Results 81 to 90 of about 15,266 (166)
Effect of Supercritical Carbon Dioxide (SCCO2) on the mechanism of change in pore and fracture structure of coal with different moisture content [PDF]
When the CO2 in a supercritical state (SCCO2) is released from deep coal seams, it reacts with minerals in coal, changing the porosity of coal, which in turn affects the effect of CO2 sequestration in coal seams and the effect of increasing methane ...
Lei HAN +4 more
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Shuitu Baochi Xuebao, 2008 探讨干旱缺水地区灌溉方式对果园土壤物理性质的影响,为采取合理的果园节水灌溉措施、有效利用灌溉水资源提供科学依据。以鲁中南山地果园为研究区域,利用分形理论,对渗灌和漫灌条件下果园土壤物理性质及其分形特征进行了研究。结果表明:(1)渗灌和漫灌土壤物理性质存在着明显的异质性,二者差异显著,土壤容重渗灌比漫灌降低6.71%;土壤总孔隙度、非毛管孔隙度和毛管孔隙度渗灌比漫灌分别高11.62%,43.84%和8.72%。(2)渗灌和漫灌土壤粒径分布存在明显差异,土壤的粘粒和粉粒含量渗灌高于漫灌 ...
高鹏 +4 more
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Study on Acoustic Emission Characteristics of Tunnel Wall Rock of North Wuyi Mountain in Laboratory [PDF]
, 2015 作为一种无损检测技术，声发射与微震监测技术常被用作研究脆性材料在荷载作用下失稳破坏的工具，它是利用声波或地震原理来探测岩爆发生前岩体破裂的前兆特性，进而对可能要发生的岩爆进行评估和预警。北武夷山隧道福建段有长约1150m施工段埋深在644.3~1100m之间，属于极高应力区。在这样的大埋深、高地应力条件下进行隧洞开挖，极易在开挖过程中引起岩爆，因此在施工掘进过程中，采用声发射与微震监测技术对隧洞围岩体稳定性进行连续、实时监测。为更好地开展施工现场的声发射微震监测预警工作 ...
林朝阳
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Surface Roughness Measuring Based on the Theory of Fractal Geometry [PDF]
, 2014 机械工业中表面粗糙度是影响机械零件和产品性能的一个重要因素，是评定各种机械工件表面加工质量的一个重要指标。因此在实际生产中对工件表面粗糙度的测量和评定十分重要。随着表面加工精度的不断提高和粗糙度评定标准的不断更新，对表面粗糙度的测量和评定提出了更高的要求。 目前触针式测量技术以其稳定性、可靠性、客观性仍被广泛运用；表面粗糙度评定方法也仍以传统轮廓法为主，即采用几组尺度相关的统计参数Ra、Rz等作为主要评定参数。然而研究表明，对同一测量表面而言 ...
吴丁贵
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Experimental study on the evolution characteristics of bituminous coal pore-fissure structure under multiple vibration loads [PDF]
Frequent mining disturbance or periodic rupture of far-field roof in coal seam mining will produce multiple vibration loads, which have an important influence on the micro pore-fissure structure and macro mechanical behavior of coal.
Chao WANG +5 more
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Zhejiang Daxue xuebao. Lixue ban, 2016 广义多项时间分数阶扩散方程已被用于描述一些重要的物理现象，目前，有关该类方程在高维情形下满足混合边界条件的研究仍较少.利用分离变量法考虑有界区域上广义二维多项时间分数阶扩散方程，方程中关于时间变量的分数阶导数采用Caputo分数阶导数的定义，其阶分别定义在[0，1]，[1，2].而关于空间变量的偏导数则定义为传统的整数阶导数（二阶），得到了有界区域上广义二维多项时间分数阶扩散方程满足非齐次混合边界条件的解析解.亦可用于求解其他类型的满足不同边界条件的分数阶微分方程的解析解.
WANGXuebin(王学彬)
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Mechanical properties and crack propagation law of coal under different CO2 adsorption time [PDF]
The structural deformation caused by CO2 adsorption has a significant effect on the stability of coal seam. The authors studied the effect of CO2 adsorption time on the mechanical properties of coal and analyzed the variation of mechanical parameters of ...
CHEN Lipeng +5 more
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Study on stress evolution and damage fracture of cut blasting in high in-situ stress roadway [PDF]
In recent years, the mining state of mineral resources has changed from open air to underground and from shallow to deep. In the drilling and blasting construction of deep rock masses, in-situ stress has a significant impact on the blasting effect.
Chenxi DING +6 more
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Shuitu Baochi Xuebao, 2011 研究了子午岭林区七种植被类型土壤>0.25 mm水稳性团聚体含量、团聚体破坏率和水稳性团聚体分形维数随植被恢复的变化规律以及这3个指标随土壤有机碳含量增加的变化规律。结果表明:植被恢复对>0.25 mm水稳性团聚体含量、团聚体破坏率和水稳性团聚体分形维数的影响可以达到70 cm土层;除白羊草群落外,0-70 cm土层上>0.25 mm水稳性团聚体含量随植被恢复逐渐提高,团聚体破坏率和水稳性团聚体分形维数随植被恢复逐渐减小,土壤结构随植被恢复逐渐改善。>0.25 mm水稳性团聚体含量 ...
马帅 +4 more
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Shuitu Baochi Xuebao, 2011 基于土壤颗粒分形维数及EPIC模型研究定植皇竹草植物篱,对三峡库区坡耕地土壤分形特征及土壤可蚀性的影响作用。结果表明:植物篱对坡面土壤粘粒的拦截作用显著,粘粒在篱前富集含量升高;土壤分形维数与土壤砂粒含量呈负相关,与粉粒、粘粒含量呈正相关,总体上表现为:粘粒>砂粒>粉粒,土壤颗粒分形维数值受细颗粒含量的影响作用显著;土壤可蚀性K值与土壤砂粒含量呈极显著的正相关,相关系数为0.870;与土壤粉粒含量、粘粒含量、有机碳含量、团聚度及土壤颗粒分形维数呈负相关,相关系数分别为-0.538,-0.739,-0 ...
马云 +6 more
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