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Conduction properties of condensed lanthanum phosphates:La(PO_3)_3 and LaP_5O_(14)

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Journal of Rare Earths 2010年第3期28卷 321-328页

作者： Ines hammas Karima horchani-Naifer Mokhtar Férid Research Unit of Rare Earth Materials National Research Center in Sciences of MaterialsB.P.95 Hammam-Lif2050Tunisia

Single crystals of LaP3O9·3h2O were prepared using a classical method of aqueous chemistry whereas those of the ultraphosphate LaP5O14 were obtained by flux *** treatment of LaP3O9·3h2O up to 700 °C allowed us to obtain the lanthanum polyphosphate La(PO3)*** conductivity as well as the vibrational study of the lanthanum ultraphosphate and polyphosphate were analysed in order to explain the mechanism of *** energies of 0.45 and 0.84 eV,deduced from the Arrhenius relation,were r...

关键词： condensed lanthanum phosphates electrical conductivity Grotthuss mechanism rare earths

Combustion synthesis and luminescence properties of LaPO4： Eu （5%）

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Journal of Rare Earths 2009年第2期27卷 182-186页

作者： Mounir Ferhi Karima horchani-Naifer Mokhtar Férid Research Unit of Rare Earth Materials National Research Center in Sciences of Materials B.P. 95 Hammam-Lif 2050 Tunisia

Rare earth doped materials are an important type of phosphors due to their excellent performance such as stability at high temperature and light emission covering the entire visible domain. The combustion synthesis at acid ph of the monoclinic LaPO4： Eu（5%） powders was described. A mixture of La（NO3）3·6h2O, EuCly6h2O and （Nh4）2hPO4 was used as anion precursor and glycin as fuel. The synthesis was followed by structure, morphology characterisation and luminescent properties of the obtained compound. The room temperature emission measurements under ultraviolet excitation at 254 nm were made for the emission transition ^5D0→^7FJ of this phosphor. The CIE （Commission Intemationale de L＇Eclairage） chromatic coordinates, dominant wavelength and colour purity were determined and compared to other luminescent materials obtained by other methods.

关键词： rare earth phosphates combustion optical materials luminescence chromaticity

Synthesis and crystal structure of sodium praseodymium polyphosphate, NaPr(PO_3)_4

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Journal of Rare Earths 2009年第1期27卷 1-3页

作者： K.horchani-Naifer J.Amami M.Férid Research Unit of Rare Earth Materials National Research Center in Sciences of Materials

Reaction of Na2CO3, Pr6O11 and h3PO4 gave the sodium praseodymium polyphosphate NaPr（PO3）*** title compound crystallized in the monoclinic P21/n space group with a=0.9965（4） nm, b=1.31437（4） nm, c=0.72271（3） nm, β=90.429（3）°, V=0.9465（4） nm3, Z=4, R=0.0493 and wR=0.1266 for 1855 independent *** structure of NaPr（PO3）4 consisted of PrO8 polyhedra sharing oxygen atoms with phosphoric group PO4 to form a three-dimensional framework, delimiting intersecting tunnels in which the sodium ion was *** Na＋ ion was bonded to seven oxygen atoms.

关键词： polyphosphate praseodymium crystal structure infrared spectroscopy rare earths

Patterns of genetic and morphometric diversity in the marbled crab(Pachygrapsus marmoratus, Brachyura, Grapsidae)populations across the Tunisian coast

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Acta Oceanologica Sinica 2015年第6期34卷 49-58页

作者： Temim Deli hiba Bahles Khaled Said noureddine Chatti Laboratory of Genetics Biodiversity and Enhancement of Bioresources (LR11ES41) University of Monastir Higher Institute of Biotechnology of Monastir

The present study reports on population structure analysis of the marbled crab Pachygrapsus marmoratus （Fabricius, 1787） from the Tunisian coast, an appropriate location to study biogeographical processes because of the presence of a well-known discontinuous biogeographic area （the Siculo-Tunisian Strait）. Patterns of morphological and genetic variation of this highly dispersive and continuously distributed decapod species were assessed among its geographically close populations which cover almost the entire Tunisian coastline. A total of 386 specimens from nine sites were collected and examined for morphometric variability at 14 morphometric traits. The results of multivariate analyses of linear morphometric traits showed the existence of sexual dimorphism in this species by PERMANOVA （Permutational multivariate analysis of variance）. In addition, both CDA （Canonical discriminant analysis） and NPMANOVA （Non parametric MANOVA test） analyses revealed statistically significant differences among the studied locations for both sexes. Overall, the outcome of CDA analysis showed that over 87% of individuals could be assigned correctly to three regional groups in both sexes （North, Center and South）. Specifically, SIMPER （Similarity Percentages） analysis showed that carapace length, carapace width and merus length were major contributors to the morphometric separation between populations. The pattern of phenotypic variation suggested by morphometric analyses was found to be highly discordant with that suggested by the analysis of a mitochondrial marker （cytochrome oxidase I, COI）. Indeed, the results inferred from restriction fragment analysis of the COI in 180 crabs, suggested high genetic homogeneity. Very low levels of haplotype diversity （h） were found in almost all the studied populations, associated with non significant genetic distances for nearly all population comparisons. Explanations to these morphometric and mtDNA patterns as well as the discrepancy between the

关键词： Pachygrapsus marmoratus Tunisian coast multivariate analysis morphological differentiation COI genetic homogeneity

Photoresponse and h2 gas sensing properties of highly oriented Al and Al/Sb doped ZnO thin films

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Progress in Natural Science:Materials International 2013年第6期23卷 519-523页

作者： hannane Benelmadjat Boubekeur Boudine Aissa Keffous noureddine Gabouze Laboratoire de Physico-Chimie des Semi-Conducteurs Departement de PhysiqueFaculte des Sciences ExactesUniversite Mentouri-Route Ain Elbey Laboratoire de Cristallographie Departement de PhysiqueFaculte des Sciences ExactesUniversite Mentouri-Route Ain Elbey Silicon Technology Development Unit

ZnO:Al and ZnO:Al/Sb thin films have been prepared and *** thin films were deposited on Si substrates by the sol-gel *** structural,optical and electrical properties of ZnO films have been investigated by spectrophotometry,ellipsometry,X-ray diffraction and current-voltage *** is found that the films exhibit wurtzite structure with a highly c-axis orientation perpendicular to the surface of the substrate,a high reflectivity in the infrared region and a response to ***,it has been found that Si/（ZnO:Al/Sb）/Al photodiode is promising in photoconduction device while Si/（ZnO:Al）/Al can be used as gas sensor responding to the low h2concentrations.

关键词： Zinc oxide Co-doping Thin films Gas sensing Photoresponse

Impact of grain size,Pr3+ concentration and host composition on non-contact temperature sensing abilities of polyphosphate nano- and microcrystals

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Journal of Rare Earths 2019年第8期37卷 812-818,I0001页

作者： S.Gharouel L.Marciniak A.Lukowiak W.Strek K.horchani-Naifer M.Férid Research Unit of Rare Earth Materials National Research Center in Sciences of MaterialsB.P.95 Hammam-Lif2050Tunisia b Institute of Low Temperature and Structure ResearchPAS Okolna St. 50-422WroclawPoland

In this article,varied praseodymium polyphosphate hosts:MI(Li,Na K)Pr(PO3)4 microcrystals and LiLa1-xPrx(PO3)4(x = 0.01 ^-1)nanocrystals were successfully synthesized by the flux method and the coprecipitation technique,*** size of stoichiometric nanocrystals of LiPr(PO3)4 was tuned by the te mpe rature of thermal treatment in range of 35-145 *** order to dete rmine the most suitable material for the non-contact optical thermometric applications,the temperature sensing measurements were carried out by using luminescence intensity ratio(LIR)of emission bands corresponding to the ^3 P1→ ^3h5 and ^3P0→ ^3 h5 electronic transitions of Pr3+ ions into the 123-423 K temperature *** influence of the host material composition of MⅠ(Li,Na,K)Pr(PO3)4 microcrystals on the sensitivity of luminescent thermometers was *** is found that the sensitivity of lithium praseodymium polyphosphate is the highest of all micropowders under ***,it is found that the nanocrystals reveal much higher relative sensitivity in respect to the microcrystalline *** highest sensitivity of LIR temperature sensing is found for LiPr(PO3)4 nanocrystals(35 nm grain size)in the whole temperature range,reaching 0.283%/K at 164 *** impact of the average grain size on the sensitivity of LIR based thermometers of LiPr(PO3)4 nanocrystals was *** is found that the reduction of the grain size from 145 to 35 nm results in the enhancement of the relative sensitivity from0.156 to 0.240%/K at 223 *** it is found that the high dopant concentration possesses favorable influence on the relative sensitivity of LiLa1-xPrx(PO3)4 nanocrystalline luminescent thermometers.

关键词： Pr^3+ Temperature sensing Luminescence intensity ratio Temperature sensitivity Grain size Dopant concentration

Influence of nitrogen sources on growth and mycotoxin production by isolates of Pyrenophora tritici-repentis from wheat

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The Crop Journal 2016年第2期4卷 119-128页

作者： noureddine Bouras Michael D.holtz Reem Aboukhaddour Stephen E.Strelkov Department of Agricultural Food and Nutritional Science410 Agriculture/Forestry CentreUniversity of Alberta Laboratoire de Biologie des Systemes Microbiens(LBSM) Ecole Normale Superieure de KoubaAlgiersAlgeria Departement de Biologie Faculte des Sciences de la Nature et de la Vie et Sciences de la TerreUniversite de Ghardaia Field Crop Development Centre Alberta Agriculture and Food

The fungus Pyrenophora tritici-repentis(Died.) Drechs. infects the leaves and kernels of wheat,causing tan spot and red smudge, respectively. Isolates of P. tritici-repentis have been reported to be both phytopathogenic and mycotoxigenic. This research investigates the influence of nitrogen sources on growth and production of mycotoxins by eight different isolates of P. tritici-repentis. A synthetic agar medium(SAM) was used with different nitrogen sources, both inorganic [(Nh4Cl, Nh4NO3and(Nh4)2SO4)] and organic(L-alanine, L-histidine, and L-lysine), at a concentration of 37.5 mmol L-1. Individual isolates exhibited different growth rates that varied according to the nitrogen source added to the medium. The choice of nitrogen source also had a major effect on production of the mycotoxins emodin, catenarin and islandicin. The highest concentrations of emodin, 54.40 ± 4.46 μg g-1, 43.07 ± 23.39 μg g-1and28.91 ± 4.64 μg g-1of growth medium, were produced on the complex medium(V8-potato dextrose agar) by the isolates Alg-h2, 331-2 and TS93-71 B, respectively. A relatively high concentration of emodin also was produced by isolates Az35-5(28.29 ± 4.71 μg g-1of medium)and TS93-71B(27.03 ± 4.09 μg g-1of medium) on synthetic medium supplemented with L-alanine. The highest concentrations of catenarin(174.54 ± 14.46 μg g-1and 104.87 ±6.13 μg g-1of medium) were recorded for isolates TS93-71 B and Alg-h2 on synthetic medium supplemented with L-alanine and Nh4 Cl, respectively. The highest concentration of islandicin(4.64 ± 0.36 μg g-1medium) was observed for isolate 331-2 in the presence of L-lysine. There was not a close relationship between mycelial growth and mycotoxin production by the fungal isolates. This is the first report on the influence of nitrogen sources on the production of mycotoxins by P. tritici-repentis.

关键词： Catenarin Emodin Islandicin Nitrogen source Tan spot Triticum aestivum

Comparative study on yields and quality parameters of argan oils extracted by conventional and green extraction techniques

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Grain & Oil Science and Technology 2021年第3期4卷 125-130页

作者： hicham Mechqoq Mohamed El Yaagoubi Svetlana Momchilova Fouad Msanda noureddine El Aouad Department of Biology Faculty of SciencesIbn Zohr UniversityAgadir 80000Morocco Institute of Organic Chemistry with Centre of Phytochemistry Bulgarian Academy of SciencesSofia 1113Bulgaria Polydisciplinary Faculty of Larache University Abdelmalek EssaadiTetouanLarache 92000Morocco

Argan oil is most frequently sold as pure oil,which can be directly applied topically due to its cosmetological proprieties or ingested in order to provide several health ***'s also commonly mixed into a number of cosmetic products like shampoos,soaps and *** this study we aimed to improve the argan oil extraction yield and quality parameters by comparing the effects of different extraction *** kernel oils were extracted using four methods:mechanical cold press,Soxhlet extraction with n-hexane,supercritical fluid extraction(SFE),and enzyme assisted extraction with three different enzyme solutions cellulase(cellulast),pectinase(Pectinex)and a mixture of carbohydrase enzymes(Viscozyme®).The quality parameters was evaluated by determining the acid,peroxide and iodine values aswell as the extinction coefficients K_(232) and K_(270) as measures of conjugated dienes and trienes,*** results showed that the highest yield(66.37%±3.3%)was obtained by enzyme assisted extraction using the carbohydrases enzymes mixture(Viscozyme®),followed by Soxhlet extraction(59.5%±3.1%)and pectinase extraction(52.03%±3.55%).All argan oils samples obtained by the different methods showed a good oxidation stability,with acid,peroxide and iodine values lower than 0.8 mg/g,15 meq/kg and 110 g/100 g according to the official argan oil norm,*** results of argan oils quality parameters demonstrated that the enzyme extracted argan oils showed low oxidation,with the following quality parameters:acid values(0.4-0.6 mg/g),iodine values(95-100 g/100 g),dienes(K_(232)he results proved that the enzyme assisted extraction method can be applied to improve the argan oil yield without affecting the oil *** enzyme extraction method may be a great alternative to solvent and cold press extractions for this eco-friendly processing approach.

关键词： Argan oil Cold press Soxhlet extraction Supercritical fluid extraction Enzyme assisted extraction

^(1)h NMR tests on damaged and undamaged XLPE and SiR samples

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high Voltage 2019年第3期4卷 203-209页

作者： Lydia Gkoura Taiji Wang Athanasios Anastasiou noureddine h.rid huw Griffiths Manu haddad Michalis Fardis Marina Karayianni Institute of Nanoscience&Nanotechnology National Centre for Scientific Research(NCSR)DemokritosAthensGreece School of Chemical Engineering National Technical University of AthensAthensGreece Department of Electrical and Computer Engineering Advanced Power and Energy Research CentreKhalifa UniversityAbu DhabiUnited Arab Emirates School of Engineering Advanced High Voltage Engineering Research CentreCardiff UniversityCardiffUK

Cross-linked polyethylene(XLPE)and silicone rubber(SiR)samples were subjected to a high-voltage AC stress plane-plane configuration and inclined plane test,*** voltage was applied such that discharge was observed across the surface of the XLPE test sample for several hours and for visible damage to occur on SiR samples also after several *** stressed samples together with virgin samples from the same manufactured batch were tested using nuclear magnetic resonance(NMR)***,^(1)h NMR spin-lattice(T_(1))and spin-spin(T_(2))relaxation time measurements were employed to examine potential changes in the chemical bonding of undamaged and damaged XLPE and SiR *** results show that there may be a moderate increase in the T_(1)and T_(2)values of the damaged samples in comparison with the undamaged *** raises the possibility that NMR can be a useful additional experimental tool in characterising material degradation.

关键词： XLPE rubber relaxation