Results 31 to 40 of about 12,014 (183)
Ultrasound in Obstetrics &Gynecology, Volume 65, Issue 3, Page 303-310, March 2025.ABSTRACT Objective Globally, one in four pregnant women is classified as overweight or obese, based on their prepregnancy body mass index (BMI). Obese pregnant women are at increased risk of adverse pregnancy outcomes and long‐term cardiovascular disease that occurs earlier in life.
M. Charakida +6 more
wiley +1 more source
Gaoya dianqi, 2018 为了研究特高压直流输电中直流偏磁引起的谐波对换相失败的影响,利用谐波换相电压时间面积的分析方法,分析直流偏磁引起的谐波与换相失败的关系。首先,在PSCAD/EMTDC中搭建了±800 kV特高压直流输电模型,并对双极平衡的运行工况以及单极—大地运行工况下,发生故障时,谐波、励磁电流、熄弧角以及阀电流的情况进行仿真。其次,对仿真结果进行分析,发生直流偏磁引起的谐波对换相失败有一定影响。最后,利用谐波的换相时间面积进行定量的计算。结果表明,直流偏磁引起的谐波会增大换相失败的风险。
常鹏 +5 more
doaj
Shuitu Baochi Xuebao, 2023 油松作为我国北方地区典型的森林植被类型,研究辐射能量在其冠层中的分配、收支及传输,是构建森林冠层辐射传输模型和生态过程模型的理论基础,对阐明森林植被群落中能量流动和物质循环机理具有重要意义。基于贺兰山生态站油松林通量塔定位观测获取的上、下行长短波辐射、光合有效辐射(photosynthetically active radiation,PAR)以及气象数据,分析2021年4—9月不同天气和季节条件下油松林冠层的辐射能量截获及传输特征。结果表明:(1)晴天条件下太阳总辐射的日变化表现为光滑的"单峰"曲线 ...
田静 +9 more
doaj
European Policy Analysis, Volume 11, Issue 1, Page 114-137, Winter 2025.Abstract In Europe, and specifically in countries bordering the Baltic Sea, preparedness issues have moved up the policy agenda since Russia's 2014 and 2022 invasions of Ukraine. “Ordinary people” are encouraged to prepare for crises—be it through stockpiling food at home, fact‐checking information, or signing up for military training.
Alexandra M. Friede
wiley +1 more source
Gaoya dianqi, 2017 运行中局部放电测试是检测GIL设备内部是否存在缺陷的最有效手段之一。文中对GIL设备运行中超声波局部放电测试发现的异常进行了分析。依据超声波局放测试、超声波/地电波/高频电流声电联合诊断测试、现场解体检查及返厂解体检查结果进行了综合分析判断,确定了局放异常产生的原因并提出运行建议。
黄和燕 +5 more
doaj
Dianci bileiqi, 2019 高压输电线路跳闸主要是由雷击引起的。研究雷击电流波形能有效地提高判别雷击故障的准确性。且雷击产生的暂态信号在特定条件下可能对行波保护和暂态量保护产生不良影响,使其误动。针对这一情况,本文分别对雷击输电线路不同位置产生的电流行波进行详细的分析。并研究了雷击闪络与雷击未闪络的机理,发现雷击闪络产生的行波总体上呈现出单调变化,雷击未闪络时产生的行波在零轴上呈正负交替变化。针对这一发现提出了一种基于零序电流的输电线路行波保护雷击干扰识別方法。
纪思 +4 more
doaj
Ultrasound in Obstetrics &Gynecology, Volume 64, Issue 5, Page 620-625, November 2024.ABSTRACT Objective To compare the diagnostic performance of different manufacturers' immunoassays for the soluble fms‐like tyrosine kinase‐1 (sFlt‐1)‐to‐placental growth factor (PlGF) ratio with that of a point‐of‐care (PoC) test for glycosylated fibronectin (GlyFn) in women with suspected pre‐eclampsia (PE).
I. Y. M. Wah +7 more
wiley +1 more source
Dianci bileiqi, 2019 采用总体经验模态分解和小波阀值去噪相结合的方法对泄漏电流进行去噪处理。对泄漏电流信号首先进行总体经验模态分解,再对高频IMF分量按照4种阀值小波去噪方法（固定阀值法、启发式阈值法、自适应阈值法和极大极小阀值法）进行去噪,最后进行重构。以泄漏电流的3个特征量（有效值、3次谐波与基次谐波之比、波形）对去噪效果进行分析,综合比较得到采用总体经验模态分解与启发式阈值小波相结合的去噪方法的去噪效果最佳,采用该方法对实际污秽绝缘子泄漏电流进行去噪处理,去噪效果良好。
赵世华 +4 more
doaj
Veterinary Dermatology, Volume 35, Issue 5, Page 500-507, October 2024.Abstract Background Canine atopic dermatitis (cAD) is a hereditary, generally pruritic and predominantly T‐cell‐driven inflammatory skin disease, involving an interplay between skin barrier abnormalities, allergen sensitisation and microbial dysbiosis.
L. Widorn +2 more
wiley +1 more source