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International Journal of Biomathematics 2016年第2期9卷 85-103页

作者： f. M. Abbasi t. Hayat A. Alsaedi Department of Mathematics Comsats Institute of Information Technology Islamabad 44000 Pakistan Department of Mathematics Quaid-I-Azam University 45320 Islamabad 44000 Pakistan Nonlinear Analysis and Applied Mathematics (NAAM) Research Group faculty of Science King Abdulaziz University Jeddah 21589 Saudi Arabia

Present study examines the mixed convective peristaltic transport of Cu-H2O nanofluid with velocity slip and convective boundary conditions. Analysis is performed using the two-phase model of the nanofluid. Viscous dissipation and heat generation/absorption effects are also taken into account. Problem is formulated using the long wavelength and low Reynolds number approach. Numerical solutions for the pressure rise per wavelength, pressure gradient, axial velocity, temperature and heat transfer rate at the boundaxy are obtained and studied through graphs. Results show that the area of peristaltic pumping decreases with an increase in the nanoparticles volume fraction. Increase in the velocity slip parameter shows an increase of the pressure gradient in the occluded part of the channel. further, addition of copper nanoparticles reduces both the axial velocity and temperature of the base fluid. temperature of the nanofluid also decreases sufficiently for an increase in the value of Blot number.

关键词： Peristalsis slip effects convective boundary conditions Cu-H2O nanofluid wavy walls.

A tV-Based Iterative Regularization Method for the Solutions of thermal Convection Problems

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Communications in Computational Physics 2013年第9期14卷 1120-1146页

作者： Eric t.Chung Jeff C.-f.Wong Department of Mathematics Lady Shaw BuildingThe Chinese University of Hong KongShatinHong Kong

Linear/nonlinear and Stokes based-stabilizations for the filter equations for damping out primitive variable(PV)solutions corrupted by uniformly distributed randomnoises are numerically studied through the natural convection(NC)aswell as the mixed convection(MC)*** most recognizable filter-scheme is based on a combination of the negative Laplace equation multiplied with the selection of the spatial scale and a linear function in order to preserve the uniqueness of the filtered solution.A more complicated filter-scheme,based on a Stokes problem which couples a filtered velocity and a filtered(art.ficial)pressure(or Lagrange multiplier)in order to enforce the incompressibility constraint,is also *** and Stokes basedfilters via nested iterative(NI)filters and the consistent splitting scheme(CSS)are proposed for the NC/MC *** by the total-variation(tV)model of image diffusion,well preserved feature flow patterns from the corrupted NC/MC environment are obtained by tV-Stokes based-filters together with the *** experimental results show that our proposed algorithms are effective and efficient in eliminating the unwanted spurious oscillations and preserving the accuracy of thermal convective fluid flows.

关键词： Linear/nonlinear differential filter Stokes differential filters Leray-alpha model total-variation regularization

Novel micro-ring structured ZnO photoelectrode for dye-sensitized solar cell

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Nano-Micro Letters 2010年第1期2卷 53-55页

作者： M.f.Hossain Z.H.Zhang t.takahashi Graduate School of Science and Engineering for Education University of Toyama Graduate School of Science and Engineering for Research University of Toyama

the micro-ring like structured zinc oxide(ZnO) film was deposited on SnO_2: f coated glass substrate by sol-gel dip-coating technique with 1.0 g polyethylene glycol(PEG) content. the surface morphology of micro-ring structured ZnO film has been confirmed by the scanning electron microscope. this ZnO film is used to fabricate the solar cell with the help of ruthenium based dye and carbon counter electrode. the photoelectric and incident photon-to-current conversion efficiency was 1.17% and 48.4%, respectively. the DSC results have been compared with ZnO films prepared without PEG contents.

关键词： Zinc oxide Dye-sensitized solar cell Polyethylene glycol

IMPROVEMENt Of tYPE IV CRACKING RESIStANCE Of 9Cr HEAt RESIStING StEEL WELDMENt BY BORON ADDItION

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 331-337页

作者： M.tabuchi M.Kondo t.Watanabe H.Hongo f.Yin f.Abe National Institute for Materials Science Tsukuba Ibaraki 305-0047 JapanNational Institute for Materials Science Tsukuba Ibaraki 305-0047 JapanNational Institute for Materials Science Tsukuba Ibaraki 305-0047 JapanNational Institute for Materials Science Tsukuba Ibaraki 305-0047 JapanNational Institute for Materials Science Tsukuba Ibaraki 305-0047 JapanNational Institute for Materials Science Tsukuba Ibaraki 305-0047 Japan

Creep lives of high Cr ferritic heat resisting steel weldments decrease due to type Ⅳ fracture, which occurs as a result of formation and growth of creep voids and cracks on grain boundaries in fine-grained heat affected zone (HAZ). Because boron is considered to suppress the coarsening of grain boundary precipitates and growth of creep voids, we have investigated the effect of boron addition on the creep properties of 9Cr steel weldments. four kinds of 9Cr3WSCoVNb steels with boron content varying from 4.7×10-5 to 1.8×10-4 and with nitrogen as low as 2.0×10-5 were prepared. the steel plates were welded by gas tungsten arc welding and crept at 923K. It was found that the microstructures of HAZ were quite different.from those of conventional high Cr steels such as P91 and P92, namely the fine-grained HAZ did not exist in the present steel weldments. Boron addition also has the effect to suppress coarsening of grain boundary carbides in HAZ during creep. As a result of these phenomena, the welded joints of present steels showed no type Ⅳ fractures and much better creep lives than those of conventional steels.

关键词： high Cr heat resistant steel welded joint boron addition type IV fracture

Predicting recrystallized grain size in friction stir processed 304L stainless steel

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Journal of Materials Science & technology 2019年第4期35卷 491-498页

作者： M.P.Miles t.W.Nelson C.Gunter f.C.Liu L.fourment t.Mathis Manufacturing Engineering Department Brigham Young University Centre de Mise en forme des Materiaux Mines ParisTech

A major dilemma faced in the nuclear industry is repair of stainless steel reactor components that have been exposed to neutron irradiation. When conventional fusion welding is used for repair, intergranular cracks develop in the heat-affected zone(HAZ). friction stir processing(fSP), which operates at much lower peak temperatures than fusion welding, was studied as a crack repair method for irradiated 304 L stainless steel. A numerical simulation of the fSP process in 304 L was developed to predict temperatures and recrystallized grain size in the stir zone. the model employed an Eulerian finite element approach,where flow stresses for a large range of strain rates and temperatures inherent in fSP were used as input. temperature predictions in three locations near the stir zone were accurate to within 4%, while prediction of welding power was accurate to within 5% of experimental measurements. the predicted recrystallized grain sizes ranged from 7.6 to 10.6 μm, while the experimentally measured grains sizes in the same locations ranged from 6.0 to 7.6 μm. the maximum error in predicted recrystallized grain size was about 39%, but the associated stir zone hardness from the predicted grain sizes was only different.from the experiment by about 10%.

关键词： Stainless steel Numerical simulation friction stir welding Recrystallized grain size

Dipole and Quadrupole Electroexcitations of the Isovector t = 1 Particle-Hole States in ^12C

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Chinese Physics Letters 2006年第10期23卷 2699-2702页

作者： f.A.Majeed R.A.Radhi Instituto de fisica Universidade Federal do Rio de Janeiro C.P. 68528 21941-972 Rio de Janeiro RJ Brazil Department of Physics College of Science Baghdad University Baghdad IRAQ

Electroexcitations of the dominantly t=1 particle-hole states of ILC are studied in the framework of the harmonic oscillator shell model. All possible t=1 single-particle-hole states of all allowed angular momenta are considered in a basis including single-particle states up to the 1f-2p shell. the Hamiltonian is diagonalized in this space in the presence of the modified surface delta interaction. Correlation in the ground state wavefunctions by mixing more than one configuration is considered and shows a major contribution that leads to enhance the calculations of the form factors. A comparison with the experiment shows that this model is able to fit the location of states and a simple scaling of the results give a good fit to the experimental form factors.

关键词： Ground state

Nanosecond Pulses Generation with Samarium Oxide film Saturable Absorber

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Chinese Physics Letters 2019年第7期36卷 48-51页

作者： N.f.Zulkipli M.Batumalay f.S.M.Samsamnun M.B.H.Mahyuddin E.Hanafi t.f.t.M.N.Izam M.I.M.A.Khudus S.W.Harun Photonics Engineering Laboratory Department of Electrical Engineering University of Malaya Kuala Lumpur 50603 Malaysia faculty of Information technology & Sciences Inti International University Perdana BBN Putra Nilai Nilai 71800 Negeri Sembilan Department of Physics University of Malaya Kuala Lumpur 50603 Malaysia Department of Physics Faculty of Science and Technology Airlangga University Surabaya Indonesia

Nanosecond pulse generation is demonstrated in a mode-locked erbium-doped fiber laser(EDfL) utilizing a samarium oxide(Sm2O3) film. the Sm2O3 film exhibits a modulation depth of 33%, which is suitable for modelocking operation. the passively pulsed EDfL operates stably at 1569.8 nm within a pumping power from 109 to 146 m W. the train of generated output pulses has a pulse width of 356 nm repeated at a fundamental frequency of 0.97 MHz. the average output power of 3.91 m W is obtained at a pump power of 146 m W, corresponding to 4.0 nJ pulse energy. the experimental result indicates that the proposed Sm2O3 saturable absorber is viable for the construction of a flexible and reliably stable mode-locked pulsed fiber laser operating in the 1.5 m region.

关键词： Nanosecond pulse generation erbium-doped fiber laser in the 1.5 m region

Mixed convection flow of jeffrey nanofluid with thermal radiation and double strat.fication

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Journal of Hydrodynamics 2016年第5期28卷 840-849页

作者： f.M.ABBASI S.A.SHEHZAD t.HAYAt M.S.ALHUtHALI Department of Mathematics COMSATS Institute of Information Technology Islamabad Department of Mathematics Comsats Institute of Information Technology Department of Mathematics Quaid-i-Azam University Nonlinear Analysis and Applied Mathematics (NAAM) Research Group Department of MathematicsFaculty of ScienceKing Abdulaziz University

this article addresses the two-dimensional laminar boundary layer flow of magnetohydrodynamic （MHD） Jeffrey nano- fluid with mixed convection. Effects of thermal radiation, thermophoresis, Brownian motion and double strat.fications are taken into account. Rosseland＇s approximation is utilized for the thermal radiation phenomenon. Convergent series solutions of velocity, tempe- rature and nanoparticle concentration are developed. Graphs of dimensionless temperature and nanoparticle concentration are prese- nted to investigate the influences of different emerging parameters. the values of skin-friction coefficient, local Nusselt and Sherwood numbers are computed and discussed for both Jeffrey and viscous fluids cases. We have observed that the temperature profile retarded for the larger values of Deborah number while an enhancement is noticed with the increasing values of ratio of relaxation to retardation times. Increasing values of thermal and nanoparticle concentration strat.fications lead to a reduction in the temperature and nanoparticle concentration. the values of local Nusselt and Sherwood numbers are larger for the viscous fluid case when compared with Jeffrey fluid.

关键词： MHD flow Jeffrey nanofluid double strat.fication thermal radiation mixed convection

tHE INtERfACIAL BEHAVIORS Of ALUMINUM MAtRIX COMPOSItE IN DIffERENt WELDING MEtHODS

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Acta Metallurgica Sinica(English Letters) 2004年第1期17卷 55-60页

作者： W.Guo J.t.Niu J.f.Zhai G.t.Zhou M.Z.Wang State Key Laboratory of Advanced Welding Production technology Harbin Institute of Technology(HIT)Harbin150001China State Key Laboratory of Metal Matrix Composite Shanghai Jiaotong University.Shanghai 200030.China

Non-interlayer liquid phase diffusion welding (China Patent) and laser welding methods for aluminum matrix composite are mainly described in this paper. In the non-interlayer liquid phase diffusion welding, the key processing parameters affecting the strength of joint is welding temperature. When temperature rises beyond solidus temperature, the bonded line vanishes. the strength of joint reaches the maximum and becomes constant when welding temperature is close to liquid phase temperature. Oxide film in the interface is no longer detected by SEM in the welded joint. With this kind of technique, particle reinforced aluminum matrix composite Al2 O3p/6061Al is welded successfully, and the joint strength is about 80% of the strength of composite (as-casted). In the laser welding, results indicate that because of the huge specific surface area of the reinforcement, the interfacial reaction between the matrix and the reinforcement is restrained intensively at certain laser power and pulsed laser beam. the laser pulse frequency directly affects the reinforcement segregation and the reinforcement distribution in the weld, so that the weldability of the composite could be improved by increasing the laser pulse frequency. the maximum strength of the weld can reach 70% of the strength of the parent.

关键词： non-interlayer liquid phase diffusion welding Al2O3p/6061 Alaluminum matrix composite laser welding interface behavior reinforcement

Solid state crack repair by friction stir processing in 304L stainless steel

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Journal of Materials Science & technology 2018年第1期34卷 140-147页

作者： C.Gunter M.P.Miles f.C.Liu t.W Nelson Manufacturing Engineering technology Brigham Young University Department of Mechanical Engineering Brigham Young University

friction stir processing （fSP） was investigated as a method of repairing cracks in 12 mm thick 304L stainless steel plate. Healing feasibility was demonstrated by processing a tapered crack using a PCBN/W- Re tool with a 25 mm diameter shoulder and a pin length of 6.4 mm. the experiment showed that it was possible to heal a crack that begins narrow and then progressively grows up to a width of 2 mm. Bead on plate experiments were used to find the best parameters for creating a consolidated stir zone with the least amount of hardness difference compared to the base metal. Grain refinement in some specimens resulted in much higher stir zone hardness, compared to base metal, A plot of grain size versus microhardness showed a very strong inverse correlation between grain size and hardness, as expected from the Hall- Perch relationship. Corrosion testing was carried out in order to evaluate the effect of fSP on potential sensitization of the stir zone. After 1000 h of intermittent immersion in 3.5% saline solution at room temperature it was found that no corrosion products formed on the base material controls or on any of the friction stir processed specimens.

关键词： Stainless steel Crack healing friction stir processing Corrosion resistance