Results 21 to 30 of about 5,176 (114)
Gaoya dianqi, 2022 由于地磁暴在大地产生感应电流以及直流输电系统单极性运行方式与大地形成回路，使得直流电流进入变压器中性点，造成变压器直流偏磁，电流发生畸变，产生谐波。文中在已经研究过的单相特高压变压器直流偏磁计算的基础之上，以230 kV三相五柱式变压器为例，依据单相变压器和三相变压器电路、磁场的区别，利用变压器磁场模型与电路模型建立微分方程，对三相变压器的直流偏磁进行了计算分析。为使计算结果能够快速稳定，在电路中人为串联大电阻，并在计算完成后使用电压补偿的方法将串联电阻所分电压补偿在电路中，根据计算结果可知 ...
王泽忠, 郭苏鑫, 李冰, 张廉杰
doaj
Study on long-term behavior of steel-reinforced concrete columns under axial sustained compression [PDF]
, 2014 随着国民经济的快速发展，钢骨混凝土结构的应用越加广泛，人们对钢骨混凝土结构的了解也越来越全面和深入，目前，对于钢骨混凝土柱的研究主要是集中在其极限承载力、粘结强度与抗震性能等方面，对于长期荷载作用下混凝土的收缩、徐变等力学特性的研究还较少。而且目前对钢-混凝土组合结构的长期荷载作用的性能的试验与理论研究主要还是针对钢管混凝土。然而，由于钢管混凝土中的混凝土处于钢管内，而钢骨混凝土中的混凝土则是外露于环境中，二者在长期荷载作用下的收缩和徐变特性必然会不同 ...
吴建清
core
Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT Photocatalytic hydrogen evolution technology is a crucial approach to achieve efficient solar energy conversion and green hydrogen production. However, traditional semiconductor photocatalysts often face issues such as weak visible‐light response, high photogenerated charge carrier recombination, and poor structural stability, severely ...
Longtao Guo +8 more
wiley +1 more source
Rare Metals, Volume 45, Issue 2, February 2026.ABSTRACT Photodetectors, based on GaAs nanowires (NWs), hold significant promise in the fields of high integration micro‐ and nano‐optoelectronics applications because of their outstanding electronic and optical properties. To date, significant efforts have been directed toward enhancing the performance of photodetectors, aiming for high detectivity ...
Yu Hao +11 more
wiley +1 more source
On the Damage Tolerance of Diffusion Bonded Titanium–Aluminum Phase Biomimetic Composites
Rare Metals, Volume 45, Issue 2, February 2026.ABSTRACT The biomimetic design principles of natural structures involve the strategic integration of stiff and compliant phases to synergistically enhance strength and toughness. Its evolutionary refined natural armor, characterized by a specialized microarchitecture, enables superior damage tolerance.
Shuai Tong +10 more
wiley +1 more source
Gaoya dianqi, 2023 为准确掌握直流偏磁下电力变压器铁心的振动特性，文中通过建立变压器电磁—结构多物理场耦合有限元分析模型，计算了变压器直流偏磁前后铁心磁通密度分布和励磁电流，分析了麦克斯韦力和磁致伸缩力作用下不同直流偏磁时的铁心振动特征，定义了S变换相对能谱熵来描述变压器铁心振动随直流偏磁程度的变化规律。对某500 kV三相五柱式自耦变压器的仿真计算结果表明，随着直流电流增加，变压器铁心振动幅值增大，振动频谱分量增多，但随后呈现饱和趋势，且铁心心柱和旁柱振动信号的S变换相对能谱熵变化各异 ...
宋奇珂, 王丰华
doaj
Rare Metals, Volume 45, Issue 1, January 2026.ABSTRACT Moist‐electric generators (MEGs) harness energy from ubiquitous ambient humidity, which has emerged as a promising way to collect energy irrespective of location and time. This study presents a high‐performance MEG employing a bilayer Janus nanofiber membrane: a hydrophilic layer (lithium chloride/citric acid/polyvinyl alcohol) for enhanced ...
Peng Chen +7 more
wiley +1 more source
Wildlife Letters, Volume 3, Issue 2, Page 46-55, June 2025.Pond and riverine turtles respond to land‐use in similar ways being sensitive to increased exposure to roads but resilient to agriculture. ABSTRACT Freshwater turtles are highly diverse in the southeastern United States, yet few studies document how diversity is distributed in agricultural and rural landscapes.
Rowland Fournier +7 more
wiley +1 more source
Gaoya dianqi, 2016 高压直流输电系统中存在直流偏磁问题,直流偏磁产生的谐波会严重危及电网的安全运行。文中基于变压器铁心的直流偏磁特性及变压器自身结构特点提出了一种基于变压器自身结构的变压器直流偏磁抑制措施,达到变压器直流偏磁抑制的目的。首先应用PSCAD软件对试验变压建模并搭建仿真回路进行了原理验证;其次研制了一台变压器模型样机并开展了直流偏磁抑制试验;最后将变压器模型样机与一台同规格变压器进行了性能对比试验研究。试验结果表明,该方法能在不增加变压器损耗、温升的条件下有效抑制变压器直流偏磁 ...
邱进, 王晓琪, 吴士普, 王玲
doaj
Understanding consumers to inform market interventions for Singapore's shark fin trade
People and Nature, Volume 6, Issue 2, Page 733-748, April 2024.Abstract Sharks, rays and their cartilaginous relatives (Class Chondrichthyes, herein ‘sharks’) are among the world's most threatened species groups, primarily due to overfishing, which in turn is driven by complex market forces including demand for fins.
Christina Choy +2 more
wiley +1 more source