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Tuning the particle size,physical properties,and photocatalytic activity of Ag_(3)PO_(4)materials by changing the Ag^(+)/PO_(4)^(3-)ratio

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Chinese Physics B 2023年第3期32卷 561-568页

作者： Hung N m Oanh L T m Chung d P Thang d v mai v T Hang L T minh N v Center for Nano Science and Technology Hanoi National University of Education136 Xuan Thuy RoadCau Giay DistrictHanoi 100000Vietnam department of Physics Hanoi National University of Education136 Xuan Thuy RoadCau Giay DistrictHanoi 100000Vietnam Hanoi University of mining and Geology Duc Thang WardNorth Tu Liem DistrictHanoi 100000Vietnam Institute of materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietHanoi 100000Vietnam Faculty of Basic Sciences Hanoi University of Natural Resources and Environment41 A Phu Dien RoadNorth Tu LiemHanoi 100000Vietnam

This study demonstrates the influence of the Ag^(+)/PO_(4)^(3-)ratio in precursor solution on the crystal structural formation,morphology,physical properties,and photocatalytic performance of a Ag_(3)PO_(4)photocatalyst that is fabricated,using a facile precipitation method,from AgNO_(3)and Na2HPO_(4)·12H_(2)*** material characterizations were carried out using x-ray diffraction(XRd),scanning electron microscopy(SEm),energy-dispersive x-ray spectroscopy(EdX),Brunauer–Emmett–Teller(BET)surface area,Fourier transform infrared(FTIR)absorption,Raman scattering,x-ray photoelectron spectroscopy(XPS),Uv-vis absorption,and photoluminescence(PL).The results show that Ag_(3)PO_(4)crystallizes better when the excess PO_(4)^(3-)content increases,and the lattice parameters decrease slightly,while the crystal diameter and the particle size *** change is also observed in the Raman scattering and FTIR spectra with the increase in the vibration frequency of the[PO_(4)]*** compression of the[PO_(4)]unit was also confirmed in the XPS spectra with the shift of P 2p peaks toward higher binding *** photocatalytic results showed that the samples synthesized from excess PO_(4)^(3-)solution exhibited higher photocatalytic performance compared to the sample with a Ag^(+)/PO_(4)^(3-)ratio of 3:1.A sample prepared from the precursor solution with a Ag^(+)/PO_(4)^(3-)ratio of 3:1.5 was optimal for RhB decomposition under both visible light and natural sunlight,completely decomposing 10 ppm RhB after 15 minutes of xenon lamp irradiation and after 60 minutes under solar light *** is attributed to the high crystallinity,small particle size and low electron–hole recombination rate of the sample.

关键词： morphology photocatalytic Ag^(+)/PO_(4)^(3-)ratio visible light

Nonlinear analysis on dynamic buckling of eccentrically stiffened functionally graded material toroidal shell segment surrounded by elastic foundations in thermal environment and under time-dependent torsional loads

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Applied mathematics and mechanics(English Edition) 2016年第7期37卷 835-860页

作者： d.v.dUNG P.m.vUONG department of mathematics Mechanics and InformaticsVietnam National University Faculty of Civil and Industrial National University of Civil Engineering

The nonlinear analysis with an analytical approach on dynamic torsional buckling of stiffened functionally graded thin toroidal shell segments is investigated. The shell is reinforced by inside stiffeners and surrounded by elastic foundations in a thermal environment and under a time-dependent torsional load. The governing equations are derived based on the donnell shell theory with the yon Karman geometrical nonlinearity, the Stein and mcElman assumption, the smeared stiffeners technique, and the Galerkin method. A deflection function with three terms is chosen. The thermal parameters of the uniform temperature rise and nonlinear temperature conduction law are found in an explicit form. A closed-form expression for determining the static critical torsional load is obtained. A critical dynamic torsional load is found by the fourth-order Runge-Kutta method and the Budiansky-Roth criterion. The effects of stiffeners, foundations, material, and dimensional parameters on dynamic responses of shells are considered.

关键词： toroidal shell segment functionally graded material (FGm) stiffened shell,critical static and dynamic torsional load thermal environment

SCIENTIFIC PRINCIPLES FOR mOdIFICATION OF WATER-SOLUBLE POLYmERS. FORmATION OF mACROmOLECULAR COmPLEXES

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Chinese Journal of Polymer Science 1998年第3期16卷 268-278页

作者： PAUTOv v.d. ANUFRIEvA E.v. KRAKOvYAK m.G. Institute of macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 RussiaInstitute of Macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 RussiaInstitute of Macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 Russia

The study of nanosecond dynamics of macromolecules with the lumines-cent methods make it possible to investigate the formation and functioning of polymericcomplexes, polymeric conjugates and macromolecular metal complexes, which are widelyused for solving many practical tasks. The nanosecond dynamics of macromolecules are ahighly sensitive indicator of interpolymer complexes (IPC) formation. It enables us to solvethe problems of studying IPC formation and stability and to investigate the interpolymerreactions of exchange and substitution. The investigation of changes in the rotational mo-bility of globular protein molecules as a whole makes it possible to determine the complexcomposition and its stability, and to control the course of polymer-protein conjugate forma-tion reaction. The nanosecond dynamics of polymers interacting with surfacants' ions (S)are the sensitive indicator of the S-polymer complex formation. A method for determin-ing the equilibrium constants of the S-polymer complex formation was developed on thebasis of the study of polymer chains mobility. It is established that nanosecond dynamicsinfluences the course of chemical reactions in polymer chains. moreover, the marked effectof the nanosecond dynamics is also revealed in the study of photophysical processes (theformation of excimers and energy migration of electron excitation) in polymers with pho-toactive groups. It was found that the efficiency of both processes increases with increasingthe mobility of side chains, the carriers of photoactive groups.

关键词： modification of water-soluble polymers Formation of complexes

Effect of synthesis conditions and surrounding medium on luminescence properties of YvO_4:Eu^(3+) nanopowders

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Journal of Rare Earths 2015年第2期33卷 129-134页

作者： E.v.Golyeva d.v.Tolstikova I.E.Kolesnikov m.d.mikhailov St.Petersburg State Polytechnical University St.Petersburg 195251 Russia Scientific and Technological Institute of Optical material Science VNTs S.I.Vavilov State Optical InstituteSt.Petersburg 192171 Russia St.Petersburg State University St.Petersburg 199034 Russia

Nanocrystalline yttrium vanadate doped with europium ions powders were synthesized via sol-gel method based on decomposition of metal-polymer complex. X-ray diffraction analysis showed that samples had pure tetragonal phase without any impurities. Scanning electron microscopy and static light scattering technique were used to study morphology and size of prepared nanoparticles. Average diameter of the nanoparticles was about 40 nm. The changes in structural and luminescence properties were observed as a function of the first and second calcination temperature. The optimal conditions for synthesis of nanoparticles were determined as Т1=500℃, t1=1 h; Т2=950 ℃, t2=1.5 h. The effect of different media surrounding the nanoparticles on their luminescence properties and lifetime was investigated and discussed in terms of effective refractive index. It was found that the observed lifetime of YvO4：Eu^3＋ 5 at.% nanophosphor was decreased from 0.64 ms in air（nmed=1） to 0.45 ms in chalcogenide glass As39S61（nmed=2.39）.

关键词： nanopowders rare earths luminescence effective refractive index lifetime

The multi-impurity system in CdSe nanoplatelets:electronic structure and thermodynamic properties

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Communications in Theoretical Physics 2024年第3期76卷 165-173页

作者： d A Baghdasaryan v A Harutynyan E m Kazaryan H A Sarkisyan Russian-Armenian University H Emin 1230051YerevanArmenia Institute of Applied Problems of Physics 25 Nersisyan St0014YerevanArmenia

This paper theoretically studies the impurity states and the effects of impurity concentration and configuration on the optical,electrical,and statistical properties of CdSe nanoplatelets(NPLs).An image charge-based model of electron-impurity interaction is *** charge-carrier energy spectra and corresponding wave functions depending on the impurity number and configuration are *** electron binding energies are calculated for different NPL *** is shown that the image charge-based interaction potential that arises due to the dielectric constants mismatch is much stronger than the interaction potential that does not take such a mismatch into ***,it is demonstrated that the binding energies are increasing with the number of *** calculate the canonical partition function using the energy levels of the electron,which in turn is used to obtain the mean energy,heat capacity,and entropy of the non-interacting electron *** thermodynamic properties of the non-interacting electron gas that depend on the geometric parameters of the NPL,impurity number,configuration,and temperature are studied.

关键词： nanoplateletes thermodynamic properties impurity states

Evaluation of influence of cold atmospheric pressure argon plasma operating parameters on degradation of aqueous solution of Reactive Blue 198(RB-198)

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Plasma Science and Technology 2020年第5期22卷 114-125页

作者： K NAvANEETHA PANdIYARAJ d vASU P v A PAdmANABHAN m PICHUmANI R R dESHmUKH v KANdAvELU Research division of Plasma Processing(RdPP) Department of PhysicsSri Shakthi Institute of Engineering and TechnologyChinniyam Palayam(post)Coimbatore-641062India department of Nanoscience and Technology Sri Ramakrishna Engineering CollegeCoimbatore-641022India department of Physics Institute of Chemical TechnologyMatungaMumbai 400019India department of Chemistry Sri Shakthi Institute of Engineering and TechnologyL&T bypassChinniyam Palayam(post)Coimbatore-641062India

The intention of this work is to remove Reactive Blue 198(RB-198)dye components from simulated water solution using cold atmospheric pressure argon plasma *** solutions of RB-198 dye were treated as a function of various operating parameters such as applied potential,reaction time and distance between the plasma jet and surface of the *** efficiency of the degradation of RB-198 molecules was explored by means of Uv-vis *** reactive species involved during the treatment process were examined by optical emission spectra(OES).The present hydroxyl radicals(OH·radical)and hydrogen peroxide(H2O2)in the plasma-treated aqueous dye solutions were investigated using various spectroscopic *** other parameters such as total organic carbon(TOC),conductivity and p H were also *** toxicity of plasma-treated RB-198 solution was finally studied by diffusion bacterial analysis and by tracking seed germination *** results show that a higher degradation percentage of99.27%was acquired for the RB-198 treated at higher reaction time and applied potential,and shorter distance between the plasma jet and water *** may be due to the formation of various reactive oxygen(OH·radical,atomic oxygen(O)and H2O2)and nitrogen species(nitric oxide(NO)radicals and N2 second positive system(N2 SPS))during the processes as confirmed by OES analysis and other spectroscopy ***(17.7%-81.8%)and pH(7.5-3.4)values of the plasma-treated RB-198 decreased significantly with respect to various operation parameters,which indicates the decomposition of RB-198 molecules in the aqueous ***,the conductivity of plasma-treated RB-198 aqueous solutions was found to have increased linearly during the plasma treatment due to the formation of various ionic species in aqueous *** toxicity analysis clearly exhibits the non-toxic behavior of plasma-treated RB-198 aqueous solution towards the bacterial growth and germination of see

关键词： RB-198 degradation non-toxicity cold atmospheric pressure plasma jet

Results of the main Phase of Ion Separation in the Process of Plasma-Optical mass Separation

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Plasma Science and Technology 2015年第10期17卷 862-868页

作者： v.m.BARdAKOv S.d.IvANOv A.v.KAZANTSEv N.A.STROKIN Institute for Physics and Technology Irkutsk State Technical University

This paper presents separation results of a mixture of nitrogen, argon and krypton ions in the process of plasma-optical mass separation on the POmS-E-3 separator model. We determined the behavior of the separation with a change in the value of magnetic field induction in the azimuthator and in the degree of compensation of the spatial charge in ion flows. An analysis is performed for experimental data by correlation with the results of a theoretical study and numerical experiments. The objectives of future experiments are outlined.

关键词： plasma-optical mass separation plasma accelerator trajectories spatial charge

Photoelectrochemical activity of ZnO:Ag/rGO photo-anodes synthesized by two-steps sol-gel method

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Chinese Physics B 2022年第5期31卷 691-702页

作者： d Ben Jemia m Karyaoui m A Wederni A Bardaoui m v martinez-Huerta m Amlouk R Chtourou Laboratory of Nanomaterials and Renewable Energy Systems LANSER Research and Technology Center of EnergyBorj-Cedria Science and Technology ParkBP 952050 Hammam-LifTunisia Faculty of Science of Tunis University of Tunis El ManarTunisia Laboratory of Physics of materials and Nanomaterials Applied to the Environment(LaPhymNE) Faculty of Sciences of GabesCite ErriadhUniversity of Gabes6079 GabesTunisia lnstitute of Catalysis and Petrochemistry CSICin MadridSpain Laboratory of Nanomaterials Nanotechnology and Energy(L2NE)University of Tunis El ManarTunisia

This work investigated the influence of silver plasmon and reduced graphene oxide(r GO)on the photoelectrochemical performance(PEC)of Zn O thin films synthesized by the sol-gel *** physicochemical properties of the obtained photo-anodes were systematically studied by using several characterization *** x-ray diffraction analysis showed that all samples presented hexagonal wurtzite structure with a polycrystalline *** and energy dispersive x-ray(EdX)studies confirmed the existence of both Ag and r GO in Zn O:Ag/r GO thin *** estimated grain size obtained from scanning electron microscopy(SEm)analysis decreased with Ag doping,then increased to a maximum value after r GO *** Uv-vis transmission spectra of the as-prepared Zn O:Ag and Zn O:Ag/r GO thin films have shown a reduction in the visible range with a redshift at the absorption *** bandgaps were estimated to be around 3.17 e v,2.7 e v,and 2.52 e v for Zn O,Zn O:Ag,and Zn O:Ag/r GO,***,the electrical measurements revealed that the charge exchange processes were enhanced at the Zn O:Ag/r GO/electrolyte interface,accompanied by an increase in the(PEC)performance compared to Zn O and Zn O:Ag ***,the photocurrent density of Zn O:Ag/r GO(0.2 m A·cm^(-2)) was around 4 and 2.22 times higher than photo-anodes based on undoped Zn O(0.05 m A·cm^(-2)) and Zn O:Ag(0.09 m A·cm^(-2)),***,from the flat band potential and donor density,deduced from the mott-Schottky,it was clear that all the samples were n-type semiconductors with the highest carrier density for the Zn O:Ag/r GO photo-anode.

关键词： zinc oxide reduced graphene oxide silver doping sol-gel photoelectrochemical performance

PROPERTIES, WELdABILITY ANd APPLICATIONS OF AdvANCEd WROUGHT SUPERALLOYS FOR GAS TURBINE ENGINES

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Acta metallurgica Sinica(English Letters) 2005年第1期18卷 1-14页

作者： d.L. Klarstrom v.R. Ishwar m.d. Rowe Haynes International Inc. Kokomo Indiana IN 46904-9013 USAHaynes International Inc. Kokomo Indiana IN 46904-9013 USAHaynes International Inc. Kokomo Indiana IN 46904-9013 USA

Alloy selection and alloy design both require consideration of an array of material attributes, including in-service properties, weldability and fabricability. Critical properties of advanced wrought superalloys for gas turbine applications include high temperature strength, thermal stability, oxidation resistance and fatigue resistance. In this paper, the properties of twelve wrought solid-solution-strengthened and six age-hardenable superalloys are compared. Weldability is an important attribute and can be a major limiting factor in the use of certain alloys. Weldability test methods are discussed and the resistance of alloys to solidification cracking and strain-age cracking is compared. The use of weldability testing in the development of modern wrought su-peralloys is discussed with several examples cited. Finally, alloy selection for gas turbine components is outlined, taking into account both alloy properties and fabricability.

关键词： wrought superalloys mechanical properties strain-age cracking of weldments selection and application of wrought superalloys