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Vortex-Induced Vibration Response Features of A Submarine Multi-Span Pipeline via Towing Tank Experimental Tests

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China Ocean Engineering 2023年第2期37卷 175-189页

作者： XU Wan-hai JIA Kun ma ye-xuan SONG Zhi-you State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China

In offshore engineering, the phenomenon of free span often occurs, and the pipeline may have multiple free spans adjacent to each other, forming a multi-span pipeline. The interaction of different spans makes the structural vibration characteristics more complex, which may change the fatigue characteristics of the pipeline and affect the safety of the structure. In this paper, model tests were designed to explore the vortex-induced vibration(VIV) characteristics of multi-span pipelines and investigate the multi-span interaction mechanism. The experimental study mainly focused on the dynamic response of double-span pipelines, and further extended to triple-span pipelines, hoping that the results can be applied to more complex environment. The effects of span-length ratio, buried depth and axial force on VIV of the pipeline were investigated and discussed. The dynamic response of the pipeline varied with the span length. There was obvious interaction between different spans of multi-span pipelines, and the pipe-sediment interaction obviously affected the vibration characteristics of pipeline. The differences of pipeline burial depth and axial force changed the structural stiffness. With the increase of buried depth, the response amplitude presented a downward trend. The spanwise evolutions were asymmetric caused by the pipe-sediment interaction and multi-span interaction. The results can help to identify multi-span pipelines in engineering, and realize the prevention and control of free spans.

关键词： vortex-induced vibration submarine pipeline pipe-sediment interaction multi-span interaction

Displacement Response Reconstruction of Slender Flexible Structures Based on Cubic Spline Fitting Method

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China Ocean Engineering 2019年第2期33卷 226-236页

作者： HAN Qing-hua ma ye-xuan FENG Xin-xin XU Wan-hai State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University School of Civil Engineering Tianjin University

How to reconstruct a dynamic displacement of slender flexible structures is the key technology to develop smart structures and structural health monitoring(SHM), which are beneficial for controlling the structural vibration and protecting the structural safety. In this paper, the displacement reconstruction method based on cubic spline fitting is put forward to reconstruct the dynamic displacement of slender flexible structures without the knowledge of modeshapes and applied loading. The obtained strains and displacements are compared with the results calculated by ABAQUS to check the method's validity. It can be found that the proposed method can accurately identify the strains and displacement of slender flexible structures undergoing linear vibrations, nonlinear vibrations, and parametric vibrations. Under the concentrated force, the strains of slender flexible structures will change suddenly along the axial direction. With locally densified measurement points, the present reconstruction method still works well for the strain concentration problem.

关键词： displacement reconstruction cubic spline fitting slender flexible structures linear vibrations parametric vibrations nonlinear vibrations

Effect of cholesterol metabolism on hepatolithiasis

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World Journal of Gastroenterology 2025年第1期31卷 157-162页

作者： Lin Zheng Zi-Yu ye Jun-Ji ma Department of Gastroenterology The Second Hospital of Hebei Medical UniversityHebei Key Laboratory of GastroenterologyHebei Institute of GastroenterologyHebei Clinical Research Center for Digestive DiseasesNo.215 Heping West RoadShijiazhuang 050000Hebei ProvinceChina

Surgical intervention is currently the primary treatment for hepatolithiasis;how-ever,some patients still experience residual stones and high recurrence rates after *** metabolism seems to play an important role in hepatoli-thiasis pathogenesis.A high cholesterol diet is one of the significant reasons for the increasing incidence of ***,regular diet and appropriate medical intervention are crucial measures to prevent hepatolithiasis and reduce recurrence rate after *** dietary cholesterol and drugs that increase cholesterol stone solubility are key therapeutic approaches in treating *** article discusses the cholesterol metabolic pathways related to the pathogenesis of hepatolithiasis,as well as food intake and targeted therapeutic drugs.

关键词： Hepatolithiasis Cholesterol metabolism High-fat diet 3-hydroxy-3-methylglutaryl-coenzyme A reductase Interlobular bile duct

带有中心钝体的固体燃料冲压发动机工作性能分析

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推进技术 2022年第8期43卷 40-47页

作者：张宁史金光王中原马晔璇南京理工大学能源与动力学院江苏南京210094 北京动力机械研究所北京100074

为提高固体燃料冲压发动机的燃烧特性和工作性能,提出了带有中心钝体的固体燃料冲压发动机方案,基于雷诺转捩和涡概念耗散方程建立了其湍流燃烧模型,并数值计算分析了其内流场、燃面退移速率、推力与总压损失。结果表明:带有中心钝体的... 详细信息

为提高固体燃料冲压发动机的燃烧特性和工作性能,提出了带有中心钝体的固体燃料冲压发动机方案,基于雷诺转捩和涡概念耗散方程建立了其湍流燃烧模型,并数值计算分析了其内流场、燃面退移速率、推力与总压损失。结果表明:带有中心钝体的冲压发动机内部流动过程较为复杂,钝体后部有四个漩涡,增强了发动机内来流空气与燃气的掺混;钝体孔隙中的高速气流与两侧的小尺度漩涡保证了钝体尾涡的稳定性;与普通固体燃料冲压发动机相比,在燃烧室中增加中心钝体能增大燃烧室内高温区面积,提高补燃室内温度,可使推进剂平均燃面退移速率提高36.5%,发动机推力提高22.1%,燃烧效率提高8.9%。

关键词：固体燃料冲压发动机涡旋燃烧燃面退移速率推力燃烧效率

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含铝固体燃料冲压发动机工作性能分析

推进技术 2022年第6期43卷 49-57页

作者：张宁史金光王中原马晔璇南京理工大学能源与动力学院江苏南京210094 北京动力机械研究所北京100074

为探究含铝固体燃料冲压发动机的燃烧特性和工作性能,基于纳米铝颗粒和端羟基聚丁二烯(HTPB)的混合固体燃料,采用雷诺转捩模型、颗粒表面反应模型和涡概念耗散模型,建立了二维两相湍流燃烧模型;数值计算分析了含铝固体燃料冲压发动机内... 详细信息

为探究含铝固体燃料冲压发动机的燃烧特性和工作性能,基于纳米铝颗粒和端羟基聚丁二烯(HTPB)的混合固体燃料,采用雷诺转捩模型、颗粒表面反应模型和涡概念耗散模型,建立了二维两相湍流燃烧模型;数值计算分析了含铝固体燃料冲压发动机内流场,以及不同含铝质量分数和粒径下的燃面退移速率、推力与比冲。结果表明:发动机的进气条件对颗粒相的燃烧与运动起主导作用;与纯HTPB推进剂相比,添加质量分数为5%的铝颗粒能够提高补燃室压强和温度,增大燃烧室内高温区面积,可使推进剂平均燃面退移速率提高18.53%,发动机推力提高21.37%,密度比冲提高2.38%,适当增加铝颗粒含量或减小粒径,对提高推进剂燃面退移速率、发动机推力和密度比冲具有积极作用。

关键词：固体燃料冲压发动机含铝推进剂燃面退移速率推力比冲

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考虑跨肩管土作用的悬跨管道涡激振动特性研究

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船舶力学 2018年第4期22卷 446-453页

作者：徐万海谢武德高喜峰马烨璇天津大学水利工程仿真与安全国家重点实验室天津300072

海底悬跨管道涡激振动是一个复杂的流场-管道结构-跨肩土体耦合问题,其发生机理和振动特性十分复杂,特别是两端跨肩处管土作用对涡激振动的影响有待深入讨论。为此,文章引入了P-y曲线描绘跨肩处管土耦合作用,提出了基于管道位移和速度... 详细信息

海底悬跨管道涡激振动是一个复杂的流场-管道结构-跨肩土体耦合问题,其发生机理和振动特性十分复杂,特别是两端跨肩处管土作用对涡激振动的影响有待深入讨论。为此,文章引入了P-y曲线描绘跨肩处管土耦合作用,提出了基于管道位移和速度的新非线性土体弹簧模型,根据能量平衡原理计算土体阻尼,采用尾流振子模型模拟悬跨管段流固耦合作用,建立了考虑流—固—土多场耦合作用的海底悬跨管道涡激振动预报模型,并重点研究了考虑跨肩管土作用时,悬跨管道涡激振动的诸多特性。

关键词：涡激振动悬跨管道管-土耦合 P-y曲线

水泥稳定类结构层横向施工缝支模施工技术研究

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公路交通科技 2022年第7期39卷 15-22页

作者：马选业王积达陈全兴蔡乾东甘肃顺达路桥建设有限公司甘肃兰州730050 陕西东道特种路面科技有限公司陕西西安712000

为提升水泥稳定类结构层横向施工缝工程质量与结构完整性,针对传统立木裁切工艺、延长铺筑长度与铲除法存在效率低、材料浪费大、费时费力及接缝处平整度差、结构不密实等问题,在现有纵向立模施工工艺的基础上,通过在铺筑作业段两端安... 详细信息

为提升水泥稳定类结构层横向施工缝工程质量与结构完整性,针对传统立木裁切工艺、延长铺筑长度与铲除法存在效率低、材料浪费大、费时费力及接缝处平整度差、结构不密实等问题,在现有纵向立模施工工艺的基础上,通过在铺筑作业段两端安装横向支撑侧模与压路机爬坡装置,利用纵横向支撑侧模的固定及支撑作用,使横向接缝部位的混合料摊铺到位、填充密实。利用纵横向两侧设置的压路机爬坡装置,扩大接缝边部碾压作业范围,使接缝部位实现纵、横向全域碾压。进一步提出了横向施工缝设置、施工装置制作、工艺流程、操作要点及施工质量控制方法。研究表明:在纵横向支撑侧模的固定、有侧限约束力及纵横向全域碾压作用下,横向接缝部位形成了密实的垂直断面,各作业段之间形成了垂直的平接缝,平接缝处均匀洒布了水泥浆,增强了接缝黏结强度与结构层的完整性,避免了接缝处混合料出现推移、塌边、脱空及错台现象;与传统立木裁切工艺相比,横向接缝处的压实度得到了改善,芯样无侧限抗压强度提高20%,平整度提高58.8%;可直接节约废弃材料、材料运输等综合施工成本达93.6%,提高了施工效率,达到了提质增效的目的,为无机结合料稳定类结构层横向施工接缝的精细化处理提供了一条可行的技术解决途径。

关键词：道路工程水泥稳定类结构层支模施工横向施工缝纵横向支撑侧模压路机爬坡装置施工缝控制

Zinc-based fiber-shaped rechargeable batteries:Insights into structures,electrodes,and electrolytes

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Nano Research 2025年第1期18卷 278-293页

作者： xuan Zhang Hongcheng Zhang Mengxiang Chen Jingqi Lu Evgeny Zhuravlev Jing Jiang Pin Liu Shengyang Dong Du Yuan Guoyin Zhu Lianbo ma Yizhou Zhang Institute of Advanced materials and Flexible Electronics(IAMFE) School of Chemistry and Materials ScienceNanjing University of Information Science and TechnologyNanjing 210044China School of materials Science and Engineering Anhui University of TechnologyMaanshan 243002China College of materials Science and Engineering Changsha University of Science and TechnologyChangsha 410004China

The rapid evolution of flexible wearable electronics has spurred a growing demand for energy storage devices,characterized by low-cost manufacturing processes,high safety standards,exceptional electrochemical performance and robust mechanical *** novel flexible devices,fiber-shaped batteries(FSBs)have emerged as prominent solutions exceptionally suited to future applications,owing to their unique one-dimensional(1D)architecture,remarkable flexibility,potential for miniaturization,adaptability to deformation and compatibility with the conventional textile *** the forefront research on fiber-shaped batteries,zincbased FSBs(ZFSBs)have garnered significant attentions,featured by the promising electrochemical properties of metallic *** enthusiasm is driven by the impressive capacity of Zn(820 mah·g^(-1))and its low redox potential(Zn/Zn^(2+):-0.76 V *** hydrogen electrode).This review aims to consolidate recent achievements in the structural design,fabrication processes and electrode materials of flexible ***,we highlight three representative structural configurations:parallel type,twisted type and coaxial *** also place special emphasis on electrode modifications and electrolyte ***,we delve into the promising development opportunities and anticipate future challenges associated with ZFSBs,emphasizing their potential roles in powering the next generation of wearable electronics.

关键词： zinc-based batteries fiber-shape parallel type twisted type coaxial type

The complex roles of m^(6)A modifications in neural stem cell proliferation, differentiation, and self-renewal and implications for memory and neurodegenerative diseases

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Neural Regeneration Research 2025年第6期20卷 1582-1598页

作者： Yanxi Li Jing Xue Yuejia ma Ke ye Xue Zhao Fangliang Ge Feifei Zheng Lulu Liu Xu Gao Dayong Wang Qing Xia Department of Biochemistry and Molecular Biology College of Basic Medical SciencesHarbin Medical UniversityHarbinHeilongjiang ProvinceChina College of Basic Medical Sciences Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Basic Medical Institute Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina Key Laboratory of Heilongjiang Province for Genetically Modified Animals Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Translational Medicine Research and Cooperation Center of Northern China Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina Dongzhimen Hospital Beijing University of Chinese MedicineBeijingChina

N6-methyladenosine(m^(6)A), the most prevalent and conserved RNA modification in eukaryotic cells, profoundly influences virtually all aspects of mRNA metabolism. mRNA plays crucial roles in neural stem cell genesis and neural regeneration, where it is highly concentrated and actively involved in these processes. Changes in m^(6)A modification levels and the expression levels of related enzymatic proteins can lead to neurological dysfunction and contribute to the development of neurological diseases. Furthermore, the proliferation and differentiation of neural stem cells, as well as nerve regeneration, are intimately linked to memory function and neurodegenerative diseases. This paper presents a comprehensive review of the roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, as well as its implications in memory and neurodegenerative diseases. m^(6)A has demonstrated divergent effects on the proliferation and differentiation of neural stem cells. These observed contradictions may arise from the time-specific nature of m^(6)A and its differential impact on neural stem cells across various stages of development. Similarly, the diverse effects of m^(6)A on distinct types of memory could be attributed to the involvement of specific brain regions in memory formation and recall. Inconsistencies in m^(6)A levels across different models of neurodegenerative disease, particularly Alzheimer's disease and Parkinson's disease, suggest that these disparities are linked to variations in the affected brain regions. Notably, the opposing changes in m^(6)A levels observed in Parkinson's disease models exposed to manganese compared to normal Parkinson's disease models further underscore the complexity of m^(6)A's role in neurodegenerative processes. The roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, and its implications in memory and neurodegenerative diseases, appear contradictory. These inconsistencies may be a

关键词： Alzheimer's disease cell self-renewal central nervous system memory microglia nerve regeneration neurodegenerative diseases neurogenesis RNA methylation