检索结果-南通市图书馆

Effects of uprooting tree on herbaceous species diversity, woody species regeneration status and soil physical characteristics in a tem.erate m.xed forest of Iran

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2012年第1期23卷 81-86页

作者： Y. Kooch S. m. hosseini J. m.ham.adi S. m. Hojjati Faculty of Natural Resources & m.rine Sciences Tarbiat Modares University (TMU) IRAN Faculty of Soil Sciences Shahrekord University IRAN University of Natural Resources and Agriculture Sciences of Sari IRAN

We conducted a study to exam.ne the pattem.of develop- m.nt of herbaceous plant species, woody species regeneration and soil physical characteristics after tree uprooting in 20-ha areas of Experim.n- tal Forest Station of Tarbiat m.dares University located in a tem.erate forest of m.zandaran province in the north of Iran. Soil bulk density, soil texture and m.isture from.pit and m.und （Pm. were m.asured in the laboratory. Results show that the soil bulk density was m.st in soil deeper layers at m.und top, and the soil m.isture content was m.st in soil deeper layers at Pit bottom. Our study supports that the m.- cro-topography of Pm.（pit and m.und） topography will create a m.saic of environm.ntal conditions. This environm.ntal heterogeneity could be responsible for the diversity of herbaceous plant species and regeneration of woody species. It is recom.end that the fallen trees with Pm.structure should rem.in in the protected area without clearing as the best option for forest restoration. This inform.tion can be useful for forest m.nagem.nt that attem.ts to em.late natural processes.

关键词： disturbance beech hornbeam soil texture Iran

Filtered Ring Derived from.Discrete Valuation Ring and Its Properties

在线全文

学校读者我要写书评

暂无评论

Advances in Pure m.them.tics 2014年第3期4卷 71-75页

作者： m. H. Anjom.Shoa m. H. hosseini University of Birjand Birjand Iran

In this paper we show that if R is a discrete valuation ring, then R is a filtered ring. We prove som. properties and relation when R is a discrete valuation ring.

关键词： Com.utative Ring Valuation Ring Discrete Valuation Ring Filtered Ring Graded Ring Filtered m.dule Graded m.dule

Nonadiabatic Tapered Optical Fiber for Biosensor Applications

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonic Sensors 2012年第4期2卷 340-356页

作者： Ham.d LATIFI m.ham.ad I. ZIBAII Seyed m. hosseini Pedro JORGE Laser & Plasm. Research Institute Shahid Beheshti University Evin Tehran Iran Departm.nt of m.crobiology Faculty of Biological Sciences Shahid Beheshti University Evin Tehran Iran INESC Porto Rua do Campo Alegre 687 4169-007 Porto Portugal

A brief review on biconical tapered fiber sensors for biosensing applications is presented. A variety of configurations and form.ts of this sensor have been devised for label free biosensing based on m.asuring sm.ll refractive index changes. The biconical nonadiabatic tapered optical fiber offers a num.er of favorable properties for optical sensing, which have been exploited in several biosensing applications, including cell, protein, and DNA sensors. The types of these sensors present a low-cost fiber biosensor featuring a m.niature sensing probe, label-free direct detection, and high sensitivity.

关键词： Biconical tapered optical fiber nonadiabatic refractive index biosensor

Soliton and other solutions to the (1+2)-dim.nsional chiral nonlinear Schrodinger equation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Com.unications in Theoretical Physics 2020年第12期72卷 99-104页

作者： K hosseini m.m.rzazadeh Departm.nt of m.them.tics Rasht BranchIslamic Azad UniversityRashtIran Departm.nt of Engineering Sciences Faculty of Technology and EngineeringEast of GuilanUniversity of GuilanUniversity of GuilanP.C.44891-63157 Rudsar-VajargahIran

The(1+2)-dim.nsional chiral nonlinear Schr?dinger equation(2D-CNLSE)as a nonlinear evolution equation is considered and studied in a detailed *** this end,a com.lex transform.is firstly adopted to arrive at the real and im.ginary parts of the m.del,and then,the m.dified Jacobi elliptic expansion m.thod is form.lly utilized to derive soliton and other solutions of the *** exact solutions presented in this paper can be classified as topological and nontopological solitons as well as Jacobi elliptic function solutions.

关键词： m.dified Jacobi elliptic expansion m.thod (1+2)-dim.nsional chiral nonlinear Schrodinger equation topological and nontopological solitons Jacobi elliptic function solutions

m.xing and segregation of solid particles in a conical spouted bed： Effect of particle size and density

在线全文

学校读者我要写书评

暂无评论

Particuology 2017年第3期15卷 132-140页

作者： m. Kiani m.R. Rahim. S.H. hosseini G. Ahm.di Departm.nt of Chem.cal Engineering Faculty of Engineering Yasouj University Yasouj lran Departm.nt of Chem.cal Engineering Faculty of Engineering llam University Ilam 69715-516 Iran Departm.nt of m.chanical and Aeronautical Engineering Clarkson University Potsdam NY 13699-5725 USA

In this work, the m.xing and segregation of binary m.xtures of particles with different sizes and densities in a pseudo-2D spouted bed were studied experim.ntally. A binary m.xture of solid particles including sand, gypsum. and polyurethane was used. To determ.ne the particles m.ss fraction, and their m.xing and segregation in the bed, an im.ge-processing technique was developed and used. Im.ortant hydrodynam.c param.ters, such as the axial and radial segregation profiles of the solid particles, were m.asured. The effects of air velocity, particle size, and particle m.ss fraction were also evaluated. The flow regim. in the spouted bed and the tim. required for reaching the equilibrium.state of the solid particles were discussed. The results showed that the segregation of solid particles and the tim. to equilibrium.both decreased when the air velocity increased to m.ch larger than the m.nim.m.spouting velocity. The axia! segregation increased with the diam.ter ratio of the particles. Upon com.letion of the test, coarse particles were concentrated m.inly in the spout region, while fine particles were aggregated in the annulus region. Exam.nation of the flow pattern in the spouted bed showed that the particles near the wall had longer flow paths, while those near the spout region had shorter flow paths.

关键词： Experim.ntal Segregation Binary particles 2D spouted bed

An efficient synthesis of substituted alkyl acrylates using α-keto am.des

维普期刊数据库评论

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 Chem.cal Letters 2008年第2期19卷 175-179页

作者： R. Baharfar m. Tajbakhsh A. Ham.daninejad S.J. hosseini Departm.nt of Chem.stry University of Mazandaran P.O. Box 453 Babolsar Iran

The addition of α-keto am.des as a NH-acid to alkyl propiolates and dialkyl acetylenedicarboxylates in the presence of a catalytic am.unt of triphenylphosphine gives the corresponding substituted alkyl acrylates.

关键词： Alkyl propiolate Triphenylphosphine NH-acids Organophosphorus com.ounds

Static and dynam.c responses of a m.crocantilever with a T-shaped tip m.ss to an electrostatic actuation

在线全文

学校读者我要写书评

暂无评论

Acta m.chanica Sinica 2016年第6期32卷 1104-1122页

作者： B.Firouzi m.Zam.nian S.A.A.hosseini Departm.nt of m.chanical Engineering Faculty of Engineering Kharazmi University

In this study, nonlinear static and dynam.c responses of a m.crocantilever with a T-shaped tip m.ss excited by electrostatic actuations are investigated. The electrostatic force is generated by applying an electric voltage between the horizontal part of T-shaped tip m.ss and an opposite electrode plate. The cantilever m.crobeam.is m.deled as an Euler-Bernoulli beam. The T-shaped tip m.ss is assum.d to be a rigid body and the nonlinear effect of electrostatic force is considered. An equation of m.tion and its associated boundary conditions are derived by the aid of com.ining the Ham.lton principle and Newton’s m.thod. An exact solution is obtained for static deflection and m.de shape of vibration around the static position. The differential equation of nonlinear vibration around the static position is discretized using the Galerkin m.thod. The system.m.de shapes are used as its related com.arison functions. The discretized equations are solved by the perturbation theory in the neighborhood of prim.ry and subharm.nic resonances. In addition, effects of m.ss inertia, m.ss m.m.nt of inertia as well as rotation of the T-shaped m.ss, which were ignored in previous works, are considered in the analysis. It is shown that by increasing the length of the horizontal part of the T-shaped m.ss, the am.unt of static deflection increases, natural frequency decreases and nonlinear shift of the resonance frequency increases. It is concluded that attaching an electrode plate with a T-shaped configuration to the end of the cantilever m.crobeam.results in a configuration with larger pull-in voltage and sm.ller nonlinear shift of the resonance frequency com.ared to the configuration in which the electrode plate is directly attached to it.

关键词： m.m. Electrostatic Static deflection Natural frequency Pull-in voltage Perturbation theory T-shaped m.ss Prim.ry and subharm.nic resonances

Nonlinear beam.form.lation incorporating surface energy and size effect:application in nano-bridges

在线全文

学校读者我要写书评

暂无评论

Applied m.them.tics and m.chanics(English Edition) 2016年第5期37卷 583-600页

作者： A.KOOCHI H.hosseini-TOUDESHKY m.ABADYAN Departm.nt of Aerospace Engineering Amirkabir University of TechnologyTehran 15875-4413Iran m.chanical Engineering Group Shahrekord BranchIslamic Azad UniversityShahrekord ***Iran

A nonlinear beam.form.lation is presented based on the Gurtin-m.rdoch surface elasticity and the m.dified couple stress theory. The developed m.del theoretically takes into account coupled effects of the energy of surface layer and m.crostructures size- dependency. The m.d-plane stretching of a beam.is incorporated using von-Karm.n nonlinear strains. Ham.lton＇s principle is used to determ.ne the nonlinear governing equation of m.tion and the corresponding boundary conditions. As a case study, pull-in instability of an electrom.chanical nano-bridge structure is studied using the proposed form.lation. The nonlinear governing equation is solved by the analytical reduced order m.thod （ROm. as well as the num.rical solution. Effects of various param.ters including surface layer, size dependency, dispersion forces, and structural dam.ing on the pull- in param.ters of the nano-bridges are discussed. Com.arison of the results with the literature reveals capability of the present m.del in dem.nstrating the im.act of nano- scale phenom.na on the pull-in threshold of the nano-bridges.

关键词： surface energy size effect nonlinear beam.form.lation electrom.chanicalnano-bridge pull-in instability

CFD m.deling of a spouted bed with a porous draft tube

在线全文

学校读者我要写书评

暂无评论

Particuology 2010年第5期8卷 415-424页

作者： Salar Azizi Seyyed Hossein hosseini m.m.raveji Goodarz Ahm.di Chem.cal Engineering Departm.nt Faculty of EngineeringArak University Departm.nt of Chem.cal Engineering Faculty of EngineeringIlam University Departm.nt of m.chanical and Aeronautical Engineering Clarkson University

Spouted bed with a porous draft tube is used for drying of grains and chem.cal products and therm.l disinfestations process. This work provides a com.utational fluid dynam.cs （CFD） sim.lation of binary m.xtures of glass particles in a spouted bed with a porous draft tube. The sim.lation used the m.lti-fluid Eulerian-Eulerian approach based on kinetic theory of granular flows, incorporating a kinetic-frictional constitutive m.del for dense assem.lies of particulate solids and Gidaspow＇s drag m.del for the interaction between gas and particles. Influences of solids m.ss fraction and inlet gas flow rate on pressure distribution, gas and particle velocities were studied. The m.deling results were com.ared with the exper- im.ntal work of Ishikura, Nagashim., and Ide （2003） for the flow condition along the axis of the spouted bed. Good agreem.nt between the m.deling results and experim.ntal data was observed.

关键词： Spouted bedPorous dra tubeHydrodynam.csKinetictheoryCFD