Results 11 to 20 of about 13,072 (157)
模拟计算中的误差可以归结为两个方面:一方面是输入资料的误差,这涉及到站网的密度、空间位置、测验仪器和流域内信息的时空分布;另一方面是模型算法、结构,这里涉及到确定性和随机计算方法所引起的误差。地形对降雨量、产流量和产沙量的影响及其估算是一个十分重要的课题,同时也是一个相当困难和研究基础十分薄弱的课题。本文选用与ArcviewGIS藕合的SWAT来分析站网密度和雨量站所处的空间位置对模拟产流量和产沙量的影响。以卢氏流域为研究区域,以卢氏24个雨量站的气象资料以及下垫面资料为模型的输入 ...
陈利群 刘昌明 郝芳华
doaj +4 more sources
为研究冻融坡面径流冲刷条件下侵蚀产沙过程,采用2个坡度(10°,15°)、3个流量(3,6,9 L/min)、2个起始解冻深度(6,12 cm)组合进行野外冲刷试验,结合近景摄影测量技术分析不同解冻深度、不同坡度和不同流量条件下的产沙量,运用线性回归方程对近景摄影测量值和实测值进行拟合。结果表明:起始解冻深度和坡度相同条件下,冻融坡面的土壤侵蚀产沙量随着径流量和坡度的增大而增大;随着时间推移,产沙量越来越小。在流量和坡度相同时,随着初始解冻深度的增大,坡面产沙量也逐渐增大;在流量和解冻深度相同时 ...
明旭辉 +4 more
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为了探究不同前期含水量条件下冻融作用对坡面降雨侵蚀的影响,采用室内冻融和人工模拟降雨方法研究了不同含水量条件下冻融坡面与未冻融坡面的降雨侵蚀特征。结果表明:黄土坡面的产流时间随前期含水量增大呈先增大后减小的规律,冻融作用使黄土坡面产流时间滞后,其中含水量为20%的坡面经过冻融作用滞后62.50%,最为明显。在产流过程中,20%含水量的冻融坡面比未冻融坡面产流总量低9.14%存在极显著性差异(P<0.01)。在产沙过程中,20%和25%含水量的冻融坡面比未冻融坡面产沙总量减小28%,存在极显著性差异(P ...
段金晓 +7 more
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ABSTRACT Background Advances in transcriptomics have driven the demand for minimally invasive, reproducible and high‐yield skin sampling methods, particularly for studying inflammatory skin diseases in companion animals. Hypothesis/Objectives We tested tolerability, feasibility and RNA quantity and quality of three minimally invasive skin sampling ...
Ina Herrmann +2 more
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ABSTRACT Aqueous zinc‐ion batteries (AZIBs) hold great promise for safe and sustainable energy storage, but their commercialization is impeded by severe Zn dendrite growth and interfacial instability. To address these challenges, we propose a defect engineering strategy employing ultrafine ZnAl2O4 (ZAO) nanoparticles (∼5 nm) with oxygen vacancy defects
Yilun Ren +9 more
wiley +1 more source
ABSTRACT The development of sodium‐ion batteries (SIBs) is limited by slow charge transfer kinetics and large material volume changes caused by the large radius of Na+. Leveraging the excellent physicochemical properties and unique heterostructures of metal selenides, ultrafine hetero‐CuFeSe2‐CoSe2 nanoparticles are in situ wrapped by ...
Ying Zhu +5 more
wiley +1 more source
ABSTRACT Two‐dimensional (2D) nonlayered niobium nitrides have attracted considerable interest for electrochemical energy storage. However, the synthesis of these materials is hampered by their nonlayered crystal structures, which are characterized by strong three‐dimensional chemical bonding.
Rui Huo +7 more
wiley +1 more source
ABSTRACT Narrowband near‐infrared (NIR) phosphor‐converted light‐emitting diodes (pc‐LEDs) featuring low full‐width at half maximum (FWHM) and high conversion efficiency are crucial for chemical content evaluation, light therapy, and bioimaging.
Chunshen Li +4 more
wiley +1 more source
ABSTRACT Objective Complete hydatidiform mole and coexisting normal fetus (CHMCF) is a rare condition for which there is significant heterogeneity in diagnosis, counseling and management of complications. The objective of this study was to summarize the prevalence of clinical outcomes in reported cases of CHMCF.
N. Salmeri +8 more
wiley +1 more source
ABSTRACT Objective To investigate whether combining abnormal morphological features observed on ultrasound in live pregnancies that ended in a first‐trimester miscarriage can predict an abnormal karyotype. Methods This retrospective observational cohort study was conducted at the early‐pregnancy assessment unit at University College London Hospital ...
T. Setty +5 more
wiley +1 more source

