Results 31 to 40 of about 4,101 (143)

谐波电流下油浸式配电变压器负载损耗及绕组热点温度分析

open access: yesGaoya dianqi, 2018
为了研究电流畸变情况下油浸式配电变压器负载损耗和绕组热点温度的变化规律,基于IEEE StdC57.110中的绕组涡流谐波损耗因子和杂散谐波损耗因子,并考虑绕组在谐波电流下的集肤效应会增强,定义了绕组电阻谐波损耗因子,从而建立了变压器在谐波电流下负载损耗计算模型。考虑到绕组涡流损耗密度分布不均对绕组热点温度的影响,利用文中所建立的变压器在谐波电流下负载损耗计算模型修正了IEEE Std C57.110:2008的绕组热点温度计算公式。分析结果表明,谐波电流会引起较大的额外负载损耗,谐波畸变率为40 ...
周卫华   +7 more
doaj  

轻质烃在双功能ZnNi/HZSM-5催化剂上的芳构化 [PDF]

open access: yes, 2002
考察了混合碳四烃、石油液化气和正己烷在双功能ZnNi/HZSM -5催化剂上的芳构化 ,同时首次将微波辐射技术应用到芳构化中 ...
万惠霖   +4 more
core  

Why are some invasive plant species so successful in nutrient‐impoverished habitats in south‐western Australia: A perspective based on their phosphorus‐acquisition strategies

open access: yesFunctional Ecology, Volume 39, Issue 2, Page 635-652, February 2025.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Invasive plants are a major cause of the global biodiversity crisis; it is therefore crucial to understand mechanisms that contribute to their success. South‐western Australia is a global biodiversity hotspot with extremely low soil phosphorus (P) concentrations.
Dan Tang   +7 more
wiley   +1 more source

基于DGM的油浸式变压器热点温度计算

open access: yesGaoya dianqi, 2015
为了准确计算油浸式变压器的热点温度,在对比了有限元法(FEM)和有限体积法(FVM)计算变压器热点温度各自特点的基础上,提出了基于间断式伽辽金方法(discontinuous Galerkin method,DGM)的一种计算变压器热点温度的全新计算方法;并以天威合肥变压器厂的一台180 MV·A-220 kV变压器为例,计算了变压器的绕组热点温度。为校验计算方法的准确性,笔者对这台主变进行了变压器绕组温升试验,监测了绕组的热点温度数据,并将利用DGM的计算结果分别与实际监测数据、IEEE导则计算数据 ...
律方成   +5 more
doaj  

XH-2/3型组合式耐硫变换催化剂的试生产和工业应用 [PDF]

open access: yes, 2007
XH-3型催化剂是在XH-2型催化剂(Co-Mo-K/γ-Al2O3)的基础上引入第3种活性组分钨而制成的。通过活性评价和工业侧线试验,结果表明XH-2、XH-3型催化剂在最佳活性温区和耐热性能方面各具特色,可以进行组合填装使用。12 t XH-2/3型组合式耐硫变换催化剂已经成功应用于合成氨的变换工序中 ...
张祖芳   +6 more
core  

Prospects for conserving freshwater fish biodiversity in the Anthropocene: A view from Southern China 人类世下淡水鱼类生物多样性保护的前景:以中国南方为视角

open access: yesIntegrative Conservation, Volume 3, Issue 4, Page 294-311, December 2024.
Freshwater biodiversity in China is threatened by multiple anthropogenic factors, and while there are some reasons to suppose it may be possible to bend the curve of biodiversity loss, the variety of threats and their likely interactions with ongoing climate change provide little basis for optimism. For example, the historic overexploitation of Yangtze
David Dudgeon
wiley   +1 more source

油浸式变压器热路模型的修正及实验验证

open access: yesGaoya dianqi, 2019
变压器绕组的热点温度是限制运行中变压器负载能力和影响变压器寿命的最大因素。快速准确地获取变压器绕组热点温度对变压器安全稳定运行具有重要意义。文中根据变压器不同的冷却方式,对变压器片式散热器的散热热阻进行了修正。并通过变压器温升实测数据与模型仿真计算数据的比较,验证了修正散热热阻后热路模型的有效性和准确性,从而得到了一个快速且较为准确的计算变压器热点温度的方法。
罗汉武   +7 more
doaj  

The Principle of Electric Hot Milling and Its Experimental Verification [PDF]

open access: yes, 2015
提出了一种通电加热铣削方法,介绍了其基本原理与实验装置。通过试验及分析用小波变换处理采集到的振动信号来证明这种方法能够大幅降低切削过程的振动,提高刀具寿命,降低表面粗糙度,并且成本低、实验装置简单实用。提出了一种基于通电加热的新型高温硬度测量方法,用该方法分析淬火钢在高温下的硬度变化情况,发现常温57HrC的淬火T10A工具钢在300℃左右,硬度就急剧降低至30HrC,这也证明了加热切削的有效性。A new electric hot milling method is proposed firstly ...
吴林涛, 周竞, 张天宇, 王希
core  

Integrated Fast Reactor Analysis and Calculation of Neutronics-thermal Coupling [PDF]

open access: yes
Integrated fast reactor exhibits distinct advantages in enhancing the utilization rate of uranium resources and minimizing high-level radioactive waste.
LI Haotian, WU Mingyu, WU Zongyun, ZHOU Zhiwei, HUO Xingkai, XIAO Yubai
core   +1 more source

Legislative developments in personal insolvency in China’s mainland: A comparative analysis of regional practices in China’s mainland, Hong Kong, and Taiwan Region

open access: yesInternational Insolvency Review, Volume 33, Issue 3, Page 473-492, Winter 2024.
Abstract With the ongoing implementation of personal insolvency practices in China’s mainland, the realization of a nationwide personal insolvency system in China’s mainland no longer appears distant. In the design of specific personal insolvency schemes, key elements to consider are establishing entry criteria, assessing the integrity of debtors ...
Pin Liu
wiley   +1 more source

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