Results 31 to 40 of about 175,497 (141)

Making Policy Evidence Traceable: A Modular Preregistration Framework for Policy Evaluation

open access: yesPolicy Studies Journal, Volume 54, Issue 4, November 2026.
ABSTRACT Preregistration is increasingly used in policy research, but its value depends on whether preregistered commitments can be clearly linked to reported analyses. Policy studies often involve multiple outcomes, evolving administrative data, consequential design and analytic choices, and adaptive implementation, making it difficult to distinguish ...
Yiyun Xia, Tianhao Zhao, Yuhao Ba
wiley   +1 more source

Inverse Thermal Softening Behavior in a High‐Entropy Alloy Under Various Strain Rates

open access: yesRare Metals, Volume 45, Issue 10, October 2026.
ABSTRACT Although face‐centered cubic high‐entropy alloys (HEAs) have received extensive attention and in‐depth research, most existing studies focus on single temperature or strain rate conditions, lacking systematic investigations into deformation mechanisms under extreme thermomechanical coupling environments.
Zhi Wang   +6 more
wiley   +1 more source

高超声速平板边界层数值模拟及试验研究

open access: yes, 2023
高超声速边界层是一个基础的科学问题。为了研究高超声速平板边界层的流场特性,结合数值模拟、理论求解和试验验证三种手段进行综合分析。数值模拟对二维Navier-Stokes (N-S)方程采用五阶精度的WENO格式离散对流项、六阶中心格式离散黏性项,时间推进项采用三阶Runge-Kutta法。理论分析利用四阶Runge-Kutta结合打靶法求解得到可压缩平板边界层层流自相似解。试验验证利用中科院力学所JF-12复现风洞测试得到大尺度平板的壁面热流,大尺度的平板模型布置传感器达到了较高的空间分辨率 ...
姜宗林, 刘美宽, 韩桂来
core   +2 more sources

6~10kV电压互感器消谐器 附视频

open access: yesDianci bileiqi, 1986
本文叙述了RXQ型电压互感器消谐器的保护原理。此消谐器既能消除中性点不接地系统中由电压互感器(PT)的非线性励磁特性所引起的过电压,又能抑制由弧光接地所引起的流过PT的过电流,进而防止了PT的烧毁。文中提出了与经典理论不同的谐振范围曲线,论证了消谐器的参数与技术要求,介绍了运行情况,并与国内数种消谐器作了有关比较。
1.西北电力试验研究所   +2 more
doaj  

Regulating the Degradation and Cytocompatibility Behavior of Additively Manufactured Pure Zinc Through Post‐Processing Surface Treatments

open access: yesRare Metals, Volume 45, Issue 10, October 2026.
ABSTRACT Zinc‐based biodegradable metals are promising implant materials, and additive manufacturing offers a powerful route for their patient‐specific fabrication. However, process‐induced surface defects can accelerate degradation and compromise biocompatibility, rendering post‐processing essential.
Yixuan Shi   +13 more
wiley   +1 more source

略谈电瓷原料中的铁质 附视频

open access: yesDianci bileiqi, 1976
本文介绍电瓷原料中的铁对原料颜色的影响,原料中的铁在贮存和加工中发生化合、分解反应,以及铁质在烧成中的主要反应和对瓷体的颜色和性能的影响。
抚顺电瓷厂试验室
doaj  

Manipulating RE‐O Bonds Engineered Thermal/Oxygen Transport Characteristics of Monoclinic‐Prime RETaO4 High‐Entropy Ceramics

open access: yesRare Metals, Volume 45, Issue 10, October 2026.
ABSTRACT Multifunctional thermal protective ceramic thermal/environmental barrier coatings (T/EBCs) are of great significance for applications of various high‐temperature components, and we propose an effective strategy for designing high‐entropy ceramics (HECs) as T/EBCs for SiC ceramic matrix composites (CMCs), where low thermal expansion ...
Qinshuo Wang   +7 more
wiley   +1 more source

Miner累积损伤理论的试验验证和统计分析

open access: yes, 1985
本文通过对LY12-CZ铝合金板材光滑试件和中心孔试件的常幅加载和变幅加载疲劳试验,对Miner累积损伤理论进行了试验验证,并对累积周比的分散性作了统计分析,发现累积周比的分散性服从Weibull分布 ...
伍义生
core   +2 more sources

Determinants of preterm pre‐eclampsia following low‐dose aspirin prophylaxis: evidence from stepped‐wedge cluster randomized trial in Asia

open access: yesUltrasound in Obstetrics &Gynecology, Volume 68, Issue 4, Page 492-503, October 2026.
ABSTRACT Objectives To identify potential risk factors – among maternal factors, pre‐eclampsia (PE)‐specific biomarkers and estimated risks derived from the first‐trimester Fetal Medicine Foundation (FMF) triple test – that are associated with the subsequent development of preterm PE, and to evaluate predictors of any‐onset PE using time‐to‐event ...
J. Lin   +46 more
wiley   +1 more source

人工污秽试验方法初步小结 附视频

open access: yesDianci bileiqi, 1974
一、前言输变电设备的外绝缘几乎都是暴露在大气条件下,其外绝缘常常受到各种污秽(煤烟、粉尘、水泥、化学气体等)和沿海的盐雾的污染。每遇到恶劣天气(雾、毛毛雨、露、溶雪等)时其外绝缘强度就会大大降低 ...
西瓷所一室试验组
doaj  

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