Results 11 to 20 of about 3,045 (163)
Complex and nonlinear climate‐driven changes in freshwater insect communities over 42 years
Conservation Biology, Volume 34, Issue 5, Page 1241-1251, October 2020., 2020 Abstract The ongoing biodiversity crisis becomes evident in the widely observed decline in abundance and diversity of species, profound changes in community structure, and shifts in species’ phenology. Insects are among the most affected groups, with documented decreases in abundance up to 76% in the last 25–30 years in some terrestrial ecosystems ...
Viktor Baranov +4 more
wiley +1 more source
Conservation Biology, Volume 34, Issue 1, Page 194-206, February 2020., 2020 Abstract Stand structure develops with stand age. Old‐growth forests with well‐developed stand structure support many species. However, development rates of stand structure likely vary with climate and topography. We modeled structural development of 4 key stand variables and a composite old‐growth index as functions of climatic and topographic ...
Yuichi Yamaura +6 more
wiley +1 more source
Rare Metals, EarlyView.ABSTRACT Polycrystalline SnSe thin film materials have gained increasing attention as a promising solution for fabricating microscale, flexible, self‐powered electronic components in the field of thermoelectric (TE) materials and devices. However, it is still a great challenge to simultaneously achieve preferred crystal orientation and optimize carrier
Wenxia Li +10 more
wiley +1 more source
The influence of the electrical boundary condition on domain structures and electrocaloric effect of PbTiO3 nanostructures [PDF]
, 2016 本文在基于金兹堡—朗道—德文希尔唯象理论的相场法理论下，应用有限差分方法及四阶龙格—库塔法数值求解，研究不同电学边界条件对铁电纳米点畴结构演化和热电温度效应的影响。本文所用的中间电学边界条件，可以用来表示表面电极与纳米点之间的黏合情况及电极对表面电荷的补偿情况，进而说明退极化电场和退极化电能对系统自由能的影响，不同以往的对退极化能进行权重处理，具有实际的物理意义。 当电学参数λ0为0时，中间电学边界可以退化为开路电学边界条件；当λ0趋向无穷大时，对应于短路电学边界条件，即表面电荷可充分补偿。λ0的值越大，
陈志英
core +1 more source
Research on the Non-uniform Temperature Field for Purifying Polysilicon in Large Directional Solidification Equipment [PDF]
, 2015 太阳能资源分布广泛并可无偿获取，使光伏发电成为新型能源的重要发展方向之一。因其发电组件具备建设周期短、安全可靠、布置灵活等优点得到了人们的青睐。硅作为光伏发电主要的基础材料，已占据市场90%以上的份额。冶金法提纯多晶硅具备投产建设速度快、提纯工艺流程短、成本较化学法低等优点，近年来发展迅速，受到国内外的广泛重视。 定向凝固是冶金法的核心。与中小型提纯相比，大型定向凝固的生产效率高，综合成本较低，但固液界面较难维持水平，晶粒不易保持垂直方向上的整齐排列，凝固和退火过程中裂锭的概率也较大，对温度场构建 ...
朱徐立
core
Focus facula measurement in graphene preparation by laser chemical vapor deposition [PDF]
, 2017 激光化学气相沉积(Laser Chemical Vapor; Deposition,LCVD)石墨烯制备受聚焦光斑影响很大。实时检测光斑,可实现石墨烯LCVD; 法可控制备。设计聚焦光斑测量光学系统,提出一种基于圆拟合的改进算法检测光斑中心和半径,计算、标定光斑面积。该方法在圆拟合基础上加入了二值化、形态; 学处理及连通性判别等预处理方法。实验表明,该方法测得圆心位置与真值误差平均为5. 58 pixel,光斑面积与真值误差平均为1.
刘婷婷, 张建寰, 李珊文, 林坤
core +1 more source
High‐Brightness Delayed Imaging Realized by Embedding Zinc Gallate Nanocrystals Into Glass
Rare Metals, EarlyView.ABSTRACT X‐ray delayed imaging technology leverages an “irradiation‐storage‐thermally stimulated readout” mode, demonstrating unique advantages in intermittent monitoring scenarios such as high‐temperature/high‐radiation environments. This typically requires materials combining abundant carrier‐trapping energy levels with structural thermostability ...
Jun‐Xiao Wu +6 more
wiley +1 more source
Using porous metals to enhance heat transfer in phase change materials (PCMs) [PDF]
, 2011 Heat transfer enhancement mechanism of Phase Change Materials (PCMs) by high-porosity metal foams was investigated in this study. The Darcy-Brinkman-Forchheimer modified flow model was employed in the numerical simulations to consider the non-Darcy ...
Tian, Y. (Yuan), Zhao, Changying
core
Highly Anisotropic TbCo11Ti: Phase Evolution, Microstructure and Magnetic Properties
Rare Metals, EarlyView.ABSTRACT Among the 1:12‐type compounds, TbCo11Ti stands out due to its high Curie temperature and pronounced magnetocrystalline anisotropy. However, its magnetic behavior at room temperature and its phase evolution process have not been clearly established.
Wei Chen +11 more
wiley +1 more source
Gaoya dianqi, 2023 800 kV穿墙套管在特高压直流输电工程中发挥着重要的作用，但在应用有限元分析方法对其进行电场仿真优化设计时，往往忽略穿墙套管实际运行时的温度对电场分布的影响。文中首先建立了±800 k V穿墙套管三维仿真模型，通过仿真计算得到穿墙套管的温度场分布，考虑了实际运行中，套管发热对内部环氧芯体电导率的影响，并在温度场分布的基础上，应用电热耦合场分析计算的方法，获得穿墙套管的电场分布。计算结果表明：正常运行时，穿墙套管载流导杆及卷制管温度呈现中间高两边低的分布规律，靠近导杆的芯体温度高，沿径向方向 ...
韩晓东 +5 more
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