Results 41 to 50 of about 25,216 (138)
Gaoya dianqi, 2010 断路器在随机关合空载变压器时会产生幅值、频率很高的励磁涌流,这种操作暂态可能导致微机继保装置误动作,降低用户电能质量和系统可靠性。根据空载变压器涌流产生的机理,采用选相关合技术消除变压器励磁涌流,研究了铁心剩磁和最佳关合相位关系;分析了断路器截流和暂态恢复电压对铁心剩磁影响,并给出了剩磁测量方法。在空载变压器选相关合原理基础上,采用ATP-EMTP软件建立空载变压器关合模型,对暂态过程进行了仿真。仿真结果表明,选相关合技术能有效消除空载变压器合闸时产生的励磁涌流,为空载变压器选相关合提供了理论基础。
李伟 +4 more
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Gaoya dianqi, 2023 随机合闸空载特高压换流变压器产生的励磁涌流容易造成合闸失败。文中分析了换流变合闸涌流的特殊性，并从理论上分析了剩磁、合闸角及合闸电阻对合闸涌流的影响，提出了合闸电阻结合选相合闸的特高压换流变压器励磁涌流抑制方法。利用PSCAD软件结合某±800 k V特高压直流换流站实际工况开展建模仿真，比较分析了合闸电阻、选相合闸及同时采用这两种措施抑制励磁涌流的效果。结果表明合闸电阻随机关合产生的励磁涌流高达额定电流的5.4倍；合闸电阻结合选相合闸抑制方法在保证选相合闸偏差时间在±2 ...
肖湃 +5 more
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ABCA12 Frameshift Deletion in Domestic Cats With Ichthyosis Fetalis
Veterinary Dermatology, EarlyView.ABSTRACT Background Ichthyosis fetalis (IF), also known as harlequin ichthyosis, is a rare and often fatal autosomal recessive congenital skin disorder. It is characterized by thickened, hard skin plaques and deep skin fissures that limit mobility and cause malformations of the eyes, lips and ears.
Jeanna M. Blake +2 more
wiley +1 more source
肾透明细胞癌差异表达基因的筛选及其核心基因相应miRNA和lncRNA 预测分析
Zhongshan Daxue xuebao. Yixue kexue ban, 2018 【目的】筛选肾透明细胞癌（ccRCC）中差异表达基因并其相关miRNA和lncRNA，寻找可作为ccRCC诊断及治疗的生物标志物。【方法】通过从TCGA数据库和GEO数据库筛选ccRCC差异表达基因并取交集，对差异表达基因进行GO功能分析和KEGG通路富集分析，使用MCODE软件筛选出差异表达基因中的核心基因，并利用mirDIP 数据库和STARBASE 数据库对核心基因上游的miRNA 和lncRNA 进行预测。【结果】共筛选出427个差异表达基因，这些差异表达基因在GO功能分析上主要与催化活性 ...
朱合欢 +5 more
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Gaoya dianqi, 2021 采用选相开关技术,可抑制电力系统暂态过程。实现断路器的位移按照给定曲线运动,降低合闸分散性,提高选相精度。传统的永磁式选相开关采用黑盒控制模型,存在控制器参数选取较困难、控制精度较低等问题。为此,建立永磁操纵机构内部数学模型,将电磁场与力场耦合,设计双闭环控制器。在Simulink中搭建仿真控制模型,改变外部电容电压,对比传统的黑盒控制模型,双闭环控制模型精度较高。以DSP28335为主控芯片,设计硬件控制系统,搭建实验平台,进行大量合闸控制实验。实验结果表明,采取上述的控制策略 ...
刘北阳 +4 more
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Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT This study presents an assessment of four representative expansive additives—calcium sulphoaluminate–calcium oxide, magnesium oxide, sodium lauryl sulfate, and sodium abietate—and their effects on the expansion behavior, mechanical development, and microstructural characteristics of cemented paste backfill (CPB).
Lijie Guo +5 more
wiley +1 more source
Genomic responses to increased temperature and pollinator selection in Brassica rapa L.
New Phytologist, Volume 250, Issue 2, Page 1231-1247, April 2026.Summary Rapid environmental change reshapes both abiotic stress and biotic interactions, yet it remains unclear how these combined forces structure plants' genomic adaptation. In particular, the joint influence of temperature and pollinator identity, two ecological axes undergoing simultaneous global shifts, has rarely been quantified at genomic ...
Yanqian Ding, Florian P. Schiestl
wiley +1 more source
Food and Energy Security, Volume 15, Issue 2, March/April 2026.ABSTRACT Net photosynthetic rate (Pn) serves as a key indicator for evaluating plant growth and yield. In order to explore an effective method for monitoring winter rapeseed Pn using unmanned aerial vehicle (UAV) multispectral technology, the winter rapeseed was taken as the research object and the multispectral images were obtained through UAVs in ...
ChengYang Ni +7 more
wiley +1 more source
应用CBCT对北京市600颗下颌第一磨牙近中中央根管的发生率及其相关因素的研究
Zhongshan Daxue xuebao. Yixue kexue ban, 2022 目的探讨下颌第一磨牙（MFM）近中中央根管（MMC）的发生率并分析其相关因素。方法筛选300名患者的600颗MFM，在CBCT阅读软件中观察其是否存在MMC，并将年龄、性别、牙位和有无根管峡区（RCI）列为可能的相关因素，用SPSS23.0 logistic回归分析筛选相关因素。结果600颗纳入的MFM中存在MMC的有80颗，且二元回归分析中年龄和有无根管峡区作为相关因素差异有统计学意义（P＜0.05）。结论MMC在MFM中的发生率约为13.3%，并非传统意义上的“罕见 ...
高莹
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How New Issues Become Polarized: Partisan Triggers and Subsystem Shopping in Early AI Policymaking
Policy &Internet, Volume 18, Issue 1, March 2026.ABSTRACT Early AI policymaking in the United States appeared bipartisan, but subsequent developments raise the question of whether AI policy will become more polarized over time. To examine how partisanship takes root around novel policy issues, we perform a mixed‐methods study, analyzing survey data from 129 state legislators in 44 states and ...
Robin Jacobson +2 more
wiley +1 more source