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Nano inhomogeneity effects on small Ag/n-Si Schottky diode parameters at high temperature

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Journal of Semiconductors 2013年第8期34卷 8-14页

作者： m.a.yeganeh R.K.mamedov A.J.Novinrooz Islamic Azad University Bonab Branch Faculty of Electronic Engineering Faculty of Physics Baku State UniversityAcademic Zahid Khalilov Str.23AZ 1148Baku Islamic Azad University Takestan Branch Faculty of Physics

Schottky diodes with an Ag/n-Si/W/Cu structure and 100μm in diameter were *** the silver metal surface coating on the n-Si substrate using a scanning probe microscopy（SPm） device showed a large number of nano patches in the surface with dimensions of 0 to 100 *** potential distribution of the patches revealed that the potential of each patch with the neighboring patches was *** electrical characteristics of the devices were studied between temperature ranges of 300 and 380 *** the temperature ideality factor approximately increases,the potential barrier height *** potential barrier height was calculated separately from theⅠ-Ⅴand C-V *** main reasons for the significant difference between room temperature and higher temperatures were the differences in patch distribution,the different potentials of each patch,and the interactions between *** effective potential barrier height depended on the degree of inhomogeneity,and thus the operating potential barrier height in the contact surface was smaller than the average value,and the ideality factor was more than *** the increase in the potential value,the ideality factor becomes close to unitary, and with increasing temperatures,the ideality factor is *** this case,the maximum potential barrier height accrues at a greater distance from the metal *** this reason,at high temperatures the average value of the potential barrier height is ***,with increasing temperature,the ideality factor is increased.

关键词： Schottky contact nano patch high temperatures Schottky parameters AFm and SPm

Cognitive-emotional feasibility of the effect of visual quality of building form on promoting the sense of place attachment(Case study:Cultural iconic buildings of Iran’s contemporary architecture)

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Frontiers of Architectural Research 2024年第1期13卷 37-56页

作者： Narmin Ariannia Negar Naseri mansour yeganeh Digital Architecture and Artificial Intelligence Lab Department of ArchitectureTarbiat Modares UniversityTehranIran Architectural Design Modeling and Fabrication LabDepartment of ArchitectureTarbiat Modares UniversityTehranIran

The present research studies the relationship between place attachment and the perception of form’s visual quality in fifteen outstanding contemporary Iranian architectural cultural *** study puts forward the hypothesis that there is a correlation between the quality of building form and the sense of place attachment,in the sense that creating high visual quality through enhancing the quality of building form increases citizens’initial satisfaction with and subsequent attachment to the *** visual quality influences people’s experience of the environment and improves the quality of *** attachment highlights how people,on a personal level,recreate a sense of place for *** present study adopts the descriptive-analytical method as its theoretical framework and the survey as the empirical *** were developed using the Likert scale and distributed among experts and ordinary *** analysis using SPSS and the adoption of descriptive-analytical statistics,correlation analysis,and regression showed the relationship among the characteristics of *** results show a positive correlation between form and place attachment mediated through visual quality,and they are causal conditions for one *** addition,only some of the buildings under study evoke the same level of place attachment.

关键词： Visual preferences Environmental quality Environmental psychology mental schemas Contemporary architecture

Prediction of vertical displacement for a buried pipeline subjected to normal fault using a hybrid FEm-ANN approach

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Frontiers of Structural and Civil Engineering 2024年第3期18卷 428-443页

作者： Hedye JALALI Reza yeganeh KHAKSAR Danial mOHAmmADZADEH S. Nader KARBALLAEEZADEH Amir H.GANDOmI Department of Civil Engineering Architecture and UrbanismSadjad University of TechnologyPO Box ***MashhadIran Department of Civil Engineering Faculty of EngineeringEqbal Lahoori Institute of Higher EducationPO Box ***MashhadIran Faculty of Civil Engineering Architectureand ArtScience and Research Branch of Islamic Azad UniversityPO Box ***TehranIran Faculty of Engineering&Information Technology University of Technology SydneyUltimoNSW 2007Australia University Research and Innovation Center(EKIK) Óbuda UniversityBudapest 1034Hungary

Fault movement during earthquakes is a geotechnical phenomenon threatening buried pipelines and with the potential to cause severe damage to critical ***,effective prediction of pipe displacement is crucial for preventive management *** study aims to develop a fast,hybrid model for predicting vertical displacement of pipe networks when they experience *** this study,the complex behavior of soil and a buried pipeline system subjected to a normal fault is analyzed by using an artificial neural network(ANN)to generate predictions the behavior of the soil when different parameters of it are *** this purpose,a finite element model is developed for a pipeline subjected to normal fault *** data bank used for training the ANN includes all the critical soil parameters(cohesion,internal friction angle,Young’s modulus,and faulting).Furthermore,a mathematical formula is presented,based on biases and weights of the ANN *** results show that the maximum error of the presented formula is 2.03%,which makes the proposed technique efficiently predict the vertical displacement of buried pipelines and hence,helps to optimize the upcoming pipeline projects.

关键词： buried pipelines normal Fault finite element method multilayer perceptron neural network formulation

An efficient tool for Parkinson's disease detection and severity grading based on time-frequency and fuzzy features of cumulative gait signals through improved LSTm networks

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medicine in Novel Technology and Devices 2024年第2期22卷 38-50页

作者： Farhad Abedinzadeh Torghabeh yeganeh modaresnia Seyyed Abed Hosseini Department of Biomedical Engineering Mashhad BranchIslamic Azad UniversityMashhadIran Department of Electrical Engineering Mashhad BranchIslamic Azad UniversityMashhadIran

Parkinson's disease(PD)is a widespread neurodegenerative condition that affects many individuals *** identification and monitoring of disease progression are crucial to effectively managing symptoms and preventing motor *** research proposes an automated PD diagnosis and severity-grading model based on time-frequency and fuzzy features using improved uni-directional and bi-directional long short-term memory networks with sensitive hyperparameters *** utilize vertical ground reaction force signals collected from Physionet's publicly available dataset recorded during regular and dual-task clinical trials of walking *** the cumulative signal of both feet was then utilized and segmented into 30-s windows without further ***,we extracted only four key time-frequency and fuzzy features from each segment,effectively capturing the signal's inherent *** optimization is employed in both detection and grading approaches to fine-tune the two critical hyperparameters:the initial learning rate and the number of hidden units in the *** detection phase yields an exceptional accuracy of 99.19%,surpassing state-of-the-art studies with the same *** the grading phase,classification based on the unified PD rating scale values achieves an accuracy of 92.28%.The proposed study delves into the potential of cumulative gait signals as a powerful diagnostic tool for PD,aiming to extract precise and intricate information by implementing straightforward and minimal processing *** method demonstrates significant effi-ciency in terms of complexity,cost,and energy consumption by utilizing a single-dimensional signal,eliminating the need for pre-processing steps,and limiting the features used for training.

关键词： Parkinson's disease grading Cumulative gait signal Vertical ground reaction force fuzzy feature Bayesian optimization Long short-term memory

Nickel doped zinc oxide nanoparticles produced by hydrothermal decomposition of nickel-doped zinc hydroxide nitrate

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Particuology 2012年第4期10卷 492-496页

作者： mohammad yeganeh Ghotbi Nanomaterials and Nanotechnology Program Ceramic Engineering DepartmentFaculty of EngineeringMalayer UniversityMalayerIran

Zinc hydroxide nitrate, an anionic exchanger layered material, undoped as well as doped with 2-10% nickel, was synthesized by using a pH-controlled precipitation method. The layered materials were then used to produce the undoped and nickel-doped zinc oxides by hydrothermal-treatment. X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy confirmed the formation of pure phase undoped and nickel-doped layered materials, as well as the products of the hydrothermal- treated materials, nanostructured zinc oxides. Optical studies of the nanostructured zinc oxides showed a decrease in band gap with increasing content of the doping agent, nicke~.

关键词： NanostructureNickel doped zinc oxideChemical synthesisBand gap

Frequency-dependent viscoelasticity effects on the wave attenuation performance of multi-layered periodic foundations

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 407-424页

作者： m.SAFI m.VAKILIFARD m.J.mAHmOODI Faculty of Civil Water&Environmental EngineeringShahid Beheshti UniversityTehran ***Iran Faculty of mechanical and Energy Engineering Shahid Beheshti UniversityTehran ***Iran

In this paper,layered periodic foundations(LPFs)are numerically examined for their responses to longitudinal and transverse modes in the time and frequency *** different unit-cells,i.e.,2-layer,4-layer,and 6-layer unit-cells,comprising concrete/rubber,concrete/rubber/steel/rubber,and concrete/rubber/steel/rubber/lead/rubber materials,respectively,are taken into ***,the viscoelasticity behavior of the rubber is modeled with two factors,i.e.,a frequency-independent(FI)loss factor and a linear frequency-dependent(FD)loss *** the extraction of the complex dispersion curves and the identification of the band gaps(BGs),the simulations of wave transmission in the time and frequency domains are performed using the COmSOL *** parametric studies evaluate the effects of the rubber viscoelasticity models on the dispersion curves and the wave transmission for the longitudinal and transverse *** results show that considering the rubber viscoelasticity enhances the wave attenuation ***,the transverse-mode damping is more sensitive to the viscoelasticity model than its longitudinal *** 6-layer unit-cell LPF exhibits the lowest BG,ranging from 4.8 Hz to 6.5 Hz.

关键词： layered metamaterial periodic foundation complex dispersion curve wave transmission diagram

Engineering of efficient visible light photocatalysts:Ti_(1-x+y)Cu_(x)La_(y)O_(2)(x=0.03;y=0,0.005,0.01) compositions

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Journal of Rare Earths 2024年第3期42卷 497-505,I0003页

作者： S.m.Yakout A.m.Youssef Inorganic Chemistry Department National Research Centre(NRC)El Buhouth StDokkiCairo12622Egypt

In dye-photocatalysis, widening the wavelengths absorption range of catalysts as well as aborting the recombination of the photoexcited charge carriers(electrons-holes pairs) are of paramount *** the current study, we report the photocatalytic characteristics of four compositions composed of TiO_(2),Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders for two harmful dyes(Congo red and methylene blue). The X-ray diffraction technique verified the configuration of mixed anatase and rutile phases in pure TiO_(2)and Ti_(0.97)Cu_(0.03)O_(2)powders while Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders possess anatase phase only. The changes of the band gap structure and dimensions of the unit cell volume of TiO_(2)confirm the substitution of Ti^(4+)sites by Cu^(2+)and La^(3+)ions. Remarkable widening of wavelengths absorption with formation of long absorption tails were found in TiO_(2)(3.13 e V) through insertion of La^(3+)plus Cu^(2+)ions. Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)samples exhibit a visible light band gap of 2.3 and 2.7 e V, respectively. Based on SEm images, incorporation of Cu^(2+)and La^(3+)ions influences the surface morphology of TiO_(2). The resulting Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders present enhanced photocatalytic activity towards Congo red dye degradation compared to pure one under natural solar spectrum. The best Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst exhibits superior photocatalytic activity of 96% for 10 ppm CR dye in 20 min as well as above average photocatalytic efficiency of 63% for 30 ppm CR dye in 120 min. As well, it showed acceptable photodegradation activity of 52% for 30 ppm mB solution in 140 min of sunlight irradiation. The heightened photodegradation efficiency of Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst can be clarified in terms of higher ch

关键词： Semiconductor TiO_(2) Rare earths Congo red methylene blue Solar spectrum Photodegradation

Superhydrophobic surface of mg alloys:A review

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Journal of magnesium and Alloys 2018年第1期6卷 59-70页

作者： m.yeganeh N.mohammadi Department of materials Science and Engineering Faculty of EngineeringShahid Chamran University of AhvazAhvazIran

In the present review,the formation of superhydrophobic(SHP)structures on the surface of mg alloys was *** methods including hydrothermal technique,chemical and electrochemical deposition,conversion and polymer coating,and etching routes were *** superhydrophobicity could form on the surface of mg alloys by the application of different chemical,electrochemical,and physical methods followed by the immersion of these alloys in the solution containing modifying agents including fatty acids or long-chain *** formed morphology,composition,and contact angle were reported and the effect of synthesis route on these characteristics was reviewed.

关键词： mg alloys Superhydrophobic surfaces Chemical deposition Electrochemical coating Conversion coating Polymer coating Etching

Nonlinear dynamic modeling of planar moving Timoshenko beam considering non-rigid non-elastic axial effects

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 479-496页

作者： m.ABBASI GAVARI m.R.HOmAEINEZHAD Faculty of mechanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible *** manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse *** accurately model the elastic behavior,Timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation *** applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(PDEs).Then,the assumed mode method(Amm)is used to solve this nonlinear system of governing equations with appropriate shape *** assumed modes can be obtained after solving the characteristic equation of a Timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the *** addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is *** the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the ***,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element *** comparison confirms the validity of the proposed dynamic model for the *** to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms.

关键词： planar moving Timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(Amm) nonlinear motion analysis