检索结果-南通市图书馆

Nano Research 2020年第1期13卷 145-150页

作者： dogan kaya Richard J.Cobley Richard E.Palmer Department of Electronics and Automation Vocational School of AdanaCukurova University01160CukurovaAdanaTurkey Nanoscale Physics Research Laboratory School of Physics and AstronomyUniversity of BirminghamEdgbastonBirminghamB152TTUK College of Engineering Swansea UniversityBay CampusFabian WaySwanseaSA18ENUK

Understanding the atomistic formation of oxide layers on semiconductors is important for thin film fabrication,scaling down conventional devices and for the integration of emerging research ***,the initial oxidation of Si(111)is studied using the scanning tunneling *** to the complete saturation of the silicon surface with oxygen,we are able to probe the atomic nature of the oxide layer *** establish the threshold for local manipulation of inserted oxygen sites to be+3.8 *** by combining imaging with local atomic manipulation are we able to determine whether inserted oxygen exists beneath surface-bonded oxygen sites and differentiate between sites that have one and more than one oxygen atom inserted beneath the *** to the creation of the thin oxide film we observe a flip in the manipulation rates of inserted oxygen sites consistent with more oxygen inserting beneath the silicon surface.

关键词： scanning tunneling microscopy(STM) local manipulation Si(111) oxidation

SYNTHESIS AND CHARACTERIZATION OF AN ACRYLATE POLYMER CONTAINING CHLORINE-1,3-DIOXALANE GROUPS IN SIDE CHAINS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2012年第5期30卷 642-651页

作者： Zulfiye Ilter Ferhat Alhanli Fatih dogan Ismet kaya Firat University Faculty of Science and ArtsDepartment of ChemistryElazigTurkey Canakkale Onsekiz Mart University Faculty of EducationSecondary Science and Mathematics Education 17100CanakkaleTurkey Canakkale Onsekiz Mart University Department of Chemistry17020CanakkaleTurkey

Poly[2-（4-chlorophenyl）-l,3-dioxolan-4-yl]methyl acrylate, poly（CPhDMA）, was synthesized with radical polymerization process using 2,2＇-azobisisobutyronitrile as radical initiator in 1,4-dioxane at 60℃. The structure of poly（CPhDMA） was confirmed by means of UV-Vis, FT-IR, 1H-NMR, and 13C-NMR spectral techniques. The molecular weight distribution values of the polymer were determined with gel permeation chromatography （GPC）. The number-average molecular weight （Mn）, weight-average molecular weight （Mw） and polydispersity index （PDI） values of poly（CPhDMA） were determined to be 10300, 21600 and 2.097, respectively. The thermal degradation kinetics of the polymer was investigated by using TG/DTG-DTA and DSC analyses at different heating rates in dynamic nitrogen atmosphere. The apparent activation energy values obtained by Flynn-Wall-Ozawa and Friedman methods were found to be 91.68 and 85.23 kJ mo1-1, respectively, for thermal decomposition of poly（CPhDMA）. Also, the thermal degradation activation energy value of poly（CPhDMA） was calculated by using the Kissinger method based on the DTG, DTA and DSC data. Then the mechanism function of it was determined by master plots method. Finally, electrical and optical properties of poly（CPhDMA） were determined by four-point probe and UV-Vis techniques, respectively.

关键词： Synthesis of acrylate polymer Thermal degradation Kinetic parameters.

Streamlined CFD simulation framework to generate wind-pressure coefficients on building facades for airflow network simulations

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2021年第4期14卷 1189-1200页

作者： Timur dogan Patrick Kastner Cornell University Department of ArchitectureEnvironmental Systems LaboratoryEast Sibley HallIthacaNY14850USA

Building energy modeling software generally comes with capable airflow network solvers for natural ventilation evaluation in multi-zone building energy models. These approaches rely on arrays of pressure coefficients representing different wind directions derived from simple box-shaped buildings without contextual obstructions. For urban or obstructed sites, or more complex building shapes, however, further evaluation is needed to avoid geometric oversimplification. In this study, we present an automated and easy-to-use simulation workflow for OpenFOAM-based exterior airflow simulations to generate arrays of pressure coefficients for arbitrary building shapes and contextual situations. The workflow is compared to other methods commonly used to obtain pressure coefficients for natural ventilation analysis. Finally, we assess for which climate zones and building types modelers should rely on more accurate CFD-based pressure coefficients and where it may be justifiable to rely on easier and readily available analytical approaches to determine pressure coefficients. Results suggest that existing workflows lead to significant error in predicted comfort hours for climates in the Global South and modelers should consider CFD-based facade pressure coeficients.

关键词： natural ventilation airflow networks EnergyPlus pressure coefficients computational fluid dynamics

Comparative New Insight into the Tectonic Origin of Folds and Thrust Faults of an Extensional Basin: Soke-Kusadasi Basin, Aegean, Western Turkey

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2020年第3期31卷 582-595页

作者： Bulent dogan Department of Geological Engineering Engineering FacultyUniversity of KocaeliUmuttepe CampusIzmit-Kocaeli 41001Turkey

The Aegean area of the western Anatolian region of Turkey,controlled by the low-angle detachment normal fault system,forms an extensional province,the West Anatolian Extensional Province(WAEP).The tectonic deformation which occurred in the Miocene Period,including the Plio–Quaternary Period has created different structures in both the basement rocks and intra-basin deposits of the *** of these structures,high-angle normal faults,controls the supradetachment Soke-Kusadasi Basin(SKB).Within this basin,there are folds with different axes and thrust faults with a north-northwestnortheast(N,NW,NE)*** folds and thrust faults in the SKB deformed the sedimentary structures of intra-basin *** folds and thrust faults,which caused the rotation of beddings and imbrications in the SKB,are mainly associated with the tectonic process of the low angle detachment normal fault,which affected the SKB and the Aegean part of western *** the SKB,during the process of extensional deformation associated with primary low angle detachment normal faulting,the ramp-flat and inversion geometry observed in the basement rocks and basin deposits of the crust caused folds and thrust faults in only intra-basin *** the WAEP,it is determined for the first time that the folds and thrust faults causing limited shortening deformed the Plio–Quaternary sediments.

关键词： low angle detachment normal fault high angle normal fault fold thrust fault bedding extensional supradetachment basin

Axial gas mixing in conical spouted beds with high density particles

在线全文

学校读者我要写书评

暂无评论

Particuology 2023年第10期81卷 45-57页

作者： Neslin dogan Murat Koksal Gorkem Kulah Department of Chemical Engineering Middle East Technical UniversityAnkaraTurkey Department of Mechanical Engineering Hacettepe UniversityBeytepeAnkaraTurkey

Conical spouted beds operating with high-density particles(ρp>2500 kg/m^(3))have recently gained attention because of their potential use as nuclear fuel coaters for next-generation nuclear *** the literature,the number of axial gas mixing studies in conical and conical-cylindrical spouted beds is very limited and all axial mixing studies were carried out with relatively light particles(ρp≤2500 kg/m^(3)).Therefore,the objective of this study was to generate experimental data that can be used to explain the gas axial mixing behavior in conical spouted beds operating with both low-and high-density *** were conducted in two(γ=30°,60°)conical spouted beds with three different types of particles:zirconia(ρp=6050 kg/m^(3)),zirconia toughened alumina(ρp=3700 kg/m^(3))and glass beads(ρp=2460 kg/m^(3)).In order to be able to compare experimental data obtained at different conditions,a 1-D convection-diffusion gas mixing model originally developed by San Joséet al.(1995)was implemented to determine the axial dispersion *** results show that the axial dispersion coefficients range between m^(2)/s and m^(2)/s,increase with superficial gas velocity and are higher than the corresponding dispersion coefficients of fixed beds,lower than the dispersion coefficients of fluidized beds and in the same range with the cylindrical spouted beds reported in the *** corresponding Peclet numbers were in the range of 0.6–7.8 for all operating conditions and slightly higher Peclet numbers were obtained with glass beads indicating the relative importance of gas convective transport over gas dispersion for light particles compared to heavy particles.

关键词： Conical spouted bed Gas dispersion coefficient Axial gas mixing High-density particles

Effect of a semi electro-mechanical engine valve on performance and emissions in a single cylinder spark ignited engine

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第2期11卷 106-114页

作者： Bülent ZDALYAN Oguzhan dogan Department of Automotive Education Karabuk UniversityKarabuk 78050Turkey

In this study, an electro-mechanical valve （EMV） system for the intake valve ofa fottr stroke, single cylinder, overhead valve and spark ignition （SI） engine was designed and constructed. An engine with the EMV system and a standard engine were tested to observe the effects of the EMV on engine performance and emissions at different speeds under full load. The EMV engine showed improved engine power, engine torque and break specific fuel consumption （BSFC）. A 66% decrease in CO emissions was also obtained with the EMV system, but hydrocarbons （HC） and NOx emissions increased by 12% and 13% respectively.

关键词： Semi electro-mechanic Camless engine Electro-mechanic engine valve Engine performance Emissions

Optical Characterization of Amorphous Hydrogenated Carbon(a-C:H)Thin Films Prepared by Single RF Plasma Method

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2015年第6期17卷 488-495页

作者： dogan MANSUROGLU Kadir GOKSEN Sinan BILIKMEN Physics Department Middle East Technical University Physics Department Duzce University

Methane （CH4） plasma was used to produce amorphous hydrogenated carbon （a- C：H） films by a single capacitively coupled radio frequency （RF） powered plasma system. The system consists of two parallel electrodes： the upper electrode is connected to 13.56 MHz RF power and the lower one is connected to the ground. Thin films were deposited on glass slides with different sizes and on silicon wafers. The influence of the plasma species on film characteristics was studied by changing the plasma parameters. The changes of plasma species during the deposition were investigated by optical emission spectroscopy （OES）. The structural and optical properties were analyzed via Fourier transform infrared （FTIR） spectroscopy, X-ray diffraction （XRD） and UV-visible spectroscopy, and the thicknesses of the samples were measured by a profilometer. The sp3/sp2 ratio and the existing H atoms play a significant role in the determination of the chemical properties of thin films in the plasma. The film quality and deposition rate were both increased by raising the power and the flow rate.

关键词： a-C:H thin film plasma deposition methane plasma sp3/sp2 ratio

Experimental analysis on the nonlinear behavior of DC barrier discharge plasmas

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2017年第1期19卷 44-50页

作者： dogan MANSUROGLU Ilker Umit UZUN-KAYMAK Physics Department CanakkaleOnsekiz Mart University Canakkale 17100 Turkey Physics Department Middle East Technical University Ankara 06800 Turkey

Nonlinear behavior of glow discharge plasmas is experimentally *** glow is generated between a barrier semiconductor electrode,Chromium doped namely Gallium Arsenide（Ga As：Cr）,as a cathode and an Indium–Tin Oxide（ITO） coated glass electrode as an anode,in reverse *** planar nature of electrodes provides symmetry in spatial *** discharge behaves oscillatory in the time domain,with single and sometimes multiperiodicities in plasma current and voltage *** this paper,harmonic frequency generation and transition to chaotic behavior is *** observed current–voltage characteristics of the discharge are discussed in detail.

关键词： DC glow discharges nonlinear behavior digital signal analysis

Structural and superconducting properties in Y_(0.6)Gd_(0.4)Ba_2(Nb)Cu_3O_(7-y) cuprates doped with niobium

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2012年第3期30卷 241-244页

作者： M. Yilmaz O. dogan A. K. Education Faculty Department of Physics Konya University

Polycrystalline YBa2Cu3O7-y （YBCO） and Y0.6Gd0.4Ba2-xNbxCu3O7-y （YGBNCO） compounds with 0≤x≤0.225 were synthesized using standard solid state reaction technique. The structure for all samples was characterized by X-ray difference （XRD） and scanning electron microscopy （SEM）. The transport properties were measured by the （FPP） method in the temperature range from 70 to 130 K. As the Nb content in the samples increased, a diffused phase indicating a niobium perovskite phase and a small amount of unidentified phase appeared. With the increase of Nb content, the superconducting transition temperature Tconset increased slowly with x≤0.125, and then it remained unchanged or slowly decreased with 0.125≤x≤0.225. It could be found that there was a slow decrease of zero-resistance temperature, Tcoffset, with the increase of Nb content. The larger transition width might result from the YBa2NbO6 phase, impurity and unidentified phases of the sample due to the Nb doping.

关键词： Y0.6Gd0.4Ba2Cu3O7-y cuprates Gd and Nb co-doping structural and superconducting properties rare earths

Effects of Different Geographical Aspects and Ontogenetic Variability on Total Hypericin Content of Hypericum triquetrifolium Turra. and Hypericum scabrum L.

在线全文

学校读者我要写书评

暂无评论

Phyton-International Journal of Experimental Botany 2020年第4期89卷 1091-1099页

作者： Emine Aslan dogan Arslan Field Crops Department Faculty of AgricultureSiirt UniversitySiirt56000Turkey

The present study was conducted to determine the total hypericin contents of Hypericum triquetrifolium *** Hypericum scabrum *** which are naturally distributed in the flora of Siirt province,*** contents of Hypericum species grown in different geographical aspects(North,South,East,and West),and it was measured at different harvest times(full bloom-ing and post blooming period).In the current study,it has been determined that total hypericin content varies considerably according to aspects,plant developmental stages(ontogenetic variance),and *** to species x aspect interaction,the highest total hypericin content was recorded from the west aspect(3.13 mg/g)in Hypericum triquetrifolium,while,the lowest hypericin content was also obtained from the west aspect(1.22 mg/g)in Hypericum *** the highest total hypericin content was analyzed according to aspect x species x harvest time interaction,the highest total hypericin content was produced from Hypericum triquetrifolium at the harvest of west aspect with 5.28 mg/g,while the minimum amount of hypericin was obtained from the same aspect in Hypericum scabrum with 0.50 mg/*** species x harvest time interaction,the highest total hypericin content was obtained from the full bloom(3.10 mg/g)harvest in Hypericum triquetrifolium,while the lowest hypericin was obtained from the full bloom(1.26 mg/g)harvest in Hypericum *** data suggest that the aver-age total hypericin content was 2.26 mg/g in Hypericum triquetrifolium and 1.28 mg/g in Hypericum scabrum.

关键词： Hypericum triquetrifolium Hypericum scabrum aspect hypericin