检索结果-南通市图书馆

An Alternative Approach to the Extraction of Structure Functions in Deep Inelastic e—p Scattering at 5 to 20 GeV

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2003年第5期39卷 573-578页

作者： N.Ghahramany M.nouri DepartmentofPhysics ShirazUniversityShiraz71548Iran

Two structure functions W1(x,Q2) and W2(x,Q2) are determined by using the cross sections measured in the deep inelastic electron-proton scattering experiments at Stanford Linac in the energy range of 5 to 20 GeV. In this paper an alternative mathematical approach have been used in such determination, resulting in a larger number of points in the graphs of the structure functions.

关键词：结构函数无弹性散射横截面交错逼近粒子模型

Effect of Surface Treatment and Metallic Coating on Corrosion Behavior and Biocompatibility of Surgical 316L Stainless Steel Implant

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

Journal of Materials Science & Technology 2012年第2期28卷 125-131页

作者： Ali Parsapour Saied nouri Khorasani Mohammad Hossein Fathi Department of Materials Engineering Isfahan University of Technology Department of Chemical Engineering Isfahan University of Technology

Surface engineering technology is a suitable method for coatings on the metal surfaces or performing surface modification treatment, which can improve corrosion resistance and biocompatibility of metals. In this research, corrosion behavior of Nb coating on H2SO4 and HNO3 treated AISI stainless steel 316L （SS） was evaluated. Nb coating was carried out using physical vapor deposition process on the SS. Characterization techniques including scanning electron microscopy （SEM） and energy dispersive X-ray （EDX） technique were used to investigate the microstructure and morphology of the coated and treated SS. Electrochemical potentiodynamic tests were performed in two types of physiological solutions and compared with the pristine SS specimens. Cyclic polarization tests were performed to evaluate resistivity against pitting. Experimental results indicate that Nb coating and surface treatment of the SS had a positive effect on improvement of corrosion behavior. The decrease in corrosion current densities was significant for coated and treated specimens. The corrosion current density was much lower than the values obtained for pristine specimens.

关键词： 316L stainless steel Corrosion behavior Nb coating Surface treatment

Analytical model of sound transmission through laminated composite cylindrical shells considering transverse shear deformation

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2008年第9期29卷 1165-1177页

作者： Kamran Daneshjou Ali nouri Roohollah Talebitooti Department of Mechanical Engineering Iran University of Science and TechnologyNarmak

Composite structures are often used in the aerospace industry due to the advantages offered by a high strength to weight ratio. Sound transmission through an infinite laminated composite cylindrical shell is studied in the context of the transmission of airborne sound into the aircraft interior. The shell is immersed in an external fluid medium and contains internal fluid. Airflow in the external fluid medium moves with a constant velocity. An exact solution is obtained by simultaneously solving the first-order shear deformation theory （FSDT） of a laminated composite shell and the acoustic wave equations. Transmission losses （TL） obtained from numerical solutions are compared with those of other authors. The effects of structural properties and flight conditions on TL are studied for a range of values, especially, the Mach number, stack sequences, and the angle of warp. Additionally, comparisons of the transmission losses are made between the classical thin shell theory （CST） and FSDT for laminated composite and isotropic cylindrical shells.

关键词： plane wave transmission loss laminated composite shell first-order

Corrosion Behavior and Biocompatibility of Hydroxyapatite Coating on H_2SO_4 Passivated 316L SS for Human Body Implant

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2013年第4期26卷 409-415页

作者： Ali Parsapour Saied nouri Khorasani Mohammad Hossein Fathi Biomaterials Research Center Department of Chemical Engineering Isfahan University of Technology Department of Materials Engineering Isfahan University of Technology

The aim of this studies at simultaneous improvement of the corrosion behavior and biocompatibility of metallic implant and bone Osseointegration simultaneously. Stainless steel 316L （SS） was used as metallic substrate and after surface treatment with 15 vol.% sulfuric acid, it was coated with hydroxyapatite coating employing plasma - spraying process. Structure characterization techniques including XRD, SEM and EDX were also utilized to investigate the microstructure, morphology, and crystallinity of the coating. Electrochemical potentiodynamic tests were performed in two types of physiological solutions in order to determine and compare the corrosion resistance behavior of the coated and uncoated specimens as an indication of biocompatibility. The results indicate that the surface treatment and hydroxyapatite coating improve the corrosion resistance behavior of SS. The corrosion current density of the surface treated and the hydroxyapatite coated SS also decrease. These also show that surface treated and hydroxyapatite coated SS can be used as human body implants with the goals of corrosion resistance improvement （biocompatibility） and bone osseointegration.

关键词： Surface treatment Hydroxyapatite coating Corrosion behavior Plasma spray Stainless steel 316L Human body implant

Nonlinear Dust Acoustic Waves in a Magnetized Dusty Plasma with Trapped and Superthermal Electrons

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2014年第6期16卷 545-551页

作者： S.Ahmadi ABRISHAMI M.nouri KADIJANI Islamic Azad University Torbateheydarieh Branch Torbateheydarieh Young Researchers and Elite Club Kashmar Branch Islamic Azad University

In this work, the effects of superthermal and trapped electrons on the oblique propa- gation of nonlinear dust-acoustic waves in a magnetized dusty （complex） plasma are investigated. The dynamic of electrons is simulated by the generalized Lorentzian （k） distribution function （DF）. The dust grains are cold and their dynamics are simulated by hydrodynamic equations. Using the standard reductive perturbation technique （RPT） a nonlinear modified Korteweg-de Vries （mKdV） equation is derived. Two types of solitary waves; fast and slow dust acoustic solitons, exist in this plasma. Calculations reveal that compressive solitary structures are likely to propagate in this plasma where dust grains are negatively （or positively） charged. The properties of dust acoustic solitons （DASs） are also investigated numerically.

关键词： dust acoustic wave trapped electrons superthermal electrons kappa distribution function

Additive manufacturing of metallic and polymeric load-bearing biomaterials using laser powder bed fusion:A review

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第35期94卷 196-215页

作者： Alireza nouri Anahita Rohani Shirvan Yuncang Li Cuie Wen School of Engineering RMIT UniversityMelbourneVictoria 3001Australia Biomedical Engineering Department Amirkabir University of TechnologyTehranIran Textile Engineering Department Amirkabir University of TechnologyTehranIran

Surgical prostheses and implants used in hard-tissue engineering should satisfy all the clinical,mechanical,manufacturing,and economic requirements in order to be used for load-bearing ***,and to a lesser extent,polymers are promising materials that have long been used as load-bearing *** the rapid development of additive manufacturing(AM)technology,metallic and polymeric implants with complex structures that were once impractical to manufacture using traditional processing methods can now easily be made by *** technology has emerged over the past four decades as a rapid and cost-effective fabrication method for geometrically complex implants with high levels of accuracy and *** ability to design and fabricate patient-specific,customized structural biomaterials has made AM a subject of great interest in both research and clinical *** different AM methods,laser powder bed fusion(L-PBF)is emerging as the most popular and reliable AM method for producing load-bearing *** layer-by-layer process uses a high-energy laser beam to sinter or melt powders into a part patterned by a computer-aided design(CAD)*** most important load-bearing applications of L-PBF-manufactured biomaterials include orthopedic,traumatological,craniofacial,maxillofacial,and dental *** unequalled design freedom of AM technology,and L-PBF in particular,also allows fabrication of complex and customized metallic and polymeric scaffolds by altering the topology and controlling the macro-porosity of the *** article gives an overview of the L-PBF method for the fabrication of load-bearing metallic and polymeric biomaterials.

关键词： Additive manufacturing Load-bearing biomaterials Powder bed fusion(PBF) Selective laser melting(SLM) Selective laser sintering(SLS)

Second Order Sliding Mode Control for Discrete Decouplable Multivariable Systems via Input-output Models

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2015年第6期12卷 630-638页

作者： Houda Romdhane Khadija Dehri Ahmed Said nouri Numerical Control of Industrial Processes National Engineering School of Gabes University of Gabes

The problem of the chattering phenomenon is still the main drawback of the classical sliding mode control. To resolve this problem, a discrete second order sliding mode control via input-output model is proposed in this paper. The proposed control law is synthesized for decouplable multivariable systems. A robustness analysis of the proposed discrete second order sliding mode control is carried out. Simulation results are presented to illustrate the effectiveness of the proposed strategy.

关键词： Discrete second order sliding mode control decoupl

Effects of Silicon Content and Intercritical Annealing on Manganese Partitioning in Dual Phase Steels

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2010年第5期17卷 44-50页

作者： A nouri H Saghafian Sh Kheirandish Department of Metallurgy and Materials Engineering Iran University of Science and Technology

Steels of constant manganese and carbon contents with silicon content of 0.34 %- 2.26% were cast. The as-cast steels were then hot rolled at 1 100 ℃ in five passes to reduce the cast ingot thickness from 80 to 4 mm, air cooled to room temperature and cold rolled to 2 mm in thickness. Dual phase microstructures with different volume fraction of martensite were obtained through the intercritical annealing of the steels at different temperatures for 15 min followed by water quenching. In addition to intercritical annealing temperature, silicon content also altered the volume fraction of martensite in dual phase steels. The partitioning of manganese in dual phase silicon steels was investigated using energy-dispersive spectrometer （EDS）. The partitioning coefficient, defined as the ratio of the amounts of alloying element in the austenite to that in the adjacent ferrite, for manganese increased with increasing intercritieal annealing temperature and silicon content of steels. It was also found that the solubility of manganese in ferrite and austenite decreased with increasing intereritical temperature. The results were discussed by the diffusivity and the solubility of manganese in ferrite and austenite existed in dual phase silicon steels.

关键词： partitioning dual phase steel intercritical annealing temperature silicon manganese

Seismic evaluation of rocking structures through performance assessment and fragility analysis

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2016年第1期15卷 115-127页

作者： Mohammad G. Vetr Abolfazl Riahi nouri Afshin Kalantari International Institute of Earthquake Engineering and Seismology (IIEES) Tehran Iran

Numerical studies have been conducted for low- and medium-rise rocking structures to investigate their efficiency as earthquake-resisting systems in comparison with conventional structures. Several non-linear time-history analyses have been performed to evaluate seismic performance of selected cases at desired ground shaking levels, based on key parameters such as total and flexural story drifts and residual deformations. The Far-field record set is selected as input ground motions and median peak values of key parameters are taken as best estimates of system response. In addition, in order to evaluate the probability of exceeding relevant damage states, analytical fragility curves have been developed based on the results of the incremental dynamic analysis procedure. Small exceedance probabilities and acceptable margins against collapse, together with minor associated damages in main structural members, can be considered as superior seismic performance for medium-rise rocking systems. Low-rise rocking systems could provide significant performance improvement over their conventional counterparts notwithstanding certain weaknesses in their seismic response.

关键词： rocking structures conventional structures seismic performance fragility curves