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Acta Metallurgica Sinica(English Letters) 2015年第7期28卷 847-857页

作者： Ajay Kumar Behera n.K.Mohanty S.K.Satpathy Banarji Behera P.nayak Materials Research Laboratory School of PhysicsSambalpur University

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5（Bi LaxFe1-xO3）–0.5（Pb Ti O3）（x = 0.05,0.10,0.15,0.20）（BLxF1-x-PT） were prepared by mixed oxide *** characterization was performed by X-ray diffraction and shows a tetragonal structure at room *** lattice parameter c/a ratio decreases with increasing of La（x = 0.05–0.20） concentration of the *** effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range（102–106Hz） at different *** nature of nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the *** electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the *** ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures（200–300 ℃）.

关键词： X-ray diffraction Composite materials Impedance spectroscopy Modulus studies Activation energy Relaxation phenomena

EPR and Magnetic Susceptibility Studies of Cr^(3+) Ions in the 70TeO_2·25B_2O_3·5PbO glass Matrix

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Journal of Materials Science & Technology 1997年第5期13卷 374-378页

作者： Peteanu M. Simon V. Muresan n. Ardelean I. Filip S. Faculty of Physics Babes-Bolyai University 3400 Cluj-Napoca Romania Dept. of Physics University of Oradea 3700 Oradea Romania

By using EPR and magnetic susceptibility measurements, the Cr ion distribution in the xCr2O3.(1-x)[70TeO2·25B2O3·5PbO] glasses with 0＜x≤20 mol% was studied. EPR investigation evidencedthe presence of Cr3+ ions in agreement with the experimentally obtained atomic magnetic moment values. For concentrations x≤3 mol%, the isolated Cr3+ ions coexist with those coupledby dipole-dipole interactions. For x＞3 mol%, the Cr3+ ions participate in superexchange interactions and are predominantly antiferromagnetically coupled.

关键词： PbO Ions in the 70TeO2 glass Matrix EPR and Magnetic Susceptibility Studies of Cr Cr

Pure and Mg-doped self-assembled ZnO nano-particles for the enhanced photocatalytic degradation of 4-chlorophenol

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Journal of Environmental Sciences 2013年第10期25卷 2157-2167页

作者： n.Clament Sagaya Selvam S.narayanan L.John Kennedy J.Judith Vijaya Catalysis and nanomaterials Research Laboratory Department of Chemistry Loyola College Materials Division School of Advanced Sciences Vellore Institute of Technology UniversityChennai Campus

A novel self-assembled pure and Mg doped ZnO nano-particles （nPs） were successfully synthesized by a simple low temperature co-precipitation method. The prepared photocatalysts were characterized by X-ray diffraction, high resolution scanning electron mi- croscopy, high resolution transmission electron microscopy, diffuse reflectance spectroscopy and photoluminescence （PL） spectroscopy. The results indicated that the prepared photocatalysts showed high crystallinity with a uniform size distribution of the nPs. The degradation of cholorphenols is highly mandatory in today＇s scenario as they are affecting the environment adversely. Thus, the photocatalytic degradation of 4-chlorophenol （4-CP）, a potent endocrine disrupting chemical in aqueous medium was investigated by both pure and Mg-doped ZnO nPs under UV-light irradiation in the present study. The influence of the Mg content on the structure, morphology, PL character and photocatalytic activity of ZnO nPs were investigated systematically. Furthermore,the effect of different parameters such as 4-CP concentration, photocatalyst amount, pH and UV-light wavelength on the resulting photocatalytic activity was investigated.

关键词： Mg-doped ZnO nanoparticles photocatalyst photocatalytic degradation 4-chlorophenol

Artificial neural network approach to assess selective flocculation on hematite and kaolinite

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International Journal of Minerals,Metallurgy and Materials 2014年第7期21卷 637-646页

作者： Lopamudra Panda P.K.Banerjee Surendra Kumar Biswal R.Venugopal n.R.Mandre R&D Tata Steel Limited Institute of Minerals and Materials Technology(Council of Scientific and Industrial Research) Department of Fuel & Minerals Engineering Indian School of Mines University

Because of the current depletion of high grade reserves, beneficiation of low grade ore, tailings produced and tailings stored in tailing ponds is needed to fulfill the market demand. Selective flocculation is one alternative process that could be used for the beneficiation of ultra-fine material. This process has not been extensively used commercially because of its complex dependency on process parameters. In this paper, a selective flocculation process, using synthetic mixtures of hematite and kaolinite in different ratios, was attempted, and the ad-sorption mechanism was investigated by Fourier transform infrared （FTIR） spectroscopy. A three-layer artificial neural network （Ann） model （4？4？3） was used to predict the separation performance of the process in terms of grade, Fe recovery, and separation efficiency. The model values were in good agreement with experimental values.

关键词： hematite kaolinite flocculation artificial neural networks back propagation algorithm Fourier transform infrared spectroscopy separation efficiency

Aqueous and organic extracts of Trigonella foenum-graecum *** the mycelia growth of fungi

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Journal of Environmental Sciences 2008年第12期20卷 1453-1457页

作者： R.HAOUALA S.HAWALA A.EL-AYEB R.KHAnFIR n.BOUgHAnMI Department of Biology Higher Institute of Biotechnology of Monastir University of Monastir Monastir 5000Tunisia. Unit of search for MycotoxinsPhycotoxins and associated Pathologies 03/UR/08-14 Statistical research Division U.S. Census Bureau U.S. Department of Commerce Washingion DC 20233 USA Department of Biology Faculty of Sciences of Bizerte Jarzouna 7021 Tunisia

Aqueous extracts from various plant parts of fenugreek(3%)(aerial parts:leaves and stems(LS),roots(R),ground seeds(gS)and not ground seeds(ngS))and petroleum ether,ethyl acetate and methanolic fractions of the aerial parts were assayed to determine their antifungal potential against Botrytis cinerea,Fusarium graminearum,Alternaria sp.,Pythium aphanidermatum,and Rhizoctinia *** fenugreek plant parts showed antifungal potential and the magnitude of their inhibitory effects was species and plant parts d...

关键词： antifungal potential aqueous extracts fungi methanol fraction minimum inhibitory concentration(MIC) Trigonella foenum-graecum L.

Oxidation of propane over substituted Keggin phosphomolybdate salts

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Journal of natural gas Chemistry 2009年第3期18卷 319-324页

作者： T.Mazari C.Roch.Marchal S.Hocine n.Salhi C.Rabia Laboratoire de Chimie du gaz naturel Faculté de ChimieUniversité des Sciences et de la Technologie Houari Boumediéne ILV-UMR 8180 CnRS-Université de Versailles-St Quentin-en-Yvelines Batiment Lavoisier45 avenue des Etats-Unis78035 Versailles CedexFrance

Ammonium salts, （nH4）6HPMo11MO40 （M = ni, Co, Fe）, have been investigated for the oxidation of propane, with molecular oxygen, at temperature ranging between 380 ℃ and 420 ℃ after in-situ pre-treatment performed at two heating rate of 5 or 9 ℃/min. They were characterized by BET method, XRD, 31p nMR, UV-Vis and IR techniques. The catalysts were found active in the propane oxidation and selective to propene or acrolein, in particular for samples pre-treated with the heating rate of 9 ℃/min.

关键词： propane oxidation propene acrolein polyoxometalates phosphomolybdate

Boron in Plants: Deficiency and Toxicity

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Journal of Integrative Plant Biology 2008年第10期50卷 1247-1255页

作者： Juan J. Camacho-Cristóbal Jesús Rexach Agustín gonzlez-Fontes Departamento de Fisiología Anatomía y Biología Celular Facultad de Ciencias Experimentales Universidad Pablo de OlavideE-41013 Sevilla Spain

Boron （B） is an essential nutrient for normal growth of higher plants, and B availability in soil and irrigation water is an important determinant of agricultural production. To date, a primordial function of B is undoubtedly its structural role in the ceil wall; however, there is increasing evidence for a possible role of B in other processes such as the maintenance of plasma membrane function and several metabolic pathways. In recent years, the knowledge of the molecular basis of B deficiency and toxicity responses in plants has advanced greatly. The aim of this review is to provide an update on recent findings related to these topics, which can contribute to a better understanding of the role of B in plants.

关键词： boron-binding molecules boron transporter cell wall-related genes gene expression nitrogen metabolism,

Computer Simulation of the Process of Quenching Large-Size Parts in Water and Aqueous Solutions

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材料热处理学报 2004年第5B期25卷 733-735页

作者： n.I.Kobasko W.S.Morhuniuk V.V.Dobrivecher A.M.Weinov Intensive Technologies Ltd. Kyiv UkraineIntensive Technologies Ltd. Kyiv UkraineIntensive Technologies Ltd. Kyiv UkraineJ.S.C. "Novokramatorsky Mashinostroitelny Zavod" Kramatorsk Ukraine

The article presents results of the computer simulation of quenching large-size parts in water and aqueous solutions. It has been shown that the main attention should be paid to eliminating film boiling and providing uniform cooling at the surface of the part to be quenched. Simplified formulas for calculating the optimal time of cooling large-size steel parts are presented.

关键词：强化淬火大型零件应力分布简化计算

High Temperature Creep and Superplasticity in a Mg-Zn-Zr Alloy

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Journal of Materials Science & Technology 2012年第5期28卷 407-413页

作者： S. Spigarelli M. El Mehtedi M. Regev E. gariboldi n. Lecis Dipartimento di Ingegneria Industriale e Scienze Matematiche Universit Politecnica delle Marche Via Brecce Bianche Ancona 60131 Italy Mechanical Engineering Dept. ORT Braude College Karmiel 21982 Israel Dipartimento di Meccanica Politecnico di Milano via La Masa 34 20156 Milano Italy

Creep and superplasticity were investigated by testing a fine-grained extruded Mg–Zn–Zr magnesium alloy under a wide range of applied stress in the temperature range between 100 and 300 ℃. grain boundary sliding became the dominating mechanism at 200 ℃, leading to a true superplastic behaviour at 300 ℃, where superplasticity was attained even under relatively high strain rates （5×10-3 s-1 ）. By contrast, for lower temperatures, the straining process was controlled by dislocation climb. A comprehensive model, taking into account the simultaneous operation of the different mechanisms, was developed to describe the strain rate dependence on applied stress.

关键词： Creep Superplasticity Magnesium alloy

Deadly oasis:Recurrent annihilation of Cretaceous desert bryophyte colonies;the role of solar,climate and lithospheric forcing

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geoscience Frontiers 2021年第1期12卷 1-12页

作者： Juan Pedro Rodríguez-Lópeza Eduardo Barrón Daniel Peyrot gary B.Hughes Department of geology.Faculty of Science.United Arab Emirates University.50009.Al Ain Abu DhabiUnited Arab Emirates Instituto geológico y Minero de Espana(IgME) Ríos Rosas 23E-28003MadridSpain School of Earth and Environment University of Western Australia.6101CrawleyWestern AustraliaAustralia Centre for Energy geosciences University of Western Australia.6101CrawleyWestern AustraliaAustralia Physics Department University of CaliforniaSanta BarbaraCA93106USA

Many oases(wet interdunes)are sedimentary systems characterized by high-frequency water-level oscillations,marked changes in salinity and intense biological activity at their *** are considered to be one of the most challenging environments on Earth for ecosystem *** dynamic,depositional settings are usually unfavourable for fossilization and subsequent preservation of vegetal *** paper describes bryophyte(liverwort)assemblages occurring in three successive horizons interpreted to represent(i)recurrent early successional phases of biological soil crust colonization of wet interdune margins or(ii)exceptional preservation of floating or riparian liverworts in oasis pond waters associated with a progressive fall of the interdune water *** record of in situ colonization surfaces characterized by delicate(***-free)three-dimensional structures represents an exceptional type of preservation herein associated with a rapid variation in phreatic interdune water level and the subsequent establishment of anoxic and reducing *** occurrence of exceptionally preserved liverwort colonies coincides with the sedimentary record of,at least,three seismite levels in the *** gathered from the site suggests that the water table of the oasis was controlled by a combination of(i)a positive creation of accommodation space due to subsidence associated with movement on syn-sedimentary extensional faults,and(ii)the rise and fall of the oasis water table controlled by the oscillations of the groundwater system due to orbital changes which appear to drive the variability of the climate *** groundwater levels flooded the oasis soil crusts and lead to the exceptional recurrent preservation of liverwort colonies at the oasis ***,considering the hypothesis of floating or riparian liverworts in the oasis pond waters,the fall in the level of the oasis water table placed the floating liverworts in contact with the

关键词： Oasis Cretaceous Liverworts Colonies Extensional tectonics Solar cyclicity