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基于面元法的分布式涵道推进系统进气道优化设计

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推进技术 2021年第11期42卷 2465-2473页

作者：王海童王掩刚周芳刘汉儒西北工业大学动力与能源学院陕西西安710129 西北工业大学深圳研究院广东深圳518057

分布式涵道推进系统被认为是一种高效率的动力布局形式,其中进气道如何使气流低损失地快速过渡到数个圆形截面的涵道风扇进口是一个亟需探索的设计问题。以分布式涵道推进系统进气道过渡段为研究对象,基于面元计算方法,发展了一种进气... 详细信息

分布式涵道推进系统被认为是一种高效率的动力布局形式,其中进气道如何使气流低损失地快速过渡到数个圆形截面的涵道风扇进口是一个亟需探索的设计问题。以分布式涵道推进系统进气道过渡段为研究对象,基于面元计算方法,发展了一种进气道内流动的快速数值预测手段。应用所发展面元法数值方法结合进气道的超椭圆参数化方法、自适应优化算法,建立了分布式涵道推进系统进气道的无经验优化设计方法。以某型悬停状态的分布式涵道推进垂直起降飞行器为例,使用该设计方法实现了从无圆滑过渡的简单初始几何到气动指标符合优化预期的光顺几何的优化设计。基于RANS的三维数值分析表明:所优化设计的进气道相比于初始几何总压畸变系数(DC)从0.0086降低到0.0067,低于基于经验设计的参考几何(DC=0.0073),且流场无明显分离及旋涡,确认了这种具有高时间效率的无经验设计方法的有效性。

关键词：面元法分布式推进进气道优化畸变

串列叶栅缝隙射流对分离流动及叶栅性能影响的研究

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推进技术 2018年第12期39卷 2728-2736页

作者：刘汉儒岳少原王掩刚张俊西北工业大学动力与能源学院陕西西安710072

为了研究串列叶栅前后叶缝隙流作用对流动分离和叶栅性能影响机制,通过非定常数值计算分析了串列叶栅轴向重合度和节距系数两种缝隙参数组合对高负荷压气机串列叶栅在大攻角11°下性能影响以及缝隙流掺混作用下前后叶流动分离的时空演... 详细信息

为了研究串列叶栅前后叶缝隙流作用对流动分离和叶栅性能影响机制,通过非定常数值计算分析了串列叶栅轴向重合度和节距系数两种缝隙参数组合对高负荷压气机串列叶栅在大攻角11°下性能影响以及缝隙流掺混作用下前后叶流动分离的时空演化机制的影响规律,并且提出了缝隙流对串列叶栅流动及性能影响的综合性参数-缝隙收缩比。研究结果表明:轴向重合度在-0.022～0.023,节距系数在0.6～0.9时,串列叶栅能取得较好气动性能;在缝隙非定常吹除作用下,后叶吸力面分离泡被周期性抑制,前叶吸力面分离泡受缝隙射流源的影响较弱;提出的缝隙收缩比作为综合匹配参数可以更清晰揭示出串列叶栅有效工作条件,在亚声速来流工况下,缝隙收缩比大于1是串列叶片能正常工作的前提,缝隙收缩比小于1,缝隙加速作用消失,叶栅性能较差,最佳的缝隙收缩比范围是1.1～1.4。

关键词：串列叶栅非定常流动分离泡压力波动特征缝隙收缩比

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募集资金投向变更对上市公司绩效的影响研究

中小企业管理与科技 2019年第27期3卷 52-55页

作者：刘函如石河子大学

融资是证券市场的一个基本功能,上市公司为了自身的可持续发展,都会选择在证券市场中募集资金。募集资金的使用效率会对企业自身的经营产生影响。论文以国内有关上市公司募集资金投向变更的研究为基础,分析了上市公司募集资金变更投向... 详细信息

融资是证券市场的一个基本功能,上市公司为了自身的可持续发展,都会选择在证券市场中募集资金。募集资金的使用效率会对企业自身的经营产生影响。论文以国内有关上市公司募集资金投向变更的研究为基础,分析了上市公司募集资金变更投向的现状,说明了其募集资金的实际使用情况,阐述了导致募集资金变更的原因,并进一步分析了变更募投项目对企业绩效的影响。最后得出变更募集资金投向是一种低效率的资金使用行为。

关键词：募集资金投向变更企业绩效

压气机叶栅非定常线性自回归气动降阶模型研究

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推进技术 2022年第5期43卷 79-86页

作者：刘汉儒胡佳伟王掩刚马岩赵星宇西北工业大学长三角研究院江苏太仓215400 西北工业大学动力与能源学院陕西西安710129

为满足叶轮机械领域高效非定常气动计算的迫切需求,采用线性带外输入的自回归(ARX)理论建立了高亚声速压气机叶栅非定常气动性能降阶模型。该降阶模型构造简单,建立较为容易。通过逐渐增加输入/输出延迟阶数,可以获得较高精度的模型超... 详细信息

为满足叶轮机械领域高效非定常气动计算的迫切需求,采用线性带外输入的自回归(ARX)理论建立了高亚声速压气机叶栅非定常气动性能降阶模型。该降阶模型构造简单,建立较为容易。通过逐渐增加输入/输出延迟阶数,可以获得较高精度的模型超参数。研究结果表明:降阶模型对线性非定常系统的气动参数响应具有较好的预测精度,但在部分无量纲总压一阶幅值比以及无量纲静压一阶相位角存在一定预测误差。非定常系统线性工况下,同一折合频率的气动参数的一阶幅值比和相位角基本不随攻角幅值的增加而变化。通过与具有泛化能力的非线性降阶模型比较,基于线性假设发展的ARX模型能获得更高精度的气动参数响应。

关键词：压气机叶栅降阶模型非定常流动带外输入自回归模型动态气动边界

Preparation and applications of calcium ferrite as a functional material:A review

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 292-310页

作者： Xiuli han Bowen Duan Lei liu Shilong Fang Weiwei Wang College of Mining Engineering North China University of Science and TechnologyTangshan 063210China Collaborative Innovation Center of Green Development and Ecological Restoration of Mineral Resources of Hebei Province Tangshan 063210China Key Laboratory of Mining Development and Security Technology of Hebei Province Tangshan 063210China

Calcium ferrite(CF)is recognized as a potential green and efficient functional material because of its advantages of magnetism,electrochemistry,catalysis,and biocompatibility in the fields of materials chemistry,environmental engineering,and ***-fore,the obtained research results need to be systematically summarized,and new perspectives on CF and its composite materials need to be *** on the presented studies of CF and its composite materials,the types and structures of the crystal are *** addition,the current application technologies and theoretical mechanisms with various properties in different fields are ***,the various preparation methods of CF and its composite materials are elaborated in *** importantly,the advantages and disadvantages of the synthesis methods of CF and its composite materials are discussed,and the existing problems and emerging challenges in practical production are ***,the key future research directions of CF and its composite materials have been prospected from the potential application technologies to provide references for its synthesis and efficient utilization.

关键词： calcium ferrite mineral functional materials preparation application perspectives

Anomalous quality factor evolution of induced transparency in a virtualized coupled-oscillator system

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 148-155页

作者： Yunhan Yang han Jia Tuo liu Yuzhen Yang Jun Yang Key Laboratory of Noise and Vibration Research Institute of Acoustics Chinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences

The phenomenon of induced transparency, characterized by a high quality(Q) factor, holds significant importance in the fields of high-precision sensing, energy storage and wave manipulation. Conventional transparency systems are often constrained by the limited experimentally accessible parameter space and the lack of independent control over intrinsic parameters, thereby hindering advanced research on high-Q effects. Here we propose a virtualized coupled-oscillator system that enables reconfigurable induced transparency in the reflection spectrum. By virtually incorporating a pair of coupled oscillators into an individual acoustic meta-atom, we achieve the manipulation of induced transparency in a decoupled, wide-ranging, and elaborate manner. Exploiting the diverse evolutions across the intrinsic parameter space, we show experimentally a counter-intuitive increase in the Q-factor of the transparency window, which is attributed to the enhanced dissipation of the bright ***, a constant group delay at the center frequency is observed accompanying this evolution. Our work demonstrates an intriguing platform as well as a novel strategy to engineer high-Q induced transparency phenomenon, and paves the way towards applications in programmable acoustic sensors, filters and slow-wave devices.

关键词： induced transparency acoustic meta-atom high quality-factor scattering programmable intrinsic parameter

Boosting hydrocarbon conversion via Cu-doping induced oxygen vacancies on CeO2 in CO2 electroreduction

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Journal of Energy Chemistry 2025年第1期100卷 66-76页

作者： Lei Xue Tong Shi Chenhui han Heng Zhang Fenrong liu Haorun Li Yan Wang Xiaojun Gu Shanghong Zeng Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials School of Chemistry and Chemical Engineering Inner Mongolia University State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences Institute of Catalysis Department of Chemistry Zhejiang University National Key Laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization Baotou Research Institute of Rare Earths

Conversion of CO2back to hydrocarbons is the most direct way of closing the“carbon cycle”,and its significance is further enlarged if this process is driven by renewable energies such as ***,precisely controlling the product selectivity towards hydrocarbons against the competitive hydrogen evolution remains challenging,especially for Cu-based ***,we report a novel defect engineering strategy,by which Cu-doping-induced oxygen vacancies on CeO2nanorods were effectively created,with adjustable vacancy/Cu *** resulting optimum catalyst shows up to 79% catalytic current density to hydrocarbons （excluding CO）,with 49% faradaic efficiency to *** and density functional theory unveil that the ratio between oxygen vacancy and Cu affects significantly the formation of*CHO and activation of H2O,which leads to the following deep hydrogenation to *** findings may spur new insights for designing and developing more controllable chemical process relevant to CO2utilization.

关键词： Oxygen vacancy Hydrocarbon production Reaction mechanism

Multi boron-doping effects in hard carbon toward enhanced sodium ion storage

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Journal of Energy Chemistry 2025年第1期100卷 730-738页

作者： Peng Zheng Wang Zhou Ying Mo Biao Zheng Miaomiao han Qin Zhong Wenwen Yang Peng Gao Lezhi Yang Jilei liu College of Materials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology Hunan University Greater Bay Area Institute for Innovation Hunan University Changsha Research Institute of Mining & Metallurgy Co. LTD.

Hard carbon （HC） has been considered as promising anode material for sodium-ion batteries （SIBs）.The optimization of hard carbon’s microstructure and solid electrolyte interface （SEI） property are demonstrated effective in enhancing the Na+storage capability,however,a one-step regulation strategy to achieve simultaneous multi-scale structures optimization is highly ***,we have systematically investigated the effects of boron doping on hard carbon’s microstructure and interface chemistry.A variety of structure characterizations show that appropriate amount of boron doping can increase the size of closed pores via rearrangement of carbon layers with improved graphitization degree,which provides more Na+storage ***-situ Fourier transform infrared spectroscopy/electrochemical impedance spectroscopy （FTIR/EIS） and X-ray photoelectron spectroscopy （XPS） analysis demonstrate the presence of more BC3and less B–C–O structures that result in enhanced ion diffusion kinetics and the formation of inorganic rich and robust SEI,which leads to facilitated charge transfer and excellent rate *** a result,the hard carbon anode with optimized boron doping content exhibits enhanced rate and cycling *** general,this work unravels the critical role of boron doping in optimizing the pore structure,interface chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced Na+storage performance.

关键词： X ray photoelectron spectroscopy

地方性高校社会指导与管理专业校企合作的现实意义与路径研究

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兰州文理学院学报（自然科学版） 2017年第5期31卷 125-128页

作者：刘仁憨郭茹芳天水师范学院体育运动与健康学院甘肃天水741001 天水市一中体育组甘肃天水741000

采用实地调研、逻辑分析等方法,对我国地方性高校社会体育指导与管理专业校企合作的现实意义及路径选择进行研究.研究表明:社会体育指导与管理专业办学中,校企合作的现实意义体现在促进师资队伍建设,完备学生知识能力,提升学生职业素养... 详细信息

采用实地调研、逻辑分析等方法,对我国地方性高校社会体育指导与管理专业校企合作的现实意义及路径选择进行研究.研究表明:社会体育指导与管理专业办学中,校企合作的现实意义体现在促进师资队伍建设,完备学生知识能力,提升学生职业素养,提高学生就业竞争力.为有效开展校企合作,提出成立校企合作教学督导委员会,扩大合作的深度和广度,发挥校企双方联合培养人才优势,共同商定人才评价标准和体系的路径选择.以期为该专业办学提供有益的理论依据和实践思考.

关键词：地方性高校社会体育指导与管理专业校企合作选择路径