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Corrosion behavior of magnesium and magnesium alloys

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中国有色金属学会会刊：英文版 2004年第1期14卷 1-10页

作者： i.m.Baghni 吴荫顺李久青张巍 mechanical Engineering Department Engineering College Tajoura Libya Corrosion & Protection Center University of Science and Technology Beijing Beijing 100083 China

The automotive industry has crossed the threshold from using magnesium alloys in interior applications such as instrument panels and steering wheels to unprotected environment such as oil pan, cylinder head and wheels. The expanding territory of magnesium leads to new challenges: mainly environmental degradation of the alloys used and how they can be protected. The present critical review is aimed at understanding the corrosion behavior of magnesium and magnesium alloys in industrial and marine environments, and the effect of microstructure, additive elements and inhibitors on the corrosion mechanism.

关键词：镁镁合金腐蚀显微结构汽车工业

Bianchi type i in f(T) gravitational theories

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Chinese Physics B 2016年第5期25卷 58-64页

作者： m i Wanas G G L Nashed O A ibrahim Astronomy Department Faculty of Science Cairo University Cairo Egypt Centre for Theoretical Physics The British University in Egypt El-Sherouk City Egypt mathematics Department Faculty of Science Ain Shams University Cairo Egypt Egyptian Relativity Group (ERG) Giza Egypt

A tetrad field that is homogeneous and anisotropic which contains two unknown functions A（t） and B（t） of cosmic time is applied to the field equations of f（T）, where T is the torsion scalar, T = T~μ_（νρ）S_μ^（νρ）. We calculate the equation of continuity and rewrite it as a product of two brackets, the first is a function of f（T） and the second is a function of the two unknowns A（t） and B（t）. We use two different relations between the two unknown functions A（t） and B（t） in the second bracket to solve it. Both of these relations give constant scalar torsion and solutions coincide with the de Sitter one. So,another assumption related to the contents of the matter fields is postulated. This assumption enables us to drive a solution with a non-constant value of the scalar torsion and a form of f（T） which represents ΛCDm.

关键词： f(T) gravitational theory Bianchi type i special solutions

The extended cubic B-spline algorithm for a modified regularized long wave equation

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Chinese Physics B 2013年第4期22卷 75-80页

作者： i.Dag D.irk m.Sari Faculty of Science and Arts Department of Mathematics and Computer Sciences Eskis ehir Osmangazi niversitesi Eskis ehir Turkey Faculty of Science and Arts Department of Mathematics Pamukkale niversitesi Denizli Turkey

A collocation method based on an extended cubic B-spline function is introduced for the numerical solution of the modified regularized long wave equation. The accuracy of the method is illustrated by studying the single solitary wave propagation and the interaction of two solitary waves of the modified regularized long wave equation.

关键词： collocation methods solitary waves

Ameliorative effect of morus alba leaves extract against developmental retinopathy in pups of diabetic and aluminum intoxicated pregnant albino rats

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Asian Pacific Journal of Tropical Biomedicine 2015年第4期5卷 300-309页

作者： Hassan El-sayyed Gamal Badawy Sobhy Hassab Elnabi ibrahim El-Elaimy Eman Al Shehari Department of Zoology Faculty of Science Mansoura University Department of Zoology Faculty of Science Menoufiya University

Objective: To investigate the possible ameliorative effect of crude water extract of morus alba(m. alba) leaves on retinopathy of rat pups maternally subjected to diabetes and/or Al ***: Both control and experimental groups were subjected to certain integrated approaches, namely, biochemical assessments, light microscopic investigation, transmission electron microscopic investigation, single cell gel electrophoresis(comet assay) and determination of DNA ***: The retina of pups of diabetic and/or Al-intoxicated mothers exhibited abnormal alterations in retinal cell layers including retinal pigmented epithelium, photoreceptor inner segment and ganglion cells. increased incidence of DNA fragmentation and apoptosis were evident in pups of diabetic and/or Al-intoxicated mothers. However, retina of pups maternally received m. alba extract plus diabetes or Al-intoxicated alone or in combination showed marked amelioration. Less degree of ameliorations was seen in retina of pups maternally subjected to combined treatment. Furthermore, application of crude water extract of *** resulted in amelioration of the alterations of maternal serum glucose as well as Al ***: Based on the results of the present study, m. alba extract is effective against experimentally diabetic and Al-induced developmental retinopathy.

关键词： morus alba Retinopathy Aluminum Diabetes TEm Comet assay

Finding Dirac Spin Effect in NUT Spacetime

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Communications in Theoretical Physics 2010年第5期53卷 864-868页

作者： m.Korunur m.Salti i.Acikgoz Department of Physics Faculty of Art and Science Dicle University

in the present study, we are interested in finding the spin precession of a Dirac particle in expanding and rotating NUT spaeetime. A tetrad with two functions to be determined is applied to the field equation of the teleparallel theory of gravity via a coordinate transformation. The vector, the axial-vector and the tensor parts of the torsion tensor are obtained. We found that the vector parts are in the radial and Ф-directions. The axial-vector torsion is along r-direction while its other components along θ and oh-directions vanish everywhere. The vector connected with Dirac spin has been evaluated as well.

关键词： NUT spacetime axial-vector torsion Dirac particle

Analytical modeling of self-powered electromechanical piezoelectric bimorph beams with multidirectional excitation

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international Journal of Smart and Nano materials 2011年第3期2卷 134-175页

作者： m.F.Lumentut i.m.Howard Department of mechanical Engineering Curtin UniversityAustralia

Unused mechanical energies can be found in numerous ambient vibration sources in industry including rotating equipment,vehicles,aircraft,piping systems,fluid flow,and even external movement of the human body.A portion of the vibrational energy can be recovered using piezoelectric transduction and stored for subsequent smart system utilization for applications including powering wireless sensor devices for health condition monitoring of rotating machines and defence communication *** vibration environment in the considered application areas is varied and often changes over time and can have components in three perpendicular directions,simultaneously or *** paper presents the development of analytical methods for modeling of self-powered cantilevered piezoelectric bimorph beams with tip mass under simultaneous longitudinal and transverse input base motions utilizing the weak and strong forms of Hamiltonian’s principle and space-and time-dependent eigenfunction series which were further formulated using *** reduced constitutive electromechanical equations of the cantilevered piezoelectric bimorph were subsequently analyzed using Laplace transforms and frequency analysis to give multi-mode frequency response functions(FRFs).The validation between theoretical and experimental results at the single mode of eigenfunction solutions reduced from multi-mode FRFs is also given.

关键词： microelectromechanical system piezoelectric energy harvesting smart sensor Hamiltonian strong weak and closed forms vibration

Effects of forced aeration on community dynamics of free and attached bacteria in copper sulphide ore bioleaching

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international Journal of minerals,metallurgy and materials 2022年第1期29卷 59-69页

作者： Wei Chen Shenghua Yin i.m.S.K.ilankoon Key Laboratory of ministry of Education for High-Efficient mining and Safety of metal University of Science and Technology BeijingBeijing 100083China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Discipline of Chemical Engineering School of EngineeringMonash UniversityJalan Lagoon SelatanBandar SunwaySelangor Darul Ehsan 47500Malaysia

Bacterial community dynamics and copper leaching with applied forced aeration were investigated during low-grade copper sulphide bioleaching to obtain better bioleaching *** illustrated that appropriate aeration improved bacterial concentrations and leaching *** highest bacterial concentration and Cu^(2+)concentration after 14-d leaching were 7.61×10^(7) cells·mL^(−1) and 704.9 mg·L^(−1),respectively,at aeration duration of 4 h·d^(−1).The attached bacteria played a significant role during bioleaching from 1 to 7 ***,free bacteria dominated the bioleaching processes from 8 to 14 *** phenomenon was mainly caused by the formation of passivation layer through Fe3+hydrolysis along with bioleaching,which inhibited the contact between the attached bacteria and ***,16S rDNA analysis verified the effect of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans on the bioleaching *** results demonstrate the importance of free and attached bacteria in bioleaching.

关键词： attached bacteria bioleaching forced aeration free bacteria low-grade copper sulphide ore

Functional films based on mechanoactivated starch with prolonged release of preservative

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Food Bioscience 2022年第3期47卷 810-818页

作者： i.m.Lipatova A.A.Yusova L.i.makarova G.A.Krestov institute of Solution Chemistry of the Russian Academy of Sciences 1 Akademicheskaya St.Ivanovo153045Russia

Use of active edible films containing an antimicrobial agent-a new method of extending the shelf life of food *** the controlled release of the preservative from the film is an urgent *** work aims to introduce a new environmentally friendly process for the production of antifungal starch films with a prolonged release of a preservative using mechanoactivation in a rotor-stator device (RSD).Active films based on mechanoactivated starch hydrogels containing 0–5.0% (w/w) benzoic acid as a preservative and chitosan as a solubilizing additive (St-BA-Ch),as well as films containing sodium benzoate (St-SB) for comparison,were obtained by the casting *** were characterized using optical and atomic force microscopy,X-ray diffraction and tensile and moisture permeability testing *** was found that benzoic acid is present in the St-BА-Ch-films in the form of submicron ***-BА-Ch films showed greater tensile strength and a lower release rate of the preservative into model media compared to St-SB *** is established that mechanical activation of casting hydrogels in RSD allows increasing the strength films by an average of 2 times,as well as reducing the release rate of the preservative and the vapor permeability of the *** antifungal activity of the films was confirmed using Aspergillus *** developed active St-BА-Ch film can be recommended for use in the food industry to extend the shelf life of food products.

关键词： Starch films Benzoic acid Sodium benzoate mechanoactivation Rotor–stator device mechanical and barrier properties

Effect of magnesium and nickel coatings on the wetting behavior of alumina toughened zirconia by molten Al-mg alloy

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international Journal of minerals,metallurgy and materials 2012年第1期19卷 77-82页

作者： H. Sharifi A.R. Khavandi m. Divandari m.i. Hasbullah School of materials and metallurgical Engineering iran University of Science and Technology Department of material Engineering Faculty of mechanical Engineering University Teknologi malaysia

The wettability of alumina toughened zirconia （ZTA） by Al-mg alloy was investigated using the sessile drop technique. The ef fects of nickel coating, magnesium content, nitrogen atmosphere, and processing temperature on the contact angle between the molten alloy and the substrate were determined. Likewise, the effect of these factors on the wetting properties was studied. The results showed that the nickel coating on the ceramic substrate caused a significant reduction in solid/liquid surface energy and the contact angle decreased obvi- ously. The presence of magnesium in the molten aluminum alloy in nitrogen atmosphere reduced the contact angle effectively. The presence of magnesium in the alloy must be at a minimum amount of 2wt%-3wt% . moreover, it was suggested that some chemical reactions in the Al-mg-N system led to the production of mg3N2 and AlN compositions. These compositions improved the wetting properties of the systems by reducing the surface energy of the molten. it was shown that increasing the temperature is also an effective factor for the enhancement of wetting properties.

关键词： wetting coatings alumina zirconia ceramic materials composite materials