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Rare-Element Pegmatites Rocks rich and Li of the Aïr Massif of the Tchirozerine: Mineralogy and Chemical Composition Agadez Region-Northem Niger

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Open Journal of Applied Sciences 2024年第1期14卷 171-181页

作者： Ntoumbé Mama Hamza Bassara Amaya Adama Awona paul Zéphyrin Nomenjanahary Limbisoa department of Mines Geology School of Geology and Mining Engineering University of Ngaoundere Meiganga Cameroon department of Geology Faculty of Sciences and Technic University of Abdou Moumouni Niger department of Geomatic and Geology Mapping School of Geology and Mining Engineering University of Ngaoundere Meiganga Cameroon National Advance School of Engineering of Yaounde Yaounde Cameroon School of Thematic doctoral Faculty of Sciences University of Antsiranana Antsiranana Madagascar

The lithium potential in the Aïr massif is represented by mineral index of spodumene pegmatites and, lepidolite pegmatites. The mineral deposits of lithium occur in cluster or veins that cut the host rock or are located near the contact between the greenstone belt and granitic massif. The evidence of lithium is in the form of clusters or disseminated and stockwerk. Mineralogical characteristics show similarities between the Air Massif pegmatites and indicate the same homogenous source during the magma-generation process. The pegmatite rocks attracted the attention due to their wide exposure and composition, well appearance, and economically hosting of significant rare earth metals such as Sn and W. The mineralogical and petrographical investigations on the eight pegmatites rocks samples observed have a relative similarity, while a little difference in the shapes attributed to the ratio in the pegmatite rocks of the minerals. The occurrence of the kink band indicates the influence of the tectonic processes which affected the Aïr massif after the emplacement of late magmatic or post-magmatic pegmatites by injection into fractured rocks in the upper part of the crust. The Air Massif pegmatite has higher concentrations Li and of all trace elements except Hf and occasionally Zr, Ti, Sn and Mg of for the economic exploration.

关键词： Pegmatite Lithium Rare Elements Hydrothermal Processes Aïr Massif

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Competitive interactions and coexistence of sympatric flagship carnivores in Asia

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Integrative Zoology 2024年第2期19卷 183-199页

作者： Zhilin LI Jiayu LU Xiaoyi SHI Li’an dUO James L.d.SMITH Tianming WANG Tianjin Key Laboratory of Conservation and Utilization of Animal diversity College of Life SciencesTianjin Normal UniversityTianjinChina department of Fisheries Wildlife and Conservation BiologyUniversity of MinnesotaSt.PaulMinnesotaUSA Ministry of education Key Laboratory for Biodiversity Science and Engineering College of Life SciencesBeijing Normal UniversityBeijingChina National Forestry and Grassland Administration Key Laboratory for Conservation Ecology of Northeast Tiger and Leopard BeijingChina

Understanding the competition and coexistence of flagship carnivores is key to creating strategies for their conservation in the face of global carnivore *** studies exploring the dynamics and competition between tigers(Panthera tigris)and leopards(***)span decades,there is a lack of understanding regarding the factors that influence their coexistence mechanisms on a broad scale,as well as the drivers determining their exploitative and interference *** gathered a comprehensive list of research papers among which 36 papers explored the interspecific interactions between tigers and leopards and tested the influence of biotic and abiotic factors on the coexistence mechanisms along three dimensions using multiple response variables regression models;we also tested the influence of ecological drivers determining the exploitative or interference competition between tigers and *** and ungulate density were the most important predictors in regulating the coexistence *** and leopards exhibited more positive relations/higher overlaps as elevation increased in the spatial *** addition,they showed a higher dietary overlap in the prey-rich *** determined that interference competition between tigers and leopards was less frequently observed in habitats with dense tree cover and homogeneous vegetation ***,studies with multiple metrics would promote the detection of interference *** study provides new insight into the competitive interactions and coexistence mechanisms of tigers and leopards on a broad ***-makers and managers should pay more attention to the factors of elevation,prey abundance,and habitat structures for the conservation of tigers and leopards.

关键词： carnivores coexistence mechanisms competitive interactions exploitative competition interference competition

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Fatty Acid Composition of Hazelnut Kernel Oil from Coula edulis Collected in the Republic of Congo

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Food and Nutrition Sciences 2024年第4期15卷 290-297页

作者： Josiane Enzonga Yoca Jean paul Latran Ossoko Yves Okandza Michel didace Mvoula Tsieri Laboratoire de Contrô le et Qualit&#233 des Aliments de l&#8217Ecole Nationale Sup&#233rieure d&#8217Agronomie et de Foresterie Universit&#233 Marien NGOUABI Brazzaville Congo Université Denis Sassou NGUESSO Brazzaville Congo

Coula edulis is non-timber forest product (NTFP) used in Africa for its hazelnuts, which contain edible seeds with a demonstrated nutritional potential. However, there have been very few scientific studies of this species in the Republic of Congo. Thus, the aim of the current study was therefore to determine the fatty acid composition of the oil extracted from Coula edulis hazelnut seeds collected at random in the Republic of Congo. The oil was extracted using the Soxhlet method and its fatty acid composition was determined by gas chromatography. The extracted oil from Coula edulis hazelnut kernels is rich in monounsaturated fatty acids (95.28%), particularly oleic acid (94.5%), which classifies it as an oleic oil and gives it interesting nutritional and therapeutic properties. On the other hand, saturated fatty acids (4.15%) and polyunsaturated fatty acids (0.35%) are not well represented. Its low poly-unsaturated fatty acid content makes it more stable when stored at room temperature.

关键词： Coula edulis Fatty Acids Oil Seeds Hazelnuts Republic of Congo NTFP

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Geochemistry,Petrogenesis and Alteration of Rare-Metal-Bearing Granitoids and Mineralized Silexite of the Al-Ghurayyah Stock,Arabian Shield,Saudi Arabia

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地球科学学刊:英文版 2023年第5期34卷 1488-1510页

作者： Hisham A.Gahlan Mokhles K.Azer paul d.Asimow Mansour H.Al-Hashim department of Geology and Geophysics College of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia Geological Sciences department National Research CentreCairoEgypt division of Geological&Planetary Sciences California Institute of TechnologyPasadena CA 91125USA

New data are presented for the rare-metal bearing A-type granitoids of the AlGhurayyah stock in the northwestern segment of the Arabian Shield, a composite pluton intruding metamorphosed volcano-sedimentary successions of the Silasia Formation. Metals in the granitoids are variably enriched, with up to 1 990 μg/g Zn, 7 680 μg/g Zr, 2 316 μg/g Nb, 232 μg/g Ta, 485 μg/g Hf, 670 μg/g Th, 137 μg/g U and 1 647 μg/g total rare earth elements(REE). The silexite is highly mineralized and yields higher maximum concentrations of several metals than the granitoids, including up to 1 860 μg/g Y, 9 400 μg/g Zr, 878 μg/g Hf, 1 000 μg/g Th, and 2 029 μg/g total REE. The Al-Ghurayyah stock has been assigned to an intraplate setting. Lithospheric delamination led to generation of mantle melts that supplied heat to melt the juvenile crust of the ANS. The fluorine and rare-metal enriched parental magma evolved by fractional crystallization. The quartz-rich silexite, distinct in character from ordinary hydrothermal vein quartz, is inferred to be co-genetic with the granitoids on the basis of their similar REE patterns;it is interpreted as a small volume of residual magma enriched in SiO2, volatiles, and trace metals. Mineralization took place both at the magmatic stage and later during a hydrothermal stage that concentrated these elements to economic grades.

关键词： Arabian Shield Al-Ghurayyah rare metals silexite peralkaline granite hydrothermal metasomatism

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On the origin of the high tensile strength and ductility of additively manufactured 316L stainless steel: Multiscale investigation

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Journal of Materials Science & Technology 2020年第6期41卷 209-218页

作者： Bassem Barkia Pascal Aubry paul Haghi-Ashtiani Thierry Auger Lionel Gosmain Frédéric Schuster Hicham Maskrot dEN-Service d’Etudes Analytiques et de Réactivitédes Surfaces CEAUniversitéParis-Saclay91191France Laboratoire de Mécanique des Sols Structures et MatériauxCentralesupélecUMR CNRS 8579UniversitéParis-Saclay92295France Arts et Métiers ParisTech PIMMUMR CNRS 800675013 ParisFrance CEA Cross-Cutting Program on Materials and Processes Skills 91191Gif-sur-YvetteFrance

We report that 316L austenitic stainless steel fabricated by direct laser deposition(dLd),an additive manufacturing(AM)process,have a higher yield strength than that of conventional 316L while keeping high *** interestingly,no clear anisotropy in tensile properties was observed between the building and the scanning direction of the 3d printed *** examination of the as-built parts shows a heterogeneous solidification cellular *** electron microscopy observations coupled with Energy dispersive X-ray Spectrometry(edS)reveal the presence of chemical micro-segregation correlated with high dislocation density at cell boundaries as well as the in-situ formation of well-dispersed oxides and transition-metal-rich *** hierarchical heterogeneous microstructure in the AM parts induces excellent strength of the 316L stainless steel while the low staking fault energy of the as-built 316L promotes the occurrence of abundant deformation twinning,in the origin of the high ductility of the AM *** additional post-process treatments,the AM 316L proves that it can be used as a structural material or component for repair in mechanical construction.

关键词： Additive manufacturing Austenitic stainless steel dislocation structure Twinning Mechanical behavior Anisotropy

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Pathobiology of the neutrophil-intestinal epithelial cell interaction:Role in carcinogenesis

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World Journal of Gastroenterology 2010年第46期16卷 5790-5800页

作者： paul M Hofman Laboratory of Clinical Experimental PathologyHuman BiobankUniversity of Nice Sophia Antipolis

The role of chronic inflammation,acting as an independent factor,on the onset of gastrointestinal carcinogenesis is now well ***,even if there is an increase in the number of elements directly involving polymorphonuclear leukocytes (PMNL),as a major actor in digestive carcinogenesis,the different cellular and molecular events occurring in this process are still not completely *** transepithelial migration of PMNL,which is the ultimate step of the afflux of PMNL into the digestive mucosa,is a complex phenomenon involving sequential interaction of molecules expressed both on PMNL and on digestive epithelial *** inflammatory areas rich in PMNL [so-called (chronic active inflammation)] and iterative transepithelial migration of PMNL certainly evoke intracellular signals,which lead toward progressive transformation of *** these different signals,the mutagenic effect of reactive oxygen species and nitrates,the activation of the nuclear factor-κB pathway,and the modulation of expression of certain microRNA are key *** the initiation of carcinogenesis,PMNL are involved in the progression and invasion of digestive carcinomas,with which they *** is noteworthy that different subpopulations of PMNL,which can have some opposite effects on tumor growth,in association with different levels of transforming growth factor-β and with the number of Cd8 positive T lymphocytes,could be present during the development of digestive *** factors that involve PMNL,such as massive elastase release,and the production of angiogenic factors,can participate in the progression of neoplastic cells through *** may play a major role in the onset of metastases,since they allow the tumor cells to cross the endothelial barrier and to migrate into the blood ***,PMNL play a role,alone or in association with other cell parameters,in the initiation,promotion,progression and dissemination of digestive carcinomas.

关键词： Neutrophils Intestinal epithelial cells Carcinogenesis Cytokines Nuclear factor-κB pathway MicroRNA Reactive oxygen species

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Promise and pitfalls of modeling grassland soil moisture in a free-air CO_(2) enrichment experiment(BioCON)using the SHAW model

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Pedosphere 2021年第5期31卷 783-795页

作者： Raquel H.FLINKER M.Bayani CARdENAS Todd G.CALdWELL Gerald N.FLERCHINGER Roy rich Peter B.REICH department of Geological Sciences The University of Texas at AustinAustin 78712(USA) Bureau of Economic Geology The University of Texas at AustinAustin 78713(USA) Agricultural Research Service United States Department of AgricultureBoise 83712(USA) Smithsonian Environmental Research Center Edgewater 20137(USA) department of Forest Resources University of MinnesotaSt.Paul 55108(USA) Hawkesbury Institute for the Environment Western Sydney UniversitySydney 2753(Australia)

Free-air carbon dioxide(CO_(2))enrichment(FACE)experiments provide an opportunity to test models of heat and water flow under novel,controlled situations and eventually allow use of these models for hypothesis *** study assesses whether the United States department of Agriculture SHAW(Simultaneous Heat and Water)numerical model of vertical one-dimensional soil water flow across the soil-plant-atmosphere continuum is able to adequately represent and explain the effects of increasing atmospheric CO_(2) on soil moisture dynamics in temperate *** in a FACE experiment,the Bio CON(Biodiversity,CO_(2),and Nitrogen)experiment,in Minnesota,USA,were compared with results of vertical soil moisture *** scenarios represented by different plots were assessed:bare,vegetated with ambient CO_(2),and similarly vegetated with high CO_(2).From the simulations,the bare plot soil was generally the wettest,followed by a drier high-CO_(2) vegetated plot,and the ambient CO_(2) plot was the *** SHAW simulations adequately reproduced the expected behavior and showed that vegetation and atmospheric CO_(2) concentration significantly affected soil moisture *** differences in modeled soil moisture amongst the plots were largely due to transpiration,which was low with high CO_(2).However,the modeled soil moisture only modestly reproduced the ***,while SHAW is able to replicate and help broadly explain soil moisture dynamics in a FACE experiment,its application for point-and time-specific simulations of soil moisture needs further *** typical design of a FACE experiment makes the experimental observations challenging to model with a one-dimensional distributed *** addition,FACE instrumentation and monitoring will need improvement in order to be a useful platform for robust model *** after this can we recommend that models such as SHAW are adequate for process interpretation of datasets from FACE exp

关键词： carbon dioxide FACE experiment soil water flow vadose zone vegetation

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Inclusion Characterization in High Strength Low Alloy Steel for Pipeline Application

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Journal of Iron and Steel Research International 2011年第S1期18卷 762-768页

作者： Wu paul McLean Alex dept.Mat.Sci.& Eng. University of TorontoOntarioCanada M5S 3E4

In this work several methods including sulphur printing,modified spark spectrum analysis and SPEed-SEM-edX methods were used to study the morphology,composition and distribution of inclusions in pipeline *** procedure for the last-mentioned method includes:metal sample preparation using Selective Potentiostatic Etching by Electrolytic dissolution (SPEed) together with inclusion observation and detection using SEM-edX *** results of sulphur printing and spark spectrum analysis showed that there was a well-defined centerline containing relatively high concentrations of sulphur in the steel slab studied in this *** results of SEM study showed that most inclusions found in the steel samples were globular in morphology,and roughly 2-5 micrometers in *** inclusions were rich in sulphur and *** inclusions with a bright globular shape contained Al,Ca,Mn and S,and were likely composed of MnS,CaS and calcium *** was concluded that sulphur printing is a convenient and inexpensive method for inclusion analysis,Spark Spectrum Analysis provides a complete and self-contained technique for inclusion detection,and the SPEed-SEM-edX procedure is best suited for in-situ and three-dimensional observation of inclusions.

关键词： pipeline steel inclusion detection segregation sulphide continuous casting HIC cracking

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Identification and expression profiling of Vigna mungo microRNAs from leaf small RNA transcriptome by deep sequencing

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Journal of Integrative Plant Biology 2014年第1期56卷 15-23页

作者： Sujay paul Anirban Kundu Amita Pal division of Plant Biology Bose Institute Center for Genomic Sciences National Autonomous University of Mexico

MicroRNAs （miRNAs） represent a class of small non-coding RNA molecules that play a crucial role in post- transcriptional gene regulation. Several conserved and species-specific miRNAs have been characterized to date, predominantly from the plant species whose genome is well characterized. However, information on the variability of these regulatory RNAs in economically important but genetically less characterized crop species are limited. Vigna mungo is an important grain legume, which is grown primarily for its protein-rich edible seeds, miRNAs from this species have not been identified to date due to lack of genome sequence information. To identify miRNAs from V. mungo, a small RNA library was constructed from young leaves. High- throughput IIlumina sequencing technology and bioinformat- ic analysis of the small RNA reads led to the identification of 66 miRNA loci represented by 45 conserved miRNAs belonging to 19 families and eight non-conserved miRNAs belonging to seven families. Besides, 13 novel miRNA candidates in V. mungo were also identified. Expressior patterns of selected conserved, non-conserved, and nove miRNA candidates have been demonstrated in leaf, stem, ant root tissues by quantitative polymerase chain reaction, ant potential target genes were predicted for most of the conserved miRNAs. This information offers genomic resour ces for better understanding of miRNA mediated post transcriptional gene regulation.

关键词： Illumina microRNA next generation sequencing quantitative polymerase chain reaction target transcript

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Study of a Melt Crystallization Process for Seawater desalination

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Journal of Mechanics Engineering and Automation 2015年第1期5卷 45-52页

作者： Anouar rich Mostapha Siniti denis Mangin Jean-paul Klein Youssef Mandri Tijani Bounahmidi Ahmed Bouhaouss Stephane Veesler Mohamed El Ganaoui Equipe de Thermodynamique Surface et Catalyse Faculte des Sciences Universite Chouaib Doukkali El Jadida 24000 Maroc LAGEP (Laboratoire d'Automatique et de Genie des Procedes) Universite Lyon 1 Villeurbanne 69622 France LASPI (Laboratoire d'Analyse et Synthese des Proeedes Industriels) Ecole Mohammadia d'Ingenieurs Universite Mohammed VRabat 10000 Maroc LNGPE (Laboratoire des Nanostructures Genie des Procedes et Environnement) Faculte des Sciences de Rabat Universite Mohammed V Rabat 10000 Maroe CINaM-CNRS (Centre Interdisciplinaire de Nanosciences de Marseille-Centre National de la Recherche Scientifique) Campus de Luminy Marseille 13288 France LERMAB-IUT (Laboratoire d'Etude et de Recherche sur le Mat~riau Bois-Institut Universitaire de Technologie Longwy) Longwy Universite de Lorraine Cosnes et Romain F-54400 France

The work aims to develop a process for freezing desalination of seawater on cold walls. The experiments were performed with water/NaCl solutions of different concentrations and with samples of seawater. The pilot crystallizer consists of a cooled tube immersed in a cylindrical double jacketed tank containing water to be treated. The complete process of desalination is conducted in two steps： the freezing step, leading to the crystallization of the ice layer and the sweating step, which consists of purifying the ice layer in depth by melting the impure zones. The systematic study of the influence of operating parameters has highlighted the important role of the cooling ramp and salinity of the solution on the purity of the ice produced. In the absence of stirring, the temperature of the double jacket also has a noticeable effect on the purity of the ice due to temperature gradients, and consequently, convection currents that may result in the solution. The results of this work show the feasibility of the technique and give a good indication of operating conditions that can be used to produce drinking water.

关键词： desalination seawater melts crystallization sweating

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