Results 61 to 70 of about 28,720 (141)

开放式伞形结构的形状和尺寸对爬电距离、形状因数和等效直径的影响

open access: yesDianci bileiqi, 2018
将开放式伞形结构细化为8项径向和3项轴向基本参数,给出了爬电距离、形状因数和等效直径的参数化表达式,并讨论了每一项参数对后三者的影响。采用数学建模的方法,将伞形优化设计问题转化为多元函数求最值的问题进行了讨论。本文的研究内容可为伞形优化设计提供参考。
李启源
doaj  

Microstructure Characteristics and Strength–Ductility Mechanisms of a Novel Neutron Shielding Al‐6Mg‐5Gd Alloy Fabricated by Laser Powder Bed Fusion

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT Al‐based neutron shielding materials suffer from poor laser powder bed fusion (LPBF) processibility, hindering their simultaneous achievement of good printability and exceptional mechanical properties. In this work, the newly developed rare‐earth Al alloy (i.e., Al‐6Mg‐5Gd) was processed by LPBF technique to meet the printability, mechanical ...
Chen Yang   +8 more
wiley   +1 more source

应用极化电流辨识油纸绝缘系统等值电路参数

open access: yesGaoya dianqi, 2016
变压器油纸绝缘系统的介质响应特性可以用扩展德拜模型等值电路来描述,研究变压器油纸绝缘系统等值电路参数的辨识方法具有十分重要的意义。文中提出一种应用极化电流辨识变压器油纸绝缘系统扩展德拜等值电路参数的方法,利用极化电流曲线末端主要取决于大时间常数指数项的特点,先在曲线末端不为零处选取初始点计算得到大时间常数支路参数的估计值,再以估计值为基础进行多次修正计算,待参数计算值稳定后再进行检验计算,从而求得各个参数较为准确的数值解;逐条计算,可以求出所有极化支路的参数 ...
蔡锋, 江修波, 蔡金锭
doaj  

Structural Modulation of Magnetic Softness in Fe‐Based Amorphous Alloys via Pulse Current Training

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT Fe‐based amorphous alloys, despite their intrinsically low magnetocrystalline anisotropy, suffer from quasi‐dislocation dipoles and localized stress fields that impede domain‐wall motion and increase coercivity. Here, we introduce pulse current training (PCT) as an energy‐efficient technique to overcome these limitations in a Fe76Si9B10P5 ...
Shumin Ye   +13 more
wiley   +1 more source

基于三参数Burr分布的悬式瓷绝缘子零值温差分布特性研究

open access: yesDianci bileiqi, 2020
提出一种基于三参数Burr分布的估计方法来描述零值悬瓷绝缘子的温度分布特性。为验证这一方法,以某省电网运行10年及以上变电站悬式绝缘子红外测零项目的红外测温数据为研究对象,通过统计分析建立了三参数Burr分布数学模型。由于该分布函数的参数在极大似然估计法下没有显式解,故采用牛顿法对其求解,可得到三参数Burr分布对绝缘子零值温差分布的拟合曲线;然后,在MATLAB中利用Kolmogorov-Smirnov方法对于该分布模型进行了参数检验。检验结果表明 ...
徐华   +8 more
doaj  

Changing trends in prenatal screening and treatment of cytomegalovirus infection in France: 7‐year national cohort study (2017–2023)

open access: yesUltrasound in Obstetrics &Gynecology, Volume 67, Issue 6, Page 756-763, June 2026.
ABSTRACT Objectives Cytomegalovirus (CMV) is the leading cause of congenital infectious neurosensory impairment. We aimed to present national epidemiological data on maternal CMV infection during pregnancy in France, focusing in particular on primary infection in the periconceptional period or first trimester, and to assess the impact of changes in ...
P. Coste‐Mazeau   +176 more
wiley   +1 more source

基于VC和UG的自动装盒机送盒凸轮参数化设计

open access: yesJixie chuandong, 2015
由于自动装盒机装盒尺寸不同,送盒凸轮大小和行程等参数都会改变,需经常更换送盒凸轮。传统的CAD/CAM软件凸轮设计既费时又困难,据此基于UG二次开发工具,结合VC++6.0开发了凸轮参数化系统软件。经运行表明,系统具有良好的人机交互性,用户只需要输入需要修改的关键参数就可以得到新的凸轮三维模型,缩短了设计时间,实现了凸轮参数化设计。为凸轮的数控加工、仿真设计与制造、参数化设计提供了参考依据。
张宪信, 郭烈恩, 王官明
doaj   +1 more source

A Global Analysis of Domestic Military Policies Governing Responses to Public Health Emergencies

open access: yesWorld Medical &Health Policy, Volume 18, Issue 2, June 2026.
ABSTRACT Throughout the COVID‐19 pandemic, militaries mobilized at an unprecedented scale to support domestic response efforts. This was consistent with the growing trend of asset mobilization for military operations other than war during public health emergencies.
Kuang Yu Hu   +4 more
wiley   +1 more source

Home‐Based Versus In‐Hospital Care in Pediatrics: A Systematic Review of Cost‐Effectiveness Studies

open access: yesWorld Medical &Health Policy, Volume 18, Issue 2, June 2026.
ABSTRACT Home‐based care has emerged as a potential alternative to traditional hospital‐based care for children and adolescents worldwide. This systematic review aimed to systematically gather and critically assess the available evidence on the cost‐effectiveness of home‐based versus in‐hospital care for pediatric populations globally.
Luís Carlos Lopes‐Júnior   +8 more
wiley   +1 more source

Rapid construction of insect–plant interaction networks via multiplexed long‐fragment DNA metabarcoding and NGS

open access: yesMethods in Ecology and Evolution, Volume 17, Issue 6, Page 1896-1909, June 2026.
Abstract Molecular identification of insect food webs can accurately reveal complex trophic interactions and serve as a foundation for understanding ecosystem functioning and advancing biodiversity conservation. This process typically involves DNA library construction, high‐throughput sequencing and subsequent steps, including data assembly, annotation,
Xiao‐man Zhang   +9 more
wiley   +1 more source

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