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Journal of Forestry Research 2014年第2期25卷 455-462页

作者： Sepide Sadat Ebrahimi Hassan Pourbabaei david Potheir Ali Omidi Javad Torkaman department of Forestry Natural Resource FacultyUniversity of Guilan Centre d’étude de la forêt (CEF) and Département des sciences du boiset de la forêtPavillon Abitibi-Price department of Forestry Natural Resources Office

Plant diversity plays key ecological roles in forest ecosystems, including influencing succession, resilience and nutrient cycling. This study was conducted to investigate the effect of livestock grazing and human uses on herbaceous species diversity. We surveyed 50 ha of protected area and 50 ha of unprotected area to evaluate herbaceous species diversity in oriental beech （Fagus orientalis Lipsky） forests in northern Iran. We calculated and compared three indices each of diversity and evenness, and species richness between the two areas. Herbaceous cover was higher in the unprotected area while leaf litter depth and tree canopy cover were higher in the protected area. The diversity indices, H （Shan- non-Wiener index ）, N~ （McArthur index）, N2 （Hill＇s index）, EQ （Modified Nee index）, E,ar （Smith-Wilson index）, E5 （modified index of Hill） and R=S （species richness） and species richness R=S were greater in the protected area than in the unprotected area, suggesting that protection from grazing results in increased numbers of plants and species. The effect of land protection on plant diversity was more pronounced for evenness than for species richness and the positive correlation between diversity and evenness indices was higher than that between diversity and richness.

关键词： grazing human uses richness evenness beech forests Caspianforest

Subsolidus phase relations in the system MgO-ZnO-SiO_2 at high pressure

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Chinese Science Bulletin 1999年第12期44卷 1146-1149页

作者： LI Jianping, Jacques Kornprobst didier Laporte guangzhou Institute of geochemistry , Chinese Academy of Sciences , guangzhou 510640, China departement des Sciences de la Terre, University Blasie Pascal, 630038 Clermont-Ferrand, France guangzhou Institute of geochemistry Chinese Academy of Sciences Guangzhou China département des sciences de la Terre Université Blasie Pascal Clermont-Ferrand France

The subsolidus phase relations were determined experimentally in the system MgO-ZnO-SiO2 at 1.0 gPa and 1 200℃, by use of the high-pressure apparatus "piston-cylinder". The results showed characteristics of the phases assemblage different from that in similar ternary systems. It is impossible to form complete Mg2SiO4-Zn2SiO4 olivine and Mg2Si2O6-Zn2Si2O6 pyroxene solid solution. This is controlled by the properties of Zn2+ with an outer layer of electron (Ar)3d10, different from others transition metal ions, like Fe2+ , Ni2+ , Co2+ .

关键词： high pressure MgO-ZnO-SiO2 system subsolidus phase relation.

ON A BI-HARMONIC EQUATION INVOLVINg CRITICAL EXPONENT: EXISTENCE ANd MULTIPLICITY RESULTS

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Acta Mathematica Scientia 2011年第4期31卷 1213-1244页

作者： Zakaria Boucheche Ridha Yacoub Hichem Chtioui Institut Prparatoire aux Etudes d'Ingenieur de Monastir Avenue Ibn Al Jazzar 5019 Monastir Tunisia dpartement de Mathmatiques Facult des Sciences de Sfax Route Soukra Sfax Tunisia

In this paper, we consider the problem of existence as well as multiplicity results for a bi-harmonic equation under the Navier boundary conditions： △2 u = K（x）u p , u 〉 0 in Ω , △u = u = 0 on Ω , where Ω is a smooth domain in R n , n 5, and p ＋ 1 = 2 n n 4 is the critical Sobolev exponent. We obtain highlightly a new criterion of existence, which provides existence results for a dense subset of positive functions, and generalizes Bahri-Coron type criterion in dimension six. Our argument gives also estimates on the Morse index of the obtained solutions and extends some known results. Moreover, it provides, for generic K, Morse inequalities at infinity, which delivers lower bounds for the number of solutions. As further applications of this Morse theoretical approach, we prove more existence results.

关键词： critical points at infinity Palais-Smale condition Morse lemma at infinity Morse inequalities

Contamination,Fractionation and Availability of Metals in Urban Soils in the Vicinity of Former Lead and Zinc Smelters,France

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Pedosphere 2013年第2期23卷 143-159页

作者： C.WATERLOT g.BIdAR A.PELFRNE H.ROUSSEL H.FOURRIER F.dOUAY Université Lille Nord de France groupe ISA Equipe Sols et Environnement Laboratoire Génie Civil et géoEnvironnement (LGCgE) Lille Nord de France (EA 4515) département des Sites et Sols Pollués Agence de I'Environment et de la Matrise de I'Energie (ADEME)

Soil contamination by metals from anthropogenic activities （e.g., mining and smelting） is a major concern for the environment and human health. Environmental availability of cadmium （Cd）, lead （Pb）, zinc （Zn）, copper （Cu）, and indium （In） in 27 urban soils located around two former Pb and Zn smelters in Northern France were studied by analysing the chemical forms of these metals and evaluating their phytoavailability. These metals were determined using flame or electrothermal absorption atomic spectrometry （FAAS or ETAAS）, depending on their concentration levels. After optimisation of the ETAAS method, characteristic mass of In in water and aqua regia were 9.9 and 18 pg, respectively, showing the high sensitivity of the analytical procedure. Metal partitioning was conducted using a four-step sequential extraction procedure. The results showed that Cd and Zn were mainly in the acid-extractable and reducible forms in the urban soils studied. In contrast, Pb and In were largely in the reducible fraction. However, in some samples, the amount of In extracted in the residual or exchangeable fraction was higher than that in the reducible fraction. Copper was mainly found in the reducible and residual fractions. A pot experiment was conducted in a glasshouse with seven soils （six contaminated and one uncontaminated） and two plant species, ryegrass and lettuce. The results showed transfer of metals from the contaminated soils to the shoots of ryegrass and the edible part of lettuce. The metal bioconcentration factor was in the order of Cd 〉〉 Cu 〉 In 〉 Zn 〉〉 Pb for lettuce leaves, whereas for ryegrass shoots, three orders were found, Cd 〉 Zn 〉 Cu 〉〉 In 〉 Pb, Cd 〉〉 In 〉 Zn 〉 Cu 〉〉Pb, and Zn 〉 Cd 〉 Cu 〉 In 〉〉 Pb, depending on the physico-chemical properties of the soils, such as pH, cation exchange capacity, carbonates, and organic matter. It was established that the metal toxicity was related to the contamination levels and the physico-chemical properties, including pH, organi

关键词： bioconcentration factor environmental availability metal toxicity sequential extraction soil physico-chemical property

Enhancing optical absorption in visible light of ZnO co-doped with europium and promethium by first-principles study through modified Becke and Johnson potential scheme

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Journal of Rare Earths 2019年第4期37卷 416-421页

作者： A.g.El Hachimi M.L.Ould NE A.El Yousfi A.Benyoussef A.El Kenz Laboratory of Condensed Matter and Interdisciplinary Sciences (LaMCScI) Associé Au CNRST (URAC 12) Département de Physique B.P.1014 Faculté des SciencesUniversité Mohammed V Hassan Ⅱ Academy of Science and Technology

By using first-principles calculations we studied the electronic, optical and magnetic properties of ZnO co-doped with Eu and Pm. In this calculation, we used Wien2 k code based on full potential linearized augmented plane waves(FP-LAPW) method with the modified Becke-Johnson(mBJ) approximation. This correction gives good band gap compared to experimental band gap. The introduction of Eu and Pm codoping leads to an increase in the band gap. Electrons can transit easily from the valence band to the conduction band, which results in an enhancement of visible light absorption in a wider absorption range. Absorption spectra reach a high value in visible and infrared light regions. With the significance of the obtained results, the studied compounds may potentially find spintronic and optoelectronic applications.

关键词： Zinc oxide Rare earth density functional theory Modified Becke-Johnson Magnetic properties Spintronics

Breaking seed dormancy in Cupressus atlantica gaussen,an endemicand threatened coniferous tree in Morocco

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Journal of Forestry Research 2012年第3期23卷 385-390页

作者： Sfairi Youssef Ouahmane Lahcen Abbad Abdelaziz direction Provinciale des Eaux et Forets et de la lutte contre ladésertification MarrakechMaroc Laboratoire de Biotechnologies Protection et Valorisation des Ressources Végétalesdépartement deBiologieEquipe de Phytochimie et Pharmacologie des Plantes Aromatiques et MédicinalesFacultédes Sciences SemlaliaUniversitéCadi AyyadMarrakechMaroc Centre Régional de Recherche Forestière Circuit de la PalmeraieMarrakechMaroc Laboratoire de Biotechnologies Protection et Valorisation desRessources Végétalesdépartement de BiologieEquipe de Phytochimieet Pharmacologie des Plantes Aromatiques et MédicinalesFacultédesSciences SemlaliaUniversitéCadi AyyadMarrakechMaroc

Cupressus atlantica gaussen （Cupressaceae） is an endemic and endangered coniferous tree geographically restricted to the N＇Fis valley in South-Western Morocco. Like many forest species, C. atlantica exhibits dormancy which delays and reduces germination. To improve seed germination, different pre-treatments were conducted on C. atlantica seeds after storage for different periods （one, two and five years） including： scarification with sandy paper; soaking seeds in hot distilled water at 60℃ and 80℃ for 15 min and soaking seeds for 48 h in a gibberellic acid （gA3） at 1,000 and 2,000 mg·L-1. Results showed that scarification with sandy paper increased the germination rate of Atlas cypress by up to 67%, indicating that the species possess essentially an exogenous dormancy （physical dormancy） due to the hard seed coat （hardseededness）. Exogenous application of gibberellic acid （gA3） at 1,000 mg.L-1 was also effective in breaking seed dormancy and germination induction. These two treatments induced faster speed germination expressed by low number of days to first germination （8-10 days） and low values of mean germination times （MgT）. However, germination rate, under any treatment, is greatly dependent on the year of seed collection. Seeds collected in year 2004 gave the highest value, suggesting that even after five years of storage, the germination capacity of C. atlantica seeds could remain high. This observation is very interesting in the ex-situ conservation of such endemic and endangered species where the production of seeds is irregular over the years.

关键词： Cupressus atlantica endemic endangered breaking seed dormancy germination capacity hand scarification ex-situ conservation

Petrostructural and geochemical Characteristics of the Metamagmatites in the External Zone of the dahomeyides Belt: Case of the KantèSerpentinites (Northern Togo)

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International Journal of geosciences 2022年第9期13卷 779-792页

作者： Mahaman Sani Tairou Yougbare Mariette Wennegouda Miningou Yawoa dzidzo da Costa Maurice Kwekam département de géologie Faculté des Sciences Université de Lomé Lomé Togo département des Sciences de la Terre Université Joseph KI-ZERBO Ouagadougou Burkina Faso département des Sciences de la Terre Université de Dschang Dschang Cameroun

Thanks to detailed field investigations, microstructural and geochemical analysis and relationship with enclosing rocks, microfabrics, magmatic typology and metamorphic evolution of the Kantè sepentinites have been specified for the first time. The Kantè serpentinites in northern Togo constitute a mega-lens of ultrabasic rocks tectonically intercalated in the sericite chlorite schists of the Atacora structural unit. The brecciated, schitotose or massive rock facies are strongly marked by an S1 schistocity plane superimposed by a flat C shear plane linked to a west vergence thrusting movement. The parageneses that compose the metamagmatites are essentially serpentinous, containing plagioclase, opaque minerals (magnetite, chromite, spinel) and pyroxene porphyroblasts. These microfabrics represent relics of a probable gabbroic protolith. In fact, the geochemical characteristics of the Kantè serpentinites suggest that their magmatic typology is that of komatiites or tholeiitic basalts with oceanic arc affinities. They would have been emplaced in an active margin environment. The retromorphic evolution of the protolith corresponds to the phase of involvement in a major tangential contact during the panafrican tectogenesis.

关键词： Tectogenesis Microfabrics Serpentinites Panafrican Northern Togo

development of new cowpea(Vigna unguiculata)mutant genotypes,analysis of their agromorphological variation,genetic diversity and population structure

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BIOCELL 2021年第2期45卷 345-362页

作者： MAdE dIOUF SARA dIALLO FRANÇOIS ABAYE BAdIANE OUMAR dIACK dIAgA dIOUF Laboratoire Campus de Biotechnologies Végétales Département de Biologie VégétaleFacultédes Sciences et TechniquesUniversitéCheikh Anta DiopDakar-FannDakar10700Sénégal Facultédes Sciences et Technologies de l’Education et de la Formation UniversitéCheikh Anta DiopDakar-FannDakar10700Sénégal

Cowpea is one of the most important legume grains in the sub-Saharan region of Africa used for human consumption and animal feed,but its production is hampered by biotic and abiotic constraints raising the need to broaden its genetic *** this purpose,seeds of two cowpea varieties Melakh and Yacine were irradiated with 300 and 340 gy of gamma-ray,*** developed mutant populations were agromorphologically characterized from M5 to M7,while the genetic diversity of the latter was evaluated using 13 ISSR *** on the agromorphological characterization,variation of flower color,pod length,seed coat color,and seed weight with 78.01,68.29,94.48,and 57.58%heritability,respectively,were recorded in the mutant *** analyses allowed to identify the elite mutants based on their agromorphological traits,while Pearson’s correlation results revealed a positive correlation between yield and yield component *** subpopulations were identified through STRUCTURE analyses,but the assignment of the individuals in each group was improved using dAPC(discriminant Analysis of Principal Components)*** of Molecular Variance revealed that the majority(85%)of the variance rather existed within groups than among(15%)***,our study allowed us to select new promising mutant genotypes that could be tested for multi-locational trials to evaluate their agronomic performance.

关键词： Agromorphological characterization Induced mutagenesis ISSR Plant breeding

Positioning Temperature Sensors for Frost Protection in Northern Cranberry Production

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Agricultural Sciences 2017年第9期8卷 960-971页

作者： Vincent Pelletier Silvio Jose gumiere Steeve Pepin Jacques gallichand Jean Caron département des Sols et de génie Agroalimentaire Université Laval Québec Canada

Frost can cause serious economic losses in cranberry fields, particularly in northern regions. When the air temperature reaches a low critical threshold, sprinklers are operated to protect vines, to insure crop production and profitability. To avoid frost injury, proper positioning of temperature sensors is critical. A field experiment was designed and conducted to determine the optimal installation height of sensors above soil surface. Temperature data was used to investigate the spatial temperature gradient in the section of a cranberry field. A computer simulation of the temperature profile was performed to simulate the effect of wind velocity on the prediction of air temperature. For optimal use, sensors should be installed at the height of the canopy and several meters away from a dike. On nights with low wind velocities, the canopy air temperature was 2.7°C below that of 500 cm above the ground. The sensors should be put at least five m away from a dike to avoid the transfer of heat from the dike to the sensor. Also, multiple sensors should be installed because of the large variations in air temperature that were measured across the experiment. The simulated temperature indicated that wind velocity strongly influenced the temperature estimation;the effect of the wind on temperatures gradients was greater when the wind velocity was low (<2.3 m/s).

关键词： Frost Protection Cranberry Production Numerical Simulation of Heat Transfer

Exact Solution of d-dimensional Klein-gordon Oscillator with Minimal Length

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Communications in Theoretical Physics 2010年第2期53卷 231-236页

作者： Y.Chargui L.Chetouani A.Trabelsi Unit de Recherche de Physique Nuclaire et des Hautes Energies Facult des Sciences de Tunis dpartement de Physique Thorique Institut de Physique Universit de Constantine Route Ain El Bey Unite de Recherche de Physique Nucleaire et des Hautes Energies Faculte des Sciences de Tunis Centre National des Sciences et Technologies Nuclaires

Specific modifications of the usual canonical commutation relations between position and momentumoperators have been proposed in the literature in order to implement the idea of the existence of a minimal observablelength. Here, we study a consequence of this proposal in relativistic quantum mechanics by solving in the momentumspace representation the Klein-gordon oscillator in arbitrary dimensions. The exact bound states spectrum and thecorresponding momentum space wave function are obtained. Following Chang et al. (Phys. Rev. d 65 (2002) 125027),we discuss constraint that can be placed on the minimal length by measuring the energy levels of an electron in a penningtrap.

关键词： Klein-gordon oscillator minimal length energy spectrum