Results 51 to 60 of about 20,838 (174)

Undetected cases after implementation of first‐trimester anomaly scan in low‐risk population: insights from the IMITAS study

open access: yesUltrasound in Obstetrics &Gynecology, Volume 67, Issue 1, Page 27-33, January 2026.
ABSTRACT Objective To assess the effectiveness of the first‐trimester anomaly scan (FTAS) performed as part of a centrally steered national screening program in The Netherlands by investigating false‐negative cases with a fetal structural anomaly that was not detected at the FTAS.
K. Bronsgeest   +18 more
wiley   +1 more source

Robust metrics for quantifying and comparing resistance and recovery in experimental studies

open access: yesMethods in Ecology and Evolution, Volume 17, Issue 1, Page 6-14, January 2026.
Abstract Various indices have been developed to experimentally quantify resistance and recovery (two components of engineering resilience) in response to anthropogenic and natural disturbances. This diversity complicates the selection of appropriate metrics for comparing resilience across ecosystems and studies.
Zewei Zhuang   +2 more
wiley   +1 more source

An AC constant current power supply design based on linearity power amplifier [PDF]

open access: yes, 2008
交流恒流源作为稳定电源的分支有广泛用途,其作为一项技术在电源的研究领域中有很重要的意义。其发展与科技的进步息息相关,在各个国家特别是发达国家的国民经济中占有十分重要的地位。近年来我国检测技术有了较大的提高,但同发达国家的电网检测技术相比,差距仍然很大,存在参数检测精度不高、抗干扰性较差,实时性比较差、电路设计复杂等缺点。针对这些问题,本课题建立了一个以AT89C51单片机为控制核心的恒流源控制系统,该系统具有速度快、精度高、实用性强、电路模块化等特点。 本课题已经顺利完成以下几部分内容: 1硬件控制系统:
周景迁
core  

Turn to the right, turn away from the green?—A nuanced analysis on how a populist radical right party affects environmental policy making in Sweden

open access: yesReview of Policy Research, Volume 43, Issue 1, January 2026.
Abstract Populist radical right parties are on the rise all over Europe. Recent literature investigates their effects on environmental policy, however, often applying an overly broad perspective on the policy area and neglecting causal mechanisms. This article addresses both gaps in an in‐depth case study of partisan effects on Swedish environmental ...
Lars E. Berker
wiley   +1 more source

应用HCSR和并联灭弧室提高气体断路器开断能力的研究

open access: yesGaoya dianqi, 2018
高耦合电抗器(HCSR)辅助开断并联灭弧室是解决大电流故障开断的一种有效方法。由于SF6电弧自身的负伏安特性会影响并联支路电流的同时过零,增加了开断并联SF6电弧支路的难度,限制了其在高电压领域的应用。结合高耦合电抗器辅助并联支路开断的设计思想,首先利用40.5 kV断路器两柱相同灭弧室,进行了小电流条件下,SF6电弧并联支路开断的试验研究,重点分析了开断电流大小、燃弧时间长短与均流、限流开断特性间的关系。其次,针对80 kA大电流条件下的并联支路开断特性,进行了单分试验的初步研究和验证。结果表明 ...
武胜斌   +5 more
doaj  

Genetic Confirmations of Dwarf Lemurs Across Madagascar Highlights Complex Biogeographic Patterns 马达加斯加全境鼠狐猴的遗传确认揭示了复杂的生物地理模式

open access: yesIntegrative Conservation, Volume 4, Issue 4, Page 665-674, December 2025.
Using a diagnostic mitochondrial marker gene, we document the presence of furry‐eared dwarf lemurs, a species known from Madagascar's eastern montane rainforests, in several forest fragments across the island's central highlands. These findings raise new questions about when this species colonized these sites, how they tolerate these changing and ...
Marina B. Blanco   +27 more
wiley   +1 more source

双断口真空断路器开断能力的探讨

open access: yesGaoya dianqi, 2002
论述了提高双断口真空断路器开断能力的原理 ,比较了双断口和单断口真空断路器的开断能力。实验结果表明 ,双断口真空断路器的开断能力较单断口高 2倍。讨论了均压电容对开断能力的影响 ,提出了对操动机构的要求 ,最后 ,介绍了多断口真空断路器的优点。
廖敏夫, 邹积岩, 段雄英
doaj  

A method of CNC handwheel connection based on serial communication [PDF]

open access: yes, 2010
为了解决总线模式数控系统中手轮信号采集、传输难的问题,采用了一种新型的手轮连接方式,即通过工业计算机现有的串口读取手轮的脉冲信号,经特定程序识别处理后,交由数控系统内核以完成相应的运动控制。实验结果表明,利用串口实现手轮连接,不仅能够达到传统连接方式下手轮工作的全部性能指标,而且能减少硬件数量,降低系统成本,简化系统结构,有利于进一步提高系统的可靠性。Aiming at the difficulty of handwheel's signal collection and transmission in
李寅, 章明众, 陈华, 陈永明
core  

Satisfaction With Health Services During the COVID‐19 Pandemic: Results From a Population‐Based Survey in a Municipality in Southeastern Brazil

open access: yesWorld Medical &Health Policy, Volume 17, Issue 4, Page 912-920, December 2025.
ABSTRACT In Brazil, the healthcare system is based on the provision of a public system that offers free and universal services to all citizens, supplemented by private initiative. Evaluating user satisfaction plays an important role in identifying improvements and promoting organizational changes that benefit everyone involved.
Patrícia Silva Bazoni   +8 more
wiley   +1 more source

高压负荷开关—熔断器组合电器转移电流的确定

open access: yesGaoya dianqi, 1994
一、概述高压负荷开关一熔断器组合电器具有很多优点,因此,在三相环网供电单元中和箱式变电站组成的开关柜中,多数采用了这种组合电器来代替传统的断路器.这种高压负荷开关一熔断器组合电器是由熔断器来承担过载电流和短路电流的开断.而由高压负荷开关来承担过载电流(此过载电流对高压负荷开关来说仍在高压负荷开关的额定开断电流范围)和正常工作电流的关合和开断,并且要求承担“转移电流”的开断.根据IEC—420标准的定义:组合电器的“转移电流”取决于熔断器触发高压负荷开关的分闸时间和熔断器的时间一电流特性.
王季梅, 卜小玉, 蔡龙权
doaj  

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