Results 51 to 60 of about 25,621 (167)

A Stretchable Sandwich Composite Film With Ultra‐Broadband Electromagnetic Interference Shielding and High‐Performance Photothermal Conversion Capability

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT With the rapid growth demand for advanced integrated electronic systems, lightweight flexible electromagnetic interference (EMI) shielding films integrated with functional properties, such as excellent mechanical properties and self‐healing capability, are a research focus in high‐tech functional materials. Herein, a sandwich‐structured aramid
Dan Guo   +9 more
wiley   +1 more source

不同形态工程堆积体产流产沙对比研究

open access: yesShuitu Baochi Xuebao, 2020
通过室内模拟降雨试验,研究了二维平面和三维锥状两种堆积体坡面在不同砾石含量条件下的产流产沙特征。结果表明:(1)坡面流速和单位面积径流率随产流时间呈"快速增大—缓慢增大—稳定波动"的变化过程;(2)平均流速和单位面积平均径流率随砾石含量的增加而减小;砾石含量相同时,二维平面坡面的流速和径流率大于三维锥状坡面;(3)二维平面坡面剥蚀率随产流时间呈"稳定—减小—稳定波动"的变化过程;三维锥状坡面剥蚀率呈"增大—稳定波动"的变化过程;(4)单位面积侵蚀量随砾石含量的增加先增大后减小;砾石含量相同时 ...
张文博, 吕佼容, 谢永生, 骆汉
doaj  

A Comparative Study on Financial Performance, Financial Policy and Financial Strategy between Company A and Company B [PDF]

open access: yes, 2015
随着中国国力不断提升,中国航空工业正处在快速发展时期,多种型号的飞机相继面世,国人欣喜若狂。但在这欢欣鼓舞的气象之下,航空动力之痛往往令国人揪心。航空发动机是工业之花,集空气动力学、工程热力学、材料科学、制造工艺、电子控制等诸多科学于一身,门槛之高,世界上仅有美、英、俄、法等少数玩家置身其间。国际航空发动机市场被美国通用电气、普拉特•惠特尼和英国罗尔斯•罗伊斯公司三巨头控制,其他公司只能游走于边缘和缝隙之间。中国航空发动机行业如何实现自我可持续发展是摆在我们面前的一个严峻课题 ...
颜冬
core  

Synergistic Effect of MOF@CMC‐Derived Magnetic Nanocomposites: Enhancing Electromagnetic Interference Shielding and Joule Heating

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Emerging as attractive alternatives for sustainable, low‐cost, and high‐performance electromagnetic interference (EMI) shielding, biomass‐derived carbon is nonetheless constrained by a limited repertoire of shielding mechanisms. Herein, a straightforward method was employed to synthesize self‐supporting Co nanoparticles embedded in porous N ...
Yingjie Xu   +6 more
wiley   +1 more source

基于BIM全景可视化的架空电力线磁场三维仿真计算研究

open access: yesGaoya dianqi, 2020
随着国家智能电网高速发展,输电网络覆盖面日趋扩大,工程设计量和难度越来越大,如何运用BIM技术有效提高磁场计算设计效率,降低电力工程实施难度成为难点。本文通过研究BIM环境下的电力线磁场仿真计算,提出了一种基于BIM全景可视化的电力线磁场三维数值算法,结合BIM全景可视化、BiotSavart定律等仿真研究,计算得出的数值结果与电力磁场计算代表CDEGS得出的结果进行比较,具有三维可视化、精度高等特点,适用于BIM三维模型,真正做到三维BIM一模多算、一体化设计 ...
同嘉
doaj  

Surface and Interfacial Structure Control of Pd and Pt Based Nanomaterials and Their Catalytic Applications [PDF]

open access: yes, 2016
贵金属纳米材料由于其独特的光学、电学、磁学和催化等性质被广泛应用于能源、环保、食品加工等重要领域。合成纳米新材料,发现新性能容易,但在分子水平上理解其性能本质却很困难。近年来的研究发现,贵金属催化剂的催化活性和选择性与催化剂的表面和界面结构密切相关。因此,制备尺寸、形貌和组成可控的贵金属纳米材料,并深入研究其尺寸、组成、表面结构和界面结构与催化性能之间的构效关系显得尤为重要。本论文的工作主要围绕钯铂纳米材料的表界面调控与催化性能之间的关系展开。全文共分为七章,各章内容概括如下: 第一章 ...
赵小静
core  

Climate stability drives multidimensional nestedness of amphibian assemblages in a Chinese sky island system

open access: yesFunctional Ecology, Volume 40, Issue 3, Page 636-654, March 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract The nested subset pattern (nestedness) has been widely used to explain species distributions in island and fragmented systems. Mountain sky islands serve as critical natural laboratories for understanding the evolutionary consequences of geographic isolation and climate
Caiwen Zhang   +5 more
wiley   +1 more source

二维、实时三维超声成像在胎儿四肢骨骼发育异常鉴别及诊断中的价值探析

open access: yesZhongguo shiyan zhenduanxue, 2018
目的探讨分析二维、实时三维超声成像对于胎儿四肢骨骼发育异常的鉴别诊断效果。方法以2016年4月-2017年4月于我院进行常规超声筛查的孕妇1373例为研究对象,先后予以二维及实时三维超声成像检查,对比两种检查方法对发育异常检出情况。结果根据产后追踪结果发现,1373例孕妇所娩出胎儿中,有7例存在四肢骨骼畸形(包括3例多指、3例并趾、1例缺趾)。对比两种超声方法的诊断结果发现,实时三维超声成像的畸形检出率85.71%显著高于二维超声的28.57%,两组比较差异具有统计学意义 ...
冯蕾, 王静
doaj  

Design and Implementation of Old Bridge Digital Museum Virtual Display System for Yunlong County of Yunnan Province [PDF]

open access: yes, 2016
博物馆是收藏、陈列展出和研究各种特定事物的场所,并对有展品按照一定历史、科学特点、考古价值、艺术价值等进行分类,为参观者提供丰富的科普知识、教育教学、欣赏收藏等的机构或建筑物。信息技术的迅速发展,使人类社会进入了一个全新的时代---数字时代,数字化技术对博物馆的展示提供了一种新的媒介。网络化、智能化、集成化的数字技术必将成为博物馆发展的必然趋势。 什么是虚拟性,虚拟性是将具象的实物用一种无形的表达方式表现出来,这种表达方式可以是声音、图象、文字,甚至是信息和知识。无形即没有固定的形态 ...
张曦
core  

Capacity‐Learning Paradox: How Hong Kong and Singapore's Crisis Responses Shape and Are Shaped by Policy Capacities

open access: yesReview of Policy Research, Volume 43, Issue 2, March 2026.
ABSTRACT This study examines the paradoxical relationship between policy learning and capacity: governments need certain capacities to learn effectively, yet these same capacities often emerge from previous learning experiences. Through a comparative analysis of Hong Kong and Singapore's responses to SARS and COVID‐19, we demonstrate how policy ...
Shubham Sharma, Xun Wu, Gleb Papyshev
wiley   +1 more source

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