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Strong emissions of blue-yellow-red regions of La and Ti modified KNaNbO_(3) ferroelectric ceramics

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journal of Advanced Ceramics 2015年第3期4卷 183-189页

作者： m.D.DURRUTHY-RODRIGUEZ m.HERNANDEZ-GARCIA j.PORTELLES j.FUENTES m.A.HERNANDEZ-LANDAVERDE m.RAmIREZ CARDONA j.m.YANEZ-LImON Departamento de Fisica Aplicada Instituto de CiberneticaMatematica y FisicaCITMA15#551VedadoLa HabanaCP 10400Cuba Facultad de Fisica Universidad de La HabanaSan Lazaro y LVedadoLa HabanaCP 10400Cuba CINVESTAV-Unidad Queretaro IPNLibramiento Norponiente 2000Fracc.Real de JuriquillaCP 76230QueretaroMexico Centro de Investigaciones en Ciencias de la Tierra y materiales Universidad Autonoma del Estado de HidalgoMexico

In this work,the results of the study on the optical properties of the perovskite structure ABO3 with La^(3+) substitution for ions K^(+) and Na^(+) in the A site and Ti^(4+) substitution for ion Nb^(5+) in the B site are *** ceramics were sintered at 1100℃ and 1190℃ and formed at 10 mPa and 80 *** ceramics were obtained with 94% of the theoretical *** piezoresponse force microscopy(PFm)showed needle-shaped grains with a size of 30 nm for the samples formed at 10 mPa at both sintering ***,the high temperature and high pressure used in formation reduced the energy of the band gap(Eg)from 3.36 to 3.09 *** emissions to 2.19,1.86,2.5,and 2.31 eV were obtained by exciting the samples at 325,373,457,and 500 nm,respectively;these emissions corresponded to blue-yellow-red regions of the visible spectrum.

关键词： emission spectra condense matter ferroelectric materials band structure X-ray diffraction(XRD)

Tapered Suction Caissons:A Numerical Investigation into Their Pull-out Performance

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China Ocean Engineering 2009年第4期23卷 695-707页

作者： m.Zeinoddini j.Keyvani m.Nabipour Faculty of Civil Engineering KNToosi University of Technology Faculty of Engineering Tarbiat Moallem University

Suction caissons have been widely used as anchors and foundations for floating and fixed offshore platforms. The pull-out performance of conventional suction caissons （with upright walls） has been investigated by a number of researchers. However, no attention has been paid to tapered suction caissons. This paper deals with the performance of tapered suction caissons under vertical pull-out loads. A numerical approach is used for this purpose. The numerical model is first verified against test data available for common upright caissons. The verified model is then used to study the pullout performance of tapered suction caissons. It is noticed that the pull-out capacities exhibited by tapered suction caissons are in general considerably higher than those from their corresponding traditional upright caissons. To obtain an insight into this superior behaviour, effects from certain soil/caisson/drainage parameters on the pull-out capacity of tapered suction caissons are studied. Soil cohesion is noticed to have a linear improving effect on the capacity of both upright and ta- pered suction caissons. The soil internal friction angle is noticed to have an exponential increasing effect on the pull-out capacity. With a constant caisson diameter, an increase in the aspect ratio is seen to particularly influence the pull-out capacity. With a constant caisson length, an increase in the aspect ratio is discovered to result in non-linear decrease in the pull-out capacity. Under undrained conditions, tapered models generally show less sensitivity to above mentioned soil/caisson parameters as compared with those under drained conditions.

关键词： suction caisson pull-out capacity numerical study upright caisson tapered caisson offshore structure sand clay drained undrained

Potential Contribution of Combined Atmospheric Ca^(2+) and mg^(2+) Wet Deposition Within the Continental U.S. to Soil Inorganic Carbon Sequestration

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Pedosphere 2013年第6期23卷 808-814页

作者： E.A.mIKHAILOVA m.A.GODDARD C.j.POST m.A.SCHLAUTmAN j.m.GALBRAITH School of Agricultural Forestand Environmental SciencesClemson University Department of Environmental Engineering and Earth Sciences Clemson University Department of Crop and Soil Environmental Sciences Virginia Tech

Soil inorganic carbon （SIC） stocks continuously change from the formation of pedogenic carbonates, a process requiring inputs of Ca2＋ and mg2＋ ions. This study ranked the soil orders in terms of potential inorganic carbon sequestration resulting from wet Ca2＋ and mg2＋ deposition from 1994 to 2003 within the continental United States. The analysis revealed that average annual atmospheric wet deposition of Ca2＋ and mg2＋ was the highest in the Central midwest-Great Plains region, likely due to soil particle input from loess-derived soils. The soil orders receiving the highest total average annual atmospheric wet Ca2＋ and mg2＋ deposition, expressed as potential inorganic carbon formation （barring losses from erosion and leaching）, were： 1） mollisols （1.1 × 10^8 kg C）, 2） Alfisols （8.4 × 10^7 kg C）, 3） Entisols （3.8 × 10^7 kg C）, and 4） Aridisols （2.8 × 10^7 kg C）. In terms of area-normalized result, the soil orders were ranked： 1） Histosols （73 kg C km-2）, 2） Alfisols and Vertisols （64 kg C km-2）, 3） mollisols （62 kg C km-2）, and 4） Spodosols （52 kg C kin-2）. The results of this study provide an estimate of potential soil inorganic carbon sequestration as a result of atmospheric wet Ca2＋ and mg2＋ deposition, and this information may be useful in assessing dynamic nature of soil inorganic carbon pools.

关键词： calcite carbon cycle dolomite pedogenic

Chemoselective Dehydrogenation of 3-[2-(3,4-Dihydro-1-naphthalenyl)ethyl]imidazolidine-2,4-diones: a New and Convenient Synthesis of 13,16-Diazaequilenin analogs

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Chinese journal of Chemistry 2004年第10期22卷 1196-1199页

作者： PARIHAR j.A RAmANA m.m.V Department of Chemistry University of Mumbai Santacruz (E) Mumbai-400098 IndiaDepartment of Chemistry University of Mumbai Santacruz (E) Mumbai-400098 India

The synthesis of the title compounds starting with the chemoselective dehydrogenation of 3-[2-(3,4-dihydro-1-naphthalenyl)ethyl]imidazolidine-2,4-diones has been described.

关键词： chemoselective dehydrogenation imide reduction intramolecular cyclization 13,16-diazasteroid

HAGEN POISEUILLE FLOW OF A GRANULAR mATERIAL IN A CYLINDER

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journal of Hydrodynamics 2001年第2期13卷 91-95页

作者： Liu, m.j. Tao, m.D. Dept. of mech. and Eng. Sci. Fudan Univ. Shanghai 200433 China

The equations of motion for rapid flow of a granular material were derived and their solutions representing flow driven by a body force along an infinitely-long cylinder were obtained by the numerical method.

关键词： Boundary conditions Cylinders (shapes) Equations of motion Flow of solids Numerical methods

Parameters for Cold Collisions of Lithium and Caesium Atoms

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Chinese Physics Letters 2011年第6期28卷 56-58页

作者： jamieson m.j Ouerdane H School of Computing Science University of GlasgowGlasgow G128QQUK mediterranean Institute of Fundamental Physics Via Appia Nuova 3100040 MarinoRomeItaly CNRT matériaux UmS CNRS 3318 6 Boulevard Maréchal Juin14050 Caen CedexFrance

We calculate the s-wave scattering length and effective range and the p-wave scattering volume for 7Li atoms interacting with 133Cs atoms via the X1Σ+molecular *** length and volume are found by fitting the log-derivative of the zero energy wave function evaluated at short range to a long range expression that accounts for the leading van der Waals dispersion potential and then incorporating the remaining long range dispersion contributions to first *** effective range is evaluated from a quadrature *** calculated parameters are checked from the zero energy limits of the scattering phase *** comment on ill-conditioning in the calculated s-wave scattering length.

关键词： potential dispersion checked

Sexual dimorphism in cranial shape and size in geomyoid rodents:multivariate and evolutionary perspectives

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Current Zoology 2022年第4期68卷 469-487页

作者： jonathan j m Calede Andrew Brown Department of Evolution Ecologyand Organismal BiologyThe Ohio State University318 W.12th Ave.300 Aronoff LaboratoryColumbusOH 43210USA The Ohio State University at marion 1459 Mount Vernon AvenueMarionOH 43302USA College of Veterinary medicine Texas A&M University660 Raymond Stotzer PkwyCollege StationTX 77843USA

Geomyoid rodents provide a great study system for the analysis of sexual *** are polygynic and many inhabit harsh arid environments thought to promote sexual *** fact,there has been extensive work published on the sexual size dimorphism of individual populations and species within this rodent ***,little work has been undertaken to assess the evolutionary patterns and processes associated with this sexual *** use multivariate analyses of cranial measurements in a phylogenetic framework to determine the distribution of size and shape dimorphism among geomyoids and test for Rensch’s *** results suggest that sexual dimorphism is more common in geomyids than heteromyids,but it is not in fact *** is evidence for variation in sexual dimorphism across ***,in many taxa,geographic variation appears to overwhelm existing sexual *** find support for the repeated independent evolution of shape and size dimorphism across geomyoid taxa,but we do not find support for an association between size and shape *** is no evidence for Rensch’s rule in geomyoids,whether at the superfamily or family ***,our findings suggest that there is no single explanation for the evolution of sexual dimorphism in geomyoids and that,instead,it is the product of numerous evolutionary *** studies incorporating phylogenetic relationships will be necessary to paint a more complete picture of the evolution of sexual dimorphism in geomyoids.

关键词： Geomyidae Heteromyidae phylogenetic comparative methods morphometrics Rensch’s rule

Simulation and calibration of granules using the discrete element method

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Particuology 2014年第1期12卷 40-43页

作者： Peter müller jürgen Tomas Institute of Process Engineering Mechanical Process EngineeringOtto-von-Guericke University MagdeburgUniversitätsplatz 239106 MagdeburgGermany

The discrete element method （DEm）, developed by Cundall and 5track to solve geomecnamcai problems, is used to simulate the mechanical behavior of granules. According to the DEm, an individ ual granule can be modeled as a realistic mechanical system consisting of primary particles bonded by interaction forces. Cranulometric properties of the model material, zeolite 4A, have been measured to determine their macro properties. To investigate the compression behavior, a compression test was performed using a strength tester on single granules between two pistons. A modeled granule consisting of more than 22,000 primary particles was generated. The micro properties of the modeled granule have been precisely set to allow its macro properties to be equivalent to the macro properties of zeolite 4A granules. To calibrate the mechanical properties, diametrical compression was simulated using two rigid walls stressed at a constant stressing velocity, The force-displacement curve of the modeled granule at compression has been calibrated by the experimental curve of zeolite 4A.

关键词： Discrete element method material behavior Granulation

Leader-following consensus control for networked multi-teleoperator systems with interval time-varying communication delays

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Chinese Physics B 2013年第7期22卷 96-103页

作者： m. j. Park S. m. Lee j. W. Son O. m. Kwon E. j. Cha School of Electrical Engineering Chungbuk National University School of Electronic Engineering Daegu University Division of IT-Convergence Daegu Gyeongbuk Institute of Science & Technology Department of Biomedical Engineering School of MedicineChungbuk National University

We study the leader-following consensus stability and stabilization of networked multi-teleoperator systems with interval time-varying communication delays. With the construction of a suitable Lyapunov–Krasovskii functional and the utilization of the reciprocally convex approach, novel delay-dependent consensus stability and stabilization conditions for the systems are established in terms of linear matrix inequalities, which can easily be solved by various effective optimization algorithms. One illustrative example is given to illustrate the effectiveness of the proposed methods.

关键词： multi-teleoperator systems interval time-varying delay leader–following consensus problem Lyapunov method