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Application of Kinetic Models in Describing Soil Potassium release Characteristics and Their Correlations with Potassium Extracted by Chemical Methods

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Pedosphere 2013年第4期23卷 482-492页

作者： A. r. HOSSEINPUr H. r. MOTAGHIAN Department of Soil Science College of Agriculture Shahrekord University

Potassium （K） release characteristics in soil play a significant role in supplying available K. Information on K-release characteristics in soils of central Iran is limited. The objectives of this study were to determine K release characteristics and correlations of K release rate constants with K extracted by different chemical methods in surface soils of ten calcareous soils of central Iran. The kinetics of K release in the soils was determined by successive extraction with 0.01 mol L-1 CaC12 in a period of 2-2017 h at 25±1℃. Soil K was extracted by distilled water, 0.5 mol L-1 MgNO3, 0.002 mol L-1 SrC12, 0.1 mol L-1 BaC12, 0.01 mol L-1 CaC12, 1 mol L-1 NaC1, 1 mol L-1 boiling HNO3, 1 mol L-1 NH4OAC, Mehlich 1, 0.002 mol L-1 SrC12 ＋ 0.05 mol L-1 citric acid, and ammonium bicarbonate-diethylenetriamine pentaacetic acid （AB-DTPA）. A plot of cumulative amounts of K released showed a discontinuity in slope at 168 h. Thus, two equations were applied to two segments of the total reaction time （2-168 and 168-2 017 h）. Cumulative amounts of K released ranged from 55 to 299 mg kg-1 in 2-168 h and from 44 to 119 mg kg-1 in 168-2 017 h. release kinetics of K in the two time segments conformed fairly well to parabolic diffusion, simplified Elovich, and power function models. There was a wide variation in the K release rate constants. Increasingly higher average concentrations of soil K were extracted by distilled water, Mehlich 1, SrC12, CaC12, SrC12 ＋ citric acid, AB-DTPA, MgNO3, NaCI, NH4OAc, BaCI2, and HNO3. Potassium release rate constants were significantly correlated with K extracted. The results of this study showed that information obtained from mathematical modeling in two reaction time segments can help to estimate the K-supplying power of soils.

关键词： chemical extraction calcareous soils mathematical modeling release rate constant time segments

Impact of reduced frequency on the time lag in pressure distribution over a supercritical airfoil in a pitch-pause-return motion

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Chinese Journal of Aeronautics 2019年第2期32卷 243-252页

作者： Haghighat Z.ESLAMI Ali r.DAVArI M.r.SOLTANI Aerospace Division Department of Engineering Science and Research Branch Islamic Azad University Department of Aerospace Engineering Sharif University of Technology

Effects of reduced frequency, stop angle, and pause duration have been studied on a thin supercritical airfoil undergoing a pitch-pause-return motion, which is one of the classic maneuvers introduced by the AIAA Fluid Dynamics Technical Committee. Experiments were conducted in a low-speed wind tunnel at both a constant mean angle of attack and an oscillation amplitude with a reduced frequency ranging from 0.01 to 0.12. The desired stop angles of the airfoil were set to occur during the upstroke motion. The unsteady pressure distribution on the airfoil was measured for below, near, and beyond static stall conditions. results showed that the reduced frequency and stop angle were the dominant contributors to the time lag in the flowfield. For stop angles in both belowand post-stall regions, the time for the flowfield to reach its steady state conditions, known as the time lag, decreased as the reduced frequency was increased. However, in the static-stall region and for a certain value of reduced frequency, a resonance phenomenon was observed, and a minimum time lag was achieved. The pressure distribution in this condition was shown to be highly influenced by this phenomenon.

关键词： Dynamic stall Pitch pause return motion reduced frequency Static stall Time lag

A simple and distinguished nebulizer approach to prepare CdS thin films

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Journal of Energy Chemistry 2017年第3期26卷 398-405页

作者： M.Girish r.Sivakumar C.Sanjeeviraja r.Gopalakrishnan Department of Physics Alagappa UniversityKaraikudi 630003India Department of Physics Alagappa Chettiar College of Engineering and TechnologyKaraikudi 630003India Department of Physics Anna UniversityChennai 600025India

In this paper, we report the substrate temperature induced change in structural, optical, morphological,luminescence and photoelectrochemical properties of CdS films deposited by a simple and facile approach called nebulized spray pyrolysis technique. X-ray diffraction study confirmed the deposited CdS films belong to hexagonal wurtzite structure, with preferential orientation along c-axis,(002) direction perpendicular to the substrate plane. The crack free, uniform, and homogeneously distributed spherical particles are witnessed from AFM image. Various optical parameters like energy band gap, optical conductivity,refractive index, extinction coefficient, dielectric constants, and dispersion energy parameters of the films were evaluated. The strong band edge emission observed in the PL study may be attributed to the recombination of excitations and/or shallowly trapped electron-hole pairs. The first and second overtone of LO modes of CdS at 302 and 600 cm-1are observed in the raman study. The photoelectrochemical properties of the films were also tested.

关键词： Semiconductors Chemical synthesis Optical properties X-ray diffraction

Sex-specific life-history trait expression in hybrids of a cave- and surface-dwelling fish (Poecilia mexicana, Poecilidae)

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Current Zoology 2024年第4期70卷 421-429页

作者： rüdiger riesch Luis r.Arriaga Ingo Schlupp Department of Biological Sciences Royal Holloway University of LondonEghamTW20 OEXUK CEFE CNRSUnivMontpellierEPHEIRDMontpellierFrance Department of Biology University of OklahomaNormanOK 73019USA

Evaluating the fitness of hybrids can provide important insights into genetic differences between species or diverging *** focused on surface-and cave-ecotypes of the widespread Atlantic molly Poecilia mexicana and raised F1 hybrids of reciprocal crosses to sexual maturity in a common-garden *** were reared in a fully factorial 2 x 2 design consisting of lighting(light ***)and resource availability(high *** food).We quantified survival,ability to realize their full reproductive potential(i.e.,completed maturation for males and 3 consecutive births for females)and essential life-history *** to the performance of pure cave and surface fish from a previous experiment,F1s had the highest death rate and the lowest proportion of fish that reached their full reproductive *** also uncovered an intriguing pattern of sex-specific phenotype expression,because male hybrids expressed cave molly life histories,while female hybrids expressed surface molly life *** results provide evidence for strong selection against hybrids in the cave molly system,but also sug-gest a complex pattern of sex-specific(opposing)dominance,with certain surface molly genes being dominant in female hybrids and certain cavemollygenes beingdominant in malehybrids.

关键词： dominance life-history evolution local adaptation postzygotic isolation selection against hybrids.

Synthesis, spectral characterization, thermal and biological studies of lanthanide(Ⅲ) complexes of oxyphenbutazone

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Journal of rare Earths 2014年第1期32卷 43-51页

作者： P.S.Binil M.r.Anoop K.r.Jisha S.Suma M.r.Sudarsanakumar Department of Chemistry S.N.College Department of Chemistry M.G.College

Lanthanide（III） complexes of 4-butyl-1-（4-hydroxyphenyl）-2-phenyl-3,5-pyrazolidinedione （OPB） were prepared by ho-mogeneous precipitation. The solid complexes were characterized by elemental analysis, magnetic susceptibility data, molar conduc-tivity measurements and Ir, UV-Vis, mass, 1H NMr and 13C NMr spectral methods. The thermal decomposition of the complexes under static air atmosphere was investigated by simultaneous TG/DTG at a heating rate of 10 °C/min. The final decomposition prod-ucts were found to be metal oxides. The spectroscopic data suggested that OPB acted as a bidentate, mono-ionic ligand coordinating through two carbonyl oxygens of the pyrazolidinedione ring. The kinetic and thermodynamic parameters such as activation energy, pre-exponential factor and entropy of activation for each step of the decomposition reactions were evaluated using Coats-redfern and MacCallum-Tanner equations. The negative entropy values of the complexes indicated that the activated complexes had a more or-dered structure than the reactant and that the reactions were slower than normal. Investigations of antimicrobial activity of the com-pounds were carried out by the disk diffusion technique.

关键词： oxyphenbutazone lanthanide(III) complexes thermal study antimicrobial activity rare earths

Simple shear extrusion versus equal channel angular pressing:A comparative study on the microstructure and mechanical properties of an Mg alloy

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Journal of Magnesium and Alloys 2023年第5期11卷 1769-1790页

作者： A.rezaei r.Mahmudi C.Cayron r.E.Logé School of Metallurgical and Materials Engineering College of EngineeringUniversity of TehranNorth Kargar StreetTehran 14395-515Iran Laboratory of Thermomechanical Metallurgy-PX Group Chair Ecole Polytechnique Fédérale de Lausanne(EPFL)Neuchâtel CH-2002Switzerland

Two severe plastic deformation(SPD)techniques of simple shear extrusion(SSE)and equal channel angular pressing(ECAP)were employed to process an extruded Mg-6Gd-3Y-1.5Ag(wt%)alloy at 553 K for 1,2,4 and 6 *** microstructural evolutions were studied by electron back scattered diffraction(EBSD)analysis and transmission electron microscopy(TEM).The initial grain size of 7.5μm in the extruded alloy was reduced to about 1.3μm after 6 SPD *** dynamic recrystallization was suggested to be operative in both SSE and ECAP,with also a potential contribution of continuous dynamic recrystallization at the early stages of *** difference in the shear strain paths of the two SPD techniques caused different progression rate of dynamic recrystallization(DrX),so that the alloys processed by ECAP exhibited higher fractions of recrystallization and high angle grain boundaries(HAGBs).It was revealed that crystallographic texture was also significantly influenced by the difference in the strain paths of the two SPD methods,where dissimilar basal plane texture components were *** compression tests,performed along extrusion direction(ED),indicated that the compressive yield stress(CYS)and ultimate compressive strength(UCS)of the alloys after both SEE and ECAP augmented continuously by increasing the number of ***-processed alloys had lower values of CYS and UCS compared to their counterparts processed by *** difference in the mechanical responses was attributed to the different configurations of basal planes with respect to the loading direction(ED)of each SPD technique.

关键词： Mg-Gd-Y alloys Severe plastic deformation Simple shear extrusion Equal channel angular pressing Dynamic recrystallization Mechanical properties

Estimation of morphological traits of foliage and effective plant spacing in NFT-based aquaponics system

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Artificial Intelligence in Agriculture 2023年第3期9卷 76-88页

作者： r.Abbasi P.Martinez r.Ahmad Aquaponics 4.0 Learning Factory(AllFactory) Department of Mechanical EngineeringUniversity of Alberta9211116 St.EdmontonAB T6G 2G8Canada Mechanical and Construction Engineering Department Northumbria UniversityNewcastle upon Tyne NE77YTUK

Deep learning and computer vision techniques have gained significant attention in the agriculture sector due to their non-destructive and contactless *** techniques are also being integrated into modern farming systems,such as aquaponics,to address the challenges hindering its commercialization and large-scale *** is a farming technology that combines a recirculating aquaculture system and soilless hydroponics agriculture,that promises to address food security *** complement the current research efforts,a methodology is proposed to automatically measure the morphological traits of crops such as width,length and area and estimate the effective plant spacing between grow *** spacing is one of the key design parameters that are dependent on crop type and its morphological traits and hence needs to be monitored to ensure high crop yield and quality which can be impacted due to foliage occlusion or overlapping as the crop *** proposed approach uses Mask-rCNN to estimate the size of the crops and a mathematical model to determine plant spacing for a self-adaptive aquaponics *** common little gem romaine lettuce,the growth is estimated within 2 cm of error for both length and *** final model is deployed on a cloud-based application and integrated with an ontology model containing domain knowledge of the aquaponics *** relevant knowledge about crop characteristics and optimal plant spacing is extracted from ontology and compared with results obtained from the final model to suggest further *** proposed application finds its signifi-cance as a decision support system that can pave the way for intelligent system monitoring and control.

关键词： Deep learning Ontology modeling Crop phenotyping Leafy crops Aquaponics Digital farming Plant spacing

Analytical solution approach for nonlinear buckling and postbuckling analysis of cylindrical nanoshells based on surface elasticity theory

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Applied Mathematics and Mechanics(English Edition) 2016年第7期37卷 903-918页

作者： r.ANSArI T.POUrASHrAF r.GHOLAMI H.rOUHI Department of Mechanical Engineering University of Guilan Department of Mechanical Engineering Lahijan BranchIslamic Azad University Department of Engineering Science Faculty of Technology and Engineering East of GuilanUniversity of Guilan

The size-dependent nonlinear buckling and postbuckling characteristics of circular cylindrical nanoshells subjected to the axial compressive load are investigated with an analytical approach. The surface energy effects are taken into account according to the surface elasticity theory of Gurtin and Murdoch. The developed geometrically nonlinear shell model is based on the classical Donnell shell theory and the von Karman＇s hypothesis. With the numerical results, the effect of the surface stress on the nonlinear buckling and postbuckling behaviors of nanoshells made of Si and Al is studied. Moreover, the influence of the surface residual tension and the radius-to-thickness ratio is illustrated. The results indicate that the surface stress has an important effect on prebuckling and postbuekling characteristics of nanoshells with small sizes.

关键词： cylindrical nanoshell surface stress nonlinear buckling postbuckling analytical method

rapid climate change-induced collapse of hunter-gatherer societies in the lower Mississippi river valley between ca. 3300 and 2780 cal yr BP

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Science China Earth Sciences 2018年第2期61卷 178-189页

作者： tristram r.kidder edward r.henry lee j.arco Department of Anthropology Washington University in St. Louis St. Louis 63130 USA Geoarehaeology Laboratory Washington University in St. Louis St. Louis 63130 USA GAI Consultants Inc. Homestead PA 15120 USA Teaching and Experimental Center for Archaeology and Cultural Heritage Protection Henan University Kaifeng 475001 China

Hunter-gatherer communities in the American Southeast reached an apogee of social and political complexity in the period between ca. 4200 and 3000 cal yr BP. In the lower Mississippi Valley(LMV) the Poverty Point culture defined this period of socio-political elaboration. However, following a significant period of climate change that led to exceptional flooding and a major reorganization of the course of the Mississippi river, this culture collapsed beginning ca. 3300–3200 cal yr BP and the LMV was abandoned for the subsequent 500 years. In this study, we use data from the Jaketown site in the Yazoo Basin of west-central Mississippi to refine the chronology of the climate event that caused the collapse of the Poverty Point culture. A large flood buried Poverty Point-era occupation deposits at Jaketown around 3310 cal yr BP. Lateral migration of the Mississippi river during flooding led to inundation of the Yazoo Basin and re-occupation of ancient river courses. A coarse sand stratum topped by a more than a meter-thick fining upward sediment package marks a crevasse deposit caused by a rupture of the natural levee at Jaketown. This levee breach was part of a larger pattern of erratic flooding throughout the LMV and is associated with major landscape evolution and the abandonment of Poverty Point sites within the valley. Early Woodland peoples re-colonized the crevasse surface after ca. 2780 cal yr BP. Following this event, the Jaketown site and the eastern Yazoo Basin witnessed a period of landscape stability that lasts to this day. These archaeological data demonstrate how climate change and natural disasters can lead to socio-political dissolution and reorganization even in relatively small-scale hunter-gatherer populations.

关键词： rapid climate change Hunter-gatherers Flooding Mississippi river Valley Poverty Point Jaketown site