Results 51 to 60 of about 15,905 (167)
, 2018 为了提高均四甲苯氧化制均苯四甲酸二酐的收率,以某二酐生产企业生产的高效钒钛催化剂,在固定床反应器中对均四甲苯气相氧化制均苯四甲酸二酐反应体系的动力学进行了研究。首先提出了可能的反应网络,然后设计相关动力学测试实验,建立均四甲苯氧化反应的幂函数宏观动力学模型。进一步的实验和统计分析表明,模型计算值与实验值吻合较好。宏观动力学方程的建立为后续将其用于相应的固定床反应器模拟提供了基础保证。新疆维吾尔自治区自然科学基金项目(2015211A004 ...
曹玲, 曹茂洪, 薛来奇, 陈秉辉
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Assessment of risk for pre‐eclampsia at mid‐gestation to define subsequent care
Ultrasound in Obstetrics &Gynecology, Volume 65, Issue 6, Page 694-702, June 2025.ABSTRACT Objective To stratify pregnancy care based on the estimated risk of pre‐eclampsia (PE) from screening at 19–24 weeks' gestation by combinations of maternal risk factors, estimated fetal weight (EFW), mean arterial pressure (MAP) and uterine artery pulsatility index (UtA‐PI).
S. Adjahou +5 more
wiley +1 more source
Ultrasound in Obstetrics &Gynecology, Volume 65, Issue 5, Page 552-559, May 2025.ABSTRACT Objective To critically review the literature and synthesize evidence on the incremental yield of prenatal exome sequencing (PES) in fetuses with an apparently normal phenotype with a normal G‐banded karyotype or chromosomal microarray (CMA).
A. Sotiriadis +5 more
wiley +1 more source
Gaoya dianqi, 2005 介绍了3种可用于定位检测GIS中SF6气体泄漏的光学成像技术。这些技术能使操作者看到泄漏气体清晰图像,快速识别泄漏源;其远距离识别和瞬时检测能力使检测者可以快速大范围地扫描GIS,泄漏能被立即识别。相对于传统的非在线检测和其它在线检测技术来说,光学成像技术在SF6气体泄漏检测方面,是一个比较大的突破。
吴变桃, 肖登明, 尹毅
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The development of online detecting system of five-axis CNC grinding machine for indexable insert [PDF]
, 2014 五轴可转位刀片磨床具有高速、高精的特点,为了使所磨的刀片符合精度要求,需要针对刀片的尺寸开发一种在线检测系统。本文所介绍的在线检测系统主要由两方面构成:一是在磨床数控系统中将测头伸缩时发出的电压信号转换为测量值;二是建立刀片尺寸的加工模型。在线检测系统通过调用系统的测量宏程序,获取刀片测量值,将此测量值输入到加工模型中,得到所加工刀片的指导尺寸。通过实验,得到了刀片的指导尺寸和测量时间,验证了此在线检测系统是可行并且可靠的。The five-axis CNC grinder of indexable ...
姚斌 +5 more
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Ultrasound in Obstetrics &Gynecology, Volume 65, Issue 4, Page 447-455, April 2025.ABSTRACT Objective A soluble fms‐like tyrosine kinase‐1 (sFlt‐1)‐to‐placental growth factor (PlGF) ratio cut‐off of 38 is currently considered optimal for ruling out pre‐eclampsia (PE); however, implementation of this ratio in clinical practice is limited.
M. N. Nan +15 more
wiley +1 more source
Dianci bileiqi, 2006 讨论了检测盘形悬式瓷绝缘子的火花间隙法、电压分布法、测量绝缘电阻法、航测法和地面初判法。认为采用火花间隙法和电压分布法检测绝缘子,有漏检、误判等现象;采用在线绝缘电阻法进行测试,可靠性较高。同时指出,航测法和地面初判法是今后在线检测的发展方向。
邬正荣
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Automatic Control for Ion Exchange in Tungsten Metallurgy [PDF]
, 2008 本文介绍横河DCS系统应用于离子交换法钨冶炼，填补了这一领域的空白，同时在使用过程，针对系统的存在的缺陷不断进行改造，同时根据工艺及扩展建设的需要进行开发，使这一系统不断完善，取得应用的成功。 本文主要讨论钨离子交换法钨冶炼的工艺过程以及自动控制系统的实现。介绍了离子交换法钨冶炼的基本工艺过程及控制需求；介绍PLC、DCS系统以及FCS系统的特点及差异性比较，同时对系统的发展方向进行了研究；介绍横河μXL及CS1000集散型控制系统的基本构成、功能特点 ...
陈志辉
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Plant nutrient‐acquisition strategies contribute to species replacement during primary succession
Journal of Ecology, Volume 113, Issue 4, Page 988-1003, April 2025.Pioneer species Hippophae acquires phosphorus and nitrogen mainly by ‘mining’ and N2‐fixing strategies and thus dominates in the beginning of primary succession. As soil nutrient availability increases with the mobilization of apatite‐P and input of N‐rich plant residues, Hippophae' strategies become less efficient than Populus's scavenging strategies.
Xiao‐Long Li +12 more
wiley +1 more source
Gaoya dianqi, 2015 笔者首先介绍了GIS局部放电特高频检测原理、技术优势,在此基础上对基于特高频的GIS移动式在线监测系统的组成和技术优势进行了简单介绍,并以某变电站为例介绍了该系统在GIS局放监测中的成功应用。结果表明,移动式在线监测系统即弥补了人工带电检测方法数据量不足的缺点,值得在GIS局放检测中大力推广。
陈贤熙, 王俊波, 余红波, 刘昊
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