(2),N_(2),etc.)into value-added products driven by electrocatalysis,photocatalysis,and ***,the challenges and outlooks of mass preparation and production of efficient and green catalysts through conventional trial and error synthesis and DFT theory are featured in accordance with its current development.

关键词： trial-and-error synthesis structure–activity relationships density functional theory(DFT)guidance nanomaterials atomically dispersed catalysts

Numerical Analysis of PRISM-PY Calculations for Hard-and Soft-Core Generic Polymer Models

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Chinese Journal of Polymer Science 2024年第4期42卷 532-543页

作者： Qiang wang Department of Chemical and Biological Engineering Colorado State University1370 Campus DeliveryFort CollinsCO80523-1370USA

Generic polymer models capturing the chain connectivity and excluded-volume interactions between polymer segments can be classified, according to whether or not the 3D integral of the latter diverges, into hard- and soft-core models. Taking homogeneous systems of compressible homopolymer melts (or equivalently homopolymer solutions in an implicit, good solvent) in the continuum as an example, we recently compared the correlation effects on the structural and thermodynamic properties of the hard- and soft-core models given by the polymer reference interaction site model (PRISM) theory with the Percus-Yevick (PY) closure (Polymers 2023, 15, 1180). Here we analyzed in detail the numerical errors and behavior of the interchain pair correlation functions (PCFs) given by the PRISM-PY calculations of these models using an efficient numerical approach that we proposed. Our numerical approach has the least number of independent variables to be iteratively solved, analytically treats the discontinuities caused by the non-bonded pair potential (such as that of the hard spheres) and takes only the inverse Fourier transform of the interchain indirect PCF between polymer segments (which is continuous and decays towards 0 with increasing wavenumber much faster than both the interchain direct and total PCFs), and is essential for us to accurately solve the PRISM-PY theory for chain length N as large as 106. To capture the correlation-hole effect, the real-space cut-off in the PRISM calculations should be proportional to the square root of N.

关键词： Generic polymer models Soft potentials Polymer reference interaction site model theory

Linear-Quadratic Pareto Cooperative Game for Mean-Field Backward Stochastic System

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Journal of Systems Science & Complexity 2024年第3期37卷 947-964页

作者： wang Yu School of Control Science and Engineering Shandong UniversityJinan 250061China

This paper focuses on a Pareto cooperative differential game with a linear mean-field backward stochastic system and a quadratic form cost functional. Based on a weighted sum optimality method, the Pareto game is equivalently converted to an optimal control problem. In the first place,the feedback form of Pareto optimal strategy is derived by virtue of decoupling technology, which is represented by four Riccati equations, a mean-field forward stochastic differential equation(MF-FSDE),and a mean-field backward stochastic differential equation(MF-BSDE). In addition, the corresponding Pareto optimal solution is further obtained. Finally, the author solves a problem in mathematical finance to illustrate the application of the theoretical results.

关键词： Backward stochastic differential equation linear-quadratic control mean-field Pareto optimality