Results 31 to 40 of about 10,358 (164)

Insights Into High‐Temperature Mechanical Properties and Oxidation Behavior of Ta‐Optimized TiAl‐Based Alloys Additively Manufactured via Directed Energy Deposition

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT Directed energy deposition (DED) is an effective method to process complex components with high efficiency, owing to its significant advantage of material saving and features of microarea metallurgy and rapid solidification. This study presents a nano‐Ta‐optimized Ti‐45Al‐8Nb (at%)‐based alloy synthesized via DED. The prepared TiAl‐based alloy
Yi Song   +8 more
wiley   +1 more source

模拟增温对川西亚高山两类针叶林土壤酶活性的影响

open access: yes, 2010
采用开顶式生长室(open top chamber,OTC)模拟增温,同步监测了亚高山人工针叶林和天然针叶林表层土壤温、湿度的变化,以及模拟增温初期土壤转化酶、脲酶、过氧化氢酶和多酚氧化酶活性的变化.结果表明:在整个生长季节中,OTC使人工林和天然林5cm土壤日平均温度分别增加0.61℃和0.56℃,10cm体积含水量分别下降4.10%和2.55%;模拟增温增加了土壤转化酶、脲酶、过氧化氢酶和多酚氧化酶活性.增温与林型的交互作用对土壤脲酶和过氧化氢酶活性有显著影响,而对转化酶和多酚氧化酶影响不显著 ...
刘庆   +5 more
core   +1 more source

Kinetic‐Controlled Growth of Iron Chalcogenide Nanosheets Featuring Besnus Transition

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT Two‐dimensional (2D) Fe‐based nanosheets have sparked wide attention owing to exotic magnetism, superconductivity and topological phases. However, the synthesis of 2D FemXn (X = Te/Se/S, m, n: integer), typically in a non‐stoichiometric ratio, remains challenging because of narrow thermodynamic windows.
Hongmei Zhang   +11 more
wiley   +1 more source

压敏电阻冲击老化过程中温度对静态参数影响分析

open access: yesDianci bileiqi, 2015
研究了冲击老化过程中温度对压敏电压和泄漏电流的影响。研究表明,压敏电压呈现弱的负温度特性。随着冲击次数增加,压敏电压与温度的相关性有增强趋势,而且压敏电压随温度变化的波动变得明显。泄漏电流受温度影响较大。随着温度上升,泄漏电流呈指数函数上升,具有较强的正温度特性,且随着冲击次数增加,正温度特性越强。
曹洪亮   +4 more
doaj  

Bio‐Inspired Continuous Gradient Nanocomposites for Ultrahigh‐Temperature Dielectric Energy Storage at 150°C–200°C

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT Dielectric polymers commonly suffer from severe performance degradation above 150°C, hindering advanced power systems. Herein, we demonstrate a polyetherimide (PEI) nanocomposite that overcomes this by mimicking the gradient architecture of nacre and bamboo, incorporating a continuous vertical gradient of fluorinated boron nitride nanosheets ...
Jian Wang   +8 more
wiley   +1 more source

架空金属线路雷电感应电流热效应分析

open access: yesDianci bileiqi, 2015
定量估算了雷电感应电流在单、双股架空铝、铜金属线上的最大温升,分析了相关参数与最大温升之间的关系,并对最大温升能熔断多大截面的架空金属导线问题进行了计算分析。结果表明:雷电感应电流在单股架空铜和铝金属线路上产生最大温升随导线截面积q的减小而成指数增大;随架空线路高度hd的增大而增大,其变化率随雷电流幅值的增加而增大;随雷击电流幅值I的增大而增大,其变化率随雷击电流波下降沿半值时间的增加而增大。雷电感应电流在双股架空铜和铝金属线路上产生最大温升随两股导线之间距离的减小而成指数增大。雷击架空金属线路附近时 ...
黄克俭, 王小飞, 李鑫, 陈仁君
doaj  

Dual‐Phosphidation‐Engineered Ni/NiO Heterojunction Nanoflowers With Synergistic Surface PO43− Group and P Doping Sites for High‐Performance and Low Temperature (−40°C) Supercapacitors

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT Nickel oxide (NiO)‐based electrodes with high theoretical specific capacitance can effectively increase the energy density of supercapacitors—the key factor limiting their practical deployment. However, several issues still restrict the production of advanced NiO‐based electrodes.
Ya‐Min Feng   +10 more
wiley   +1 more source

Tuning Y‐Mg Supports for Improved Ni‐Catalyzed NH3 Decomposition: Structural Modulation and Mechanistic Insights

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT Catalytic NH3 decomposition has garnered substantial attention for hydrogen transformation and storage. Ni‐based catalysts continue to suffer from limited thermal stability and suboptimal low‐temperature activity, largely attributed to an incomplete understanding of the structure‐activity relationships and reaction mechanisms governing their ...
Tao Wen   +8 more
wiley   +1 more source

模拟增温对红雉凤仙花传粉的生物学效应

open access: yes, 2013
传粉是种子植物有性生殖过程中一个关键的环节,植物与传粉者的相互作用对于种群的维持和发展以及提供必要的生态系统服务功能具有重要意义。全球气候变暖背景下,植物与传粉者相互作用的变化,将影响群落的组成和结构,进而影响生态系统的功能。因此,本研究以峨眉山中低山地区虫媒草本植物红雉凤仙花为研究对象,通过红外加热器模拟增温,以植物与访花者相互作用为研究核心,以“开花 — 传粉 — 结果 — 种子萌发 — 幼苗生长”为研究主线,经过两年增温实验,系统研究了增温对开花物候、花部特征、传粉特征、种子产量和质量 ...
王琼
core  

Research and prospects for response mechanisms of soil respiration to experimentalwarming.

open access: yes, 2016
土壤呼吸是土壤碳库向大气碳库输入的主要途径,而温度升高会影响土壤呼吸从而改变全球碳平衡.据预测在21世纪末,全球平均地表温度将升高0.3~4.8℃,因此野外自然条件下的模拟增温试验对土壤呼吸的影响是全球变化研究的热点之一.本文综述了不同时空格局下土壤呼吸对模拟增温的响应特征,指出短期增温能提高土壤呼吸,而长期增温下无统一规律,并且不同生态系统之间也存在差异;重点讨论了模拟增温对土壤呼吸的影响机制,指出增温能直接影响土壤呼吸,同时增温也能通过影响土壤水分、盐分、土壤理化性质等环境因子以及光合作用 ...
韩广轩   +2 more
core   +1 more source

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