Results 11 to 20 of about 746,569 (154)
, 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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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
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
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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
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Filling Uniformity of AgNPs in EMI Shielding Patch Regulated by Surface Morphology
Rare Metals, Volume 45, Issue 1, January 2026.ABSTRACT Silver nanoparticles (AgNPs) are extensively employed for electromagnetic interference (EMI) shielding owing to their remarkable conductivity, and are commonly incorporated into polymer matrices. Therefore, the uniformity of the AgNP distribution within the polymer matrix is a crucial factor that affects the EMI shielding performance.
Jie Yang +8 more
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Integrative Conservation, Volume 4, Issue 3, Page 476-490, September 2025.The leaf functional traits of angiosperms and gymnosperms in mountain ecosystems significantly influence phyllosphere fungal diversity. These traits are critical for understanding fungal stress resistance and elevational adaptation, which aids in predicting plant responses to climate change.
Xiaocheng Yu +7 more
wiley +1 more source
Gaoya dianqi, 2019 高压输电线路表面磨损会对线路电晕放电造成影响。粗糙系数是根据导线表面状态预测起晕场强的重要参数。文中研究了表面粗糙度与高压直流导线起晕场强以及粗糙系数之间的关系,基于触针法测量了圆截面导线的表面粗糙度,利用圆柱电晕笼获得了导线正负极直流起晕电压,得到了粗糙系数与导线表面粗糙度之间的变化规律。导线粗糙度在0.5μm到2.5μm的范围内变化时,粗糙系数随表面粗糙度增大而减小。与正极相比,表面粗糙度对负极电晕放电影响更大。表面粗糙度越大,粗糙度变化对粗糙系数的影响越明显。
王东来 +4 more
doaj
Gaoya dianqi, 2021 文中的目标是研究真空中火花老炼对电极表面状况的影响。通过比较真空间隙火花老炼前后电极的表面状况,分别研究了Cu和SUS304两种电极的老炼过程对于电极表面状况的影响。同时在实验回路中加入限流电阻,研究老炼过程中不同击穿能量对于电极表面状况的影响规律。实验结果表明了针对Cu电极的真空间隙,火花老炼后电极的表面状况与老炼过程中的击穿能量有关,与电极表面的初始粗糙度无关。击穿能量越小,电极表面越平滑。因此,较小的击穿能量能将真空间隙的绝缘强度老炼得更高 ...
刘庆 +6 more
doaj
Study on learning from examples based on rough sets theory(基于粗糙集理论的示例学习研究)
Zhejiang Daxue xuebao. Lixue ban, 2002 到目前为止,一些启发式算法被提出用于基于扩张矩阵理论的示例学习研究.该文基于粗集理论研究示例学习问题,提出了粗集理论下的几个新概念,如:必要选择子,核选择子集,约简选择子集和所产生复合的评价指标:精确度、覆盖度和简单性,给出了扩张矩阵的粗糙集算法,并提出了基于覆盖度和简单性的遗传算法最优示例学习方法.
HANGXiao-shu(杭小树) +1 more
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Indicator system optimization and evaluation method based on rough set(基于粗糙集的指标体系优化及评价方法研究)
Zhejiang Daxue xuebao. Lixue ban, 2010 粗糙集方法能客观、有效地对有限指标数据进行挖掘,通过属性约简剔除冗余指标,并根据属性重要度生成指标权重,系统地探讨了利用粗糙集进行指标体系优化和综合评价的全过程思路及方法,并通过同行评议专家科技信用评价实例,验证了方法的实用性.
LIYuan-yuan(李远远), YUNJun(云俊)
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