Results 51 to 60 of about 15,266 (166)

广东省不同母质发育土壤颗粒分布的分形维数特征

open access: yesShuitu 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  

Thermodynamics‐Driven Phase‐Field Kinetics Simulation for Experiment‐Validated Design of CoNi‐Based Superalloys

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT Thermodynamic prediction‐driven phase‐field kinetic simulation, with experimental verification, is utilized to explore the high‐performance cobalt–nickel based (CoNi‐based) superalloys. The roles of aluminum (Al) in microstructural evolution and precipitation kinetics of ordered L12‐γ′ strengthened Co–Ni–xAl superalloys are revealed. The alloy
Kun‐Ning Niu   +6 more
wiley   +1 more source

胶东半岛丘陵区冲沟分形特征及其影响因素研究

open access: yesShuitu 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 ...
  +4 more
doaj  

岩石节理粗糙系数(JRC)的分形估计 [PDF]

open access: yes, 1994
根据传统的Koch曲线;我们建立了节理剖面的理论分形模型来模拟节理剖面的粗糙性。由这个模型;节理的分形维数D可以直接由两个统计参数L*和h*(这里L*和h*分别为节理粗糙度的平均基长和平均高度)来估计;即 D=log4/log[2(1+costg~(-1)(2h*/L*))]。 这个分形维数很强地相关于岩石节理粗糙系数(JRC)值: JRC=85.2671(D-1)~(0.5679 ...
W.G.Pariseau, 谢和平
core  

Adaptive Chemical Strain Boundary in Freestanding BiSmFe2O6 Double‐Perovskite Membranes

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT Double‐perovskite multiferroic systems have attracted increasing attention due to their highly tunable structures and chemical adaptability. The uncontrollable performance changes caused by the release of boundary conditions are an important factor hindering the development of freestanding membranes.
Jie Tu   +14 more
wiley   +1 more source

局部放电识别中分维数分布的研究

open access: yesGaoya dianqi, 2001
本文将分形理论应用于局部放电模式识别 ,从统计图谱中提取分形特征。在局部放电模式试验基础上 ,采用计盒数的分形维数算法 ,从大量的局部放电样本中提取分形网格维数特征参数 ,提高了局部放电模式的准确性。
李剑   +4 more
doaj  

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)

open access: yesZhejiang 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)
doaj   +1 more source

CHINA’S LAND FINANCE AS ACTIVE MODE OF LAND DEVELOPMENT AND INFRASTRUCTURE DELIVERY: Reality, History and Prospects

open access: yesInternational Journal of Urban and Regional Research, Volume 50, Issue 1, Page 191-220, January 2026.
Abstract Henry George advocated for capturing land value increases for public ends. The active approach of public authorities organizing and financing land development can help capture higher land value increases, as Hartman and Spit indicate. However, this approach hardly happens in developing countries, where the coalition of private developers and ...
Nannan Xu
wiley   +1 more source

Research on the evolution and prediction of the heights of water-conducting fracture zones in overlying rocks during layered mining of extremely thick coal seams [PDF]

open access: yes
Current research on the developing heights of water-conducting fracture zones mainly focuses on the heights of water-conducting fracture zones in single coal seam mining, while research on the prediction of the developing heights of water-conducting ...
CHENG Xianggang, MENG Hailun, QIAO Wei
core   +1 more source

World‐wide impacts of climate change and nitrogen deposition on vegetation structure, composition, and functioning of shrublands

open access: yesNew Phytologist, Volume 247, Issue 3, Page 1117-1128, August 2025.
Summary Environmental changes and their effects are among the most pressing topics of today's ecological research. Shrublands, although widespread across the globe, remain understudied in this respect. We conducted a global meta‐analysis of 81 shrubland sites subjected to experimental warming, shifts in precipitation (e.g.
Daijun Liu   +11 more
wiley   +1 more source

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