Results 31 to 40 of about 13,790 (168)
Study on the influence of close range coal seam mining relationship on the deformation law of surrounding rock in lower roadway [PDF]
When the mining relationship between the upper coal seam working face and the lower coal seam roadway in the close distance coal seam changes, the deformation and instability mechanism of the surrounding rock of the roadway will be more complicated.
MA Yang, SUN Jiarui, ZHANG Xiaojun
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Legislating Uncertainty: Election Policies and the Amplification of Misinformation
Policy Studies Journal, EarlyView.ABSTRACT Can state election policies affect the spread of misinformation? This paper studies the role played by ballot processing policies, which determine when ballots can be examined and organized, in the online spread of political misinformation. We present evidence from the 2020 U.S.
Morgan Wack +5 more
wiley +1 more source
Gaoya dianqi, 2021 不同结构型式的特高压直流滤波器耦联回路中滤波电容在地震作用下地震响应特征相差较大,其抗震性能需要进行深入研究。文中以某特高压悬吊式直流滤波电容器和支撑式直流滤波电容器为原型结构,建立了两类特高压直流滤波器耦联回路有限元模型,从位移、内力和加速度3个方面对比了三向地震作用下两类回路中滤波电容器抗震性能。结果表明:在顶层高压管母线连接处悬吊式滤波电容器的水平双向合位移比支撑式大,且悬吊式加速度响应峰值多集中在底层而支撑式多集中在顶层。悬吊式滤波电容器内力安全系数满足规范建议值且富余度较大 ...
赖炜煌 +4 more
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Temporal and spatial evolution law of microseisms and induced impact mechanism in complex spatial structure area of steep and extremely thick coal seam [PDF]
The occurrence of coal mine rock burst disasters is closely related to the spatial structure, especially in the complex spatial structure area. It is of great significance to master the law of coal and rock catastrophe and reveal its mechanism in the ...
Changliang LU +8 more
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Wildlife Letters, Volume 4, Issue 1, Page 32-41, March 2026.Effective wildlife law enforcement is important in the drive for biodiversity conservation. This study examined the challenges of wildlife law enforcement in Oyo and Lagos States of Nigeria across four security outfits (Nigerian Police Force [NPF], Nigerian Customs Service [NCS], National Environmental Standards and Regulations Enforcement Agency ...
Oluwatosin Mercy Dada +2 more
wiley +1 more source
Jianzhu Gangjiegou Jinzhan, 2016 H形钢悬臂柱柱脚焊缝的疲劳性能对钢柱疲劳寿命起控制作用,应用热点应力的表面外推法,通过建立数值计算模型,对弯矩、扭矩和弯扭共同作用下柱脚焊缝热点应力进行了分析。选取翼缘与底板厚度比(t1/t2)、翼缘和腹板厚度比(t1/t3)、腹板厚度(t3)与型钢截面高度(h)作为影响因素,对热点应力集中系数SCFhs进行参数分析。分析结果表明,其它条件不变的情况下,弯矩作用下的热点应力集中系数SCFmhs随着(t1/t3)和(t3)的增大而减小,但与(t1/t2)关系不大,h增加可导致SCFhs增大,建议取为1 ...
张晨阳, 芦燕
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Jianzhu Gangjiegou Jinzhan, 2021 针对我国装配式钢结构建筑推广应用过程中的标准化、模块化和产业化需求,提出了一种竖向承重体系和抗侧力体系相分离的新型组合结构体系,并基于这一概念提出了一系列适用于多层和高层住宅建筑的高性能结构方案。通过大比例试验、高效数值模拟和性能评价等方法对该种新型体系的抗震性能开展了深入研究,充分证明了其在地震区应用的可行性。另外,开展了与该新型结构体系相配套的集成式楼盖和一体化外围护墙板的研究,分别围绕集成式楼盖及节点的力学机理和一体化外围护墙板的保温性能、隔声性能、受弯性能以及与结构的协同受力性能展开了系列研究 ...
赵鹤 +8 more
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Study on pressure relief range of overlying strata and accurate gas extraction of adjacent strata in superimposed mining of coal seam [PDF]
Aiming at the mining problem of No.9 coal seam with strong outburst danger in Xinyuan Coal Mine, we proposed that to mine No.3 coal seam as the upper protective layer first, by analyzing the failure mechanism of roof and floor after coal seam mining, the
Haidong WANG +5 more
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Experimental methods for wind tunnel studies of seed dispersal by wind
Applications in Plant Sciences, Volume 14, Issue 1, January-February 2026.Abstract The complexity and variability of natural environments make quantitative studies of seed wind dispersal challenging. Wind tunnel experiments offer a controlled alternative to investigate the mechanisms of seed wind dispersal. This review focuses on wind tunnels and the associated technologies used for studying seed wind dispersal, including ...
Liang Tian +5 more
wiley +1 more source
基于AWE GCB/GIS自力型触头接触压力分析及应力集中系数初探
Gaoya dianqi, 2014 为实现参数化分析,在AWE（ANSYS workbench environment）集成的DM（design modeler）环境中建立模型,并合理简化。在AWE集成开发环境下,设置自力型触头的工况对其进行接触压力分析,并对结果进行了理论计算校核。考虑到触指根部两侧小范围存在应力集中现象,利用DOE法（the design of experiments method）建立对应的参数化数值模拟,并对其小样本采集分析。根据计算结果确定其应力集中系数在1.201.27范围内变动。
张沛文, 陈伯荣, 周庆清
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