Results 51 to 60 of about 13,853 (179)
, 2009 通过岩石加载的室内试验方法,测试不同岩石破裂全过程的力学特征及其声发射特性,得到岩石破坏全过程力学特性——岩石的全应力-应变曲线、声发射事件累积数、声发射事件率等相关曲线及参数,给出声发射事件数、事件率与应力水平、时间之间的关系。着重讨论一次性加载过程中塑性变形阶段明显的岩石在加载接近峰值强度时单位时间内的应力增长速度减小,也即这一阶段出现明显的"耗时"现象;并且在此阶段监测到的声发射事件率出现明显下降,出现声发射相对平静阶段;而对于塑性变形阶段不明显的岩石来说,这一阶段则基本不存在明显的"耗时"现象 ...
唐海燕 +3 more
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Study on pore structure and fractal characteristics of middle rank coal reservoir in Longtan Formation of Panguan syncline [PDF]
In order to study the pore structure characteristics of middle rank coal reservoirs, we qualitatively and quantitatively analyzed the pore structure characteristics of 15 middle rank coal samples from different coal seams in 8 parameter wells in the ...
Jun CHEN, Wei GAO, Yu LONG, Zhonghu WU
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Ultrasound in Obstetrics &Gynecology, Volume 65, Issue 5, Page 624-632, May 2025.ABSTRACT Objectives Placental insufficiency contributes to many obstetric pathologies, but there is no bedside clinical tool to evaluate placental perfusion. We have developed a method to acquire multiple three‐dimensional (3D) power Doppler (PD) ultrasound (US) volumes of placental vasculature, with infrared camera tracking of the precise spatial ...
A. Xue +5 more
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Shuitu Baochi Xuebao, 2016 采集广东省主要成土母质（玄武岩、砂页岩、第四纪红土和花岗岩）发育的林地、耕地和园地土壤剖面各发生层土壤，测定了土壤颗粒组成、有机质、CEC等理化性质，探讨了不同母质发育土壤颗粒分布的分形维数特征及其与土壤理化性质的关系。结果表明，玄武岩、第四纪红土、花岗岩和砂页岩发育土壤分形维数变幅分别为2.923 9～2.981 2，2.858 8～2.937 7，2.769 3～2.923 1和2.544 6～2.885 6；玄武岩和第四纪红土发育土壤颗粒分布分形维数与砂页岩发育土壤存在显著差异 ...
姜 坤 +5 more
doaj
Impacts of coal fracture roughness and aperture on the seepage of injected water: An experimental study [PDF]
ObjectiveWater injection into coal seams is recognized as a critical technical measure for dust removal and the prevention and control of coal and gas outbursts and rock bursts in coal mines.
Gang WANG +4 more
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China's Eco‐Civilisation, Climate Leviathan, and Hobbesian Energy Transition
Antipode, Volume 57, Issue 3, Page 830-861, May 2025.Abstract Scholars have hitherto tended to theorise China's ecological civilisation project either as a form of environmental authoritarianism or as a vision of eco‐socialism. This paper contributes to the conversation by conducting a textual analysis of Chinese scholarly discussions on eco‐civilisation.
David Chen
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Shuitu Baochi Xuebao, 2016 以胶东半岛丘陵区7个集水区为研究对象，采用SA模型提取研究区冲沟系统，测算冲沟沟长盒维数，分析沟长分形特征及其与地形参数和土地利用类型间的关系，厘定研究区内冲沟发育演化的特征及规律。结果表明：(1) 东部构造活动性强的隆起区分维值明显高于西部构造活动性弱的沉积凹陷区沉降区，沟长分形特征主要受区域地质构造控制。(2) 沟长分维数与平均坡度、地表粗糙度、剖面曲率、沟壑密度和沟头密度等地形参数之间相关性显著，而与集水区面积和沟长没有相关性。(3) 沟头密度、沟壑密度与沟长分维数间具有极显著正相关性 ...
王 +4 more
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Damage and failure mechanism of pre-static loaded rock under cyclic impact [PDF]
To study the damage and failure mechanism of rocks under the coupling effect of high ground stress static load and cyclic impact disturbance generated by mining and excavation, the multi-strain rate dynamic static superposition rock mechanics test system
Bing ZHANG +4 more
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Building resilient social protection: Lessons from Türkiye's earthquake response
International Social Security Review, Volume 78, Issue 2-3, Page 97-122, April-September 2025.Abstract This article assesses the functioning and disaster response capacity of the Turkish social security system in the aftermath of the Kahramanmaraş‐centred earthquake that struck southeastern Türkiye on 6 February 2023, affecting 11 provinces. Türkiye's social security infrastructure, which was restructured after the 1999 Marmara earthquake, has ...
Oğuz Karadeniz
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Chaotic phenomenons in observation series of water consumption(用水量时间观测序列中的分形和混沌特性)
Zhejiang Daxue xuebao. Lixue ban, 2004 探讨了城市不同用水量时间观测序列中的分形和混沌特性.对城市日用水量、时用水量及各日典型时段(9 时、2时）用水量观测序列按照关联维数求算吸引子维数.计算结果表明，不同城市用水量观测序列的吸引子维数均以分数形式存在，且各时段用水量序列分形维计算结果明显不同；相反，相同序列不同起始时刻的计算结果比较接近和稳定.研究初步表明用水量观测序列中除了通常认为的周期性、趋势性及随机扰动性成分以外，还存在有较为明显的混沌成分.以上结论的得出对用水量需求预测的方法研究和系统建模具有积极意义.
LIUJing-qing(柳景青)
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