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Two-photon reduction： a cost-effective method for fabrication of functional metallic nanostructures

Science China(Physics,Mechanics & Astronomy) 2017年第3期60卷 25-41页

作者： sahar Tabrizi YaoYu Cao Han Lin BaoHua Jia Centre for Micro-Photonics Faculty of Science Engineering and Technology Swinburne University of Technology Hawthorn Victoria 3122 Australia

Metallic nanostructures have underpinned plasmonic-based advanced photonic devices in a broad range of research fields over the last decade including physics, engineering, material science and bioscience, The key to realizing functional plasmonie resonances that can manipulate light at the optical frequencies relies on the creation of conductive metallic structures at the nanoscale with low structural defects. Currently, most plasmonic nanostructures are fabricated either by electron beam lithography （EBL） or by focused ion beam （FIB） milling, which are expensive, complicated and time-consuming. In comparison, the direct laser writing （DLW） technique has demonstrated its high spatial resolution and cost-effectiveness in three-dimensional fabrication of micro/nanostrucmres. Furthermore, the recent breakthroughs in superresolution nanofabrication and parallel writing have significantly advanced the fabrication resolution and throughput of the DLW method and made it one of the promising future nanofabrication technologies with low-cost and scalability. In this review, we provide a comprehensive summary of the state-of-the-art DLW fabrication technology for nanometer scale metallic structures. The fabrication mechanisms, different material choices, fabrication capability, including resolution, conductivity and structure surface smoothness, as well as the characterization methods and achievable devices for different applications are presented. In particular, the development trends of the field and the perspectives for future opportunities and challenges are provided at the end of the review. It has been demonstrated that the quality of the metallic structures fabricated using the DLW method is excellent compared with other methods providing a new and enabling platform for functional nanophotonic device fabrication.

关键词： two photon photoreduction metallic nanostructures nanofabrication plasmonics

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Neotectonics of the Avaj region(NW Iran): left-lateral strike-slip and range-parallel reverse faults

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Journal of Mountain Science 2020年第4期17卷 838-850页

作者： Reza alIPOOR Amir Hossein SADR sahar GHAMARIAN Geology Department Faculty of Basic ScienceBu-Ali Sina UniversityHamedan 009881Iran

The aim of this study is the geomorphological analysis of neotectonic deformation in the Avaj region in the NW part of the Iranian Plateau. We use observations from detailed field surveys and the analysis of digital elevation model(DEM) and satellite images(Landsat-7 ETM+, 30-m resolution) to explore a new E-W trending strike-slip fault system in the study area. The major active faults of the Avaj region are the NW-SE trending Avaj and Hassanabad fault zones. The Avaj Fault is a SWdipping reverse fault with a transport toward NE and the Hassanabad Fault is a NE-dipping reverse fault that has moved Paleozoic rocks over Cenozoic sedimentary units. Moreover, there are some E-W trending left-lateral strike-slip faults which cut Late Quaternary deposits. The relationship between the NW-SE and E-W faults indicates that the slip at the termination of the NW-SE faults changes from reverse to left-lateral strike-slip faults. The activity of the left-lateral faults has formed a series of offsets and displacements in drainage paths. These left-lateral faults probably initiated in 5±2 Ma because of the convergence between the Central Iran and the South Caspian blocks.

关键词： Active tectonic Offset Earthquake Geomorphology Avaj Fault South Caspian

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A narrative overview of utilizing biomaterials to recapitulate the salient regenerative features of dental-derived mesenchymal stem cells

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International Journal of Oral Science 2021年第2期13卷 117-128页

作者： Sevda Pouraghaei Sevari sahar Ansari alireza Moshaverinia Weintraub Center for Reconstructive Biotechnology Division of Advanced ProsthodonticsSchool of DentistryUniversity of CaliforniaLos AngelesLos AngelesCAUSA California NanoSystems Institute University of CaliforniaLos AngelesLos AngelesCAUSA

Tissue engineering approaches have emerged recently to circumvent many limitations associated with current clinical *** elegant approach utilizes a natural/synthetic biomaterial with optimized physiomechanical properties to serve as a vehicle for delivery of exogenous stem cells and bioactive factors or induce local recruitment of endogenous cells for in situ tissue *** by the natural microenvironment,biomaterials could act as a biomimetic three-dimensional(3D)structure to help the cells establish their natural *** a strategy should not only employ a biocompatible biomaterial to induce new tissue formation but also benefit from an easily accessible and abundant source of stem cells with potent tissue regenerative *** human teeth and oral cavity harbor various populations of mesenchymal stem cells(MSCs)with self-renewing and multilineage differentiation *** the current review article,we seek to highlight recent progress and future opportunities in dental MSC-mediated therapeutic strategies for tissue regeneration using two possible approaches,cell transplantation and cell ***,this paper develops a general picture of current innovative strategies to employ dental-derived MSCs combined with biomaterials and bioactive factors for regenerating the lost or defective tissues and offers information regarding the available scientific data and possible applications.

关键词： biomaterials utilizing utilize

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Dysprosium cerate nanostructures:facile synthesis,characterization,optical and photocatalytic properties

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Journal of Rare Earths 2017年第8期35卷 805-812页

作者： Zahra Salehi sahar Zinatloo-Ajabshir Masoud Salavati-Niasari Institute of Nano Science and Nano Technology University of Kashan Young Researchers and Elites Club Arak BranchIslamic Azad University

A facile approach was developed to prepare Dy2Ce2O7 nanostructures. Dy2Ce2O7 nanostructures were prepared by applying cerium（IV） ammonium nitrate and dysprosium nitrate as Ce and Dy precursors. It was found that the kind of connecting agent, space-filling template and chelating agent were significant factors for the control in shape and size. Transmission electron microscopy（TEM）, X-ray diffraction（XRD）, diffuse reflectance UV-vis spectroscopy（DR-UV-vis）, field emission scanning electron microscopy（FESEM）, photoluminescence spectroscopy（PL） and energy dispersive X-ray microanalysis（EDX） techniques were applied to characterize the Dy2Ce2O7 nanostructures and investigate their optical characteristics. To examine the photocatalytic activity of as-produced Dy2Ce2O7 nanostructures, the photocatalytic degradation of erythrosine dye as water pollutant was carried out. The results of the photocatalytic investigations suggest as-obtained nano-sized Dy2Ce2O7 product as a new, proper and efficient candidate for photocatalytic usages under UV illumination.

关键词： dysprosium cerate nanostructures photocatalyst rare earths optical properties

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Effect of buried plates on scour profiles downstream of hydraulic jump in open channels with horizontal and reverse bed slopes

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Water Science and Engineering 2016年第4期9卷 329-335页

作者： Akram Abbaspour sahar Parvini ali Hosseinzadeh Dalir Department of Water Engineering University of Tabriz

Local scour downstream of sluice gates in erosive beds is one of the main concerns of hydraulic engineers because it can cause considerable damage to *** researchers have conducted various studies to predict the maximum depth and length of scour holes and to develop new methods to control this *** the methods that have recently been examined,embedded buried plates are used to control the scour in the erosive *** this study,using a physical model,the effect of buried plates in erosive beds on the depth of scour downstream of a hydraulic jump was *** experiments were performed in which plates were buried at 50° and 90° angles at different distances from the apron in open channels with horizontal and reverse bed *** results of experiments in which the scour profiles were drawn in dimensionless forms show that the angle and position of the plates are important to controlling and reducing scour *** fact,by reducing the angle of buried plates,the maximum depth of scour is also ***,comparison of the results of a single buried plate and double buried plates shows that using two buried plates at the distances of 30 and 45 cm from the non-erodible bed is more effective in reducing the scour *** best distances of the buried plates with angles of 90° and 50° from the non-erodible bed are 45 cm and 30 cm,respectively,in the condition with a single buried plate.

关键词： Local scour Buried plates Hydraulic jump Horizontal and reverse bed slopes

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Illumination and Voltage Dependence of Electrical Characteristics of Au/0.03 Graphene-Doped PVA/n-Si Structures via Capacitance/Conductance-Voltage Measurements

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Chinese Physics Letters 2015年第11期32卷 92-96页

作者： sahar alialy AHMET Kaya I Uslua EMSETTIN altmdal physics Department Faculty of Sciences Gazi University Ankara 06500 Turkey Opticianry Department Vocat Sch IVied Sci 7hrkey Turgut Ozal University Ankara 78050 Turkey Department of Chemistry Education Faculty of Education GazJ University Ankara 06500 Turkey

Au/n-Si （MS） structures with a high dielectric interlayer （0.03 graphene-doped PVA） are fabricated to investigate the illumination and voltage effects on electrical and dielectric properties by using capacitance-voltage （C-V） and conductance-voltage （G/w-V） measurements at room temperature and at 1 MHz. Some of the main electrical parameters such as concentration of doping atoms （ND）, barrier height （ ФB（ C - V））, depletion layer width （WD） and series resistance （Rs） show fairly large illumination dispersion. The voltage-dependent profile of surface states （Nss） and resistance of the structure （Ri ） are also obtained by using the dark-illumination capacitance （Cdark- Cm） and Nicollian-Brews methods, respectively, For a clear observation of changes in electrical parameters with illumination, the values of ND, WD, ФB（O- V） and Rs are drawn as a function of illumination intensity. The values of ND and WD change almost linearly with illumination intensity. On the other hand, Rs decreases almost exponentially with increasing illumination intensity whereas ФB（C - V） increases. The experimental results suggest that the use of a high dielectric interlayer （0.03 graphene-doped PVA） considerably passivates or reduces the magnitude of the surface states. The large change or dispersion in main electrical parameters can be attributed to generation of electron-hole pairs in the junction under illumination and to a good light absorption. all of these experimental results confirm that the fabricated Au/0.03 graphene-doped PVA/n-Si structure can be used as a photodiode or a capacitor in optoelectronic applications.

关键词： Si PVA Illumination and Voltage Dependence of Electrical Characteristics of Au/0.03 Graphene-Doped PVA/n-Si Structures via Capacitance/Conductance-Voltage Measurements

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An evaluation of central Iran’s protected areas under different climate change scenarios (A Case on Markazi and Hamedan provinces)

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Journal of Mountain Science 2020年第1期17卷 68-82页

作者： Peyman KARAMI sahar REZAEI Shabnam SHADLOO Morteza NADERI Department of Environmental Sciences Faculty of Natural Resources and Environment SciencesMalay er UniversityMalayer65719-95863HamedanIran Department of Environmental Sciences Faculty of Natural Resources and Environment SciencesUniversity of GuilanSowmehsara419961-3778GuilanIran Department of Environmental Sciences Faculty of Agriculture and Natural SciencesArak UniversityArak 38156-8-8349Iran

Global climate change poses a new challenge for species and can even push some species toward an extinction vortex. The most affected organisms are those with narrow tolerance to the climatic factors but many large mammals such as ungulates with a wider ecological niche are also being affected indirectly. Our research mainly used wild sheep in central Iran as a model species to explore how the suitable habitats will change under different climatic scenarios and to determine if current borders of protected areas will adequately protect habitat requirements. To create habitat models we used animal-vehicle collision points as an input for species presence data. We ran habitat models using Max Ent modeling approach under different climatic scenarios of the past, present and future(under the climatic scenarios for minimum(RCP2.6) and maximum(RCP8.5) CO2 concentration trajectories). We tried to estimate the overlap and the width of the ecological niche using relevant metrics. In order to analyze the effectiveness of the protected areas, suitable maps were concerted to binary maps using True Skill Statistic(TSS) threshold and measured the similarity of the binary maps for each scenario using Kappa index. In order to assess the competence of the present protected areas boundary in covering the distribution of species, two different scenarios were employed, which are ensemble scenario 1: an ensemble of the binary maps of the species distribution in Mid-Holocene, present, and RCP2.6;and ensemble scenario 2: an ensemble of binary suitability maps in Mid-Holocene, present, and RCP8.5. Then, the borders of modeled habitats with the boundaries of 23 existing protected areas in two central provinces in Iran were compared. The predicted species distribution under scenario 1(RCP2.6) was mostly similar to its current distribution(Kappa = 0.53) while the output model under scenario 2(RCP8.5) indicated a decline in the species distribution range. Under the first ensemble scenario, curr

关键词： Climatic Scenarios Species Distribution Modeling Protected area Niche modeling Wild Sheep

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Effect of pyrite content of feed and configuration of locked particles on rougher flotation of copper in low and high pyritic ore types

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International Journal of Mining Science and Technology 2018年第2期28卷 167-176页

作者： sahar Agheli Ahmad Hassanzadeh Behzad Vaziri Hassas Mohammad Hasanzadeh Mining Engineering Department Shahid Bahonar University of Kerman Faculty of Mines Mineral Processing Engineering Department Istanbul Technical University Department of Mineral Resources Engineering Montan University of Leoben College of Mines and Earth Science University of Utah Drug Applied Research Center Tabriz University of Medical Sciences

Misreported pyrite into copper concentrates dramatically declines copper grade and recovery. Copper flotation can be also more complicated if flotation feed comes from an elevated-pyritic copper ore. In this investigation, the effect of two different ore types(high pyritic and low pyritic feeds) was studied on rougher stage of industrial copper flotation circuit. Samples were taken from different streams and the structure of chalcopyrite within the pyrite and non-sulfide gangue minerals was examined in various size fractions for mentioned ore types. Results indicated that 72% and 56% of the total floated pyrite was transferred to concentrate in first four cells in the low and high pyritic feeds, respectively. Whereas, this proportion for floated SiO_2 in last ten cells was detected as 72% and 71%, respectively. A detailed interpretation of the effect of locked particles in different size fractions on rougher flotation cells is studied from industrial point of view.

关键词： Liberation degree High pyritic feed Pyrite Froth flotation Chalcopyrite

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Evaluating organic acids as alternative leaching reagents for rare earth elements recovery from NdFeB magnets

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Journal of Rare Earths 2023年第4期41卷 621-631页

作者： sahar Belfqueh alain Seron Simon Chapron Guilhem Arrachart Nourredine Menad BRGM Direction de l'Eaude l'Environnementdes Procédés et AnalysesOrleansFrance ICSM Univ.MontpellierCEACNRSENSCMMarcouleFrance

This study proposes an advanced leaching method using organic acids to recover rare earth elements(REEs)from NdFeB permanent magnets from end-of-life computers hard disk drives(HDDs).The end-oflife HDDs were first dismantled in order to recover NdFeB magnets,which were then thermally demagnetized at 350℃during 30 min before crushing in a ball mill under inert *** electron microscopy/energy dispersive X-ray spectroscopy(SEM/EDS)analyses performed on the NdFeB magnets show the heterogeneous structure containing the major matric phase Nd_(2)Fe_(14)B and the REEsrich phase containing Nd and Pr ***,X-ray diffraction(XRD)and Mossbauer spectroscopy(MS)analyses on the ground NdFeB magnet show that grinding NdFeB magnets under inert atmosphere helps to minimize its *** analysis shows that the composition of the ground sample is Nd:22.8 wt%,Pr:3.3 wt%,Dy:1.2 wt%,Fe:62.6 wt%,Co:1.5 wt%,B:0.9 wt%,Ni:0.6 wt%.Diagrams of speciation and equilibrium phases(E_(h) ***)were calculated to determine the predominance of the formed species in the REEs-organic acids *** influence of the organic acid type(acetic acid,formic acid,citric acid and tartaric acid),the acid concentration(10 vol%,up to saturation),and the solid/liquid(S/L)ratio(0.5%-10%)on NdFeB magnets leaching was investigated employing an optimal experimental design conceived by the statistical software *** acid(CH_(3)COOH)shows the highest leaching performance of REEs,allowing leaching yields over 90%for Nd,Dy and Pr in the acid concentration range of 1.6-10 mol/L and the S/L ratio range of 0.5%-5%at a temperature of 60℃.The results presented in this investigation suggest that REEs can be recovered from magnets of end-of-life HDDs using an eco-friendly method assisted by organic acids.

关键词： NdFeB magnets Rare earth elements Leaching Organic acids Acetic acid

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Effect of probiotics on pro-inflammatory cytokines and NF-κB activation in ulcerative colitis

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World Journal of Gastroenterology 2010年第33期16卷 4145-4151页

作者： sahar K Hegazy Mohamed M El-Bedewy Department of Clinical Pharmacy Faculty of PharmacyTanta University Internal Medicine Faculty of MedicineTanta University

AIM:To demonstrate the therapeutic effect of probiotics in patients with ulcerative colitis(UC),and their effect on inflammatory mediators and nuclear factor(NF)κB activation in these ***:Thirty patients with mild to moderate UC were randomly classified into two groups:sulfasalazine group,who received sulfasalazine 2400 mg/d;and probiotic group,who received sulfasalazine 2400 mg/d with *** patients were investigated before and after 8 wk of treatment with probiotic(Lactobacillus delbruekii and Lactobacillus fermentum).Colonic activity of myeloperoxidase(MPO)was assayed with UV spectrophotometry,the colonic content of interleukin(IL)-6 was determined by enzyme-linked immunosorbent assay(ELISA),fecal calprotectin was determined by ELISA,and expression of NF-κB p65 and tumor necrosis factor (TNF)-αproteins in colonic tissue was identified by immunohistochemistry and reverse transcription polymerase chain reaction,***:At the start of the study,colonic mucosal injury and inflammation were demonstrated in UC patients by hematoxylin and eosin staining,and an increase in colonic MPO activity,fecal calprotectin,and expression of colonic TNF-αand NF-κB p65 *** use of probiotic for 8 wk significantly ameliorated the inflammation by decreasing the colonic concentration of IL-6,expression of TNF-αand NF-κB p65,leukocyte recruitment,as demonstrated by a decrease in colonic MPO activity,and the level of fecal calprotectin compared to sulfasalazine group and the control group(Pal supplementation with probiotics could be helpful in maintaining remission and preventing relapse of UC.

关键词： Ulcerative colitis Probiotics Interleukin-6 Nuclear factor-κB

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