Results 61 to 70 of about 32,077 (249)

Configuration Optimization Design of Magnetic Circuit for Large Magnetostrictive Devices Based on TbDyFe Alloy

open access: yesRare Metals, EarlyView.
ABSTRACT Reliable operation of high‐performance magnetostrictive devices, composed of the giant magnetostrictive material (GMM), that is, the TbDyFe alloy, critically depends on an optimally tailored bias magnetic field. Sufficient intensity and uniformity are essential to induce the ideal initial strain in the GMM, enabling peak reciprocating output ...
Jinan Yu   +12 more
wiley   +1 more source

基于有限元的电力变压器绕组弹塑性变形分析

open access: yesGaoya dianqi, 2019
电力变压器绕组受短路电磁力作用后,可能出现可恢复的弹性变形或不可恢复的塑性变形。文中通过电磁-结构耦合有限元分析,对短路电流冲击作用下的变压器绕组弹、塑性变形特性进行理论分析和三维数值模拟,以揭示绕组弹性和塑性变形机理。首先通过有限元电磁计算分析了绕组内部短路电磁力分布,其中绕组线饼的周向电磁力分布不均是导致绕组变形的重要原因。在弹性变形计算的基础上,依据材料学的弹塑性变形分析理论,构建了绕组累积变形的量化分析模型,能够反映多次短路电磁力作用后绕组变形的累积效应。最后,以一台110 kV/25 000 ...
张海军   +4 more
doaj  

NIR‐Responsive Nano‐Integrated Magnesium Phosphate Cement Promotes Bone Regeneration via Osteoblast‐Exosome‐Osteoclast Crosstalk

open access: yesRare Metals, EarlyView.
ABSTRACT The limited osteogenic capacity of magnesium phosphate cement (MPC) has constrained its biomedical applications, underscoring the necessity to develop MPC with enhanced physical properties and bone‐forming capabilities. In this study, a multifunctional MPC system was developed by incorporating zoledronic acid‐loaded near‐infrared (NIR ...
Bin Wang   +8 more
wiley   +1 more source

泥石流频发区不同盖度草地土壤颗粒的分形特征

open access: yesShuitu Baochi Xuebao, 2011
运用土壤粒径质量分布原理与分形理论,研究泥石流频发区蒋家沟3种不同盖度草地土壤粒径分形特征。结果表明:不同盖度草地的土壤粒径分布具有不同的分形特征,其分形维数在2.520 8~2.669 1之间,其关系为:低盖度草地>高盖度草地>中盖度草地 ...
谢贤健, 韦方强
doaj  

肺多形性癌1例及文献复习

open access: yesZhongguo shiyan zhenduanxue, 2020
肺多性癌(Pulmonary pleomorphic carcinoma PC)是指鳞状细胞癌、腺癌或大细胞癌中含有梭形细胞和/或巨细胞成分(梭形细胞或巨细胞成分至少占整个肿瘤的10%),或仅含有梭形细胞和巨细胞成分的癌,是一类分化较差的非小细胞肺癌[1]。肺多形性癌极少见 ...
陈常娣, 于金燕, 王娇, 尹金植
doaj  

Fermi Surface Structure Revealed by Quantum Oscillations in Half‐Heusler Semimetal LuAuSn

open access: yesRare Metals, EarlyView.
ABSTRACT The Fermi surface structure in the half‐Heusler semimetallic compound LuAuSn was systematically investigated using quantum oscillation studies of high‐quality single crystals and first‐principles calculations. Clear bulk quantum oscillation signals were observed for multiple complementary physical properties, including magnetization, Hall ...
Yue Lu   +12 more
wiley   +1 more source

流域地貌分形特征与侵蚀产沙定量耦合关系试验研究

open access: yesShuitu Baochi Xuebao, 2006
流域地貌形态科学、准确和综合量化成为建立具有广泛适用性的流域土壤侵蚀预报模型的关键科学问题之一。分形理论的提出为流域地貌形态定量研究开辟了新的思路。本文依据分形理论,在建立小流域概化模型基础上,采用模拟降雨试验、高精度摄影测量和GIS技术,对流域模型地貌形态分形特征与侵蚀产沙定量耦合关系进行了研究。结果表明,基于消除了降雨特征影响的相对输沙率,可将流域模型侵蚀产沙过程划分为初期、活跃期和稳定期3个阶段;在不同侵蚀产沙时段,流域模型地貌形态分形信息维数Di呈现与相对输沙率Sr基本类似的变化趋势 ...
崔灵周   +4 more
doaj  

Dual‐Stage Heat Treatment for Enhanced Hydrogen Storage Properties of Mg−Ni−Y Alloys

open access: yesRare Metals, EarlyView.
ABSTRACT Mg−Ni−Y alloy is considered to be one of the most promising hydrogen storage materials, but its high dehydrogenation energy barrier hinders its practical application. A dual‐stage heat treatment (490°C × 4 h + 550°C × 4 h) is applied to optimize the microstructure and hydrogen storage performance of a vacuum‐melted Mg94Ni3Y3 alloy.
You Lv   +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  

Conformations of ring polymer chain in nanocomposites(纳米复合体系中环形高分子链的构型)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2018
采用分子动力学模拟方法对纳米复合体系中环形高分子链的构型及纳米粒子的集聚行为进行了研究.在不同纳米粒子/高分子链吸附能作用下,复合体系中纳米粒子表现出3种集聚行为:直接接触集聚、均匀分散以及高分子与纳米粒子间的桥接集聚.同时考虑了环形高分子链的刚性强度,得到了环形高分子链的3个构型:中间吸附、马鞍型吸附和轨道绕行型吸附.研究发现,增强环形高分子链的刚性将有助于促进纳米复合体系中纳米粒子间的分散.
SONGQingliang(宋青亮)   +1 more
doaj   +1 more source

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