检索结果-南通市图书馆

Computational Study of Electromagnetic Fields,Eddy Currents and Induction Heating in Thin and Thick Workpieces

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2010年第6期8卷 211-225页

作者： mohammad hossein Tavakoli hossein Karbaschi Feridoun Samavat Physics Department Bu-Ali Sina UniversityHamedan 65174Iran

A set of 2D steady state finite element numerical simulations of electromagnetic fields,eddy currents distribution and induction heating pattern has been done for different thicknesses of a metal *** between the calculation results show the importance of workpiece thickness on induction heating process including electromagnetic field distribution,eddy currents pattern,heating structure and coil efficiency.

关键词： Computer simulation finite element analysis modeling induction heating metals

Evaluating and modeling the spatiotemporal pattern of regional-scale salinized land expansion in highly sensitive shoreline landscape of southeastern Iran

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 Arid Land 2018年第6期10卷 946-958页

作者： mohammad SHAFIEZADEH hossein MORADI Sima FAKHERAN Department of Natural Resources Isfahan University of Technology

Taking an area of about 2.3×10~4 km~2 of southeastern Iran, this study aims to detect and predict regional-scale salt-affected lands. Three sets of Landsat images, each set containing 4 images for 1986, 2000, and 2015 were acquired as the main source of data. Radiometric, atmospheric and cutline blending methods were used to improve the quality of images and help better classify salinized land areas under the support vector machine method. A set of landscape metrics was also employed to detect the spatial pattern of salinized land expansion from 1986 to 2015. Four factors including distance to sea, distance to sea water channels, slope, and elevation were identified as the main contributing factors to land salinization. These factors were then integrated using the multi-criteria evaluation (MCE) procedure to generate land sensitivity map to salinization and also to calibrate the cellular-automata (CA) Markov chain (CA-Markov) model for simulation of salt-affected lands up to 2030, 2040 and 2050. The results of this study showed a dramatic dispersive expansion of salinized land from 7.7 % to 12.7% of the total study area from 1986 to 2015. The majority of areas prone to salinization and the highest sensitivity of land to salinization was found to be in the southeastern parts of the region. The result of the MCE-informed CA-Markov model revealed that 20.3% of the study area is likely to be converted to salinized lands by 2050. The findings of this research provided a view of the magnitude and direction of salinized land expansion in a past-to-future time period which should be considered in future land development strategies.

关键词： soil salinization remote sensing CA-Markov salt land expansion southeastern Iran

QUASI-PERMUTATION REPRESENTATIONS OF ALTERNATING AND SYMMETRIC GROUPS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2007年第2期27卷 297-300页

作者： Houshang Behravesh mohammad hossein Jafari Department of Mathematics University of Urmia UrmiaIran Department of Mathematics University of Tabriz TabrizIran

The quantities c（G）, q（G） and p（G） for finite groups were defined by H. Behravesh. In this article, these quantities for the alternating group An and the symmetric group Sn are calculated. It is shown that c（G... 详细信息

关键词： Quasi-permutation representations alternating groups symmetric groups character theory

Two-dimensional Modeling of a Salt-gradient Solar Pond with Wall Shading Effect and Thermo-physical Properties Dependent on Temperature and Concentration

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第4期20卷 362-370页

作者： Mohsen Mazidi mohammad Hassan Shojaeefard mohammad Sh.Mazidi hossein Shojaeefard Mechanical Engineering Department Islamic Azad University School of Mechanical Engineering Iran University of Science and Technology Management Business Administration Department Amirkabir University of Technology

In this paper,the behavior of a salt-gradient solar pond with the square cross-section has been studied experimentally and numerically.A small-scale solar pond were designed and built to provide quantitative data.A two-dimensional,transient heat and mass transfer model has been solved numerically by using finite-control-volume *** this study,all the thermo-physical properties are variable as the function of temperature and salt *** results as obtained for the experimental pond have been satisfactorily compared and validated against measured ***,the wall shading effect has been elaborated to improve the agreement between two sets of *** temperature of the storage zone is predicted well by the *** also can be observed that the initial concentration profile is preserved with *** stability of the pond in time has been investigated in order to distinguish the critical ***,the application of an energy analysis gives an efficiency of about 12%for the pond.

关键词： solar energy salt-gradient solar pond transient heat and mass transfer temperature and concentration profiles stability thermal efficiency

Application of diazo-thiourea and gold nano-particles in the design of a highly sensitive and selective DNA biosensor

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2015年第1期26卷 160-166页

作者： mohammad hossein Mashhadizadeh Rasoul Pourtaghavi Talemi Faculty of Chemistry Kharazmi(Tarbiat Moallem)University

An effective procedure for constructing a DNA biosensor is developed based on covalent immobilization of NH2 labeled,single strand DNA（NH2-ssDNA） onto a self-assembled diazo-thiourea and gold nanoparticles modified Au electrode（diazo-thiourea/GNM/Au）.Gold nano-particles expand the electrode surface area and increase the amount of immobilized thiourea and single stranded DNA（ssDNA） onto the electrode ***-thiourea film provides a surface with high conductibility for electron transfer and a bed for the covalent coupling of NH2-ssDNA onto the electrode *** immobilization and hybridization of the probe DNA on the modified electrode is studied by differential pulse voltammetry（DPV） using methylene blue（MB） as a well-known electrochemical hybridization *** linear range for the determination of complementary target ssDNA is from 9.5（±0.1） × 10^-13 mol/L to1.2（±0.2） x 10^-9 mol/L with a detection limit of 1.2（±0.1）〉 10^-13 mol/L.

关键词： DNA biosensor Gold nano-particles Thiourea Methylene blue

Assessment of land suitability and agricultural production sustainability using a combined approach (Fuzzy-AHP-GIS):A case study of Mazandaran province,Iran

在线全文

学校读者我要写书评

暂无评论

Information Processing in Agriculture 2020年第3期7卷 384-402页

作者： Sherwin Amini Abbas Rohani mohammad hossein Aghkhani mohammad hossein Abbaspour-Fard mohammad Reza Asgharipour Department of Biosystems Engineering Faculty of AgricultureFerdowsi University of MashhadIran Unit of Agroecology Department of AgronomyFaculty of AgricultureUniversity of ZabolZabolIran

This research was conducted to evaluate the sustainability of rice production using fuzzy logic in Mazandaran province,*** untapped use of modern agricultural technology,such as agricultural machinery,has become a global dilemma,which has forced governments and environmentalists to take a serious stand against the dangers of massive non-standard agricultural practices in the *** types of mechanization,socioeconomic,and economic modeling were used to determine the sustainability and their values were collected through interview method using a 320-item questionnaire from 2016 to *** evaluation was carried out using soil and climate characteristics,so that about 27.4%of the area was in the perfectly suitable range(S1),35.2%in the appropriate range(S2),19.5%in the critical range(S3),and 17.9%in the inappropriate range(N)for rice *** were selected from two regions(R1 and R2)by the GIS on two lower levels and more than one hectare(A1,A2)according to agricultural methods(mechanical and traditional).The results showed that the highest and lowest means of the product were 4314.44 and 3501.95 kg ha1,*** sustainability of production was within the range of“sustainability”and“almost sustainable”in terms of mechanistic and economic factors in the fuzzy range of“moderate sustainability”and also with respect to social factors that are in a better position than mechanistic and economic *** of final sustainability model showed that the average of the lasting sustainability index was in the range of“almost unsustainable”and“moderate sustainability”.

关键词： Sustainable agriculture Fuzzy logics Environmental management Rice GIS AHP

Ophthalmic practice during COVID-19 pandemic

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2021年第5期14卷 639-642页

作者： mohammad Soleimani mohammad Mehrpour hossein mohammad-Rabei Ocular Trauma and Emergency Department Eye Research CenterFarabi Eye HospitalTehran University of Medical SciencesTehran ***Iran Basir Eye Health Research Center Tehran ***Iran

Coronavirus disease 2019(COVID-19) pandemic has caused significant changes in ophthalmic practice. The initial strategy of strict restriction of elective activities has been replaced with various guidelines to revitalize ophthalmic procedures considering the new safety concerns. In this manuscript, we reviewed recent recommendations for ophthalmic practice in different fields of ophthalmology during the COVID-19 pandemic.

关键词： ophthalmic practice COVID-19 pandemics recent

Numerical Simulation of the Mechanical Properties of Sintered and Bonded Perforated Hollow Sphere Structures (PHSS)

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 Materials Science & Technology 2010年第8期26卷 730-736页

作者： Andreas chsner Seyed mohammad hossein hosseini Markus Merkel Department of Applied Mechanics Technical University of Malaysia Centre for Mass and Mechanical Transport in Engineering Materials The University of Newcastle CallaghanNewSouth Wales 2308Australia Department of Mechanical Engineering University of Applied Sciences Aalen

This paper investigated the uniaxial mechanical properties of a new type of hollow sphere structures. For this new type, the sphere shell was perforated by several holes in order to open the inner sphere volume and surface. The mechanical properties, i.e. elastic properties and initial yield stress of perforated hollow sphere structures （PHSS） in a primitive cubic arrangement were numerically evaluated for different hole diameters and different joining techniques of the hollow spheres. The results are compared to classical configurations without perforation.

关键词： Mechanical properties Cellular material Porous structure Finite element method

Investigation of Hydrous Pyrolysis on Type-Ⅱ Kerogen-bearing Source Rocks from Iran and its Application in Geochemical and Kinetic Analyses of Hydrocarbon Products

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2021年第5期95卷 1736-1745页

作者： Shahryar KASHI mohammad hossein SABERI Faramarz HORMOZI Faculty of New Science and Technology Department of Petroleum EngineeringSemnan UniversitySemnan ***Iran Faculty of Chemical Petroleum and Gas EngineeringSemnan UniversitySemnan ***Iran

Hydrous pyrolysis(HP)practiced on type-Ⅱ kerogen-bearing oil shale samples from the Sargelu Formation in the Ghali-Kuh Area,western Iran,using a specially designed apparatus was performed at different temperatures(250-350℃),with hydrocarbon generation evaluated at each *** comparison,the samples subjected to Rock-Eval pyrolysis before proceeding to HP resulted in T_(max)=418℃,HI=102,and TOC=4.33%,indicating immaturity and hence remarkable hydrocarbon(especially oil)generation potential,making them appropriate for ***,the samples were deposited in a low-energy reductive marine environment,with maximum oil and gas generation(739 mg and 348 mg out of50 g of rock sample,respectively)observed at 330℃ and 350℃,*** oil generated at 330℃ was subjected to gas chromatography(GC)and isotopic analyses to assess hydrocarbon quality and *** hydrocarbon generation data was devised to estimate kinetic indices of the Arrhenius equation and to investigate the gas-oil ratio(GOR)and overall conversion *** on the producible hydrocarbon quantity and quality,the findings contribute to the economic assessment of oil shales across the study *** developed kinetic model indicates the history of hydrocarbon generation and organic matter(OM)maturity.

关键词： unconventional hydrocarbons oil shale hydrous pyrolysis organic matter maturity Arrhenius equation Sargelu Formation Lurestan province