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An interpretation of wave refraction and its influence on foreshore sediment distribution

Acta Oceanologica Sinica 2019年第5期38卷 151-160页

作者： Vincent Jayaraj Joevivek Nainarpandian Chandrasekar Ramakrishnan Jayangondaperumal Vikram Chandra Thakur Krishnan Shree Purniema Akshaya College of Engineering and Technology Centre for GeoTechnology Manonmaniam Sundaranar University Francis Xavier Engineering College structure and tectonics group Wadia Institute of Himalayan Geology

To analyze the grain size and depositional environment of the foreshore sediments, a study was undertaken on wave refraction along the wide sandy beaches of central Tamil Nadu coast. The nearshore waves approach the coast at 45° during the northeast(NE) monsoon, at 135° during the southwest(SW) monsoon and at 90° during the non-monsoon or fair-weather period with a predominant wave period of 8 and 10 s. A computer based wave refraction pattern is constructed to evaluate the trajectories of shoreward propagating waves along the coast in different seasons. The convergent wave rays during NE monsoon, leads to high energy wave condition which conveys a continuous erosion at foreshore region while divergent and inept condition of rays during the SW and non-monsoon, leads to moderate and less energy waves that clearly demarcates the rebuilt beach sediments through littoral sediment transport. The role of wave refraction in foreshore deposits was understood by grain size and depositional environment analysis. The presence of fine grains with the mixed population, during the NE monsoon reveals that the high energy wave condition and sediments were derived from beach and river environment. Conversely, the presence of medium grains with uniform population, during SW and non-monsoon attested less turbulence and sediments were derived from prolong propagation of onshore-offshore wave *** upshots are apparently correlated with the in situ beach condition. On the whole, from this study it is understood that beaches underwent erosion during the NE monsoon and restored its original condition during the SW and non-monsoon seasons that exposed the stability of the beach and nearshore condition.

关键词： foreshore grain size wave refraction sediment transport beach India

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SPONTANEOUS DISPERSION OF SOME ACTIVE COMPONENTS ONTO THE SURFACES OF CARRIERS

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Science China Chemistry 1983年第4期26卷 337-350页

作者：谢有畅杨乃芳刘英骏唐有祺 Laboratory for structure of Matter Surface structure group Peking University Institute of Physical Chemistry

If an ionic or molecular crystalline solid is mixed with a carrier of high specific surface and then heated at a suitable temperature below its melting point for several hours, the crystalline solid will disperse spontaneously onto the surface of the carrier. It has been proved by the fact that the X-ray diffraction peaks of the crystalline phase either diminish sharply or disappear completely according as whether the amount of the solid mixed with each unit weight of carrier exceeds the critical amount or not and this critical amount of solid is closely related to and usually varies directly as the specific surface of the *** the active component of a catalyst is a compound instead of a metal, and its quantity is not enough to cover the surface of the carrier, it often disperses somewhat as a monolayer, because the ions or molecules of the active component combine strongly with the surface ions or groups of the carrier. This paper presents some fundamental points and methods of investigation in

关键词： AI SPONTANEOUS DISPERSION OF SOME ACTIVE COMPONENTS ONTO THE SURFACES OF CARRIERS

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Dynamic interactions of an integrated vehicle–electromagnetic energy harvester–tire system subject to uneven road excitations

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Acta Mechanica Sinica 2017年第2期33卷 440-456页

作者： Jing Tang Xing Zhe Sun Sulian Zhou Mingyi Tan Fluid structure Interactions group FEEUniversity of Southampton College of Shipbuilding Engineering Harbin Engineering University

An investigation is undertaken of an integrated mechanical-electromagnetic coupling system consisting of a rigid vehicle with heave, roll, and pitch motions, four electromagnetic energy harvesters and four tires subject to uneven road excitations in order to improve the passengers' riding comfort and harvest the lost engine energy due to uneven roads. Following the derived mathematical formulations and the proposed solution approaches, the numerical simulations of this interaction system subject to a continuous sinusoidal road excitation and a single ramp impact are completed. The simulation results are presented as the dynamic response curves in the forms of the frequency spectrum and the time history, which reveals the complex interaction characteristics of the system for vibration reductions and energy harvesting performance. It has addressed the coupling effects on the dynamic characteristics of the integrated system caused by: (1) the natural modes and frequencies of the vehicle; (2) the vehicle rolling and pitching motions; (3) different road excitations on four wheels; (4) the time delay of a road ramp to impact both the front and rear wheels, etc., which cannot be tackled by an often used quarter vehicle model. The guidelines for engineering applications are given. The developed coupling model and the revealed concept provide a means with analysis idea to investigate the details of four energy harvester motions for electromagnetic suspension designs in order to replace the current passive vehicle isolators and to harvest the lost engine energy. Potential further research directions are suggested for readers to consider in the future.

关键词： Vibration-energy-harvesters Electromagnetic suspensions Mechanical electromagnetic interactions Vehicle dynamics Vibration isolations

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Investigation of Hydroelastic Ship Responses of An ULOC in Head Seas

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China Ocean Engineering 2016年第5期30卷 687-702页

作者： WANG Xue-liang Pandeli TEMAREL HU Jia-jun GU Xue-kang Marine structure Department China Ship Scientific Research Center Wuxi 214082 China Fluid-structure Interactions group Faculty of Engineering and the Environment University of Southampton Southampton U

Investigation of hydroelastic ship responses has been brought to the attention of the scientific and engineering world for several decades. There are two kinds of high-frequency vibrations in general ship responses to a large ocean-going ship in its shipping line, so-called springing and whipping, which are important for the determination of design wave load and fatigue damage as well. Because of the huge scale of an ultra large ore cartier （ULOC）, it will suffer seldom slamming events in the ocean. The resonance vibration with high frequency is springing, which is caused by continuous wave excitation. In this paper, the wave-induced vibrations of the ULOC are addressed by experimental and numerical methods according to 2D and 3D hydroelasticity theories and an elastic model under full-load and ballast conditions. The influence of loading conditions on high-frequency vibration is studied both by numerical and experimental results. Wave-induced vibrations are higher under ballast condition including the wave frequency part, the multiple frequencies part, the 2-node and the 3-node vertical bending parts of the hydroelastic responses. The predicted results from the 2D method have less accuracy than the 3D method especially under ballast condition because of the slender-body assumption in the former method. The applicability of the 2D method and the further development of nonlinear effects to 3D method in the prediction of hydroelastic responses of the ULOC are discussed.

关键词： hydroelastic ship response experiment wave-induced vibration ultra large ore carrier

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Exhuming the Meso-Cenozoic Kyrgyz Tianshan and Siberian Altai-Sayan:A review based on low-temperature thermochronology

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Geoscience Frontiers 2016年第2期7卷 155-170页

作者： Stijn Glorie Johan De Grave Centre for tectonics Resources and Exploration(TRaX)Department of Earth SciencesSchool of Physical SciencesThe University of Adelaide Dept.Geology & Soil Science MINPET GroupGhent University

Thermochronological datasets for the Kyrgyz Tianshan and Siberian Altai-Sayan within Central Asia reveal a punctuated exhumation history during the Meso-Cenozoic. In this paper, the datasets for both regions are collectively reviewed in order to speculate on the links between the Meso-Cenozoic exhumation of the continental Eurasian interior and the prevailing tectonic processes at the plate margins. Whereas most of the thermochronological data across both regions document late Jurassic -Cretaceous regional basement cooling, older landscape relics and dissecting fault zones throughout both regions preserve Triassic and Cenozoic events of rapid cooling, respectively. Triassic cooling is thought to reflect the Qiangtang-Eurasia collision and/or rifting/subsidence in the West Siberian basin. Alternatively, this cooling signal could be related with the terminal terrane-amalgamation of the Central Asian Orogenic Belt. For the Kygyz Tianshan, late Jurassic-Cretaceous regional exhumation and Cenozoic fault reactivations can be linked with specific tectonic events during the closure of the Palaeo-Tethys and Neo-Tethys Oceans, respectively. The effect of the progressive consumption of these oceans and the associated collisions of Cimmeria and India with Eurasia probably only had a minor effect on the exhumation of the Siberian Altai-Sayan. More likely, tectonic forces from the east （present-day co- ordinates） as a result of the building and collapse of the Mongol-Okhotsk orogen and rifting in the Baikal region shaped the current Siberian Altai-Sayan topography. Although many of these hypothesised links need to be tested further, they allow a first-order insight into the dynamic response and the stress propagation pathways from the Eurasian margin into the continental interior.

关键词： Central Asia Tianshan Altai Sayan Thermochronology Exhumation Fault reactivation

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WELD ROOT MAGNIFICATION FACTORS FOR SEMI-ELLIPTICAL CRACKS IN T-BUTT JOINTS

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Acta Mechanica Solida Sinica 2013年第3期26卷 317-330页

作者： Zhanxun Song Yeping Xiong Jilong Xie Jing Tang Xing School of Mechanical Electronic & Control EngineeringBeijing Jiaotong University Faculty of Engineering & the Environments Fluid-Structure Interaction Research GroupUniversity of Southampton

Many researchers have focused their efforts on fatigue failures occurring on weld toes. In recent years, more and more fatigue failures occur on weld roots. Therefore, it is important to explore the behaviour of weld root fatigues. This paper investigates numerically the Magnification factors （Mk） for types of semi-elliptical cracks on the weld root of a T-butt joint. The geometry of the joint is determined by four important parameters： crack depth ratio, crack shape ratio, weld leg ratio and weld angle. A singular element approach is used to generate the corresponding finite element meshes. For each set of given four parameters of the semi-elliptical root crack, the corresponding T-butt joint is numerically simulated and its Mk at the deepest point of the weld root crack is obtained for the respective tension and shear loads. The variation range of the four parameters covers 750 cases for each load, totaling 1500 simulations are completed. The numerical results obtained are then represented by the curve to explore the effects of four parameters on the Mk. To obtain an approximate equation representing Mk as a function of the four parameters for each load, a multiple regression method is adopted and the related regression analysis is performed. The error distributions of the two approximate equations are compared with the finite element data. It is confirmed that the obtained approximate functions fit very well to the database from which they are derived. Therefore, these two equations present a valuable reference for engineering applications in T-butt joint designs.

关键词： welded root cracks singular element method stress intensity factors magnificationfactors multiple regressions

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Magmatic Processes of Ashi Volcano, Western Kunlun Mountains, China

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Acta Geologica Sinica(English Edition) 2014年第2期88卷 530-543页

作者： YU Hongmei XU Jiandong ZHAO Bo SHEN Huanhuan LIN Chuanyong Key Laboratory of Active tectonics and Volcano Institute of GeologyChina Earthquake Administration

The Ashikule volcanic cluster （AVC） in western Kunlun Mountains is located in a graben region at the convergence of the Altun and Kangxiwa fault zones,and consists of more than 10 main volcanoes and dozens of *** Ashi volcano lies in the central part of the volcanic *** lithology,chemical composition and texture of Ashi volcanic rocks were studied in detail,and their implication in magmatic processes was *** phenocrysts in Ashi volcanic rocks consist mainly of plagioclase and pyroxene,and the statistical results of phenocryst contents show that the rocks can be subdivided into two *** group A,the content of pyroxene phenocrysts is generally higher than that of plagioclase phenocrysts,but an inverse relation occurs in group *** TAS diagram,the compositions of both groups fall into the trachyandensite field,but they are obviously concentrated into two *** two clusters exist also in the oxide *** pyroxene phenocrysts comprise augite,bronzite and hypersthene,and their Mg# histogram shows two *** phenocrysts with reaction rim are observed in rocks of both *** An values of the core are generally 30-40,and those of the rim are 44-48,which are closer to those of euhedral *** bronzites are in equilibrium with the melt,and two sets of magma depths,i.e.,18-25 km and 13-18 km,can be estimated by using thermobarometer proposed by *** hypersthenes are not in equilibrium with the melt,and can be assigned to *** crystal size distribution （CSD） curves of plagioclase appear as kinked lines indicative of magma *** above analyses show that two magma pockets might exist beneath the Ashi *** is likely that they are connected with each *** one has more evolved and contains more acidic magma,and the other is a trachyandensite magma pocket characterized by *** magma from the upper part of the trachyandensite magma pocket might mix with more acidic magma,r

关键词： texture chemical composition crystal size distribution Ashi volcano Ashikule volcanic cluster

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THE EFFECT OF ADDITIVE La2O3 ON THE DISPERSION AND THERMOSTABILITY OF NICKEL IN METHANATION CATALYST

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Science in China,Ser.B 1984年第6期27卷 549-557页

作者：谢有畅钱民协唐有祺 group of Surface structure Institute of Physical Chemistry Department of Chemistry Peking University Peking University

It is showed that La2O3 and NiO could disperse on γ-Al2O3 as a monolayer and theirutmost monolayer capacities determined by quantitative XRD are 0.28g/100m2 and 0.09g/100m2respectively. In the methanation catalyst, Ni/La2O3/γ-Al2O3, the La2O3 is dispersed on thesurface of γ-Al2O3 as a monolayer and the metallic nickel crystallites are supported on thesurface with La2O3. It has been found by the XRD peak broadening that the average size ofnickel crystallites on the surface with La2O3 is much smaller than that without La2O3. Thismay be one of the main reasons for the increase of activity and thermostability of the La2O3containing methanation catalyst. This idea of modifying support surface by monolayercompound can also be applied to other catalysts.

关键词： XRD THE EFFECT OF ADDITIVE La2O3 ON THE DISPERSION AND THERMOSTABILITY OF NICKEL IN METHANATION CATALYST OC La Ni

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Amyloid-beta pathology-induced nanoscale synaptic disruption:the case of the GABA_B-GIRK assembly

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Neural Regeneration Research 2025年第5期20卷 1409-1410页

作者： Rafael Lujan Alejandro Martín-Belmonte Sergi Ferré Francisco Ciruela Synaptic structure Laboratory Instituto de Biomedicina de la UCLM(IB-UCLM)Departamento de Ciencias MédicasInstituto de Investigación en Salud de Castilla-La Mancha(IDISCAM)Facultad de MedicinaUniversidad Castilla-La ManchaCampus BiosanitarioC/AlmansaAlbaceteSpain Integrative Neurobiology Section National Institute on Drug AbuseIntramural Research ProgramNational Institutes of HealthBaltimoreMDUSA Pharmacology Unit Department of Pathology and Experimental TherapeuticsSchool of Medicine and Health SciencesInstitute of NeurosciencesUniversity of BarcelonaNeuropharmacology&Pain GroupNeuroscience ProgramBellvitge Institute for Biomedical ResearchL’Hospitalet de LlobregatSpain

Alzheimer's disease (AD) is characterized by an imbalance between excitatory and inhibitory brain networks,leading to aberrant homeostatic synaptic *** has progressively been recognized as syna ptopathy and syna ptic dysfunction has been identified as a key component of its pathogenesis (Schirinzi et al.,2020).Syna ptic dysfunction is believed to precede synapse loss,a primary biological correlate of cognitive decline in AD,inevita bly associated with neuronal death.

关键词： Alzheimer pathology

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Geochemistry of Triassic Siliceous Rocks of the Muyinhe Formation in the Changning-Menglian Belt of Southwest China

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Journal of Earth Science 2016年第3期27卷 403-411页

作者： Tsuyoshi Ito Xin Qian Qinglai Feng State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Stratigraphy and tectonics Research group Institute of Geology and Geoinformation Geological Survey of Japan School of Earth Sciences China University of Geosciences

The Changning-Menglian belt, distributed over southwestern Yunnan Province in Southwest China, contains oceanic rocks that are considered to be remnants of the Paleotethys. This study observed Triassic siliceous rocks of the Muyinhe Formation in the Changning-Menglian belt and analyzed their geochemistry. The samples have high concentrations of SiO2（81.65 wt.%–88.38 wt.%; average： 84.99 wt.%±2.14 wt.%）. Most of the samples were plotted in the non-hydrothermal field on the Al-Fe-Mn diagram. Most of the samples were plotted in the continental margin field on the Fe2O3/TiO2-Al2O3/（Al2O3＋Fe2O3） and（La/Ce）N-Al2O3/（Al2O3＋Fe2O3） diagrams. Moreover, the samples show a flat REE（rare earth element） pattern normalized to NASC（North America shale composite）. These geochemical results, in addition to the lack of rhythmical bedding of the siliceous rocks, strongly suggest that the siliceous rocks are unlikely to represent pelagic deposits. Although previous studies have suggested that the siliceous rocks are pelagic deposits, the present results indicate that the extent of the pelagic ocean basins in the Paleotethys during the Triassic is probably less than previously believed. These non-pelagic deposits may represent the closure stage of the Paleotethys.

关键词： geochemistry Triassic siliceous rock Paleotethys Muyinhe Formation Changning-Menglian belt

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