Results 51 to 60 of about 34,473 (149)
ABSTRACT Objectives First, to evaluate whether the ratio of soluble fms‐like tyrosine kinase‐1 to placental growth factor (sFlt‐1/PlGF) is associated with hemodynamic changes in ophthalmic artery (OA) Doppler in near‐term pregnancy. Second, to assess the performance of OA Doppler to rule in and rule out angiogenic factor imbalance.
M. F. Tinajero +7 more
wiley +1 more source
为解决500 kV瓷绝缘子串红外图像分割问题,提出了一种基于分水岭算法的图像分割方法。通过调整红外图像G分量消除云雾干扰,图像预处理后采用灰度拉伸法进行图像增强;然后利用Otsu算法将灰度图像二值化,通过Hough变换确定绝缘子串基准线,并据此使用Floodfill算法提取绝缘子串目标区域;角度校正后做欧式距离变换,以局部最小值为标记符避免过分割,再采用分水岭算法进行绝缘子片分割。据此对湖南省某座500 kV变电站700张红外图像进行分析,结果表明,本文所提方法具有良好的自适应性和实用性 ...
刘正庭 +6 more
doaj
Hypertension at 5 months postpartum in women with gestational diabetes
ABSTRACT Objective Gestational diabetes mellitus (GDM) is associated with future maternal cardiovascular disease, independent of the development of Type‐2 diabetes mellitus. As a major cardiovascular risk factor, we examined the incidence and predictors of hypertension at 5 months postpartum in women with previous GDM.
C. Gómez Fernández +7 more
wiley +1 more source
油中溶解气体分析(DGA)是诊断普通电力变压器故障的重要方法,但牵引变压器有着自身的特点,若仿效普通电力变压器的故障诊断方法,在诊断牵引变压器故障时精度较低。文中针对牵引变压器发生故障时的气体特征,提出了一种基于改进的灰关联度分析模型用于牵引变压器故障诊断的方法。该方法充分利用了牵引变压器油中气体数据的全部信息,且发挥了灰关联度适用于小样本、贫信息系统的优势,避免了局部关联和信息损失的缺陷。实例分析结果表明,该方法可以很好地判断牵引变压器故障类型,提高诊断精度。
赵峰, 李硕
doaj
Ectomycorrhizal roots of Pinus armandii release more carboxylates than non‐mycorrhizal root segments, mobilizing Al‐bound inorganic P. Under the lowest available P conditions, they also secrete more phosphatase, promoting the mineralization of Al‐bound organic P.
Jun Zhou +7 more
wiley +1 more source
证明了二维Mallat分解算法可通过二维循环卷积来计算 ,从而 ,快速计算循环卷积的方法 ,如快速数论变换 (FNTT) ,FFT等 ,均可用来实现二维Mallat分解算法 ,这也就提供了快速小波变换的一个新算法 .作者分别比较了直接用二维Mallat分解算法和用FNTT实现二维Mallat分解算法的乘法和加法运算的次数 ,分析表明 ,在通常情况下 ,新算法的乘、加法次数均会少一些 ,并在微机PC/ 5 86( 166MHz)上用FNTT通过二维Mallat分解算法对一个 2 5 6× 2 5 ...
孙琦, 唐远炎, 马洪, 任德斌
doaj
Inferring alternative ecosystem states with field survey data
Abstract Many ecosystems potentially exhibit alternative stable states, where distinct states can coexist under identical environmental conditions. While simulation models have generated key hypotheses in alternative stable states theory, they often rely on scale‐free parameters disconnected from real ecosystems.
Ning Chen +10 more
wiley +1 more source
Abstract The design of experiments to investigate the combined effects of multiple stressors requires exposing target organisms to multiple combinations of stressor doses. Concurrent manipulation of stressors is often infeasible with wildlife, but long‐lasting health effects allow individual health to be used as an integrator of prior stressor exposure.
Enrico Pirotta +24 more
wiley +1 more source
温升是影响油浸式变压器正常运行的重要因素,为了得到变压器的温度场分布,提出一种基于混合方法的多物理场计算方法。对于油浸式变压器流体场和温度场的强耦合问题,混合方法考虑了温度对媒质物性参数的影响,采用迎风有限体积法和迎风有限元法依次计算流体场和温度场,即流体场和温度场依次循环求解,最终得到油浸式变压器启动过程瞬态温度场和稳态温度场。为了验证文中算法的有效性,采用换流变压器二维简化模型,分别采用文中方法和多物理场仿真软件Comsol计算了常温下的稳态温度场,计算结果验证了混合方法的准确性和有效性 ...
刘刚 +4 more
doaj
Structured machine learning modeling to support conservation of deep‐sea benthic biodiversity
Abstract Biodiversity monitoring programs need to deliver accurate, timely, and actionable predictions. To establish a predictive monitoring program for deep‐sea benthos of the Santos Basin, Brazil, we developed a two‐stage structured model that allowed comparison of biodiversity predictions obtained from environmental simulations (2M‐Sim).
Gustavo Fonseca +23 more
wiley +1 more source

