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Quiet in the nest:The nest environment attenuates song in a grassland songbird

Avian Research 2023年第4期14卷 623-629页

作者： Sarah L.Dobney mikayla m.K.Bornais D.Ryan Norris Amy E.m.Newman Heather Williams Stéphanie m.Doucet Daniel J.mennill Department of Integrative Biology University of WindsorWindsorOntarioN9B 3P4Canada Department of Integrative Biology University of GuelphGuelphOntarioN1G 2W1Canada Biology Department Williams CollegeWilliamstownMA01267USA

The nest environment may limit the ability of nest-bound birds to hear sounds from the outside *** vocal learning species,such as humans and songbirds,it is vital for young animals to hear the voices of conspecific animals early in *** songbirds,nest structure varies considerably across species,and the resulting impact on sound transmission may have consequences for vocal learning in *** this study,we tested the hypothesis that the nest environment attenuates song of Savannah Sparrows(Passerculus sandwichensis),grassland songbirds that build nests on the ground under cover of dense *** recorded live Savannah Sparrows singing at variable distances from 21 *** recorded songs using one microphone inside the nest(the typical position of a nestling)and another placed 1 m directly above the nest(a typical position of an adult).We found a substantial reduction in signal-to-noise ratio,where songs recorded inside the nest were an average of 11 dB lower than songs recorded directly above the *** estimate that the attenuation imposed by the nest reduced the maximum acoustic environment from 117.7 m(for recordings above the nest),to 78.6 m(for recordings within the nest),which is analogous to listening from a position 39.1 m farther away from the *** research estimated that song transmits up to 100 m in this species,so any adult male within 100 m of a young bird was previously considered a potential vocal *** reducing the nestling acoustic environment from 100 m to 78.6 m,the number of male tutors available to nestlings is reduced by an average of 27%.Given the growing evidence that song learning begins very early in life,future research on vocal development should account for how the structural properties of the natal environment affect the songs that nestlings hear.

关键词： Acoustic environment Nest environment Songbird Sound attenuation Vocal learning

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Simulation of cooling channel rheocasting process of A356 aluminum alloy using three-phase volume averaging model

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中国有色金属学会会刊:英文版 2005年第2期15卷 389-394页

作者： T.Wang B.Pustal m.Abondano T.Grimmig A.Bührig-Polaczek m.Wu A.Ludwig Foundry Institute Aachen University of TechnologyAachenD-52072Germany Department of metallurgy University of LeobenLeobenA-8700Austria Research Center of Foundry Engineering Dalian University of TechnologyDalian 116024China

The cooling channel process is a rehocasting method by which the prematerial with globular microstructure can be produced to fit the thixocasting process.A three-phase model based on volume averaging approach is proposed to simulate the cooling channel process of A356 Aluminum *** three phases are liquid,solid and air respectively and treated as separated and interacting continua,sharing a single pressure *** mass,momentum,enthalpy transport equations for each phase are *** developed model can predict the evolution of liquid,solid and air fraction as well as the distribution of grain density and grain *** effect of pouring temperature on the grain density,grain size and solid fraction is analyzed in detail.

关键词： A356 alloy modeling cooling channel three-phase semi-solid

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Biocompatibility and biotoxicity of in-situ synthesized carboxylated nanodiamond-cobalt oxide nanocomposite

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Journal of materials Science & Technology 2017年第8期33卷 879-888页

作者： L.Syam Sundar Naser A.Anjum m.C.Ferro Eduarda Pereira manoj K.Singh A.C.m.Sousa TEmA-Department of mechanical Engineering University ofAveiroAveiroPortugal CESAm-Centrefor Environmental&marine Studies and Department of Chemistry University of Aveiro3810-193AveiroPortugal CICECO Department of Material Engineering and CeramicsUniversity of AveiroPortugal

A nanocomposite that incorporates cobalt oxide（Co3O4） and nanodiamond（ND） can present both high magnetism（Co3O4） and high hardness（ND）. ND particles have potential applications in a variety of fields such as protein immobilization, biosensors, therapeutic molecule delivery and bio-imaging. However,limited information is available in literature on the in-situ synthesis of biocompatible magnetic materials and also on their potential biotoxicity as a result of their entry into environmental compartments and subsequent interaction with biota. In this work, a new kind of bio-compatible magnetic material –carboxylated nanodiamond（c ND） and Co3O4 was synthesized to obtain the c ND-Co3O4 *** synthesis procedure involved in-situ and chemical reduction of cobalt chloride（CoCl（26）H2O） and sodium borohydrate（NaBH4）. The synthesized cND-Co3O4 nanocomposite was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The cyto-genotoxicity of the synthesized nanocomposite material was studied by using onion（Allium cepa L.） as a test model with concentrations of 5, 10 and 20 μg/ml. The study was also extended to cND and Co3O4 materials for comparison purpose. Co3O4 and cND exhibited their contrasting effects on mitosis and other cyto-genotoxic indices studied herein. This work provided fundamental data on the synthesis and the bio-toxicity of the c ND-Co3O4 nanocomposite, which, in turn, can help to expand their multidisciplinary applications.

关键词： Nanodiamond Cobalt oxide Nanodiamond Nanocomposite Bio-toxicity Allium cepa

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Experimental Investigation of TARmAX model for modeling of Hydrodynamic Forces on Cylinder-like Structures

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Journal of marine Science and Application 2011年第3期10卷 281-288页

作者： m. A. Lotfollahi Yaghin A. mojtahedi m. m. Ettefagh m. H. Aminfar Department of Civil Engineering University of Tabriz Department of mechanical Engineering University of Tabriz

A new approach that models lift and drag hydrodynamic force signals operating over cylindrical structures was developed and validated. This approach is based on stochastic auto regressive moving average with exogenous （ARmAX） input and its time-varying form, TARmAX. model structure selection and parameter estimation were discussed while considering the validation stage. In this papel; the cylindrical structure was considered as a dynamic system with an incoming water wave and resulting forces as the input and outputs, respectively. The experimental data, used in this study, were collected from a full-scale rough vertical cylinder at the Delft Hydraulics Laboratory. The practicality of the proposed method and also its efficiency in structural modeling were demonstrated through applying two hydrodynamic force components. For this purpose, an ARmAX model is first used to capture the dynamics of the process, relating in-line forces provided by water waves; secondly, the TARmAX model was applied to modeling and analysis of the lift forces on the cylinder. The evaluation of the lift force by the TARmAX model shows the model is successful in modeling the force from the surface elevation.

关键词： cylindrical piles wave force system identification parametric models

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Histochemical pattern of gastrocnemius muscle in fluoride toxicity syndrome

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Asian Pacific Journal of Tropical medicine 2010年第2期3卷 136-140页

作者： Shashi A Bhushan B Bhardwaj m Department of Zoology Punjabi University

Objective:To evaluate the effect of sodium fluoride(NaF) on cytochemical distribution of proteins,DNA,and RNA in the gastrocnemius muscle of rat in experimental ***: Young Sprague Dawley albino rats were administered with NaF at 30,45,and 75 mg/kg bw/ day subcutaneously for 15 and 30 days,*** control animals were given the vehicle(1cc deionized double distilled water/kg bw/day).Results:In the first phase of 15 days experimentation,the gastrocnemius muscle of rats intoxicated with NaF at 30,45,and 75 mg /kg bw/ day showed decline in proteins including a amino acids as compared to control. In the second phase of 30 days experimentation,the muscle fibers of rat showed elevation in sarcolemmal and sarcoplasmic proteins in 30 mg NaF dose group,and angulated fibers exhibited increase in sarcolemmal proteins in 45 mg NaF *** marginal regions of angular and rim fibers showed deeply stained rings of sarcoplasmic proteins whereas the split fibers were faindy stained in rats treated with NaF at 75 mg/kg bw/day for 30 *** rats treated with NaF at 30 mg/kg bw/day for 15 days,the hypertrophied peripheral muscle fibers contained more DNA,however the atrophied fibers had more *** 45 mg NaF group,RNA was located in sarcolemmal regions,while DNA content decreased as compared to *** 75 mg NaF group,the muscle fibers had dark and light staining regions of DNA and *** the 30 days of experimentation,the DNA level decreased whereas RNA content increased in the gastrocnemius muscle fibers of the rat treated with NaF at 30 mg/kg bw/*** treatment group with NaF at 45 mg/kg bw/day,the RNA content slighdy declined in comparison to control,in all treatments for 15 days as well as in treatment group with NaF at 30 mg/kg bw/day for 30 days whereas the amount of DNA slightly increased as compared to treatment group with NaF at 75 mg/kg bw/day for 15 *** highest dose group revealed elevated amount of RNA whereas DNA content remained stable.C

关键词： Albino rats DNA Gastrocnemius muscle Proteins RNA Sodium fluoride

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mechanical properties of SWNT X-Junctions through molecular dynamics simulation

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International Journal of Smart and Nano materials 2012年第1期3卷 33-46页

作者： B.A.Stormer N.m.Piper X.m.Yang J.Tao Y.Fu m.Kirca A.C.To Department of mechanical Engineering and materials Science&Department of Civil and Environmental Engineering University of PittsburghPittsburghPAUSA Department of Power Engineering North China Electric Power UniversityBaoding 071003China

The mechanical behavior of seven different carbon nanotube(CNT)X-junctions with a varying number of bonds was investigated through molecular dynamics *** X-junctions are composed of two(6,0)single-walled carbon nanotubes(SWNTs)created via vibration-assisted heat *** junctions,containing anywhere between one and seven bonds,are subject to uniaxial tensile,shear and torsional strain,and then the stiffness values are determined for each *** subjected to tensile and shear strain,both the arrangement and orientation of bonds are found to affect the stiffness of junctions more substantially than the number of bonds,bond length or bond ***,anisotropic shear behavior is observed in the X-junctions,which can be attributed to the junction’s bond ***,the stiffness of X-junctions tested under an applied torque(torsion)differs from the stiffness under tensile and shear strain,however,in that it is more substantially affected by the number of bonds present in the junction than by any other property.

关键词： carbon nanotube molecular dynamics X-junction stiffness

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marsh persistence under sea-level rise is controlled by multiple,geologically variable stressors

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Ecosystem Health and Sustainability 2017年第10期3卷 22-38页

作者： m.mitchell J.Herman D.m.Bilkovic C.Hershner Virginia Institute of marine Science College of William&MaryGloucester PointVAUSA

Introduction:marshes contribute to habitat and water quality in estuaries and coastal *** importance to continued ecosystem functioning has led to concerns about their ***:Concurrent with sea-level rise,marshes are eroding and appear to be disappearing through ponding in their interior;in addition,in many places,they are being replaced with shoreline stabilization *** examined the changes in marsh extent over the past 40 years within a subestuary of Chesapeake Bay,the largest estuary in the United States,to better understand the effects of sea-level rise and human pressure on marsh ***:Approximately 30 years ago,an inventory of York River estuary marshes documented the historic extent of *** were resurveyed in 2010 to examine shifts in tidal marsh extent and *** change varied spatially along the estuary,with watershed changes between a 32%loss and an 11%gain in marsh *** of marsh was apparent in high energy sections of the estuary while there was marsh gain in the upper/riverine section of the estuary and where forested hummocks on marsh islands have become *** showed little change in the small tributary creeks,except in the creeks dominated by fringing marshes and high shoreline ***:Differential resilience to sea-level rise and spatial variations in erosion,sediment supply,and human development have resulted in spatially variable changes in specific marsh extents and are predicted to lead to a redistribution of marshes along the estuarine gradient,with consequences for their unique communities.

关键词： Chesapeake Bay climate change coastal resilience marsh change salt marsh sea-level rise tidal wetlands

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An Investigation on the Formation of Submerged Bar Under Surges in Sandy Coastal Region

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China Ocean Engineering 2012年第3期26卷 535-546页

作者： mustafa DEmIRCI m.Sami AKZ Civil Engineering Department Engineering FacultyMustafa Kemal UniversityskenderunHatay 31040Turkey Civil Engineering Department Engineering and Architecture Facultyukurova UniversityAdana 01100Turkey

Cross-shore sediment transport rate exposed to waves is very important for coastal morphology, the design of marine structures such as seawalls, jetties, breakwaters etc, and the prevention of coastal erosion and accretion due to onoff shore sediment transportation. In the present study, the experiments on cross-shore sediment transport are carried out in a laboratory wave channel with initial beach slopes of 1/8, 1/10 and 1/15. By using the regular waves with different deep-water wave steepnesses generated by a pedal-type wave generator, the geometrical characteristics of beach profiles under storm conditions and the parameters affecting on-off shore sediment transport are investigated for the beach materials with medium diameters of d50=0.25, 0.32, 0.45, 0.62 and 0.80 mm. The offshore bar geometric characteristics are the horizontal distances from the shoreline to the bar beginning （Xb）, crest （Xt）, and ending （Xs） points, the depth from the bar crest to the still water level （ht）, and the bar volume （Vbar）. The experimental results have indicated that when the deep-water steepness （Ha/L0） increased, the net movement to seaside increased. With the increasing wave steepness, the bars moved to widen herewith the vertical distances from still water level to the bar beginning （Xb）, crest （Xt） and ending （Xs） points and the horizontal distances from the coast line to the bar beginning, crest and ending points increased. It was also shown from experimental results that the horizontal distances from the bar beginning and ending points to the coast line increased with the decrease of the beach slope. The experimental results obtained from this study are compared with previous experimental work and found to be of the same magnitude as the experimental measurements and followed the expected basic trend.

关键词： cross-shore sediment transport beach profiles bar parameters experimental study

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Disturbance and forest recovery in the monarch Butterfly Biosphere Reserve,mexico

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Journal of Forestry Research 2020年第5期31卷 1551-1566页

作者： Jose Lopez-Garcıa Rafael m.Navarro-Cerrillo Instituto de Geografıa Universidad Nacional Autonoma de MexicoCiudad UniversitariaC.P.04510 CoyoacanDFMexico Departamento de Ingenierıa Forestal Universidad de CordobaCampus de RabanalesCarretera Nacional IV km 39614014 CordobaSpain

Analysis of the change in forest cover is important to determine stand dynamics and the processes involved in disturbance and *** of the core zone of the monarch Butterfly Biosphere Reserve were studied using photo interpretation techniques,considering biennial changes between 1999 and 2013 and changes over the whole period of study 1999–*** matrices were elaborated to determine the processes of change involved in both recovery and *** biennial changes for the whole period amounted to 2274 ha;343 ha accounted as degraded in more than one biennial *** total changes in forest cover between 1999 and 2013 involved 4902 ha,out of which,2912 ha were affected by disturbance,and 1990 ha were *** density and 2013 vegetation cover maps,the overall accuracy was 95.6%and 90.2%,*** combining both maps,gradual processes were revealed that were not evident in separate *** methodology is useful for the management and conservation of natural protected areas.

关键词： Illegal logging Forest density change Forest recovery Conifer forests monarch Butterfly Biosphere Reserve

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Numerical simulation for symmetric diffraction patterns of 8-hydroxyquinolin-1-ium 4-aminobenzenesulfonate

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Optoelectronics Letters 2022年第5期18卷 283-287页

作者： A.Ghanem m.D.Zidan m.S.EL-Daher A.Allahham Higher Institute for Laser Research and Applications Damascus UniversiySyria Department of Physics AECP.O.Box 6091DamascusSyria

We reported the formation of diffraction ring patterns induced by transmitted Gaussian laser beam through 8-hydroxyquinolin-1-ium 4-aminobenzenesulfonate(8 HQABS) solution as absorbing medium. Theoretical model depending on the Fresnel-Kirchhoff diffraction(FKD) theory was used to generate diffraction rings with respect to the sample position. Analysis of the generated diffraction rings shows a reasonable agreement between the features of the experimental and numerical diffraction rings. Our results are considered to be useful to understand the way of propagation and interaction of laser beam with liquid absorbing medium.

关键词： benzene rings absorbing

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