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Formation of high-silica adakites and their relationship with slab breakoff:Implications for generating fertile Cu-Au-Mo porphyry systems

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Geoscience Frontiers 2024年第6期15卷 454-468页

作者： Fazilat yousefi David R.Lentz Department of earth Sciences University of New BrunswickFrederictonNew Brunswick E3B 5A3Canada

In recent years,the characteristics and sources of fertile adakites has received considerable *** well,most recently the geodynamic environment of convergent margins subducting oceanic crust aiding arc formation,evolving to slab rollback,then slab break-off after collision(***-to post-collisional slab failure(arc-like magmatism)and transpression)has gained more recognition,although their relationship to each other has yet to be *** geochemical characteristics imply that adakites/adakite-like,in particular high-silica adakites(HSA),can form by partial melting of subducting hydrothermally altered oceanic crust in convergent plate boundary settings during the terminal stages of subduction,lithosphere thickening,and then failure(all late to post collisional),while the melting of the mantle wedge during subduction-related dehydration creates more typical calc-alkaline basalt-andesite-dacite-rhyolite series(ADR)to form intraoceanic island arc to intracontinental margin arc systems,before the collisional *** are characterized by high-silica(SiO2>67 wt.%),Al2O3>15 wt.%,Sr>300 ppm,Y50),and La/Yb(>10).Some specific geochemical features,such as high Mg#(ave 0.51),Ni(ave 924 ppm),and Cr(ave 36 ppm),in HSAs are typical,in contrast to calc-alkaline arcs,although both groups display similar but less pronounced negative anomalies of Nb,Ta,and Ti in primitive mantle-normalized trace element spider diagram *** unique geochemical features are likely ascribed to the involvement of garnet,hornblende,and titanite either during partial melting of hydrous MORB-like oceanic crust with only minor assimilation and fractional crystallization(AFC)within the mantle and crustal during ascent in a transpressional collisional *** for origin of HSA derivative from melting in convergent margins from young,hot oceanic plates subducting into the mantle is applicable to only some a

关键词： High-silica adakites Slab break-off Altered oceanic crust Upwelling asthenosphere Fertile Cu-Au-Mo porphyry systems

Identifying porphyry-Cu geochemical footprints using local neighborhood statistics in Baft area, Iran

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Frontiers of earth Science 2021年第1期15卷 106-120页

作者： Saeid GHASeMZADeH Abbas MAGHSOUDI Mahyar yousefi Department of Mining and Metallurgical engineering Amirkabir University of TechnologyTehran 95799-79167Iran Faculty of engineering Malayer UniversityMalayer 65719-95863Iran

Identifying geochemical anomalies related to ore deposition processes facilitates the practice of vectoring toward undiscovered mineral deposit *** districtscale exploration studies,analysis of dispersion patterns of ore-forming elements results in more-reliable ***,deriving significant geochemical footprints and mapping the ensuing geochemical anomalies are of important issues that lead exploration geologists toward anomaly sources,e.g.,*** paper aims to examine the effectiveness of local relative enrichment index and singularity mapping technique,as two methods of local neighborhood statistics,in the delineation of anomalous areas for further exploration.A data set of element contents obtained from stream sediment samples in Baft area,Iran,therefore was applied to illustrate the procedure *** close relationship between anomalous patterns recognized and known Cu-occurrences demonstrated that the procedures proposed can efficiently model complex dispersion patterns of geochemical anomalies in the study *** results showed that singularity mapping method is a better technique,compared to local relative enrichment index,to delineate targets for follow-up exploration in the *** made this comparison because,as pointed out by exploration geochemists,dispersion patterns of geochemical indicators in stream sediments vary in different areas even for the same deposit *** variety in the dispersion patterns is due to the operation of post-mineralization subsystems,which are affected by local factors such as landscape of the areas under ***,the effectiveness of the methods should be evaluated in every area for every targeted deposit.

关键词： local neighborhood statistics robust principal component analysis singularity mapping technique local relative enrichment index exploration targets

Gd impurity effect on the magnetic and electronic properties of hexagonal Sr ferrites: A case study by DFT

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Chinese Physics B 2020年第7期29卷 521-527页

作者： Masomeh Taghipour Mohammad yousefi Reza Fazaeli Masoud Darvishganji Department of Chemistry Science and Research BranchIslamic Azad UniversityTehranIran Department of Chemistry Yadegar-e-Imam Khomeni(RAH)shahr-e-Rey BranchIslamic Azad UniversityTehranIran Department of Chemistry South Tehran BranchIslamic Azad UniversityTehranIran Department of Chemistry Qaemshahr BranchIslamic Azad UniversityQaemshahrIran

The electronic and magnetic properties of strontium hexa-ferrite(SrFe12O19)are studied in pure state(SrFe12O19)and with dopant in the positions 2 and 3 of Fe atoms(SrGdFe11O19-I and SrGdFe11O19-Ⅱ,respectively)by utilizing a variety of the density functional theory(DFT)approaches including the Perdew-Burke-ernzerhof generalized gradient approximation(PBe-GGA)and GGA plus Hubbard U parameter(GGA+U).The pure SrFe12O19 is a hard magnetic half-metal with an integer magnetic moment of 64.00μB,while using the GGA+U functional,the magnetic intensity increases,resulting in a magnetic semiconductor with a high integer magnetic moment of 120μ*** doping the Gd atom in the two different positions of Fe,the magnetic moment is increased to 71.68μB and 68.00μB,*** magnetic moment increases and remains an integer;hence,SrGdFe11O19-Ⅱcan be very useful for application in magnetic ***,applying the Hubbard parameter turns SrGdFe11O19-I and SrGdFe11O19-Ⅱto magnetic semiconductors with a magnetic moment of 124μB,and the energy gap of both doped structures at spin down is found to be less than the pure *** studying the electronic density diagram of the atoms of the crystal,it is found that the major effect to create magnetization in the pure case is due to the Fe ***,in the doped case,the elements Gd and Fe have the highest moment in the crystal respectively.

关键词： magnetic properties density functional theory half-metal doping

Modeling of two-phase particulate flows in a confined jet with a focus on two-way coupling

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Particuology 2018年第4期16卷 78-87页

作者： Babak yousefi-Lafouraki Abas Ramiar Ali Akbar Ranjbar Faculty of Mechanical engineering Semnan University lran Faculty of Mechanical engineering Babol Noshirvani University of Technology Iran

A computational fluid dynamics model is used for the simulation of laminar flow ofwater-Al2O3 nanofluid in a confined slot impinging jet. The （steady-state and two-dimensional） eulerian-Lagrangian model is used considering fluid-particle and particle-wall interactions （i.e., two-way coupling）. A collocated grid and the SIMPLe algorithm are used for the coupling of pressure and velocity fields. The deposition model is used to investigate the effect of particle deposition on the impingement surface. Results indicate that the particle trajectory becomes stable farther from the jet with a rising Reynolds number and jet- impingement surface distance ratio. The heat transfer coefficient of the mixture model is higher than that of the eulerian-Lagrangican model.

关键词： eulerian-Lagrangian approach Two-way coupling Particle tracing Mixture model

Influence of growth conditions on the electrochemical synthesis of SnS thin films and their optical properties

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International Journal of Minerals,Metallurgy and Materials 2016年第3期23卷 348-357页

作者： Hosein Kafashan Farid Jamali-Sheini Reza ebrahimi-Kahrizsangi Ramin yousefi Advanced Materials Research Center Materials Engineering DepartmentNajafabad BranchIslamic Azad UniversityNajafabadIsfahanIran Department of Physics Ahvaz BranchIslamic Azad UniversityAhvazIran Department of Physics Masjed-Soleiman BranchIslamic Azad University(I.A.U)Masjed-SoleimanIran

Tin sulfide （SnS） thin films were prepared by electrodeposition onto fluorine-doped tin oxide （FTO） glass substrates using an aqueous solution containing SnCl2 and Na2S2O3 at various deposition potentials （L） and bath concentrations. The pH value and temperature of the solution were kept constant. The deposited films were characterized using X-ray diffraction （XRD）, field-emission scanning electron microscopy （FeSeM）, photoluminescence （PL）, and ultraviolet-visible （UV-Vis） spectroscopy. The FeSeM images demonstrated that changes in the deposition potential （e） and solution concentration led to marked changes in the morphology of the deposited SnS films. energy-dispersive X-ray analysis （eDXA） results showed that the SrdS atomic ratio strongly depended on both the solution concentration and the deposition potential. To obtain an SrdS atomic ratio approximately equal to l, the optimal Sn2＋/S2O2- 3 molar ratio and e parameter were 1/8 and -1.0 V, respectively. The XRD patterns showed that the synthesized SnS was obviously polycrystalline, with an orthorhombic structure. The effects of the variations of bath concentration and deposition potential on the band-gap energy （eg） were studied using PL and UV-Vis experiments. The PL spectra of all the SnS films contained two peaks in the visible region and one peak in the infrared （IR） region. The UV-Vis spectra showed that the optical band-gap energy varies from 1.21 to 1.44 eV.

关键词： tin sulfide thin films electrodeposition structural properties optical properties

Directly Simulation of Second Order Hyperbolic Systems in Second Order Form via the Regularization Concept

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Communications in Computational Physics 2016年第6期20卷 86-135页

作者： Hassan yousefi Seyed Shahram Ghorashi Timon Rabczuk Division of Computational Mechanics Ton Duc Thang UniversityHo Chi Minh CityViet Nam a2 Institute of Structural Mechanics Bauhaus-Universitat Weimar99423 WeimarGermany Research Training Group 1462 Bauhaus-UniversitatWeimar99423WeimarGermany Faculty of Civil engineering Ton Duc Thang UniversityHo Chi Minh CityViet Nam.

We present an efficient and robustmethod for stresswave propagation problems(second order hyperbolic systems)having discontinuities directly in their second order *** to the numerical dispersion around discontinuities and lack of the inherent dissipation in hyperbolic systems,proper simulation of such problems are *** proposed idea is to denoise spurious oscillations by a post-processing stage from solutions obtained from higher-order grid-based methods(e.g.,high-order collocation or finite-difference schemes).The denoising is done so that the solutions remain higher-order(here,second order)around discontinuities and are still free from spurious *** this purpose,improved Tikhonov regularization approach is *** means to let data themselves select proper denoised solutions(since there is no pre-assumptions about regularized results).The improved approach can directly be done on uniform or non-uniform sampled data in a way that the regularized results maintenance continuous derivatives up to some desired *** is shown how to improve the smoothing method so that it remains conservative and has local estimating *** confirm effectiveness of the proposed approach,finally,some one and two dimensional examples will be *** will be shown how both the numerical(artificial)dispersion and dissipation can be controlled around discontinuous solutions and stochastic-like results.

关键词： Second order hyperbolic systems Tikhonov regularization Numerical(artificial)dispersion

Phylogenetic relationship and genetic differentiation of Populus caspica and Populus alba using cpDNA and ITS noncoding sequences

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Journal of Forestry Research 2019年第2期30卷 451-461页

作者： Hamed Yousefzadeh Abasalt Hosseinzadeh Colagar effat yousefi Maryam Badbar Gregor Kozlowski Department of environmental Science Faculty of Natural Resources Tarbiat Modares University Department of Molecular and Cell Biology Faculty of Basic Science University of Mazandaran Department of Biology and Botanic Garden University of Fribourg

Populus caspica Bornm.(section Leuce and subsection Albida), one of the most endangered endemic tree species in the Hyrcanian Forest in Iran, has numerous morphological characteristics that are closely similar to Populus alba; to clarify their taxonomic relatedness and genetic differentiation and thus inform conservation strategies, we used the noncoding regions of chloroplast DNA(cpDNA; trnL-F and trnH-psbA) and the internal transcribed spacer(ITS). Leaf samples were collected from six populations across northern Iran. cpDNA and ITS fragments were amplified by universal primers using the PCR technique and directed sequencing. The results showed that P. caspica is genetically differentiated from ***, and two ITS variants were detected within some *** individuals. Conflicts between topologies from ITS and plastid genomes were observed. High differentiation of P. caspica from the other Populus species shown in this study confirmed the diverging taxonomic status of this endangered species. We recommend in situ conservation measures(e.g., protected areas) for at least several populations of this species, especially in the plain regions of the Hyrcanian forest.

关键词： endangered endemic species DNA barcoding Hyrcanian forest Taxonomic status

Novel azo dyes derived from 8-methyl-4-hydroxyl-2-quinolone:Synthesis,UV-vis studies and biological activity

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Chinese Chemical Letters 2013年第5期24卷 425-428页

作者： e.O.Moradi Rufchahi H.Pouramir M.R.Yazdanbakhsh H.yousefi M.Bagheri M.Rassa Department of Chemistry Faculty of ScienceLahijan BranchIslamic Azad University Department of Chemistry Faculty of SciencesUniversity of Guilan Department of Biology Faculty of SciencesUniversity of Guilan

In this study,N,N＇-di-（2-methylphenyl）malonamide was synthesized and reacted with polyphosphoric acid to afford *** novel azo disperse dyes were then synthesized by linking diazotized p-substituted aniline derivatives with *** solvatochromism of these azo dyes in various solvents was *** the compounds were then evaluated for their antibacterial activity against four bacteria,*** *** luteus, Salmonella enterica,and Pseudomonas *** results showed that some of these compounds have high levels of antibacterial activity.

关键词： Azo dyes Disperse dyes Hydroxyl quinolone Absorption spectrum Antibacterial studies

A 1.8 GHz Power Amplifier Class-e with Good Average Power Added efficiency

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Circuits and Systems 2013年第8期4卷 504-509页

作者： Mousa yousefi Ziaadin Daie Koozehkanani Jafar Sobhi Hamid Jangi Faculty of electrical and Computer engineering University of Tabriz Tabriz Iran

This paper presents a 1.8 GHz class-e controlled power amplifier (PA). The proposed power amplifier is designed with two-stage architecture. The main advantage of the proposed technique for output control power is a high 37 dB output power dynamic range with good average power adding efficiency. The measurement results show that the PA achieves a high power gain of 23 dBm and power added efficiency (PAe) by 38%. The circuit was post layout simulated in a standard 0.18 μm CMOS technology.

关键词： Power Added efficiency Power Amplifier Class-e Dynamic Range Polar Modulation Output Power