Results 11 to 20 of about 15,266 (166)
Influence of diameter of empty hole on the fragmentation effect of parallel cut blasting under confining pressure [PDF]
, 2023 Cut blasting is the key technology for roadway blasting excavation. High confining pressure has obvious inhibition effect on cut blasting effect, while empty hole is of great significance to improve cut blasting efficiency, but the relevant research is ...
Baohe ZHU +6 more
core +1 more source
Electrical response and pore structure evolution affected by cyclical plasma breakdown [PDF]
, 2023 Artificial improvement of coal seam permeability is the key to solve the low gas drainage efficiency and prevent gas dynamic disaster. Plasma based on physical discharge is one of the effective means of coal seam antireflection. However, previous studies
Baiquan LIN +3 more
core +1 more source
Permeability and microstructure of pyrolysis lignite [PDF]
, 2023 In order to study the influence of micro pore fissure structure on permeability under the thermal-fluid-solid coupling during lignite pyrolysis, real-time CT scanning of lignite during low-temperature pyrolysis was carried out by using the μCT225kVFCB ...
Feng LIN +3 more
core +1 more source
Zhejiang Daxue xuebao. Lixue ban, 2017 分形维数是壳聚糖絮凝中药水提液絮体的重要参数，采用图像法测定絮体的分形维数，并应用Zeta电位仪测定了絮凝体系的ζ电位，对絮凝机理和絮凝效果进行了研究.选用壳聚糖作为絮凝剂，对白芍水提液进行净化除杂，通过改变絮凝剂投加量、絮凝温度、絮凝pH值等操作条件，探究这些因素对絮凝效果的影响，分析不同条件下絮体分形维数的变化规律：随着絮凝剂投加量的增加，絮体分形维数呈下降趋势；絮体分形维数随温度或pH值的升高出现先增大后降低的情况.通过正交实验确定白芍水提液的最佳工艺条件为絮凝剂投加量0.310 g • L-1 ...
ZHANGJianwei(张建伟) +3 more
doaj +1 more source
Zhejiang Daxue xuebao. Lixue ban, 2023 以研究二维自治g-Navier-Stokes方程解的全局渐近性为目的，用算子分解方法证明了在有界区域上含非线性阻尼的二维自治g-Navier-Stokes方程解的双全局吸引子存在性，并估计了其Hausdorff 维数和Fractal维数。结果表明，该方程解的双全局吸引子存在且具有有限的Hausdorff 维数和有限的分形维数。
王小霞(WANG Xiaoxia) +2 more
doaj +1 more source
Computer simulation for fractal aggregates on nonlattice substrates(无格点基底表面分形凝聚体的计算机模拟)
Zhejiang Daxue xuebao. Lixue ban, 2000 对具有周期性边界条件的无格点正方形基底表面分形凝聚体的形成进行了计算机模拟。凝聚体由二种大小不同的圆盘组成。结果表明，凝聚体的分形维数几乎与表面覆盖率成正比，其斜率随圆盘的平均直径的增大而减小。当表面覆盖率很小时，分形维数几乎与圆盘的平均直径无关，约为1.45；当表面覆盖率较大时，分形维数随圆盘的平均直径的增大而减小。
XIAA-gen(夏阿根) +3 more
doaj +1 more source
Fracture network complexity of tight sandstone and its influencing factors [PDF]
Objective Fracture network analysis plays an important role in oil and gas exploration and development. However, complexity analysis of tight sandstone fracture networks and their control factors is relatively lagging.
FENG Xingqiang +4 more
core +1 more source
Zhejiang Daxue xuebao. Lixue ban, 2005 计算一类Sierpinski地毯的Hausdorff测度，利用投影降低分形维数及分形的分细分析方法，得到了这一类Sierpinski地毯的Hausdorff测度准确值.当这类Sierpinski地毯的Hausdorff维数s ∈ [log54，1]时，有Hausdorff测度准确值为Hs(S) = 1.
HEQin-bin(贺勤斌)
doaj +1 more source
Zhejiang Daxue xuebao. Lixue ban, 2008 在扩散限制凝聚(DLA)模型基础上，采用Monte Carlo方法模拟了具有幂次相互作用的磁性粒子动力学凝聚过程.重点研究了在不同幂指数α值下团簇的形貌及其分形维数Df随耦合参数βC的演化规律.模拟结果表明：对于较大的α值，即α=5时，团簇形貌随βC的变化较小，其分形维数Df 一般在1.60~1.70；而随着α值的减小，团簇形貌随参数βC有一明显的演化过程，在模拟范围内，分形维数Df在1.20~1.95.
WANGFeng-fei(王凤飞) +2 more
doaj +1 more source
PFU微型生物群落监测中异养性指数的应用研究及其分形分析 [PDF]
, 2004 对常德和汉江的异养性指数(HI)进行了分形分析,表明异养性指数在二维空间分布具有自相似性.异养性指数数据点与化学综合污染指数(P)数据点在双对数坐标中分段拟合时,当常德和汉江的LogP分别小于0 602和0 493时,常德和汉江的分形维数分别为0 39332和0 74110;当常德和汉江的LogP大于0 602和0 493时,常德和汉江的分形维数分别为0 30678和0 27239.拐点的出现表明异养性指数的变化在两个尺度域内遵从着不同的规律.拐点尺度以前,分维数较高,表明群落组成复杂 ...
冯伟松,沈韫芬
core