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Chinese Physics B 2013年第12期22卷 323-332页

作者： Khaled S.Mekheimer Soliman R.Komy Sara I.Abdelsalam Mathematics & Statistics Department Faculty of Science Taif University Department of Mathematics Faculty of Science (Men) Al-Azhar University Department of Mathematics Faculty of Science Helwan University Basic Science Department Faculty of Engineering The British University in Egypt

Peristaltic motion induced by a surface acoustic wave of a viscous, compressible and electrically conducting Maxwell fluid in a confined parallel-plane microchannel through a porous medium is investigated in the presence of a constant magnetic field. The slip velocity is considered and the problem is discussed only for the free pumping case. A perturbation technique is employed to analyze the problem in terms of a small amplitude ratio. The phenomenon of a “backward flow” is found to exist in the center and at the boundaries of the channel. In the second order approximation, the net axial velocity is calculated for various values of the fluid parameters. Finally, the effects of the parameters of interest on the mean axial velocity, the reversal flow, and the perturbation function are discussed and shown graphically. We find that in the non-Newtonian regime, there is a possibility of a fluid flow in the direction opposite to the propagation of the traveling wave. This work is the most general model of peristalsis created to date with wide-ranging applications in biological, geophysical and industrial fluid dynamics.

关键词： peristaltic flow Maxwell fluid porous medium slip flow microchannel

Production of HfO_2 thin films using different methods: chemical bath deposition, SILAR and sol–gel process

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International Journal of Minerals,Metallurgy and Materials 2014年第8期21卷 832-838页

作者： Ì.A.Kariper Education faculty Erciyes University

Hafnium oxide thin films （HOTFs） were successfully deposited onto amorphous glasses using chemical bath deposition, successive ionic layer absorption and reaction （SILAR）, and sol-gel methods. The same reactive precursors were used for all of the methods, and all of the films were annealed at 300℃ in an oven （ambient conditions）. After this step, the optical and structural properties of the films produced by using the three different methods were compared. The structures of the films were analyzed by X-ray diffTaction （XRD）. The optical properties are investigated using the ultraviolet-visible （UV-VIS） spectroscopic technique. The film thickness was measured via atomic force microscopy （AFM） in the tapping mode. The surface properties and elemental ratios of the films were investigated and measured by scanning electron microscopy and energy-dispersive X-ray spectroscopy （EDX）. The lowest transmittance and the highest reflectance values were observed for the films produced using the SILAR method. In addition, the most intense characteristic XRD peak was observed in the diffraction pattern of the film produced using the SILAR method, and the greatest thickness and average grain size were calculated for the film produced using the SILAR method. The films produced using SILAR method contained fewer cracks than those produced using the other methods. In conclusion, the SILAR method was observed to be the best method for the production of HOTFs.

关键词： hafnium oxide thin films optical properties structural properties chemical deposition absorption sol-gel process

Lagrange-Noether method for solving second-order differential equations

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Chinese Physics B 2009年第9期18卷 3647-3650页

作者：吴惠彬吴润衡 faculty of Science Beijing Institute of Technology faculty of Science North China University of Technology

The purpose of this paper is to provide a new method called the Lagrange-Noether method for solving second-order differential equations. The method is, firstly, to write the second-order differential equations completely or partially in the form of Lagrange equations, and secondly, to obtain the integrals of the equations by using the Noether theory of the Lagrange system. An example is given to illustrate the application of the result.

关键词： differential equation Lagrange equation Noether theory integral

Preparation and Mechanical Properties of Misch Metal Based Bulk Metallic Glasses

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Journal of Rare Earths 2005年第6期23卷 727-731页

作者：武晓峰邱克强孟力凯赵威索忠源 faculty of Materials and Chemical Engineering Liaoning Institute of Technology Jinzhou 121001 China faculty

The formation, thermal stability and mechanical properties of Misch metal （Mm）-based alloy bulk metallic glasses （BMGs） with composition of Mm55Al25Cu10Ni5Co5 were investigated by means of X-ray diffraction, differential scanning calorimetry, differential thermal analysis and compression test. The results indicate that the Mm-based BMGs exhibit a distinct glass transition and a wide supercooled liquid region Δ Tx（〉 60 K） before crystallization. The alloy can be fabricated into bulk glassy form of 3 mm in diameter by copper mold casting methods. Compared with the La55Al25Cu10 Ni5Co5 BMG, the Mm55Al25Cu10Ni5Co5 BMG shows higher compression fracture strength and lower cost. A new parameter γ and melting temperature Tl are closely correlated with the glass forming ability （GFA） of Mm-based alloys.

关键词： bulk metallic glasses misch metal thermal analysis mechanical properties rare earths

SYNTHESIS, CHARACTERIZATION AND SPECTROSCOPIC INVESTIGATION OF PYRAZINOPORPHYRAZINE NETWORK POLYMER-SUPPORTED METAL (Ⅱ)-BASED CATALYSTS

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Chinese Journal of Polymer Science 2013年第2期31卷 242-250页

作者： H.H. Abdel-Razik B.H. Asghar E. Kenawy Chemistry Department Faculty of Science Mansoura University Chemistry Department Faculty of Science Taif University Chemistry Department Faculty of Applied Sciences Umm Al-Qura University Chemistry Department Polymer Research Group Faculty of Science Tanta University

Chloranil through condensation reaction with vicinal diamine such as diaminomaleonitrile produced heterocyclic monomer, p-benzoquinonebis[2,3-b; 2＇,3＇-b＇]pyrazine-5,6-dinitrile. The tetranitrile monomer was cyclo-tetramerised using lithium/pentanol and acetic acid affording the corresponding tetrap-benzoquinone bis[2,3-b; 2＇,3＇-b＇]pyrazinoporphyrazine）]- based network polymer （2H-Pz）. The tetranitril monomer was cyclo-tetramerised using metal salt and quinoline affording the corresponding porphyrazinato-metal II-based network polymers （M-Pz）, M = Co, Ni or Cu. Elemental analytical results, IR and NMR spectral data of the prepared molecules are consistent with their assigned formulations. Molecular masses and metal contents of the synthesized polymers proved to be of high molecular masses which confirm the efficiency of tetramerization polymerization and complexation reactions. The prepared pyrazinoporphyrazines were used as efficient catalysts for the oxidation of thiophenol and benzylthiol to their disulfides in the presence of air atmosphere. The results of oxidation of thiophenol and benzylthiol show that after 15 min the maximum yield of the corresponding disulfides reached 95%, 91%, respectively.

关键词： Pyrazinoporphyrazine Polymer-supported metal (II)-based catalysts Chloranil.

A comprehensive study for mass attenuation coefficients of different parts of the human body through Monte Carlo methods

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Nuclear Science and Techniques 2016年第3期27卷 31-39页

作者： E.E.Ermis F.B.Pilicer E.Pilicer C.Celiktas Physics Department Faculty of ScienceEge University Physics Department Faculty of Arts and ScienceUludag University

The gamma-ray mass attenuation coefficients of blood,bone,lung,eye lens,adipose,tissue,muscle,brain and skin were calculated at different energies(60,80,150,400,500,600,1000,1250,1500,and 2000 keV) by various theoretical methods such as FLUKA,GEANT4 Monte Carlo(MC) methods and XCOM program in this *** coefficients were also compared with the National Institute of Standards and Technology(NIST) *** results were highly in accordance with each other and NIST *** results showed that FLUKA was quite convenient in comparison to GEANT4 in the calculation of the mass attenuation coefficients of the used human body samples for low-energy photons(60,80,and 150 keV) when compared with the NIST values.

关键词：质量衰减系数蒙特卡洛方法 Geant4 部位 NIST 美国国家标准能量计算眼晶状体

Effect of yttrium on photosynthesis and water relations in young maize plants

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Journal of Rare Earths 2014年第4期32卷 371-378页

作者： Ivana Maksimovi Rudolf Kastori Marina Putnik-Deli Milan Boriev faculty of Agriculture University of Novi Sad Department of Biology and Ecology Faculty of SciencesUniversity of Novi Sad

Despite an increase in spectrum of industrial applications of yttrium （Y） and the fact that it is widely present in the soils and plants, some of which are agronomically important crops, its effects on plant growth and metabolism are still obscure. Therefore, the aim of this work was to examine the effect of different concentrations of Y on its accumulation and distribution, photosynthetic responses, water relations, free proline concentration and growth of young maize plants. The experiment was done with maize （Zea mays L., hybrid NS-640）, in water cultures, under semi-controlled conditions of a greenhouse. Plants were supplied with half-strength complete Hoagland nutrient solution, to which was added either 0 （control）, 10-5, 10-4 or 10-3 mol/L Y, in the form of Y（NO）3·5H2O. Each variant was set in thirteen replications, with six plants in each replication. Plants were grown for 21 d and they were at the stage of 3 and 4 leaves when they were analyzed. The presence of Y reduced maize growth and photosynthetic performance. Dimensions of stomata significantly decreased while their density significantly increased on both adaxial and abaxial epidermis. Plant height, root length, total leaf area and dry mass also declined. Concentration of photosynthetic pigments （chl a and b and carotenoids） and free proline decreased. Photosynthesis and transpiration were impaired in the presence of Y-their intensities were also reduced, and the same stands for stomatal conductance of water vapor, photosynthetic water use efficiency （WUE） and water content. Although the highest concentration of Y was found in maize roots in each treatment, Y concentration in the second leaf and shoot also significantly increased with an increase in Y concentration in the nutrient solution. Albeit Y concentration was much higher in roots than in shoots, shoot metabolism and growth were much more disrupted. The results demonstrated that young maize plants accumulated significant amount of Y and that th

关键词： yttrium maize photosynthesis water use efficiency rare earths

Perfect spin filtering controlled by an electric field in a bilayer graphene junction:Effect of layer-dependent exchange energy

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Chinese Physics B 2016年第7期25卷 488-496页

作者： Kitakorn Jatiyanon I-Ming Tang Bumned Soodchomshom Department of Physics Faculty of Science Kasetsart University Department of Materials Science Faculty of Science Kasetsart University

Magneto transport of carriers with a spin-dependent gap in a ferromagnetic-gated bilayer of graphene is *** focus on the effect of an energy gap induced by the mismatch of the exchange fields in the top and bottom layers of an AB-stacked graphene bilayer. The interplay of the electric and exchange fields causes the electron to acquire a spindependent energy gap. We find that, only in the case of the anti-parallel configuration, the effect of a magnetic-induced gap will give rise to perfect spin filtering controlled by the electric field. The resolution of the spin filter may be enhanced by varying the bias voltage. Perfect switching of the spin polarization from ＋100% to -100% by reversing the direction of electric field is predicted. Giant magnetoresistance is predicted to be easily realized when the applied electric field is smaller than the magnetic energy gap. It should be pointed out that the perfect spin filter is due to the layer-dependent exchange energy. This work points to the potential application of bilayer graphene in spintronics.

关键词： bilayer graphene spin filter magnetoresistance spintronics

Paraconductivity study in ErBa_2Cu_(3-x)M_xO_(7-δ)(M=Zn, Fe) superconductors

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Chinese Physics B 2013年第11期22卷 562-568页

作者： A.Sedky S.B.Mohamed Physics Department Faculty of Science King Faisal University Physics Department Faculty of Science Assiut University

We report here the paraconductivity of ErBa2Cu3-xMxO7-δ （M = Zn and Fe） superconductors. The logarithmic plots of excess conductivity Δσ and reduced temperature C reveal two different exponents corresponding to crossover temperature as a result of shifting the order parameter from 2 to 3. The first exponent in the normal field region is close to 1, in which the order parameter dimensionality （OPD） is 2. The second exponent in the critical field region is close to 0.5, in which the OPD is 3. The coherence length, interlayer coupling, interlayer separation and carrier concentration decrease with increasing doping content, and their values for Fe samples are different from those of Zn samples. While anisotropy is increased with increasing doping content, it is generally higher for a Zn sample than that for an Fe sample. We also estimate several physical parameters such as upper critical magnetic fields in the a–b plane and along the c axis （Bab and Bc）, and critical current density J at 0 K. Although Bab and Bc are generally increased with doping content increasing, the value of Bab is found to be twice more than that of Bc. A similar behavior is obtained for J （0 K） and its value is higher in the Fe sample than that in the Zn sample. These results are discussed in terms of oxygen deficiency, localization of carriers, and flux pinning, which are produced by doping.

关键词： ceramics chemical synthesis X-ray diffraction electrical properties transport properties

Modeling and Analysis of Mechanization Projects of Wheat Production by GERT Networks

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Agricultural Sciences in China 2010年第7期9卷 1078-1083页

作者： Reza Abdi Hamid Reza Ghasemzadeh Shamsollah Abdollahpour Majid Sabzeparvar Adel Dabbag Mohamadi Nasab faculty of Agriculture University of Tabriz faculty of Industrial University of Science and Industry(Iran)

In crop production systems,all operations such as seed bed preparation,etc.,must be accomplished on time,if yield reduction and low quality product are to be *** all operations in mechanized cropping projects require precise scheduling,planning and *** basic approach in all scheduling techniques is to form a network of activities and events relationships that graphically portrays the sequential relations between the tasks in a *** a network would as a powerful tool available a farm manager to plan,schedule,monitor and control a *** GERT（Graphical Evaluation and Review Technique） networks have most of advantages associated with networks and available system analyst in exact evaluation of certain types of networks,in this research it was used and mechanized wheat production system was simulated,modeled and *** activities,events and path were *** showed that the network model was able to answer any statistic questions concerning with the *** models,particularly GERT networks are increasingly powerful tool for modeling,scheduling,planning,controlling,and analyzing of agricultural mechanization projects.

关键词： GERT networks mechanization project scheduling wheat