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

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

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Influences of anionic and cationic dopants on the morphology and optical properties of PbS nanostructures

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Chinese Physics B 2014年第10期23卷 566-572页

作者： ramin yousefi Mohsen Cheragizade Farid Jamali-Sheini M. R. Mahmoudian Abdolhossein Saaédi Nay Ming Huang Depertment of Physics Masjed-Soleiman Branch Islamic Azad University (I.A.U.) Masjed-Soleiman Iran Department of Electrical Engineering Bushehr Branch Islamic Azad University (I.A.U.) Bushehr Iran Department of Physics Ahwaz Branch Islamic Azad University Ahwaz Iran Department of Chemistry Shahid Sherafat University of Farhangian 15916 Tehran Iran Low Dimensional Materials Research Center Department of Physics Faculty of Science University of Malaya 50603 Kuala Lumpur Malaysia

Selenium and zinc are used as anionic and cationic dopant elements to dope PbS nanostructures. The undoped and doped PbS nanostructures are grown using a thermal evaporation method. Scanning electron microscopy （SEM） results show similar morphologies for the undoped and doped PbS nanostructures. X-ray diffraction （XRD） patterns of three sets of the nanostructures indicate that these nanostructures each have a PbS structure with a cubic phase. Evidence of dopant incorporation is demonstrated by X-ray photoelectron spectroscopy （XPS）. Raman spectra of the synthesized samples con- firm the XRD results and indicate five Raman active modes, which relate to the PbS cubic phase for all the nanostructures. Room temperature photoluminescence （PL） and UV-Vis spectrometers are used to study optical properties of the undoped and doped PbS nanostructures. Optical characterization shows that emission and absorption peaks are in the infrared （IR） region of the electromagnetic spectrum for all PbS nanostructures. In addition, the optical studies of the doped PbS nanos- tructures reveal that the band gap of the Se-doped PbS is smaller, and the band gap of the Zn-doped PbS is bigger than the band gap of the undoped PbS nanostructures.

关键词： PbS nanostructures anionic dopant cationic dopant thermal evaporation optical properties

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Excellent photocatalytic performance under visible-light irradiation of ZnS/rGO nanocomposites synthesized by a green method

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Frontiers of Materials Science 2016年第4期10卷 385-393页

作者： Hassan Rayat AZIMI Mahmood GHORANNEVISS Seyed Mohammad ELAHI Mohammad Reza MAHMOUDIAN Farid JAMALI-SHEINI ramin yousefi Plasma Physics Research Center Science and Research Branch Islamic Azad University Tehran Iran Department of Chemistry Shahid Sherafat University of Farhangian 15916 Tehran Iran Advanced Surface Engineering and Nano Materials Research Center Department of Physics Ahvaz Branch Islamic Azad University Ahvaz Iran Department of Physics Masjed-Soleiman Branch isiamic Azad University Masjed-Soleiman Iran

ZnS/graphene nanocomposites with different graphene concentrations （5, 10 and 15 wt.%） were synthesized using L-cysteine as surfactant and graphene oxide （GO） powders as graphene source. Excellent performance for nanocomposites to remove methylene blue （MB） dye and hexavalent chromium （Cr（VI）） under visible-light illumina- tion was revealed. TEM images showed that ZnS NPs were decorated on GO sheets and the GO caused a significant decrease in the ZnS diameter size. XRD patterns, XPS and FTIR spectroscopy results indicated that GO sheets changed into reduced graphene oxide （rGO） during the synthesis process. Photocurrent measurements under a visible- light source indicated a good chemical reaction between ZnS NPs and rGO sheets.

关键词： ZnS/rGO nanocomposites graphene photocatalytic performance watertreatment green nanotechnology

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Laser beam effect on the entanglement of elastic collisions in quantum plasma

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Communications in Theoretical Physics 2024年第8期76卷 147-155页

作者： ramin Roozehdar Mogaddam Nasser Sepehri Javan Hosein Mohammadzadeh Department of Physics Ferdowsi University of MashhadPO Box 1436MashhadIran Department of Physics University of Mohaghegh ArdabiliPO Box 179ArdabilIran

In the quantized field formalism, using Kramers-Henneberger unitary transformation as the semi-classical counterpart of Block-Nordsieck transformation, the dynamics of entanglement during the low energy scattering processes in bi-partite systems at the presence of a laser beam fields are studied. The stationary-state Schrodinger equation for the quantum scattering process is obtained for such systems. Then, using partial wave analysis, we introduce a new form of entanglement fidelity considering the effect of high-intensity laser beam fields. The effective potential of hot quantum plasma including plasmon and quantum screening effects is used to obtain the entanglement fidelity ratio as a function of the laser amplitude, and plasmon and Debye length parameters for the elastic electron-ion collisions. It is shown that the plasma free electrons oscillations under interaction with laser beam fields improve the correlations between charged particles and consequently lead to the increase in the system entanglement.

关键词： laser entanglement quantum plasma elastic collision plasmon fidelity

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A thermo-mechanical simulation for the stability analysis of a horizontal wellbore in underground coal gasification

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Petroleum 2024年第2期10卷 243-253页

作者： Mohammadreza Shahbazi Mehdi Najafi Mohammad Fatehi Marji ramin Rafiee Department of Mining and Metallurgical Eng. Yazd UniversityYazdIran Department of Mining Petroleum&Geophysics Eng.Shahrood University of TechnologyShahroodIran

The stability analysis of horizontal wells is essential for a successful underground coal gasification(UCG)*** this paper,a new 3D coupled thermo-mechanical numerical modeling is proposed for analyzing the stability of UCG horizontal *** this model,the effect of front abutment stresses,syngas pressure,syngas temperature and thermal stresses is considered to predict the mud weight window and drilling mud pressure during UCG *** results show that the roof caving in UCG panel has a greatest impact on the stability of horizontal ***,when the time of coal gasification is increased,the well convergence increases and for more stability it is necessary to increase the drilling mud *** research was carried out on the M2 coal seam in Mazino coal deposit(Iran).The results showed that the mud weight window for horizontal well drilling is between 0 and 33 *** appropriate stress for the maximum stability of the horizontal well,taking all the thermal and mechanical parameters into account,is 28 *** suggested numerical method is a comprehensive and consistent way for analyzing the stability of horizontal wells in UCG sites.

关键词： Underground coal gasification Thermo-mechanical simulation Numerical modeling Stress distribution Horizontal well

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Investigation of pore geometry influence on fluid flow in heterogeneous porous media:A pore-scale study

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Energy Geoscience 2024年第1期5卷 72-88页

作者： ramin Soltanmohammadi Shohreh Iraji Tales Rodrigues de Almeida Mateus Basso Eddy Ruidiaz Munoz Alexandre Campane Vidal Ingram School of Engineering Texas State UniversitySan MarcosTX78666USA Department of Mechanical Engineering(FEM) State University of Campinas(UNICAMP)CampinasSP13083-855Brazil Department of Geology and Natural Resources Geosciences Institute(IG)State University of Campinas(UNICAMP)CampinasSP13083-855Brazil Center of Energy and Petroleum Study(CEPETRO) State University of Campinas(UNICAMP)CampinasSP13083-855Brazil

Brazilian pre-salt reservoirs are renowned for their intricate pore networks and vuggy nature,posing significant challenges in modeling and simulating fluid flow within these carbonate *** possessing excellent petrophysical properties,such as high porosity and permeability,these reservoirs typically exhibit a notably low recovery factor,sometimes falling below 10%.Previous research has indicated that various enhanced oil recovery(EOR)methods,such as water alternating gas(WAG),can substantially augment the recovery factor in pre-salt reservoirs,resulting in improvements of up to 20%.Nevertheless,the fluid flow mechanism within Brazilian carbonate reservoirs,characterized by complex pore geometry,remains *** study examines the behavior of fluid flow in a similar heterogeneous porous material,utilizing a plug sample obtained from a vugular segment of a Brazilian stromatolite outcrop,known to share analogies with certain pre-salt *** conducted single-phase and multi-phase core flooding experiments,complemented by medical-CT scanning,to generate flow streamlines and evaluate the efficiency of water ***,micro-CT scanning of the core sample was performed,and two cross-sections from horizontal and vertical plates were *** cross-sections were then employed as geometries in a numerical simulator,enabling us to investigate the impact of pore geometry on fluid *** of the pore-scale modeling and experimental data unveiled that the presence of dead-end pores and vugs results in a significant portion of the fluid remaining stagnant within these ***,the injected fluid exhibits channeling-like behavior,leading to rapid breakthrough and low areal swept ***,the numerical simulation results demonstrated that,irrespective of the size of the dead-end regions,the pressure variation within the dead-end vugs and pores is *** the stromatolite's favorable petrophysica

关键词： Pore-scale modeling Pore geometry Flow streamlines Computational modeling Digital rock analysis

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Risk of hepatitis B virus reactivation in cancer patients undergoing treatment with tyrosine kinase-inhibitors

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World Journal of Gastroenterology 2024年第24期30卷 3052-3058页

作者： Bansi P Savaliya ramin Shekouhi Fatima Mubarak Harsheen K Manaise Paola Berrios Jimenez Gabrielle Kowkabany Reed A Popp Kyle Popp Emmanuel Gabriel Department of Surgery Medical Academy Named after SI Georgievsky of Vernadsky Crimean Federal UniversitySimferopol 295015CrimeaRussia Division of Plastic and Reconstructive Surgery Department of SurgeryUniversity of FloridaGainesvilleFL 32608United States Department of Surgery Aga Khan UniversityKarachi 74800SindhPakistan Department of Surgery Government Medical College and HospitalChandigarh 160030PunjabIndia Department of Surgery University of Puerto Rico School of MedicineSan Juan 00921Puerto Rico Department of Chemical and Biological Engineering University of AlabamaTuscaloosaAL 35487United States Department of Surgery University of Florida College of MedicineGainesvilleFL 32610United States Department of Surgery Florida State UniversityTallahasseeFL 32306United States Department of Surgery Mayo ClinicJacksonvilleFL 32224United States

This editorial commented on an article in the World Journal of Gastroenterology titled“Risks of Reactivation of Hepatitis B Virus in Oncological Patients Using Tyrosine Kinase-Inhibitors:Case Report and Literature Analysis”by Colapietro et *** this editorial,we focused on providing a more comprehensive exploration of hepatitis B virus reactivation(HBVr)associated with the usage of tyrosine kinase inhibitors(TKIs).It includes insights into the mechanisms underlying HBV reactivation,the temporal relationship between TKIs and HBV reactivation,and preventive *** aim is to understand the need for nucleos(t)ide analogs(NAT)and serial blood tests for early recognition of reactivation and acute liver injury,along with management *** are considered to be an intermediate(1%-10%)of *** guidelines stipulate that patients receiving therapy with high or moderate risks of reactivation or recent cancer diagnosis must have at least tested hepatitis B surface antigen,anti-hepatitis B core antigen(HBc),and anti-hepatitis B surface ***-HBc screening in highly endemic areas means people with negative tests should be vaccinated against *** or nucleotide analogs(NAs)like entecavir(ETV),tenofovir disoproxil fumarate(TDF),and tenofovir alafenamide(TAF)form the basis of HBV reactivation prophylaxis and treatment during ***,lamivudine,telbivudine,and adefovir are generally discouraged due to their reduced antiviral efficacy and higher risk of fostering drug-resistant viral ***,these less effective NAs may still be utilized in cases where ETV,TDF,and TAF are not feasible treatment options.

关键词： Hepatitis B virus Reactivation Chronic hepatitis B Tyrosine-kinase inhibitor Immunomodulators Immunosuppressant Nucleoside analogue Hemato-oncology

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Myelopathy as a Presentation of Cervical Spine Metastasis: A Case Report

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Open Journal of Modern Neurosurgery 2024年第1期14卷 64-71页

作者： ramin Shayan-Moghadam Mosayeb Soleymani Hassan Zolghadr Mohammad Hossein Nabian Saeed Reza Mehrpour Department of Orthopedic and Trauma Surgery Shariati Hospital Tehran University of Medical Sciences Tehran Iran Center for Orthopedic Trans-Deciplinary Applied Research Tehran University of Medical Sciences Tehran Iran

Cervical myelopathy is a consequence of spinal cord compression in the cervical spine. Degenerative cervical spondylosis, osteophytes, discosteophyte complex, degenerative spondylolisthesis and hypertrophy of ligamentum flavum are the main etiologies of cervical myelopathy. Metastasis to cervical spine could be a rare cause of cervical myelopathy. The present study is a case report;presented a 36-year-old male with severe pain in cervical region, gait disability and impairment in sensory and motor function of upper left extremity. The patient had a history of thyroidectomy and cervical lymph node dissection due to follicular thyroid carcinoma (FTC) with improper follow-ups. He was diagnosed with metastatic cervical myelopathy and underwent surgical treatment. Cervical myelopathy due to metastasis is a rare condition and only few cases have been reported so far. So myelopathies can be a complication of metastatic cancers, and it should be considered by health professionals.

关键词： Myelopathy Metastasis Thyroid Cancer

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Piezo1 expression in chondrocytes controls endochondral ossification and osteoarthritis development

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Bone Research 2024年第1期12卷 199-214页

作者： Laura J.Brylka Assil-ramin Alimy Miriam E.A.Tschaffon-Müller Shan Jiang Tobias Malte Ballhause Anke Baranowsky Simon von Kroge Julian Delsmann Eva Pawlus Kian Eghbalian Klaus Püschel Astrid Schoppa Melanie Haffner-Luntzer David J.Beech Frank Timo Beil Michael Amling Johannes Keller Anita Ignatius Timur A.Yorgan Tim Rolvien Thorsten Schinke Department of Osteology and Biomechanics University Medical Center Hamburg-Eppendorf20246 HamburgGermany Department of Trauma and Orthopedic Surgery University Medical Center Hamburg-Eppendorf20246 HamburgGermany Institute of Orthopedic Research and Biomechanics University Medical Center UlmBadenWürttemberg89081 UlmGermany Department Legal Medicine University Medical Center Hamburg-Eppendorf20246 HamburgGermany Leeds Institute of Cardiovascular and Metabolic Medicine School of MedicineUniversity of LeedsLS29JT LeedsUK

Piezo proteins are mechanically activated ion channels,which are required for mechanosensing functions in a variety of cell *** we and others have previously demonstrated that the expression of Piezo1 in osteoblast lineage cells is essential for boneanabolic processes,there was only suggestive evidence indicating a role of Piezo1 and/or Piezo2 in *** we addressed the question if and how chondrocyte expression of the mechanosensitive proteins Piezo1 or Piezo2 controls physiological endochondral ossification and pathological osteoarthritis(OA)*** with chondrocyte-specific inactivation of Piezo1(Piezo1^(Col2a1Cre)),but not of Piezo2,developed a near absence of trabecular bone below the chondrogenic growth plate ***,all Piezo1^(Col2a1Cre) animals displayed multiple fractures of rib bones at 7 days of age,which were located close to the growth *** skeletal growth was only mildly affected in these mice,OA pathologies were markedly less pronounced compared to littermate controls at 60 weeks of ***,when OA was induced by anterior cruciate ligament transection,only the chondrocyte inactivation of Piezo1,not of Piezo2,resulted in attenuated articular cartilage ***,osteophyte formation and maturation were also reduced in Piezo1^(Col2a1Cre) *** further observed increased Piezo1 protein abundance in cartilaginous zones of human ***,we identified Ptgs2 and Ccn2 as potentially relevant Piezo1 downstream genes in ***,our data do not only demonstrate that Piezo1 is a critical regulator of physiological and pathological endochondral ossification processes,but also suggest that Piezo1 antagonists may be established as a novel approach to limit osteophyte formation in OA.

关键词： Piezo1 markedly ossification

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Depth in Bucket Recursive Trees with Variable Capacities of Buckets

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Acta Mathematica Sinica,English Series 2014年第2期30卷 305-310页

作者： ramin KAZEMI Department of Statistics Faculty of SciencesImam Khomeini International University

We consider bucket recursive trees of sizen consisting of all buckets with variable capacities1,2,...,b and with a specifc stochastic growth *** model can be considered as a generalization of random recursive trees like bucket recursive trees introduced by Mahmoud and Smythe where all buckets have the same *** this work,we provide a combinatorial analysis of these trees where the generating function of the total weights satisfes an autonomous frst order diferential *** study the depth of the largest label（i.e.,the number of edges from the root node to the node containing label n）and give a closed formula for the probability *** we prove a limit law for this quantity which is a direct application of quasi power theorem and compute its mean and *** results for b=1 reduce to the previous results for random recursive trees.

关键词： Bucket-increasing tree bucket-recursive tree exponential generating function completeand incomplete nodes depth

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