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THE　STATISTIC　CHARACTERISTICS　OF　IRREGULAR　BREAKING　WAVE　FORCES　ON　VERTICAL　WALLS

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Journal of Hydrodynamics 1995年第1期7卷 50-57页

作者： Li yu-cheng Liu Da-zhong (Dept.of civil engineering,Dalian university of Technology,Dalian 116023, P. R. China) Dalian Univ of Technology Dalian China

When irregular waves attack a vertical wall, standing waves and breaking (or broken) waves will occur in front of the wall. The statistic characteristics of standing wave forces on vertical wall are the same as that of incident waves. But for breaking or broken waves, only large waves break, so the statistic characteristics of breaking wave forces are different to that of standing waves or incident waves. Following a series model test of irregular breaking waves on vertical wall the statistic characterisitics of breaking wave *** were analyzed in this paper. It is found by authors that Weibul distribution may be used to express the statistic distribution of breaking wave forces acting on vertical wall. msed on the analysis of model test data, it is indicated in this paper that the shape parameter m in Weibul distribution is a function of and , in which H is the wave height, d1 is the water depth at the toe of vertical wall and d is the water depth in front of the whole structure; and the theoretical value of scale parameter a can be determined from shape parameter m.

关键词： irregular waves breaking waves wave forces vertical wall.

Enhancing visible-light-driven NO oxidation through molecular‐level insights of dye-loaded sea sands

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Rare Metals 2024年第2期43卷 543-554页

作者： yu-Han Li Bang-Fu Chen Sónia A.C.Carabineiro You-yu Duan Ping Tan Wing-Kei Ho Fan Dong engineering Research Center for Waste Oil Recovery Technology and Equipment Ministry of EducationChongqing Key Laboratory of Catalysis and New Environmental MaterialsChongqing Technology and Business UniversityChongqing400067China Nanchang Institute of Technology Nanchang33044China LAQV-REQUIMTE Department of ChemistryNOVA School of Science and TechnologyUniversidade NOVA de Lisboa2829-516CaparicaPortugal College of Physics and Center of Quantum Materials and Devices Chongqing UniversityChongqing401331China department of Science and environmental Studies The Education University of Hong KongHong Kong999077China

Natural minerals,abundant and easily obtained through simple physical processing,offer a cost-effective and environmentally friendly solution for dyeing wastewater disposal and air pollution *** study investigates the photocatalytic removal of NO using natural different types of dyes,loaded on natural sand,under visible light *** examining various coating concentrations of dyes and sand weights,we discovered that sand loaded with Rhodamine B(RhB)exhibits high activity for the photo-oxidation of NO.A combination results of X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric(TG)analyses confirm the presence of SiO_(2),CaCO_(3),Al_(2)O_(3)and iron oxides as the main components of the ***,studying RhB-loaded individual components reveals that CaCO_(3)plays a crucial role in enhancing the NO removal *** results and theoretical calculations demonstrate the establishment of a directional charge transfer channel from CaCO_(3)to RhB,facilitating the adsorption and activation of molecular NO and O_(2).This work not only promotes the utilization of natural mineral resources but also enriches the fields of environmental photochemistry and semiconductor photocatalysis.

关键词： Sand dyes Rhodamine B Photo-oxidation of NO Visible light illumination

A PARTIALLY-AVERAGED NAVIER-STOKES MODEL FOR hiLL AND CURVED DUCT FLOW

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Journal of Hydrodynamics 2011年第4期23卷 466-475页

作者： MA Jia-mei WANG Fu-jun yu xin LIU Zhu-qing College of Water Conservancy and civil engineering China Agricultural University Beijing 100083 China

Turbulent flows past hill and curved ducts exist in many engineering applications. Simulations of the turbulent flow arc carried out based on a newly developed technique, the Partially-Averaged Navier-Stokes （PANS） model, including separation, recirculation, reattachment, turbulent vortex mechanism. The focus is on how to accurately predict typical separating, reattaching and secondary motion at a reasonable computational expense. The effect of the parameter, the unresolved-to-total ratio of kinetic energy （ fk ）, is examined with a given unresolved-to-total ratio of dissipation （ fE ） for the hill flow with a much coarser grid system than required by the LES. An optimal value of fk can be obtained to predict the separation and reattachment locations and for more accurate simulation of the resolved turbulence. In addition, the turbulent secondary motions are captured by a smaller fi as compared with the RANS method with the same grid.

关键词： Partially-Averaged Navier-Stokes (PANS) flow separation recirculation reattachment resolved turbulence

Solvent-Resistant Wearable Triboelectric Nanogenerator for Energy-Harvesting and Self-Powered Sensors

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Energy & environmental Materials 2024年第5期7卷 380-390页

作者： Yongtao yu yuelin yu Hongyi Wu Tianshuo Gao Yi Zhang Jiajia Wu Jiawei Yan Jian Shi hideaki Morikawa Chunhong Zhu Graduate School of Medicine Science and Technology Shinshu University Institute for Fiber engineering (IFES) Interdisciplinary Cluster for Cutting Edge Research (ICCER) Shinshu University Faculty of Textile Science and Technology Shinshu University

Wearable triboelectric nanogenerators （TENGs） have attracted attention owing to their ability to harvest energy from the surrounding environment without maintenance. Herein, polyetherimide–Al2O3（PAl） and polyvinylidene fluoride-co-hexafluoropropylene （PVDF-HFP, PH） nanofiber membranes were used as tribo-positive and tribo-negative materials, respectively. Phytic aciddoped polyaniline （PANI）/cotton fabric （PPCF） and ethylenediamine （EDA）-crosslinked PAl （EPAl） nanofiber membranes were used as triboelectrode and triboencapsulation materials, respectively. The result showed that when the PAl–PH-based TENG was shaped as a circle with a radius of 1 cm, under the pressure of 50 N, and the frequency of 0.5 Hz, the open-circuit voltage (Voc)and short-circuit current (Isc) reached the highest value of 66.6 V and-93.4to 110.1 nA, respectively. Moreover, the PH-based TENG could be used as a fabric sensor to detect fabric composition and as a sensor-inductive switch for light bulbs or beeping warning devices. When the PAl–PH-based TENG was shaped as a 5×5 cm2rectangle, a 33μF capacitor could be charged to15 V in 28 s. Interestingly, compared to PAl nanofiber membranes, EPAl nanofiber membranes exhibited good dyeing properties and excellent solvent resistance. The PPCF exhibited hing,bending, and stretching.

关键词： energy-harvesting power supply sensors solvent-resistant wearable triboelectric nanogenerator

Improving pixel-based regional landslide susceptibility mapping

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Geoscience Frontiers 2024年第4期15卷 196-216页

作者： xin Wei Paolo Gardoni Lulu Zhang Lin Tan Dongsheng Liu Chunlan Du Hai Li State Key Laboratory of Ocean engineering Department of Civil EngineeringShanghai Jiao Tong University800 Dongchuan RoadShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration(CISSE) Shanghai 200240China Shanghai Key Laboratory for Digital Maintenance of Buildings and Infrastructure Shanghai 200240China department of civil and environmental engineering MAE Center:Creating a Multi-Hazard Approach to EngineeringUniversity of Illinois at Urbana-Champaign205 N.Mathews AveUrbana IL 61801United States Chongqing Bureau of Geology and Minerals Exploration Chongqing 401121China Hydrogeology&engineering Team 208 Chongqing Bureau of Geology and Minerals Exploration(Chongqing Reconnaissance and Design Academy of Geological Disasters Prevention and Treatment Engineering)Chongqing 400700China

Regional landslide susceptibility mapping(LSM)is essential for risk *** deep learning algorithms are increasingly used in LSM,their extensive parameters and scarce labels(limited landslide records)pose training *** contrast,classical statistical algorithms,with typically fewer parameters,are less likely to overfit,easier to train,and offer greater ***,integrating physics-based and data-driven approaches can potentially improve *** paper makes several contributions to enhance the practicality,interpretability,and cross-regional generalization ability of regional LSM models:(1)Two new hybrid models,composed of data-driven and physics-based modules,are proposed and *** ModelⅠcombines the infinite slope stability analysis(ISSA)with logistic regression,a classical statistical *** ModelⅡintegrates ISSA with a convolutional neural network,a representative of deep learning *** physics-based module constructs a new explanatory factor with higher nonlinearity and reduces prediction uncertainty caused by incomplete landslide inventory by pre-selecting non-landslide *** data-driven module captures the rela-tion between explanatory factors and landslide inventory.(2)A step-wise deletion process is proposed to assess the importance of explanatory factors and identify the minimum necessary factors required to maintain satisfactory model performance.(3)Single-pixel and local-area samples are compared to understand the effect of pixel spatial neighborhood.(4)The impact of nonlinearity in data-driven algorithms on hybrid model performance is *** landslide-prone regions in the Three Gorges Reservoir,China,are used as the study *** results show that,in the testing region,by using local-area samples to account for pixel spatial neighborhoods,Hybrid ModelⅠachieves roughly a 4.2%increase in the ***,models with 30 m resolution land-cover data surpass those using 1

关键词： Landslide susceptibility mapping Logistic regression Convolutional neural network Hybrid model Interpretability Cross-regional generalization

NUMERICAL STUDY ON THE MIxinG OF UNSORTED SEDIMENT PARTICLES DISCHARGED INTO A CROSS-FLOW BY MULTIPHASE PARTICLE-IN-CELL (MP-PIC) METHOD

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International Journal of Sediment Research 2007年第2期22卷 150-159页

作者： Jie GU1, Chiwai LI2, Hong YANG1 and Yong ZHAN31 department of environmental engineering, College of Marine Science and Technology, Shanghai Fisheries university, 334 Jungong Road, Shanghai 200090, China2 department of civil and Structural engineering, The Hong Kong Polytechnic university, Hunghom, Kowloon, Hong Kong, China3 department of environmental engineering, College of Urban Construction and Environment, university of Shanghai for Science and Technology, 516 Jungong Road, Shanghai 200093, China Shanghai Fisheries Univ Coll Marine Sci & Technol Dept Environm Engn Shanghai 200090 Peoples R China Hong Kong Polytech Univ Dept Civil & Struct Engn Kowloon Hong Kong Peoples R China Shanghai Univ Sci & Technol Coll Urban Construct & Environm Dept Environm Engn Shanghai 200093 Peoples R China

The mixing characteristics of dredged sediments of variable size discharged into cross-flow are studied by an Eulerian-Lagrangian method. A three-dimensional (3D) numerical model has been developed by using the modified k-ε parameterization for the turbulence in fluid phase/water and a Lagrangian method for the solid phase/sediments. In the model the wake turbulence induced by sediments has been included as additional source and sink terms in the k-ε model; and the trajectories of the sediments are tracked by the Lagrangian method in which the sediment drift velocities in cross-flow are computed by a multiphase particle-in-cell (MP-PIC) method and the diffusion process is approximated by a random walk model. The hydrodynamic behavior of dumped sediment cloud is governed by the total buoyancy on the cloud, the drag force on each particle and velocity of cross-flow. The cross-flow destroys more or less the double vortices occurred in stagnant ambience and dominates the longitudinal movement of sediment cloud. The computed results suggest satisfactory agreement by comparison with the experimental results of laboratory.

关键词： 3D numerical model Two-phase flow Eulerian-Lagrangian method Sediment particle cloud Cross-flow Multiphase particle-in-cell (MP-PIC) method

Influence of the Atlantic Multidecadal Oscillation and Interdecadal Pacific Oscillation on Antarctic surface air temperature during 1900 to 2015

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Acta Oceanologica Sinica 2024年第3期43卷 48-58页

作者： Cuijuan Sui Lejiang yu Alexey yuKarpechko Licheng Feng Shan Liu Key Laboratory of Marine Hazards Forecasting National Marine Environmental Forecasting CenterMinistry of Natural ResourcesBeijing 100081China Key Laboratory for Polar Science Polar Research Institute of ChinaMinistry of Natural ResourcesShanghai 200136China Finnish Meteorological Institute HelsinkiFI-00101Finland

The importance of the Atlantic Multidecadal Oscillation(AMO)and Interdecadal Pacific Oscillation(IPO)in influencing zonally asymmetric changes in Antarctic surface air temperature(SAT)has been ***,previous studies have primarily concentrated on examining the combined impact of the contrasting phases of the AMO and IPO,which have been dominant since the advent of satellite observations in *** study utilizes long-term reanalysis data to investigate the impact of four combinations of+AMO+IPO,–AMO–IPO,+AMO–IPO,and–AMO+IPO on Antarctic SAT over the past 115 ***+AMO phase is characterized by a spatial mean temperature amplitude of up to 0.5℃over the North Atlantic Ocean,accompanied by positive sea surface temperature(SST)anomalies in the tropical eastern Pacific and negative SST anomalies in the extratropical-mid-latitude western Pacific,which are indicative of the+IPO *** Antarctic SAT exhibits contrasting spatial patterns during the+AMO+IPO and+AMO–IPO ***,during the–AMO+IPO period,apart from the Antarctic Peninsula and the vicinity of the Weddell Sea,the entire Antarctic region experiences a warming *** most pronounced signal in the SAT anomalies is observed during the austral autumn,whereas the combination of–AMO and–IPO exhibits the smallest magnitude across all the *** wavetrain excited by the SST anomalies associated with the AMO and IPO induces upper-level and surface atmospheric circulation anomalies,which alter the SAT ***,downward longwave radiation anomalies related to anomalous cloud cover play a crucial *** the future,if the phases of AMO and IPO were to reverse(AMO transitioning to a negative phase and IPO transitioning to a positive phase),Antarctica could potentially face more pronounced warming and accelerated melting compared to the current observations.

关键词： Atlantic Multidecadal Oscillation(AMO) Interdecadal Pacific Oscillation(IPO) surface air temperature Antarctic wavetrain Rossby wave source

基于双特征提取网络的复杂环境车道线精准检测

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吉林大学学报（工学版） 2024年第7期54卷 1894-1902页

作者：张云佐郑宇鑫武存宇张天石家庄铁道大学信息科学与技术学院石家庄050043 石家庄铁道大学河北省电磁环境效应与信息处理重点实验室石家庄050043

为解决现有方法在复杂环境中检测精度低的问题,提出了一种基于双特征提取网络的复杂环境车道线精准检测算法。首先,搭建双特征提取网络,获取不同尺度的特征图,提取更有效的特征,提高模型在复杂环境下的特征提取能力。然后,构建跨通道联... 详细信息

为解决现有方法在复杂环境中检测精度低的问题,提出了一种基于双特征提取网络的复杂环境车道线精准检测算法。首先,搭建双特征提取网络,获取不同尺度的特征图,提取更有效的特征,提高模型在复杂环境下的特征提取能力。然后,构建跨通道联合注意力模块,提高模型对车道线细节的关注度,抑制无用信息。最后,结合改进的空洞空间金字塔池化模块扩大图像感受野,提高模型对上下文信息的利用率,以强化算法的检测能力。经实验验证,本文算法在CULane数据集上的F_(1)-measure达到了72.43%,相比于基线模型提升了4.03%,在复杂的场景中对车道线进行检测时效果提升明显。

关键词：计算机应用车道线检测双特征提取多尺度跨通道联合注意力

碱激发下粉煤灰-市政污泥固废基混凝土抗冻融性能

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工程科学与技术 2024年第3期56卷 277-286页

作者：贺盛夏鑫覃志笛于鹏广西大学土木建筑工程学院广西南宁530004 广西博世科环保科技股份有限公司广西南宁530007 广西大学广西防灾减灾与工程安全重点实验室广西南宁530004 广西大学工程防灾与结构安全教育部重点实验室广西南宁530004

为改善市政污泥对混凝土抗冻融性能的劣化效果,在氢氧化钠及水玻璃的复合激发下,用经生石灰改性后的市政污泥取代10%细骨料,粉煤灰分别取代10%、20%与30%水泥,制备了混凝土;分析不同冻融循环次数下,混凝土的表观现象、相对质量、相对动... 详细信息

为改善市政污泥对混凝土抗冻融性能的劣化效果,在氢氧化钠及水玻璃的复合激发下,用经生石灰改性后的市政污泥取代10%细骨料,粉煤灰分别取代10%、20%与30%水泥,制备了混凝土;分析不同冻融循环次数下,混凝土的表观现象、相对质量、相对动弹性模量、相对抗压强度及微观结构随粉煤灰掺量与碱当量的变化规律;分别以相对动弹性模量与相对抗压强度为损伤变量建立不同的冻融损伤模型。研究结果表明:随冻融循环次数增加,混凝土表观损伤愈发严重,内部孔隙增多,相对动弹性模量及相对抗压强度逐渐降低;与对照组相比,粉煤灰及碱激发剂的加入可以改善市政污泥对混凝土冻融耐久性的劣化效果,降低混凝土在冻融循环作用下的质量损失、动弹性模量损失及抗压强度损失;当粉煤灰掺量10%、碱当量4%时,粉煤灰会在碱激发剂及改性污泥中残余碱的联合作用下被较充分地激发,消纳改性污泥中的残余碱,减弱市政污泥对混凝土抗冻融性能的劣化效果,此时,混凝土水化程度最高,在冻融循环作用下的质量损失、动弹性模量损失及抗压强度损失最小,且服役寿命最长,约为16 a以上;相对动弹性模量与相对抗压强度相关性良好,分别以两者为损伤变量的冻融损伤模型与试验结果均吻合良好。

关键词：市政污泥固废资源化利用冻融循环微观结构冻融损伤模型