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Inflow and outflow permeability tests in a very soft clay under low stresses

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Journal of rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3270-3283页

作者： J.W.s.Vargas F.A.B.Danziger F.r.Lopes T.Lunne Federal University of rio de Janeiro Rio de JaneiroBrazil Norwegian Geotechnical Institute OsloNorway

In situ inflow and outflow permeability tests with the BAT probe at sarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low *** pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the *** role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe *** show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early *** inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading *** sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests *** are presented concerning the relationship between index parameters and the in situ coefficient of permeability for sarapuíII clay,which plot outside the range of existing databases.

关键词： permeability test soft clay BAT probe Inflow and outflow tests

Effect of radiative loss mechanisms on FIr thermometric parameters of Nd^(3+)-doped lithium tellurite glasses

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Journal of rare Earths 2024年第7期42卷 1250-1257,I0002页

作者： C.Y.Morassuti A.p.L silva L.A.O.Nunes s.M.Lima L.H.C.Andrade Optical and photothermal spectroscopy Group(GEOF) Center for Studies in Natural Resources(CERNA)State University of Mato Grosso do Sul(UEMS)C.P.351DouradosMSBrazil renato Archer Information Technology Center Dom Pedro I Highway(SP-65)Km 1436-Chácaras Campos dos AmaraisCampinasSPBrazil Institute of physics of são Carlos University of São PauloSão CarlosSPBrazil

Nd^(3+)-doped tellurite glasses are promising materials for thermometers based on the fluorescence intensity ratio(FIr)***,at high Nd^(3+)concentrations,energy transfer(ET)processes such as optical reabsorption and cross-relaxation can affect the Nd^(3+)emission,which has been little explored in the ***,the present work investigated the use of Nd^(3+)-doped tellurite glass(samples doped with Nd^(3+)at 0.2 mol%,0.5 mol%,2.0 mol%,and 4.0 mol%)in fluorescence thermometers,in the temperature range from 299 to 371 *** results indicate a strong dependence of the FIr parameters on the Nd^(3+)concentration,due to changes in the emission band profiles caused by optical reabsorption of the Nd^(3+)emissions and cross-relaxation processes.A decrease of the relative sensitivity of the ratio^(4)F_(5/2)→^(4)I_(9/2)/^(4)F_(3/2)→^(4)I_(9/2)is observed for samples doped with higher amounts of Nd^(3+).The maximum relative sensitivity at 299 K is 3.00%/K,which is the highest value among the reported Nd^(3+)ions.

关键词： Nd^(3+)-doped tellurite glass Fluorescence intensity ratio Optical thermometry Judd-Ofelt rare earths

Exploring one material for dual applications:A red-emitting Mg_(2)GeO_(4):Eu^(3+)nanophosphor for future generation energy efficient WLEDs and dosimetric applications

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Journal of rare Earths 2024年第10期42卷 1835-1845页

作者： Akshay Arjun G.p.Darshan s.C.sharma H.Nagabhushana D.V.sunitha H.B.premkumar Department of physics Faculty of Mathematical and Physical SciencesM.S.Ramaiah University of Applied SciencesBengaluru560054India Honorary professor of Law and Forensic Materials Jain UniversityBengaluru560069India C.N.r.rao Centre for Advanced Materials Tumkur UniversityTumkur572103India school of Applied sciences(physics) REVA UniversityBengaluru560064India

The envisaged design and developme nt of individual mate rials to excavate a broader spectrum of desired properties and offer multiple applications are highly *** this in mind,a series of forsterite-structured Mg_(2)GeO_(4):Eu^(3+)(1 mol%-9 mol%)nanophosphors was synthesized via a solution combustion method using oxalyl dihydrazide as a *** X-ray diffraction patterns confirm the orthorhombic crystal system with a puma space *** results clearly show irregularly shaped cluster-like structures with aggregation of the *** diffuse reflectance spectra,the optical energy band gap of the Mg_2GeO_4:Eu^(3+)(1 mol%-9 mol%)nanophosphors was estimated and obtained to be~4.12-4.32 *** photoluminescence emission spectra exhibit intense peaks at~579,589,610,661,and 707 nm,which are due to characteristic~5D_(0)→~7F_(0),~5D_(0)→~7F_(1),~5Do→~7F_(2),~5D_(0)→~7F_(3)and~5D_(0)→~7F_(4)transitions of Eu^(3+)ions,*** Commission International de L'Eclairage color coordinates are gradually tuned from pale red(0.5980,0.4012)to a pure red(0.6385,0.3611)*** glow peaks showcase excellent super-linear response at low doses ofγ-irradiations,indicating that the prepared phosphor can be used in thermoluminescent personal dosimetry which is a biological tissue *** aforementioned results demonstrate that the prepared Mg_2GeO_4:Eu^(3+)(1 mol%-9 mol%)nanophosphors are considered an excellent candidate for dual applications,i.e.,red component in future generation white-light-emitting diodes(WLEDs)and personal dosimetric applications.

关键词： Nanophosphors photoluminescence Thermoluminescence Dosimetry photometric properties rare earths

Nonlinear Coupling of Kinetic Alfvén Waves and Ion Acoustic Waves in the Inner Heliosphere

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research in Astronomy and Astrophysics 2024年第10期24卷 141-158页

作者： Mani K.Chettri Vivek shrivastav rupak Mukherjee Nidhi Gaur r.p.sharma Hemam D.singh Department of physics Sikkim UniversityGangtokSikkimIndia DAV public school Sector 14GurugramHaryanaIndia plasma simulation Laboratory Department of Energy Science and EngineeringIndian Institute of Technology DelhiDelhiIndia

We study the nonlinear coupling of kinetic Alfvén waves with ion acoustic waves applicable to the Earth’s radiation belt and near-sun streamer belt solar wind using dynamical equations in the form of modified Zakharov *** simulations show the formation of magnetic field filamentary structures associated with density humps and dips which become turbulent at later times,redistributing the energy to higher *** magnetic power spectra exhibit an inertial range Kolmogorov-like spectral index value of-5/3 for k_(⊥)ρ_(i)steeper dissipation range spectra with indices~-3 for the radiation belt case and~-4 for the nearsun streamer belt solar wind case,here k_(⊥)andρ_(i)represent the wavevector component perpendicular to the background magnetic field and the ion thermal gyroradius,*** quasilinear theory in terms of the Fokker-planck equation in the region of wavenumber turbulent spectra,we find the particle distribution function flattening in the superthermal tail population which is the signature of particle energization and plasma heating.

关键词： sun:chromosphere sun:corona sun:heliosphere

Antibacterial HA-coatings on bioresorbable Mg alloy

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Journal of Magnesium and Alloys 2024年第5期12卷 1965-1985页

作者： K.V.Nadaraia D.V.Mashtalyar M.A.piatkova A.I.pleshkova I.M.Imshinetskiy M.s.Gerasimenko E.A.Belov V.V.Kumeiko D.N.Kozyrev K.A.Fomenko V.V.Mostovaya B.r.Torpanov A.r.Biktimirov I.s.Osmushko s.L.sinebryukhov s.V.Gnedenkov Institute of Chemistry FEB rAs 159 Pr.100-letiya VladivostokaVladivostok 690022Russia Far Eastern Federal University 10 Ajax BayRussky IslandVladivostok 690922Russia A.V.Zhirmunsky National scientific Center of Marine Biology FEB rAs 17 St.PalchevskogoVladivostok 690041Russia regional Clinical Dermatovenerological Dispensary 18 V St.GamarnikaVladivostok 690033Russia NMIC“Treatment and rehabilitation Center” 3 Ivankovskoe highwayMoscow 125367Russia

In this study,a calcium-phosphate coating was formed on a Mg-Mn-Ce alloy by the plasma electrolytic oxidation(pEO).The antibiotic vancomycin,widely used in the treatment of infections caused by staphylococcus aureus(***),was impregnated into the *** with vancomycin showed high bactericidal activity against *** mechanical and electrochemical properties of the formed coatings were studied,as well as in vitro cytotoxicity tests and in vivo tests on mature male rats were *** to sEM,EDs,XrD and Xps data,coatings had a developed morphology and contained hydroxyapatite,which indicates high *** analysis of roughness of coatings without and with vancomycin did not reveal any differences,confirming the high roughness of the *** electrochemical tests,an increase in corrosion resistance by more than two times after the application of pEO coatings was *** to the results of an in vivo study,after 28 days of the implantation of samples with calcium phosphate pEO coating and vancomycin,no signs of inflammation were observed,while an inflammatory reaction developed in the area of implantation of bare alloy,followed by *** release tests from the coatings show a sharp decrease in the concentration of the released antibiotic on day 7 and then a gradual decrease until day *** the experiment,no significant deviations in the condition and behavior of the animals were observed;clinical tests did not reveal a systemic toxic reaction.

关键词： Bioactive coatings Biocompatibility Mg alloy plasma electrolytic oxidation Hydroxyapatite Vancomycin

A transient shift in equatorial hydrology and vegetation during the Eocene Thermal Maximum 2

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Geoscience Frontiers 2024年第5期15卷 174-181页

作者： Gaurav srivastava Harshita Bhatia poonam Verma Yogesh p.singh shailesh Agrawal Torsten Utescher r.C.Mehrotra Birbal sahni Institute of palaeosciences 53 University RoadLucknow 226007India Academy of scientific and Innovative research(AcsIr) Ghaziabad 201002India senckenberg research Institute and Natural History Museum Frankfurt/M.Senckenberg Research Station of Quaternary PalaeontologyWeimerGermany Institute for Geosciences University of BonnNussallee 853115 BonnGermany

The equatorial evergreen forests nourish the world’s biodiversity hotspots and are considered the lungs of the ***,their future survival is uncertain,due to anthropogenically increased carbon emissions and changes in the hydrological *** the changes in the hydrological cycle in the equatorial region due to an increase in carbon emission is of prime *** early paleogene hyperthermal events are potential analogs to understand the consequences of high carbon emission on the hydrological *** this communication,we quantify the terrestrial seasonal climate using the plant proxy and infer that during the Eocene Thermal Maximum 2 when atmospheric carbon dioxide concentration was>1000 ppmv near the palaeo-equator(~0.6°N),the rainfall decreased significantly,leading to the expansion of deciduous *** study raises important questions about the future survival of equatorial rainforests and biodiversity hotspots under increased carbon emissions.

关键词： Coexistence approach Climate ETM-2 Global warming Hyperthermal paleogene

Construction of 2D/2D Ti_(3)C_(2)T_(x)MXene/Cds heterojunction with photothermal effect for efficient photocatalytic hydrogen production

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Journal of Materials science & Technology 2024年第4期171卷 1-9页

作者： T.Y.Huang Z.Yang s.Y.Yang Z.H.Dai Y.J.Liu J.H.Liao G.Y.Zhong Z.J.Xie Y.p.Fang s.s.Zhang Key Laboratory for Biobased Materials and Energy of Ministry of Education Guangdong Laboratory for Lingnan Modern AgricultureCollege of Materials and EnergySouth China Agricultural UniversityGuangzhou 510643China school of physics and Optoelectronics South China University of TechnologyGuangzhou 510640China school of Chemical Engineering and Energy Technology Guangdong Provincial Key Laboratory of Distributed Energy SystemsDongguan University of TechnologyDongguan 523808China

The insensitivity of semiconductors to visible and infrared light is a key constraint on the utilization of light energy in photocatalytic *** photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semiconductor ***,a novel stable Ti_(3)C_(2)T_(x)MXene/Cds heterojunction catalyst is obtained by in-situ epitaxial growth of two-dimensional(2D)Cds nanosheets on 2D MXene interface via a solvothermal *** exceptional light absorption properties of MXene confer outstanding full-spectrum driven photocat-alytic hydrogen evolution capability upon the heterogeneous *** unique 2D/2D structure effectively mitigated the recombination of photogenerated carriers,enhancing the photocatalytic performance of the ***,the composite catalyst exhibits a significantly higher surface temperature of 80.4℃under visible light irradiation at an intensity of 0.1 W/cm^(2),which is 1.84 times higher than that of *** irradiation of visible and near infrared light,the composite catalyst with photothermal ef-fect demonstrates a remarkable hydrogen evolution rate of 65.4 mmol g^(-1)h^(-1),which is 7.2 times higher than that of Cds *** study introduces a novel approach for constructing full-spectrum absorption catalysts and expands the application of the photothermal effect in photocatalytic hydrogen evolution research.

关键词： Two-dimensional structure Heterostructure photothermal effect photocatalyst Hydrogen evolution

BaTiO_(3)solid solutions co-doped with Gd^(3+)and Eu^(3+):synthesis,structural evolution and dielectric properties

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Journal of rare Earths 2024年第10期42卷 1920-1926页

作者： r.Martínez-López M.pérez-Labra J.A.romero-serrano F.r.Barrientos-Hernández M.reyes-pérez M.I.Valenzuela-Carrillo G.Urbano-reyes V.E.reyes-Cruz G.I.Dávila-pulido Academic Area of Earth sciences and Materials Autonomous University of Hidalgo StateRoad Pachuca-Tulancingo Km 4.5 Mineral de La Reforma.Hidalgo42184Mexico Metallurgy and Materials Department ESIQIE-IPNUPALMZacatencoCiudad de Mexico07738Mexico Autonomous University of Coahuila Boulevard Adolfo López Mateos S/nNueva RositaCoahuila26800Mexico

In this paper,the synthesis,structural evolution,and dielectric properties of BaTiO_(3)solid solutions codoped with rare earth elements(Gd^(3+)and Eu^(3+))prepared using the solid-state reaction method are *** pure precursor powders of BaCl_3,TiO_(2),Gd_(2)O_(3),and Eu_(2)O_(3)were mixed in stoichiometric proportions,ground in an agate mortar before being uniaxially pressed at 250 Mpa and sintered at 1300℃in air atmosphere for 6 h to obtain Ba_(1-3x)Gd_(2x)Ti_(1-3x)Eu_(4x)O_(3)(x=0,0.0015,0.01 and0.1).X-ray diffraction(XrD)and rietveld's refinement results reveal the crystal phase ferroelectric tetragonal BaTiO_(3)for the samples with x=0,0.0015 and 0.01,as well as a consistent increment in the lattice parameters caused by the *** solubility limit of Gd^(3+)and Eu^(3+)in the BaTiO_(3)structure is reached for the sample with x>0.01,and the orthorhombic Eu_2TiO_(5)and monoclinic BaTi_(2)O_(5)secondary phases were *** raman results show the characteristic peaks of ferroelectric tetragonal BaTiO_(3)around 716 cm^(-1)(LO of A1 symmetry),515 cm^(-1)(TO of A1 symmetry),and 305 cm^(-1)(B1).The maximum relative permittivity measured at 1 kHz was recorded to be 6151.8 for the sample with x=0.0015,and a decrease in the Curie temperature to 105℃with respect to the undoped sample was *** punctual microanalysis for the samples with x=0.0015,0.01,and 0.1 reveals grains composed of Ba,Ti,O,Gd,and Eu homogeneously distributed in the BaTiO_(3)*** Ba/Ti ratios for samples with x=0.0015,0.01 and 0.1 are 2.86,2.91,and 0.68,respectively,indicating substitution at the Ti site for samples with x=0.0015 and 0.01 and a substitution at the Ba site for the sample with x=0.1.

关键词： BaTiO_(3) Doping Gadolinium Europium synthesis rare earths

prediction and control of cholera outbreak:study case of

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Infectious Disease Modelling 2024年第3期9卷 892-925页

作者： C.Hameni Nkwayep r.GlèlèKakaï s.Bowong Laboratory of Mathematics Department of Mathematics and Computer ScienceUniversity of DoualaPO Box 24157DoualaCameroon IrD Sorbonne UniversityUMMISCOF-93143BondyFrance Biomathematics and Forest Modeling University of Abomey-CalaviCalaviBenin

This paper deals with the problem of the prediction and control of cholera outbreak using real data of *** first develop and analyze a deterministic model with seasonality for the cholera,the novelty of which lies in the incorporation of undetected *** present the basic properties of the model and compute two explicit threshold parametersr_(0)and r_(0).that bound the effective reproduction number,from below and above,that is r_(0)≤r_(0)≤r_(0).We prove that cholera tends to disappear whenr_(0)≤1,while when r_(0)>1,cholera persists uniformly within the ***,assuming that the cholera transmission rates and the proportions of newly symptomatic are unknown,we develop the EnKf approach to estimate unmeasurable state variables and these unknown parameters using real data of cholera from 2014 to 2022 in *** use this result to estimate the upper and lower bound of the effective reproduction number and reconstructed active asymptomatic and symptomatic cholera cases in Cameroon,and give a short-term forecasts of cholera in Cameroon until *** simulations show that(i)the transmission rate from free Vibrio cholerae in the environment is more important than the human transmission and begin to be high few week after May and in October,(ii)90%of newly cholera infected cases that present the symptoms of cholera are not diagnosed and(iii)60.36%of asymptomatic are detected at 14%and 86%of them recover *** future trends reveals that an outbreak appeared from July to November 2023 with the number of cases reported monthly peaked in October *** impulsive control strategy is incorporated in the model with the aim to avoid or prevent the cholera *** the first year of monitoring,we observed a reduction of more than 75%of incidences and the disappearance of the peaks when no control are available in Cameroon.A second monitoring of control led to a further reduction of around 60%of incidences the following year,showing how

关键词： Vibrio cholerae Mathematical models Ensemble Kalman filterBasic reproduction number Impulsive control