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Tb^(3+)substituted strontium hexaferrites:Structural,magnetic and optical investigation and cation distribution

Journal of Rare Earths 2020年第4期38卷 402-410页

作者： m.A.Almessiere Y.Slimani H.Gungunes m.Sertkol m.Nawaz N.A.Algarou A.Baykal I.Ercan Department of Biophysics Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.O.Box 198231441 DammamSaudi Arabia Department of physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 198231441 DammamSaudi Arabia Department of physics Hitit University19030Cevre Yolu Bulvari-CorumTurkey Deanship of preparatory Year Imam Abdulrahman Bin Faisal UniversityP.O.Box 198231441 DammamSaudi Arabia Department of Nanomedicine Research Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.O.Box 198231441 DammamSaudi Arabia

In this study,SrFe12-xTbxO19(0.00≤x≤0.1)hexaferrites(HFs)were prepared successfully by citrate solgel approach.X-ray powder diffraction analyses affirm the hexagonal structure of *** phase starts to appear for x≥*** crystallites sizes were estimated to be in the range of 33-46 *** the products exhibit inhomogeneous distribution of grain size detected through *** analyses of magnetization versus applied magnetic field,m(H),were *** measurements were done at room(300 K;RT)and low(10 K)*** different magnetic parameters including saturation magnetization ms,remanence mr,squareness ratio(SQR=mr/ms),coercivity Hc,and magnetic moment nB are deduced and discussed in *** both considered temperatures,m(H)results show ferrimagnetic nature for all *** is shown that the Tb substitutions significantly affect m(H)data.A significant increase in the ms,mr,and nB is observed for x=0.02 *** SQR values are around 0.5 indicating the single domain nature with uniaxial *** obtained magnetic results were investigated deeply with relation to structural and microstructural *** spectroscopy results were also *** to mossbauer results,the Tb3+ions preferentially occupy 12 k and 4f2 sites.

关键词： m-type hexaferrites Structure mossbauer spectroscopy Optical properties magnetization Rare earths

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THE BLOCH SpACE ON THE UNIT BALL OF A HILBERT SpACE: mAXImALITY AND mULTIpLIERS

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Acta mathematica Scientia 2021年第3期41卷 899-906页

作者： pablo GALINDO mikael LINDSTRÖm Departamento de Análisis matemático Universidad de Valencia.C/Dr.Moliner 50.46.100BurjasotValenciaSpain Department of mathematics Abo Akademi University.FI-20500ÅboFinland

We prove that, as in the finite dimensional case, the space of Bloch functions on the unit ball of a Hilbert space contains, under very mild conditions, any semi-Banach space of analytic functions invariant under automorphisms. The multipliers for such Bloch space are characterized and some of their spectral properties are described.

关键词： Analytic functions on Hilbert space invariance under automorphisms multiplier

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Changes in soil organic carbon,nitrogen and sulphur along a slope gradient in apple orchard soils of Kashmir Himalaya

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Journal of mountain Science 2021年第9期18卷 2377-2387页

作者： Javaid m DAD Lotfollah ABDOLLAHI Department of Botany University of KashmirHazratbalSrinagar(J&K)India Faculty of Agriculture Payame Noor UniversityTehranP.O.Box 19395-3697Iran

Accumulation and losses of soil organic carbon(SOC),total nitrogen(TN)and sulphur(S)influence food security and global ***,their spatial distribution and variability at regional scale,and their relation to topographical variables are of great *** this study,the variability of SOC,TN and S content was evaluated in apple orchard soils of Kashmir region,at three depths(D1:0-10,D2:10-20,and D3:20-30 cm)on slope gradient i.e.:flat,medium,and *** an increase in slope,a significant decrease of SOC and TN was observed,with concentration of SOC and TN recorded highest(14.3±2.06 g kg-1&0.97±0.35 g kg-1)in flat slope orchards and lowest(9.6±2.07 g kg-1&0.84±0.41 g kg-1)in high slope *** stock basis,the values recorded for flat,medium,and high slope orchards,for SOC and TN were 54.62±4.24 mg ha-1&0.38±0.06 mg ha-1,44.13±5.11 mg ha-1&0.32±0.09 mg ha-1,and 38.73±5.94 mg ha-1&0.28±0.10,*** differences for S concentration and stocks were modest,with flat(0.21±0.15 mg kg-1&0.09±0.0.003 mg ha-1)>high(0.16±0.07 mg kg-1&0.06±0.007 mg ha-1)>medium(0.12±0.04 mg kg-1&0.075±0.009 mg ha-1).Across slopes,SOC,TN and S decreased with increasing soil depth,suggesting clear downward ***,SOC and TN increased with the increase of altitude,precipitation and clay content while its relationship with soil acidity and soil bulk density was *** findings may provide scientific basis to structure agricultural development plans or prioritize regions for soil conservation efforts.

关键词： Apple orchards Slope Soil organic carbon Sulphur Total nitrogen Soil bulk density

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Textural changes in metallurgical coke prepared with polyethylene

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International Journal of minerals,metallurgy and materials 2014年第10期21卷 969-973页

作者： Stanislav S.Gornostayev Jyrki J.Heino Tommi m.T.Kokkonen Hannu T.makkonen Satu m.m.Huttunen Timo m.J.Fabritius Laboratory of process metallurgy University of Oulu

The effect of high-density polyethylene （HDpE） on the textural features of experimental coke was investigated using polar- ized-light optical microscopy and wavelet-based image analysis. metallurgical coke samples were prepared in a laboratory-scale furnace with 2.5%, 5.0%, 7.5%, 10.0%, and 12.5% HDpE by mass, and one sample was prepared by 100% coal. The amounts and distribution of textures （isotropic, mosaic and banded） and por^s were obtained. The calculations reveal that the addition of HDpE results in a decrease of mosaic texture and an increase of isotropic texture. Ethylene formed from the decomposition of HDpE is considered as a probable reason for the texture modifications. The approach used in this study can be applied to indirect evaluation for the reactivity and strength of coke.

关键词： metallurgical coke texture image analysis polyethylene

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Induction plasma spheroidization of tungsten and molybdenum powders

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中国有色金属学会会刊：英文版 2006年第1期16卷 13-17页

作者：蒋显亮 m.BOULOS Institute of Surface and Coatings Technology School of Materials Science and Engineering Central South University Changsha 410083 China plasma Technology Research Center University of Sherbrooke Sherbrooke J1K 2R1 Canada

The melting, evaporation and oxidation behaviors as well as the solidification phenomena of tungsten and molybdenum in induction plasma were studied. Scanning electron microscopy was used to examine the morphology and the cross section of plasma-processed powders. X-ray diffraction was used to analyze the oxides formed on the particle surface of these two metals. The influence of spray chamber pressure on the spheroidization and oxidation phenomena was discussed. The results show that fewer mo particles than W particles are spheroidized at the same powder feed rate under the same plasma spray condition although molybdenum has a lower melting point. A small fraction of tungsten is evaporized and condensed either on the surface of tungsten particles nearby or on the wall of spray chamber. Tungsten oxides were found in tungsten powder processed under soft vacuum condition. Extremely large grains form inside some spheroidized particles of tungsten powder.

关键词：球化处理钨粉钼粉熔炼蒸发氧化等离子体冶金

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Effect of Electroplating parameters on microstructure of Nanocrystalline Nickel Coatings

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Journal of materials Science & Technology 2010年第1期26卷 82-86页

作者： A.m. Rashidi A. Amadeh Faculty of Engineering Razi University School of metallurgy & materials Engineering University College of Engineering University of Tehran

In order to achieve the optimum conditions for electroplating nanocrystalline nickel coating from Watts-type bath, the effect of some process parameters namely, bath temperature, current density, and saccharin addition on grain size and texture coefficient （TC= I（200）/I（111）） of the deposits were investigated by X-ray diffraction （XRD）. The results showed that in a bath containing 5 g/L saccharin, by increasing the bath temperature from 45℃ to 55℃, the grain size decreased, whereas further increase of bath temperature resulted in a contrary effect. By increasing the current density from 10 to 75 mA/cm^2, both the grain size and TC decreased, while further increase in current density had no significant effect on the grain size. At a given current density, the grain size and TC decreased rapidly by increasing the saccharin content before leveling off at 3 g/L of saccharin. Finally, based on the grain refining the optimum conditions for producing nanocrystalline nickel coating from Watts-type bath have been proposed.

关键词： Electroplating Grain size Nanocrystalline Coating

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Accretion onto the magnetically Charged Regular Black Hole

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Chinese physics Letters 2017年第7期34卷 38-40页

作者： m.Azam A.Aslam Division of Science and Technology University of Education Lahore 54590 Pakistan

We investigate the accretion process for static spherically symmetric geometry, i.e., magnetically charged regular black hole with isotropic fluid. W＇e obtain generalized expressions for the velocity （u（r））, speed of sound （cs2）, energy density （ρ（r）） and accretion rate （m） at the critical point near the regular black hole during the accretion process. We also plot these physical parameters against fixed values of charge, mass and different values of equation of state parameter to study the process of accretion. We find that radial velocity and energy density of the fluid remain positive and negative as well as rate of change of mass is increased and decreased for dust, stiff, quintessence fluid and phantom-like fluid, respectively.

关键词： Accretion onto the magnetically Charged Regular Black Hole

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Synthesis,structure and spectroscopic studies of europium complex with S(+)-mandelic acid

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Journal of Rare Earths 2011年第12期29卷 1188-1191页

作者： m.Babij A.mondry Faculty of Chemistry University of Wrocaw

The Eu^3＋ complexes with S（＋）-mandelic acid were synthesized in the form of powders by mixing aqueous solutions of EuCl3, S（＋）-mandelic acid and NaOH in different molar ratios. The powders were characterized by elemental analysis, X-ray powder diffraction （XRpD.） method, Fourier transform infrared （FTIR） and Raman spectroscopy, UV-vis reflectance and luminescence spectra as well as luminescence lifetime measurements. It was found that all studied powders of Eu^3＋ complexes with S（＋）-mandelic acid were isostructural and crystalline and formed compounds with the formula Eu（man）3（H2O）2.

关键词： europium mandelic acid emission FTIR spectroscopy Raman sDectroscopy rare earths

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Use of the area of main influence to fix a relevant boundary for mining damages in Germany

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International Journal of mining Science and Technology 2018年第1期28卷 79-83页

作者： Denise müller Axel preusse Faculty of Georesources and materials Engineering Institute for Mine Surveying Mining Subsidence Engineering and Geophysics in Mining RWTH Aachen University

In 2010, the fracking discussion in Germany caused a number of changes in German law, which came into force in *** the production of gas had to be *** the legislation amendment, the Subsidence-Area mining Regulation has been revised, *** changes expand the compensation of mining damages, especially to the extraction with drilling from the surface and underground *** the Subsidence-Area mining Regulation has been revised, the area of main influence(subsidence of 10 cm)remains to determine a relevant boundary for mining *** determination and prediction of this boundary above caverns are presented in this *** addition, further elements of ground movements and their relevance to mine damages are *** usage of the area of main influence to fix a relevant boundary for mining damages does not correspond to the relevant elements of ground movements.A limit for differences in subsidence(tilt) or horizontal changes in length should be preferred to describe the relevance of mining damages on ***, this paper outlines the meaning of using the area of main influence to fix a relevant boundary for mining damages.

关键词： Ground movements Area of main influence Boundary for mining damages Subsidence-area mining regulation Subsidence detection modeling above caverns

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细分图的Wiener多项式(英文)

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工程数学学报 2011年第3期28卷 411-418页

作者： p.S.Ranjini V.Lokesha m.A.Rajan 堂波斯考技术学院数学系 Acharya技术学院数学系塔塔信息技术有限公司

本文研究做为最古老的基于距离的拓朴指标之一—Wiener指标.对于Tadpole图Tn,k,循环图Cn,轮式图Wn+1和Helm图Hn+1,文中分别导出了它们的细分图的Wiener多项式的表达式.

关键词： Wiener多项式细分图 Tadpole图轮式图 Helm图

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