检索结果-南通市图书馆

Microsphere-assisted quantitative phase microscopy:a review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Advanced Manufacturing) 2024年第1期5卷 131-150页

作者： vahid abbasian Tobias Pahl Lucie Hüser Sylvain Lecler Paul Montgomery Peter Lehmann Arash Darafsheh Department of Radiation Oncology Washington University School of Medicine in St.LouisSt.LouisMO 63110USA Imaging Science Program McKelvey School of EngineeringWashington University in St.LouisSt.LouisMO 63130USA Measurement Technology Group Faculty of Electrical Engineering and Computer ScienceUniversity of KasselWilhelmshöher Allee 7134121 KasselGermany ICube Research Institute INSA StrasbourgUniversitéde StrasbourgCNRS67000 StrasbourgFrance

Light microscopes are the most widely used devices in life and material sciences that allow the study of the interaction of light with matter at a resolution better than that of the naked *** microscopes translate the spatial differences in the intensity of the reflected or transmitted light from an object to pixel brightness differences in the digital ***,a phase microscope converts the spatial differences in the phase of the light from or through an object to differences in pixel *** microscopy,a phase-based approach,has found application in various *** interferometry has brought nanometric axial resolution,the lateral resolution in quantitative phase microscopy(QPM)has still remained limited by diffraction,similar to other traditional microscopy *** the resolution has been the subject of intense investigation since the invention of the microscope in the 17th *** the past decade,microsphere-assisted microscopy(MAM)has emerged as a simple and effective approach to enhance the resolution in light *** can be integrated with QPM for 3D label-free imaging with enhanced ***,we review the integration of microspheres with coherence scanning interference and digital holographic microscopies,discussing the associated open questions,challenges,and opportunities.

关键词： Phase microscopy Digital holographic microscopy Microsphere Resolution

Experimental determination of gas holdup and volumetric mass transfer coefficient in a jet bubbling reactor

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 Chemical Engineering 2021年第6期34卷 61-67页

作者： Mostafa abbasian-arani Mohammad Sadegh Hatamipour Amir Rahimi Chemical Engineering Department University of IsfahanIsfahanIran

The hydrodynamics and mass transfer characteristics of a lab-scale jet bubbling reactor(JBR)including the gas holdup,volumetric mass transfer coefficient and specific interfacial area were assessed experimentally investigating the influence of temperature,pH and superficial gas *** reactor diameter and height were 11 and 30 cm,*** was equipped with a single sparger,operating at atmospheric pressure,20 and 40℃,and two pH values of 3 and *** height of the liquid was 23 cm,while the superficial gas velocity changed within 0.010-0.040 m·s^(-1)*** were conducted with pure oxygen as the gas phase and saturated lime solution as the liquid *** liquid-side volumetric mass transfer coefficient was determined under unsteady-state oxygen absorption in a saturated lime *** gas holdup was calculated based on the liquid height change,while the specific interfacial area was obtained by a physical method based on the bubble size distribution(BSD)in different superficial gas *** results indicated that at the same temperature but different pH,the gas holdup variation was negligible,while the liquid-side volumetric mass transfer coefficient at the pH value of 6 was higher than that at the pH=*** a constant pH but different temperatures,the gas holdup and the liquid-side volumetric mass transfer coefficients at 40℃were higher than that of the same at 20℃.A reasonable and appropriate estimation of the liquid-side volumetric mass transfer coefficient(kla)in a pilot-scale JBR was provided which can be applied to the design and scale-up of JBRs.

关键词： Jet bubbling reactor Liquid-side volumetric mass transfer coefficient Gas holdup Specific interfacial area Experimental analysis

Finite element analysis of controlled low strength materials

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2019年第5期13卷 1243-1250页

作者： vahid ALIZADEH Gildart Haase School of Computer Sciences & Engineering Fairleigh Dickinson UniversityTeaneckNJ 07666USA

Controlled low strength materials (CLSM) are flowable and self-compacting construction materials that have been used in a wide variety of applications. This paper describes the numerical modeling of CLSM fills with finite element method under compression loading and the bond performance of CLSM and steel rebar under pullout loading. The study was conducted using a plastic-damage model which captures the material behavior using both classical theory of elasto-plasticity and continuum damage mechanics. The capability of the finite element approach for the analysis of CLSM fills was assessed by a comparison with the experimental results from a laboratory compression test on CLSM cylinders and pullout tests. The analysis show's that the behavior of a CLSM fill w'hile subject to a failure compression load or pullout tension load can be simulated in a reasonably accurate manner.

关键词： CLSM finite element method compressive strength pullout numerical modeling plastic damage model

Experimental and modeling study of the kinetics of methane hydrate formation and dissociation

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 Chemical Engineering 2021年第1期34卷 365-374页

作者： Vafa Feyzi vahid Mohebbi Ahvaz Petroleum Faculty Petroleum University of Technology(PUT)AhvazIran

In this work,several experiments were conducted at isobaric and isothermal condition in a CSTR reactor to study the kinetics of methane hydrate formation and *** were performed at five temperatures and three pressure levels(corresponding to equilibrium pressure).Methane hydrate formation and dissociation rates were modeled using mass transfer limited kinetic models and mass transfer coefficients for both formation and dissociation were *** of results,shows that mass transfer coefficients for methane hydrate dissociation are one order greater than formation *** transfer coefficients were correlated by polynomials as relations of pressure and *** results and the method can be applied for prediction of methane production from naturally occurring methane hydrate deposits.

关键词： Methane hydrate Kinetics Formation Dissociation Mass transfer

Dynamic analysis of the composite laminated repaired perforated plates by using multi-patch IGA method

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2021年第1期34卷 266-280页

作者： Jamshid FAZILATI vahid KHALAFI Aeronautical Science and Technology Department Aerospace Research InstituteTehran 14657-74111Iran Aerospace Engineering Department Shahid Sattari Aeronautical University of Science and TechnologyTehranIran

The bonded repair techniques seem to be the most frequent procedures in the aviation *** achieved composite repaired perforated thin-walled plate is a complex geometry with high numerical analysis *** NURBS-based Isogeometric Analysis(IGA)proposes a sensible and affordable tool to carry out such geometry *** this context,a well-known technique is to divide the original geometry assembly into number of simple neighbors connected *** the present study the free vibration analysis of the perforated plates repaired on one side with an external bonded composite laminated patch is investigated.A multi-patch geometry modeling approach is implemented in line with the first order shear deformation theory of *** order to hold the geometry integrity and uniformity,all the degrees of freedom between adjacent geometry patches are completely tied through implementing a Nitsche *** show the effectiveness and accuracy of the developed formulation,some representative results are extracted and compared with those from *** effects of geometrical as well as material parameters including boundary condition,cutout shape,and repair layup on the dynamic response of the repaired perforated plates are then investigated.

关键词： Composite laminate Perforated plate Bonded repair Isogeometric analysis(IGA) Multi-patch model

Ocean Chemistry Revealed by Mineralogical and Geochemical Evidence at the Permian——Triassic Mass Extinction,Offshore the Persian Gulf,Iran

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2016年第5期90卷 1852-1864页

作者： vahid TAVAKOLI School of Geology College of ScienceUniversity of Tehran

The Upper Permian Dalan Formation and the Lower Triassic Kangan Formation in the Persian Gulf area are mainly composed of shallow marine facies limestone and *** subsurface-cored intervals were investigated in order to understand the original mineralogy and paleoceanic *** decreasing trend of Sr concentration in these deposits shows that aragonite was precipitated during the Late Permian and then gradually changed to calcite toward the Permian-Triassic boundary（PTB）.The dissolution rate of aragonite decreased from 60 m below the PTB toward the boundary,with the only exception at 10 m below the Permian-Triassic Boundary（PTB） due to the Permian-Triassic unconformity in this *** increasing trend of Mg/Ca ratio in a global scale at the end-Permian time shows that the interpreted variation of mineralogy does not result from the change of this *** increasing p（CO2） and decreasing pH are considered to be the main controlling *** increase of Ca2＋ at the end-Permian time due to the input of meteoric waters is too little to fully compensate this effect.A local maximum of the Si content just at the PTB confirms the input of runoff waters.

关键词： Permian Triassic carbonate mineralogy elemental composition Iran Persian Gulf

Effects of foundation rocking and uplifting on displacement amplification factor

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2018年第3期17卷 511-525页

作者： Mohammad Khanmohammadi vahid Mohsenzadeh School of Civil Engineering University of Tehran Department of Civil Engineering Mc Master University

Prediction of displacement demand to assess seismic performance of structures is a necessary step where nonlinear static procedures are *** such predictions have been well established in literature for fixed-base structures,fewer bodies of researches have been carried out on the effect of rocking and uplifting of shallow foundations supported by soil,on such *** paper aimed to investigate the effect of soil structure interaction on displacement amplification factor C1 using the beam on nonlinear Winkler foundation concept.A practical range of natural period,force reduction factors,and wide range of anticipated behavior from rocking,uplifting and hinging are considered and using thousands nonlinear time history analysis,displacement amplification factors are *** results indicate that the suggested equations in current rehabilitation documents underestimate displacement demands in the presence of foundation rocking and ***,using regression analyses,new equations are proposed to estimate mean values of C1.

关键词： soil-structure interaction rocking and uplifting foundations displacement amplification factor

Data driven models for compressive strength prediction of concrete at high temperatures

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2020年第2期14卷 311-321页

作者： Mahmood AKBARI vahid JAFARI DELIGANI Department of Civil Engineering Faculty of EngineeringUniversity of KashanKashan ***Iran

The use of data driven models has been shown to be useful for simulating complex engineering processes,when the only information available consists of the data of the *** this study,four data-driven models,namely multiple linear regression,artificial neural network,adaptive neural fuzzy inference system,and K nearest neighbor models based on collection of 207 laboratory tests,are investigated for compressive strength prediction of concrete at high *** addition for each model,two different sets of input variables are examined:a complete set and a parsimonious set of involved *** results obtained are compared with each other and also to the equations of NIST Technical Note standard and demonstrate the suitability of using the data driven models to predict the compressive strength at high *** addition,the results show employing the parsimonious set of input variables is sufficient for the data driven models to make satisfactory results.

关键词： data driven model compressive strength oncrete high temperature

Mechanical Properties and Microstructure Evolution of AA1100 Aluminum Sheet Processed by Accumulative Press Bonding Process

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2016年第8期29卷 735-741页

作者： Amir Mostafapor vahid Mohammadinia Department of Mechanical Engineering University of Tabriz Department of Mechanical Engineering University of Maragheh

Accumulative press bonding（APB） is a novel variant of severe plastic deformation processes,which is devised to produce materials with ultra-fine *** the present work,the mechanical properties and microstructural evolution of AA1100 alloy,which is produced by APB technique,were *** study of the microstructure of AA1100 alloy was performed by optical *** results revealed that the grain size of the samples decreased to 950 nm after six passes of APB *** yield strength of AA1100 alloy after six passes of the process increased up to 264 MPa,which is three times higher than that of the as-cast material（89 MPa）.After six passes,microhardness values of AA1100 alloy increased from 38 to 61 ***,the results showed that the behavior of variations in mechanical properties is in accordance with the microstructural changes and it can be justified by using the Hall-Patch ***,the rise in the yield strength can be attributed to the reduction in the grain size leading to the strain hardening.

关键词： Severe plastic deformation Accumulative press bonding Mechanical properties Metallurgical properties AA1100 alloy