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Magnetic properties of sn-substituted Ni-Zn ferrites synthesized from nano-sized powders of NiO, ZnO, Fe2O3, and snO2

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Chinese Physics B 2017年第7期26卷 377-382页

作者： M A Ali M M Uddin M N i Khan F U Z Chowdhury s M Hoque s i Liba Department of Physics Chittagong University of Engineering and Technology (CUET) Materials science Division Atomic Energy Center

A series of Ni0.6-x/2Zn0.4-x/2snxFe2O4(x = 0.0, 0.05, 0.1, 0.15, 0.2, and 0.3)(NZsFO) ferrite composities have been synthesized from nano powders using a standard solid state reaction technique. The spinel cubic structure of the investigated samples has been confirmed by x-ray diffraction(XRD). The magnetic properties such as saturation magnetization(Ms),remanent magnetization(Mr), coercive field(Hc), and Bohr magneton(μ) are calculated from the hysteresis loops. The value of Msis found to decrease with increasing sn content in the samples. This change is successfully explained by the variation of A-B interaction strength due to sn substitution in different sites. The compositional stability and quality of the prepared ferrite composites have also been endorsed by the fairly constant initial permeability(μ’) over a wide range of frequency. The decreasing trend of μ’ with increasing sn content has been observed. Curie temperature TChas been found to increase with the increase in sn content. A wide spread frequency utility zone indicates that the NZsFO can be considered as a good candidate for use in broadband pulse transformers and wide band read-write heads for video recording. The composition of x = 0.05 shows unusual results and the possible reason is also mentioned with the established formalism.

关键词： magnetic properties saturation magnetization permeability Curie temperature

stability analysis and modeling for the three-dimensional Darcy-Forchheimer stagnation point nanofluid flow towards a moving surface

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Applied Mathematics and Mechanics(English Edition) 2021年第3期42卷 357-370页

作者： Yuming CHU M.i.KHAN M.i.U.REHMAN s.KADRY s.QAYYUM M.WAQAs Department of Mathematics Huzhou UniversityHuzhou 313000Zhejiang ProvinceChina Hunan Provincial Key Laboratory of Mathematical Modeling and Analysis in Engineering Changsha University of Science&TechnologyChangsha 410114China Department of Mathematics Riphah International UniversityFaisalabad CampusFaisalabad 38000Pakistan Department of Mathematics Quaid-i-Azam UniversityIslamabad 44000Pakistan Department of Mathematics and Computer science Beirut Arab UniversityBeirut 11072809Lebanon NUTECH school of Applied sciences and Humanities National University of TechnologyIslamabad 44000Pakistan

in this research,the three-dimensional(3D)steady and incompressible laminar Homann stagnation point nanofluid flow over a porous moving surface is *** disturbance in the porous medium has been characterized by the Darcy-Forchheimer *** slip for viscous fluid is *** energy equation is organized in view of radiative heat flux which plays an important role in the heat transfer *** governing flow expressions are first altered into first-order ordinary ones and then solved numerically by the shooting *** solutions are obtained for the velocity,skin friction coefficient,temperature,and Nusselt number subject to sundry flow parameters,magnetic parameter,Darcy-Forchheimer number,thermal radiation parameter,suction parameter,and dimensionless slip *** this research,the main consideration is given to the engineering interest like skin friction coefficient(velocity gradient or surface drag force)and Nusselt number(temperature gradient or heat transfer rate)and discussed numerically through *** conclusion,it is noticed from the stability results that the upper branch solution(UBs)is more reliable and physically stable than the lower branch solution(LBs).

关键词： viscous slip Darcy-Forchheimer relation thermal radiation stagnation point flow dual solution heat generation/absorption stability result

A simple semiempirical model for the static polarizability of ions

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Chinese Physics B 2023年第8期32卷 32-45页

作者： Alexander s sharipov Boris i Loukhovitski Central institute of Aviation Motors Aviamotornaya 2Moscow 111116Russia

A concise analytical model for the static dipole polarizability of ionized atoms and molecules is created for the first *** input,it requires,alongside the polarizability of neutral counterpart of a given ion,only the charge and elemental *** physically motivated semiempirical model is based on a number of established regularities in polarizability of charged monatomic and polyatomic *** order to adjust it,the results of quantum chemistry calculations and gas-phase measurements available for a broad range of ionized multielectron species are *** counteract the appreciable bias in the literature data toward polarizability of monoatomic ions,for some molecular ions of general concern the results of the authors'own density functional theory calculations are additionally invoked.A total of 541 data points are used to optimize the *** is demonstrated that the model we suggested has reasonable(given the substantial uncertainties of the reference data)accuracy in predicting the static isotropic polarizability of arbitrarily charged ions of any size and atomic *** resulting polarizability estimates are found to achieve a coefficient of determination of 0.93 for the assembled data *** created analytic tool is universally applicable and might be advantageous for some applications where there is an urgent need for rapid low-cost evaluation of the static gas-phase polarizability of ionized atoms and *** is especially relevant to constructing the complex models of nonequilibrium chemical kinetics aimed at precisely describing the observable refractive index(dielectric permittivity)of plasma *** data sets that support the findings of this study are openly available in science Data Bank at https://***/10.57760/sciencedb.07526.

关键词： polarizability ions semiempirical model quantum chemistry

Hawking Radiation of Grumiller Black Hole

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Communications in Theoretical Physics 2014年第5期61卷 558-564页

作者： s.F.Mirekhtiary i.sakalli Department of Physics Eastern Mediterranean University

in this paper, we consider the relativistic Harnilton-Jacobi （HJ） equation and study Hawking radiation （HR） of scalar particles from uncharged Grumiller black hole （GBH） which is affordable for testing in astrophysics. it is a/so known as Rindler modified schwarzschild BH. Our aim is not only to investigate the effect of the Rindler parameter a on the Hawking temperature （TH ）, but to examine whether there is any discrepancy between the computed horizon temperature and the standard TH as well. For this purpose, in addition to its naive coordinate system, we study on the three regular coordinate systems, which are Painlevd--Gullstrand （PG）, ingoing Edding^on-Finkelstein （iEF）, and Kruskal-szekeres （Ks） coordinates. in o21 coordinate systems, we calculate the tunneling probabilities of incoming and outgoing scalar particles from the event horizon by using the HJ equation. it has been shown in detail that the considered HJ method is concluded with the conventional T~ in all these coordinate systems without giving rise to the famous factor-2 problem. Filrthermore, in the PG coordinates Parikh-Wilczek＇s tunneling （PWT） method is employed in order to show how one can integrate the quantum gravity （QG） corrections to the semiclassical tunneling rate by including the effects of self-gravitation and back reaction. We then show how this yields a modification in the TH.

关键词： Hawking radiation relativistic Hamilton Jacobi equation Grumiller black hole quantum tunneling back reaction effect pioneer anomaly

identification of meta-instable stress state based on experimental study of evolution of the temperature field during stick-slip instability on a 5° bending fault

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science China Earth sciences 2012年第6期55卷 869-881页

作者： MA Jin s i sHERMAN GUO Yanshuang state Key Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China institute of the Earth＇s Crust siberian Branch of Russian Academy of sciences lrkutsk 664033 Russia

identification of the meta-instable stress state and study of its mechanism and evolution of relevant physical fields would be of great significance for determination of potential seismic risks and estimation of critical times. in laboratory experiments, that the specimen enters the meta-instable is marked by accelerated stress release. Could we use the experimental result to identify the earthquake in natural conditions? Because the observational data from one station can only reflect the stress state beneath this station, the key problem for identification of the meta-instability is how to recognize regional stress state through observational data from many stations. in this work, we choose the evolution of the temperature field over varied deformation stages during a stick-slip event on a 5 bending fault as an example, and attempt to find the response features of the physical quantity when the fault enters the meta-instable state. We discuss the characteristics of stages for the stress build-up, stress-time process deviating from linearity before instability, meta-instability, instability, and post-instability, respectively. The result shows that the fault instability slide is a conversion process from independent activities of each fault segment to synergism activity. The instability implies completion of the synergism. The stage deviating from linearity is the onset of stress release, and it is also the onset of the synergism. At the meta-instability stages, stress release becomes dominant, while the synergism tends to finish. Therefore, the analysis of the regional overall stress state should not start from individual stations, and instead it should begin with the evolution of the whole deformation field.

关键词： earthquake risk stress state meta-instable state evolution of the temperature field synergism bending fault

Processes underlying the laser photochromic effect in colloidal plasmonic nanoparticle aggregates

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Chinese Physics B 2020年第3期29卷 412-419页

作者： A E Ershov V s Gerasimov i L isaev A P Gavrilyuk s V Karpov institute of Computational Modeling sB RAs 660036KrasnoyarskRussia siberian Federal University Krasnoyarsk660041Russia Kirensky institute of Physics Federal Research Center KSC SB RAS660036KrasnoyarskRussia siberian state University of science and Technology Krasnoyarsk 660014Russia

We have studied the dynamic and static processes occurring in disordered multiparticle colloidal Ag aggregates with natural structure and affecting their plasmonic absorption spectra under pico-and nanosecond pulsed laser radiations, as well as the physical origin responsible for these processes. We have shown that depending on the duration of the laser pulse,the mechanisms of laser modification of such aggregates can be associated both with changes in the resonant properties of the particles due to their heating and melting(picosecond irradiation mode) and with the particle shifts in the resonant domains of the aggregates(nanosecond pulses) which depend on the wavelength, intensity, and polarization of the *** mechanisms result in formation of a narrow dip in the plasmonic absorption spectrum of the aggregates near the laser radiation wavelength and affect the shape and position of the dip. The effect of polydispersity of nanoparticle aggregates on laser photochromic reaction has been studied.

关键词： nanoparticle surface plasmon resonance photochromic process pulsed laser radiation

Near-surface Correction on seismic and Gravity Data

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Journal of Earth science 2015年第6期26卷 851-857页

作者： s.Bychkov i.Y.Mityunina Perm state University Mining Institute of Ural Branch of Russian Academy of Sciences

it is important and urgent to work out better statics correction methods to facilitate seismic prospecting. This paper presents a new method of statics correction calculation based on development of a seismic-gravity model of the near surface. Gravity interpretation includes determination of the local component caused by the near surface effects and calculation of the near-surface rock density by solving the linear inverse gravity problem. To obtain the near-surface velocities, priori seismic data such as time fields of the first waves recorded in the initial part of common depth point（CDP） seismograms are used. An optimal near-surface model is retrieved on the basis of the successive solution of the inverse and forward seismic problems, correlating with the observed seismic data. Matching of seismic and gravity model of the near surface yields the maximum coefficient of correlation between the values of velocities and densities. At the end of the interactive iterative process we get values of the near-surface seismic wave velocities, used for statics evaluation, and values of gravity anomalies, calculated with a variable density of the interbedded layer. The applications of the proposed method at geophysical exploration of oil and gas confirm the possibility of calculation of statics correction using the gravimetric data by constructing a coherent seismic-gravity model of the near surface.

关键词： gravity near-surface velocity seismic-gravity model statics correction.

The performance of activated carbon/NiFe_(2)O_(4) magnetic composite to retain heavy metal ions from aqueous solution

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Chinese Journal of Chemical Engineering 2021年第1期34卷 135-145页

作者： s.i.Moussa M.M.s.Ali Reda R.sheha Nuclear Chem.Dept. Hot Lab CenterAtomic Energy AuthorityCairo 13759Egypt Analytical Chem.Dept. Hot Lab CenterAtomic Energy AuthorityCairo 13759Egypt

A novel magnetic activated carbon composite(AC/NiF) was synthesized by a precipitation method and applied in retention of Cu(Ⅱ),and Zn(Ⅱ) ions from aqueous *** impact of different sorption parameters such as:equilibration time,solution pH value,competing cations and ionic strength on the amount sorbed of Cu(Ⅱ),and Zn(Ⅱ) was *** illustrated that the magnetic composite had retention ability towards both metal ions significantly higher than that of activated carbon(AC).The magnetic composite exhibited an affinity to adsorb Cu(Ⅱ) higher than Zn(Ⅱ) *** maximum sorption capacities(Q_(max)) of the applied magnetic composite(AC/NiF)towards Cu(Ⅱ) and Zn(Ⅱ) were 105.8 and 75.1 mg·g^(-1),*** of Cu(Ⅱ) and Zn(Ⅱ) was proposed to be achieved though an ion exchange and surface adsorption in neutral conditions,while precipitation was believed to be the relevant mechanism in their removal from basic *** kinetic studies showed that sorption process followed the kinetics of pseudo-second-order reactions with rate constant of 3 × 10^(-3) and 2 × 10^(-3) min^(-1)for sorption of Cu(Ⅱ) and Zn(Ⅱ) onto AC/NiF *** of Cu(Ⅱ) slightly decreased with increasing the ionic strength of aqueous solution,using NaCl as a background *** contrast,presence of Mn(Ⅱ),Mg(Ⅱ)and Co(Ⅱ) in reaction solutions highly depressed the sorption of Cu(Ⅱ) and Zn(Ⅱ) with a competing efficiency followed the order:Mg(Ⅱ)> Mn(Ⅱ)> Co(Ⅱ).The magnetic composite was rapidly recovered from aqueous solution by an external magnetic field,and effectively regenerated using 0.1 mol L^(-1) HCl and 0.1 mol L^(-1) FeCl_(3) as *** of Cu(Ⅱ) and Zn(Ⅱ) onto the surface of AC/NiF composite occurred via a spontaneous *** thermodynamically favorable process had ΔH~o values of 30.9 kJ·mol^(-1) and 19.7 kJ·mol^(-1),*** results confirm that the magnetic composite can be viewed as a promising novel composite opens new opportunities f

关键词： Activated carbon Nickel ferrite Composite Mechanism

Data-driven drug repositioning using olfactory omics profiles:challenges and perspectives in neurodegeneration

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Neural Regeneration Research 2025年第7期20卷 1997-1998页

作者： Paz Cartas-Cejudo Adriana Cortés Mercedes Lachén-Montes Elena Anaya-Cubero Joaquín Fernández-irigoyen Enrique santamaría Clinical Neuroproteomics Unit Proteomics PlatformNavarrabiomedHospitalario Universitario de Navarra(HUN)Universidad Pública de Navarra(UPNA)IdiSNANavarra Institute for Health ResearchPamplonaSpain

Data-driven drug repositioning using olfactory omics profiles-challenges and perspectives in neurodegeneration:Neurodegenerative diseases are characterized by progressive degeneration and loss of neuronal function in the central nervous *** diseases are often characterized as proteinopathies,which are disorders primarily driven by the aggregation or misfolding of specific amyloid proteins within cells,leading to their dysfunction and eventual *** the gain-of-function hypothesis related to the aggregation of these proteins,recently,an alternative hypothesis regarding the loss-of-function of the soluble monomeric proteins during the process of aggregation into amyloids is gaining *** last event is called proteinopenia and refers to conditions characterized by a deficiency or decrease in the levels of specific soluble proteins in the body(Ezzat et al.,2023).it has been demonstrated that levels of soluble proteins involved in neurodegenerative diseases are decreased.

关键词： diseases drug amyloid