Results 21 to 30 of about 939,081 (129)
Gaoya dianqi, 2022 开关柜是配电系统的重要组成部分，主回路梅花触头的安全运行直接关系到开关柜的可靠性。为了提高梅花触头电接触的导电性和减摩抗磨的能力，在其接触部位进行了镀银处理，镀银层的厚度、粗糙度和硬度参数直接决定着梅花触头的使用寿命，因此有必要针对梅花触头电接触性能与不同镀银层厚度、粗糙度和硬度之间的关系进行深入的研究。文中以KYN28-12开关柜内的梅花触头为研究对象，运用有限元分析法建立了三维电—热—力的多物理场耦合模型，分析了在不同镀银层厚度、粗糙度和硬度条件下梅花触头的温度场分布特性 ...
祁海洋 +6 more
doaj
Kongjian kexue xuebao, 2023 卫星散射计通过测量海表粗糙度反演全球海面风场。对于Ku波段散射计，海表粗糙不仅和海面风场相关，还受海表温度的二阶效应调制。定量研究了海表温度对中法海洋卫星（CFOSAT）散射计（CSCAT）反演风速和后向散射测量的影响。结果表明，CSCAT两种极化方式测量的后向散射系数都会受到海表温度的影响，但是垂直极化中低入射角（θ < 36°）测量的后向散射系数几乎不随温度变化。因此CSCAT的风速偏差也随海表温度的变化而变化，且随着入射角的增大和风速的减小，海表温度对风速偏差的影响程度增大 ...
赵 晓康 +3 more
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Rare 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
, 1994 根据传统的Koch曲线;我们建立了节理剖面的理论分形模型来模拟节理剖面的粗糙性。由这个模型;节理的分形维数D可以直接由两个统计参数L*和h*(这里L*和h*分别为节理粗糙度的平均基长和平均高度)来估计;即 D=log4/log[2(1+costg~(-1)(2h*/L*))]。 这个分形维数很强地相关于岩石节理粗糙系数(JRC)值: JRC=85.2671(D-1)~(0.5679 ...
谢和平, W.G.Pariseau
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Rare Metals, Volume 45, Issue 9, September 2026.ABSTRACT Aiming at the problems of insufficient forming quality and poor surface performance in the preparation of Ti‐6Al‐4V alloy by laser powder bed fusion (LPBF), this study proposed a laser in situ forging additive manufacturing (LIF‐AM) technology, which integrates LPBF with femtosecond laser in situ shock forging and realizes defect control and ...
Peng He +10 more
wiley +1 more source
, 2013 采用直接数值模拟方法计算了上壁面光滑,下壁面粗糙的充分发展的槽道湍流。基于光滑壁面的黏性速度和槽道半宽的黏性雷诺数Re=180。粗糙壁面采用在光滑壁上设置横向等间距方形长条的简化模型。运用浸入边界方法来处理这些粗糙单元。为了避免在粗糙单元后形成稳定的涡,采用了粗糙单元间距w与单元高度h之比为7的K型粗糙壁面。通过数值模拟 ...
耿晨晖, 晋国栋, 何国威
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The Photogrammetric Record, Volume 41, Issue 195, July‐September 2026.Tri‐stereoscopic PeruSat‐1 imagery enables the simultaneous generation of 0.70 m‐resolution topography and spatially distributed Manning roughness maps, achieving 0.434 m vertical accuracy. Integrated into HEC‐RAS, these products provide consistent, high‐resolution inputs that improve hydraulic modelling and flood risk assessment in data‐scarce river ...
Jorge L. Miranda‐Pita +3 more
wiley +1 more source
Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT MCrAlX coatings are widely used as bond coats in thermal barrier coating systems to protect turbine blades from high‐temperature oxidation. However, their oxidation resistance is often restricted by uncontrolled microstructures, surface roughness, and aggregation of reactive elements (REs). In this study, high‐repetition‐rate femtosecond laser
Wei Qian +7 more
wiley +1 more source
Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT NiFe‐based MIL‐55 metal‐organic frameworks (MOFs) face challenges in achieving atomically precise composition and reliable methods for uniform growth. This study addresses these challenges by applying a slow evaporation crystallization technique to crude colloidal MIL‐55 products from hydrothermal synthesis, resulting in highly uniform ...
H. R. Haris +10 more
wiley +1 more source
, 2022 解析粗糙单元的直接数值模拟(DNS)和大涡模拟(LES)计算量较大。使用壁模型避免要解析粗糙度元素尺度的流动,为模拟粗糙壁湍流提供了一种有效的选择。在这项工作中,我们评估了LES中粗糙壁模型的预测能力,将其结果与解析粗糙度的DNS槽道湍流结果进行比较。观察到粗糙壁模化大涡模拟准确预测了平均流向速度,所得到的雷诺应力也与DNS结果有较好吻合。然而,其预测的分散应力(dispersive stresses)、积分尺度和时空关联与DNS结果存在较大的差异。在外区,粗糙壁模型预测的积分尺度低于DNS的结果 ...
李世隆, 杨晓雷
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