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Hygroelasticity analysis of an elastically restrained functionally graded porous metamaterial circular plate resting on an auxetic material circular plate

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Applied Mathematics and Mechanics(English Edition) 2020年第9期41卷 1359-1380页

作者： A.BEHRAVAN-rad M.jafari Faculty of Mechanical and Mechatronics Engineering Shahrood University of TechnologyShahrood ***Iran

The main objective of this research is to investigate the hygroelastic behavior of a non-homogeneous circular plate made up of porous metamaterial resting on an auxetic material *** mechanical properties of the main plate,as well as moisture concentration,vary as an exponential function in the transverse ***’s ratio is *** elastic supporting medium is developed by considering the structurestructure *** on the linear hygroelasticity theory,the governing state equations in terms of displacements and moisture concentration are *** first,the Fickian equation is solved to compute the nonlinear distribution of moisture through the plate thickness,and then the state equations are semi-analytically solved using the statespace(SS)method and the differential quadrature(DQ)rule to predict the elastic field quantities.A comprehensive parametric analysis is accomplished to elucidate the effects of key parameters on the steady-state response of the plate under the mechanical and hygral loads.

关键词： metamaterial hygroelasticity auxeticity hygral interaction

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Total Restrained Bondage in Graphs

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Acta Mathematica Sinica,English Series 2013年第6期29卷 1033-1042页

作者： Nader jafari rad Roslan HASNI Joanna RACZEK Lutz VOLKMANN Department of Mathematics Shahrood University of Technology Department of Mathematics Faculty of Science and Technology University Malaysia Terengganu Department of Mathematics Gdansk University of Technology Lehrstuhl II fr Mathematik RWTH Aachen University

A subset S of vertices of a graph G with no isolated vertex is a total restrained dominating set if every vertex is adjacent to a vertex in S and every vertex in V （G） S is also adjacent to a vertex in V （G） S. The total restrained domination number of G is the minimum cardinality of a total restrained dominating set of G. In this paper we initiate the study of total restrained bondage in graphs. The total restrained bondage number in a graph G with no isolated vertex, is the minimum cardinality of a subset of edges E such that G E has no isolated vertex and the total restrained domination number of G E is greater than the total restrained domination number of G. We obtain several properties, exact values and bounds for the total restrained bondage number of a graph.

关键词： Domination total restrained domination bondage

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Effect of Multi-Step Tempering on Retained Austenite and Mechanical Properties of Low Alloy Steel

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Journal of Iron and Steel Research(International) 2011年第12期18卷 49-56页

作者： Hamid Reza Bakhsheshi-rad Ahmad Monshi Hossain Monajatizadeh Mohd Hasbullah Idris Mohammed Rafiq Abdul Kadir Hassan jafari Materials Engineering Department Islamic Azad University Materials Engineering Department Faculty of Mechanical EngineeringUniversity Technology Malaysia Materials Engineering Department Faculty of Mechanical EngineeringShahid Rajaee Teacher Training University

The effect of multi-step tempering on retained austenite content and mechanical properties of low alloy steel used in the forged cold back-up roll was *** evolutions were characterized by optical microscope,X-ray diffraction,scanning electron microscope and Feritscope,while the mechanical properties were determined by hardness and tensile *** results revealed that the content of retained austenite decreased by about 2% after multi-step ***,the content of retained austenite increased from 3.6% to 5.1% by increasing multi-step tempering *** hardness and tensile strength increased as the austenitization temperature changed from 800 to 920 ℃,while above 920 ℃,hardness and tensile strength *** addition,the maximum values of hardness,ultimate and yield strength were obtained via triple tempering at 520 ℃,while beyond 520 ℃,the hardness,ultimate and yield strength decreased sharply.

关键词： cold back-up roll retained austenite mechanical property austenite grain size

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Some NP-Complete Results on Signed Mixed Domination Problem

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Journal of Mathematical Research with Applications 2017年第2期37卷 163-168页

作者： Yancai ZHAO Huahui SHANG H.Abdollahzadeh AHANGAR N.jafari rad Department of Basic Science Wuxi City College of Vocational Technology Department of Basic Science Yongcheng Vocational College Department of Mathematics Babol Noshirvani University of Technology Department of Mathematics Shahrood University of Technology

Let G =（V, E） be a simple graph with vertex set V and edge set E. A signed mixed dominating function of G is a function f:V∪E→ {-1, 1} such that ∑;f（y）≥ 1for every element x∈V∪E, where N;（x） is the set of elements of V∪E adjacent or incident to x. The weight of f is w（f） =∑;f（x）. The signed mixed domination problem is to find a minimum-weight signed mixed dominating function of a graph. In this paper we study the computational complexity of signed mixed domination problem. We prove that the signed mixed domination problem is NP-complete for bipartite graphs, chordal graphs, even for planar bipartite graphs.

关键词： signed mixed dominating function signed mixed domination number NP-completeness

Porphyry Copper Mineral Prospectivity Mapping Using Interval Valued Fuzzy Sets Topsis Method in Central Iran

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Journal of Geographic Information System 2011年第4期3卷 312-317页

作者： Ali Reza jafari rad W. Busch 不详

Geospatial Information System (GIS) provide tools to quantitatively analysis and combination of datasets from geological, geophysical, remote sensing and geochemical surveys for decision-making processes. Excellent coverage of well-documented and good quality data enables testing of variable exploration modeling in an efficient way. The study area of this research is the most important part of Cu (Mo) porphyry—type mineralization belt in Iran. There are some well-known porphyry copper deposits in this region like Sarcheshmeh and Meiduk mines, but certainly there are same grounds to search for new porphyry deposits. The risks of developing mineral resources need to be known as accurately as possible, with regarding to all features those are effective in mineralization. These features can be recognized respect to Critical Genetic Factors (CGF’s) using Critical Recognition Criteria (CRC) for each type of mineralization. CGF’s can be employed for designing a Conceptual Genetic Model (CGM). Evidence maps create on the basis of CGM and then integrate together for production of Mineral Prospectivity Map (MPM). This map categorizes the areas based on their exploration importance. There are several techniques for creation of MPM. Interval Valued Fuzzy Sets (IVFSs) TOPSIS method was applied in this research. This method as a knowledge-driven method, allocate appropriate weights to layers on the basis of the effective membership, non membership, and non-certainty. The fundamental concept of TOPSIS is that the chosen alternatives should have the shortest distance from the positive ideal points (A*) and the farthest distance from negative ideal points (A-).

关键词： Mineral Prospectivity Mapping Porphyry Copper IVFSs TOPSIS Iran

Geochemistry of Host and Altered Rocks in the Nahran Area, Tarom Zone (NW Iran): Implication for Determining of Mineralization Processes in the Alteration Environment

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Open Journal of Geology 2017年第3期7卷 374-394页

作者： Nasrin Bayrami Tosanloo Hamid Reza Peyrowan Seyed Jamal Sheikhzakariee Ali Reza jafari rad Department of Geology Science and Research Branch Islamic Azad University Tehran Iran Soil Conservation and Watershed Management Research Institute Tehran Iran

The Nahran area is located in the Northeast of Zanjan in the Northwest of Iran. This area with 20,000 km2 is part of the Tarom volcanic-plutonic zone which lies between the longitudes 49°7'7.8"E and 36°41'25.74"E near to the Nahran village. The Nahran altered zone is part of large-scale syncline, which is oriented from Sirdan to Altinkosh with an axial length of 9 km. A systematic study of petrographical and geochemical data of Nahran samples reveals they are andesite, trachyandesite to dacite composition and have metaluminous to peraluminous and calc-alkaline affinity. Four alteration zones of propylitic, medium and advanced argillic and silicific zones could be identified in the area. According to our finding, combination of both supergene and hypogene process has an effective role in the development of alteration in the Nahran alteration zone.

关键词： Tarom Nahran Alteration Hypogene Supergene