Results 31 to 40 of about 471 (119)

掺镱双包层结构石英光纤的优化设计及制作

open access: yesGuangtongxin yanjiu, 2003
文章主要介绍了用MCVD工艺及溶液掺杂法制备掺Yb3+双包层结构石英光纤的优化设计、原理及制作工艺.制作出Yb3+掺杂浓度高(吸收损耗在976nm时为2~10dB/m)、本底损耗低(在1.3μm时为10dB/km)的掺Yb3+双包层结构石英光纤.
衣永青, 宁鼎, 荆光明, 梁小红
doaj  

Tailoring Spin States of CuNNi3 via d‐d Orbital Coupling for High Performance Water Splitting

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Against the backdrop of escalating global energy crises and environmental challenges, the development of clean and sustainable hydrogen energy has become increasingly imperative. Hydrogen production via water electrolysis is widely regarded as a promising approach due to its green and efficient characteristics.
Weigao Zhong   +6 more
wiley   +1 more source

光纤掺氟化合物及其研究

open access: yesGuangtongxin yanjiu, 1982
用氟代硼掺杂到光纤中也可使纤维的折射率降低,並能改善纤维的性质。掺氟用化合物要求沸程在0°~100℃范围,适合此沸程的氟化合物很少。提出通过代入重卤素到碳硅硫的氟化物中的方法来获得适宜的掺杂用化合物,並对这些化合物在制备上进行了探讨。最后讨论了它们在掺杂过程中所发生的反应。
袁启华   +3 more
doaj  

The effect of Cu doping on catalytic performance of Fe/β catalyst for NH3-SCR(铜掺杂对Fe/β催化剂NH3-SCR催化性能的影响)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2017
制备了一系列Cu掺杂量不同的Fe/β(40)催化剂,并采用ICP-AES、XRD、H2-TPR、UV-vis和XPS等表征技术分析了催化剂的物化性质.结果表明,适量的铜掺杂能大大提高Fe/β(40)催化剂的低温活性,拓宽其活性温度窗口,但过量的Cu掺杂会降低催化剂的N2选择性.Cu掺杂质量比为1.27%Cu-2%Fe/β(40)的催化剂具有最佳的SCR性能,这与催化剂中存在较多离子交换位的Fe3+和Cu2+物种有关,而存在较多的CuO物种会促进氨高温氧化,使催化剂的N2选择性降低且高温窗口变窄 ...
ZHAORu(赵茹)   +2 more
doaj   +1 more source

In Situ Construction of S‐Scheme VIn‐Zn2In2S5/O‐Zn2In2S5 p–n Homojunctions for Enhanced Photocatalytic Hydrogen Evolution

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT The construction of p–n homojunctions represents a promising strategy for effective solar‐driven photocatalytic hydrogen evolution, owing to their inherent advantages of superior lattice matching and minimized charge transfer resistance. However, this approach remains largely unexplored.
Yueqiang Lin   +6 more
wiley   +1 more source

Synergistic Anode/Cathode Optimization Engineering by Hierarchical Porous N‐Doped Carbon Fibers for Efficient Zinc Batteries

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT The poor Zn chemistry of Zn metal anode and sluggish reaction kinetics of cathodes at high mass loadings are two crucial issues for hindering the application of aqueous Zn‐ion batteries (AZIBs). Herein, the hierarchical porous N‐doped carbon fibers (HPNCFs) were proposed to simultaneously optimize the reversibility of Zn plating/stripping of ...
Song Yang   +6 more
wiley   +1 more source

稀土掺杂碲酸盐玻璃放大光纤研究综述

open access: yesGuangtongxin yanjiu, 2004
文章介绍了光纤放大的研究历史,分析了掺铒光纤放大器(EDFA)和光纤拉曼放大器的优势和劣势,指明了稀土掺杂碲酸盐放大光纤的应用领域.文章介绍了掺铒和掺铥放大光纤的光放大机理,综述了掺铒碲酸盐和掺铥碲酸盐玻璃放大光纤的研究近况,得出了稀土掺杂碲酸盐玻璃放大光纤越来越接近实用化的结论.
崔群凤, 成煜, 陈伟, 陆大方
doaj  

N,W‐Cooperative Modulation of Ni3S2 for Efficient Electrocatalytic Oxidation of 5‐Hydroxymethylfurfural to 2,5‐Furandicarboxylic Acid

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Ni3S2 has emerged as a promising catalyst for the electrochemical oxidation of biomass‐derived 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA), driven by its distinctive physicochemical properties. However, its practical catalytic efficiency is severely hindered by abundant electrochemically inactive surface sites and poor ...
Cheng‐Feng Yi   +5 more
wiley   +1 more source

交直流复合电压下纳米Al2O3改性绝缘纸板介电与电荷特性研究

open access: yesGaoya dianqi, 2022
换流变压器油纸绝缘系统长期工作于复杂的电应力下,容易出现绝缘问题。通过纳米改性改变纸板的介电与电荷特性,进而提高纸板在复合电压下的绝缘性能是一种可行的方法。针对上述问题,研究了不同掺杂浓度下纳米Al2O3改性绝缘纸板的介电常数、介质损耗、体积电阻率与击穿场强,随后对改性纸板在交直流复合电压下的空间电荷特性进行了探究与分析。研究表明,纳米Al2O3的掺杂可有效降低绝缘纸板的介电常数和介电损耗,并且提高绝缘纸板的电阻率。在交流、直流、交直流复合电压下,3%掺杂浓度改性纸板的击穿场强最高 ...
黄峻峰   +3 more
doaj  

Fabrication‐Driven Oxidation Pathways in Y/Hf‐Modified High‐Entropy Alloys: From Elemental Segregation to Oxide Homogeneity

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT This study elucidates the oxidation mechanisms governing Y/Hf‐doped AlCoCrFeNiTi high‐entropy alloys (HEAs) and reveals the pivotal role of fabrication processes in dictating high‐temperature oxidation behavior. We demonstrate that casting and spark plasma sintering (SPS) promote Y/Hf segregation, resulting in heterogeneous oxide formation and
Huaqing Yi   +5 more
wiley   +1 more source

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