Results 31 to 40 of about 13,853 (179)

Study on mechanical properties and fractal evolution law of containing tectonic coal combination [PDF]

open access: yes
To study the mechanical properties of tectonic coal combination specimens, based on the occurrence characteristics of coal seam in a high gas mine, this study carried out the mechanical properties test experiment of loading and fracture process of ...
Li GUO   +6 more
core   +1 more source

How Different Patterns of Policy Attention Drive Policy Diffusion: Evidence From China's River Chief System

open access: yesPolicy Studies Journal, EarlyView.
ABSTRACT Despite extensive research on policy diffusion, the ways in which policy attention influences this process remain underexplored. This study addressed this gap by distinguishing between three types of policy attention—political speeches, policy issuance and field visits—and investigating their differential impacts when delivered by central and ...
Xiangning Chen, Yahua Wang
wiley   +1 more source

Informal Digital Learning of English (IDLE) as Form‐Focused and Meaning‐Focused Activities: Refining its Measurement and Examining its Predictive Role in L2 Achievement and Confidence

open access: yesInternational Journal of Applied Linguistics, Volume 36, Issue 1, Page 393-408, February 2026.
ABSTRACT Acknowledging the limitations of existing measurement instruments in adequately capturing the distinct cognitive processes (e.g., form‐focused vs. meaning‐focused) involved in informal digital learning of English (IDLE), this paper asserts a pressing need to develop and validate robust instruments that measure form‐focused and meaning‐focused ...
Minlin Zou   +3 more
wiley   +1 more source

汉中荒草地整治后耕作层土壤颗粒分形特征

open access: yesShuitu Baochi Xuebao, 2016
运用分形模型,结合野外调查和室内试验分析汉中市荒草地整治后耕作层土壤颗粒分形特征,探讨土壤颗粒分形维数与土壤质地、粒径组成以及养分含量的关系,建立整治后耕作层土壤分形维数预测函数。结果表明:(1)整治后土壤颗粒分形维数D介于2.55~2.95之间,均值为2.77,标准差为0.134,土壤颗粒分形维数与土壤质地有一定的关系,表现为土壤质地越细,分形维数越大。(2)土壤颗粒分形维数主要是由黏粒含量决定,分形维数与黏粒含量呈显著线正相关(R2=0.978 0);利用分形维数与土壤黏粒(≤0.002 mm ...
雷, 韩霁昌
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

广元市不同土地利用类型土壤的分形特征

open access: yesShuitu Baochi Xuebao, 2007
以8个植被类型、2个农地和2个退耕地的土壤颗粒组成数据为基础,运用分形模型计算这12个土地利用类型土壤颗粒的分形维数,研究了土壤颗粒分形维数与土壤性状的关系。结果表明:(1)12个土地利用类型表层土壤颗粒的分形维数介于2.8185~2.9249之间。与退耕地和玉米地相比,各林地土壤颗粒分形维数小;与1990年的2.8633相比,2006年土壤颗粒分形维数(2.8592)减小;各团聚体分形维数规律不明显。(2)决定土壤颗粒分形维数大小的首先是〈o.002mm的含量,其次是0.05~0.25mm和0 ...
李进峰   +4 more
doaj  

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

基于变分法和GIS的小流域模型三维地貌分形特征量化研究

open access: yesShuitu Baochi Xuebao, 2008
实现具有三维立体特征的流域地貌分形维数直接准确计算,是目前分形地貌学研究所面临的主要问题之一。依据变分法求解三维表面分形维数的基本原理,以DEM栅格数据为基础,利用ArcGIS9.2中的窗口分析功能,对所建立的小流域模型不同发育阶段的三维地貌闵可夫斯基维数进行研究。结果表明,变分法和GIS的有机结合使三维地貌分形维数的直接计算成为可能,小流域模型不同发育阶段的三维地貌在各自无标度区内呈显著的分形特征,三维地貌闵可夫斯基维数不仅能有效表达小流域模型不同发育阶段地貌的差异性(变化范围达0.452 ...
王民, 李占斌, 崔灵周, 李鹏
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  

Pore fractal characteristics of granulated blast furnace slag-carbide slag cementitious material and its effect on heavy metal adsorption [PDF]

open access: yes
Coal has long occupied the main position of energy consumption structure in China. The problem of heavy metal pollution in mine water has become increasingly severe due to washing and processing as well as tunnel development activities.
Jianmin LI, Jiayong ZHANG, Liwen GUO
core   +1 more source

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