Results 11 to 20 of about 2,636 (118)

First‐trimester ultrasound detection of fetal heart anomalies: systematic review and meta‐analysis

open access: yesUltrasound in Obstetrics &Gynecology, Volume 59, Issue 1, Page 11-25, January 2022., 2022
ABSTRACT Objectives To determine the diagnostic accuracy of ultrasound at 11–14 weeks' gestation in the detection of fetal cardiac abnormalities and to evaluate factors that impact the detection rate. Methods This was a systematic review of studies evaluating the diagnostic accuracy of ultrasound in the detection of fetal cardiac anomalies at 11–14 ...
J. N. Karim   +26 more
wiley   +1 more source

静电除尘效率的影响因素研究

open access: yesGaoya dianqi, 2021
通过试验研究了影响静电除尘器捕集效率的因素,分析了微粒粒径、电场强度、气流流速、电离电压、电离电极洁净程度对捕集效率的影响规律。结果表明,静电除尘器中的微粒捕集效率随粒径的增大而提高;同样的带电微粒,随电场强度增大,其捕集效率增加;随着气流速度加大,捕集效率变小;随电离电压增大,微粒所带电荷增加,捕集效率亦增大;气流通过电离区时,会有极少的微粒被捕集到电离电极表面,微粒自身有一定的电阻率,导致放电电流下降,大多数微粒荷电减少,除尘器捕集效率降低。采用Deutsch模型估算试验中带电微粒的迁移速度 ...
庞海龙   +4 more
doaj  

Enhanced Low‐Frequency Microwave Absorption and Corrosion Resistance of FeSiAl Using Low‐Melting‐Point Glass Phase Coatings

open access: yesRare Metals, EarlyView.
ABSTRACT This study developed a FeSiAl@LMPGP composite material to address the demand for low‐frequency electromagnetic absorption. Through controllable heat treatment, FeSiAl particles and PbO nanoparticles self‐assembled into a high‐density Mott–Schottky heterointerface structure, which exhibited a significant built‐in electric field (BIEF) effect ...
Yuqi Wang   +5 more
wiley   +1 more source

Interfacial Dipole Engineering With Taurine‐Modified SnO2 Electron Transport Layer for Efficient and Stable Perovskite Solar Cells

open access: yesRare Metals, EarlyView.
ABSTRACT Organic‐inorganic metal halide perovskite solar cells (PSCs) are promising for photovoltaics due to their excellent optoelectronic properties. However, achieving high efficiency and stability remains challenging, mainly due to defects and energy losses at the electron transport layer (ETL)/perovskite interface.
Jiahui Jin   +8 more
wiley   +1 more source

A High Capacity‐Long Cycling Concurrent Strategy of Ti3C2/MgH2 for Lithium Storage

open access: yesRare Metals, EarlyView.
ABSTRACT The excellent electrical conductivity and superior cycling stability render Ti3C2 MXene a promising Li ion battery anode. Nevertheless, the practical implementation of Ti3C2 MXene in commercial applications faces significant challenges, predominantly due to the low specific capacity.
Tingting Xu   +9 more
wiley   +1 more source

Carbon‐Insertion‐Engineered WS2 Hierarchical Heterostructure Enabling Superior Sodium‐Ion Storage

open access: yesRare Metals, EarlyView.
ABSTRACT Tungsten disulfide (WS2) is considered a promising anode material for sodium‐ion batteries (SIBs). However, its practical application is hindered by poor electrical conductivity, large volume changes during cycling, and sluggish ion diffusion kinetics, which lead to unsatisfactory electrochemical performance.
Xiuli Hu   +9 more
wiley   +1 more source

International clinical practice recommendations on the definition, diagnosis, assessment, intervention, and psychosocial aspects of developmental coordination disorder – Chinese (Mandarin) translation

open access: yesDevelopmental Medicine &Child Neurology, Volume 61, Issue 3, Page E1-E35, March 2019., 2019
目的 本国际临床指南由欧洲残疾儿童学会(the European Academy of Childhood Disability,EACD)牵头制定,旨在解决发育性协调障碍(developmental coordination disorder,DCD)的定义、诊断、评估、干预以及与社会心理方面的临床应用关键问题。 方法 本指南针对五个领域的关键问题,通过文献综述和专家团队的正式讨论达成共识。为保证指南的循证基础,以“机制”、“评估”和“干预”为检索词, 对2012年更新以来提出的最新建议以及新增的“社会心理问题”和“青少年/成人”为检索词进行检索。根据牛津大学循证医学中心证据等级 (证据水平 [level of evidence, LOE]1–4) 将结果进行分类,最终转化为指南建议。并由国际 ...
Jing Hua   +6 more
wiley   +1 more source

Electronic Modulation of CoNi Nanoparticles by N‐Doped Carbon for Efficient Lignin Hydrogenolysis to Aromatic Monomers

open access: yesRare Metals, EarlyView.
ABSTRACT Cost‐effective and efficient non‐noble‐metal catalysts for selective lignin hydrogenolysis remain elusive, representing a significant challenge in biorefinery. Here, we prepared a nitrogen‐doped carbon supported CoNi bimetallic catalyst, which was successfully derived from zeolitic imidazolate framework (ZIF) via high‐temperature pyrolysis ...
Xingwei Luo   +3 more
wiley   +1 more source

基于时间触发机制的温控负荷集群综合惯性控制研究 [PDF]

open access: yes全球能源互联网
面对新型电力系统的低惯量趋势,规模庞大而位置分散的温控负荷在参与电力系统频率响应的同时,能够为电网提供虚拟惯量和一次调频支撑将是提升电网频率安全的新思路。为此,以集中-分布式调控框架下的温控负荷集群为研究对象,首先在详细分解控制层调控中心、协调层聚合商、响应层温控负荷终端三者在辅助调频过程中的采样、计算、控制、执行一系列实时任务的基础上,设计了事件触发与时间触发相结合的温控负荷集群终端异步响应机制,实现温控负荷集群功率遵从综合惯性控制律的效果。随后 ...
周特   +6 more
doaj   +1 more source

Systematic Study of Fermi‐Level Pinning at Crystalline Metal/GaN Interfaces: First‐Principles Calculations and Diode Characterization

open access: yesRare Metals, EarlyView.
ABSTRACT The Schottky barrier height (SBH), which serves as a pivotal determinant of charge carrier injection efficiency in electronic devices, critically governs electrical behavior at metal/semiconductor interfaces. However, pronounced metal‐induced gap states at metal contact interfaces induce Fermi‐level pinning, which constrains the ...
Xiaofei Liu   +10 more
wiley   +1 more source

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