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Radiolarian and Planktic Foraminifera Biostratigraphy of the Early Albian Organic Rich Beds of Fahdene Formation,Northern Tunisia

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Journal of Earth Science 2014年第1期25卷 45-63页

作者： M Ben Fadhel T Zouaghi A Amri M Ben Youssef département de géologie Faculté des Sciences de Gafsa-Campus Universitaire Sidi Ahmed Zarrouk–2112 département des géoressources CERTE–Technopole de Borj Cédria

The lower part of Fahdene Formation outcropping in northeastern Tunisia is repre- sented by pelagic sequences and characterized by an important siliciclastic fraction that includes ra- diolarian and organic-rich beds of Allam Member. Litho-biostratigraphic analysis based on planktic foraminifera and radiolaria shows that deposition of organic-rich beds of Allam Member is confined to the Microhedbergella rischi Zone through the lower part of Ticinella primula Zone. Age diagnostic radiolaria recovered from these beds has been identified to constrain a direct age of black shale depo- sition. The assemblages can be correlated with the radiolarian biochronozone U.A.10-11 indicating an Early Albian to early Middle Albian in age. Radiolarian assemblages composed of species characteris- tic of U.A.10 biochronozone （A. montisserei, d. gracilis） are associated with radiolarian taxa belonging to Costata Zone （U.A.9 Pseudoeucyrtis hanni and Thanarla pseudodecora）, which can be correlated with dercourt Member in the Ionian Zone and Paquier level of the Vocontian Basin （southeast of France）. Biostratigraphic and abundance curves analysis has demonstrated significant diversification of cryptocephalic Nassellaria and Archaeodictyomitrae, probably adapted to eutrophic conditions that characterized the Aptian-Albian transition. Ecological conditions may have governed the stratigraphic range of many cosmopolitan taxa （i.e., Pseudodictyomitrae lodogaensis） compared with stratigraphic distributions schemes reported from other domains. The timing of black shales deposition was dia- chronic due to local geodynamic conditions and upwelling currents distribution. The Allam black shales are correlative with the oceanic anoxic event OAElb which is characterized by the widespread of supraregionnally organic-rich beds in the Mediterranean Tethys basins across the Aptian-Albian transition.

关键词： northeastern Tunisia Albian Allam Member black shale radiolaria planktic foraminifera.

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Static Analysis of Functionally graded Sandwich Plates Using an Efficient and Simple Refined Theory

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Chinese Journal of Aeronautics 2011年第4期24卷 432-433页

作者： Hadj Henni ABdELAZIZ Hassen Ait ATMANE Ismail MECHAB Lakhdar BOUMIA Abdelouahed TOUNSI Adda Bedia El ABBAS Laboratoire des Matériaux et Hydrologie Université de Sidi Bel Abbes département de génie Civil Université Ibn Khaldoun département de génie Civil Faculté de Génie Civil et d'Architecture Univesité de Chlef département de Physique Université de Sidi Bel Abbes

In this paper, a new displacement based high-order shear deformation theory is introduced for the static response of functionally graded sandwich plate. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The theory presented is variationally consistent, has strong similarity with classical plate theory in many aspects, does not require shear correction factor, and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolically across the thickness satisfying shear stress free surface conditions. Two common types of functionally graded sandwich plates, namely, the sandwich with fimctionally graded facesheet and homogeneous core and the sandwich with homogeneous facesheet and functionally graded core, are considered. governing equations are derived from the principle of virtual displacements. The closed-form solution of a simply supported rectangular plate subjected to sinu- soidal loading has been obtained by using the Navier method. The validity of the present theory is investigated by comparing some of the present results with those of the classical, the first-order and the other higher-order theories. It can be concluded that the proposed theory is accurate and simple in solving the static bending behavior of functionally graded sandwich plates.

关键词： functionally graded materials sandwich plates refined plate theory bending Navier solution

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Feed supplementation with arginine and zinc on antioxidant status and inflammatory response in challenged weanling piglets

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Animal Nutrition 2017年第3期3卷 236-246页

作者： Nadia Bergeron Claude Robert Frédéric guay département des sciences animales Université Laval

Although supplementing the diet with zinc oxide and arginine is known to improve growth in weanling piglets, the mechanism of action is not well understood. We measured the antioxidant status and inflammatory response in 48 weanling castrated male piglets fed diets supplemented with or without zinc oxide(2,500 mg Zn oxide per kg) and arginine(1%) starting at the age of 20 days. The animals were injected with lipopolysaccharide(100 μg/kg) on day 5. Half of them received another injection on day *** samples were taken just before and 6, 24 and 48 h after injection and the mucosa lining the ileum was recovered following euthanizing on days 7 and 14. Zinc supplementation increased reduced and total glutathione(gSH)(reduced and total) during days 5 to 7 and arginine decreased oxidized gSH measured on days 5 and 12 and the ratio of total antioxidant capacity to total oxidative status during days12 to 14. Zinc decreased plasma malondialdehyde measured on days 5 and 12 and serum haptoglobin measured on day 12 and increased both metallothionein-1 expression and total antioxidant capacity measured in the ileal mucosa on day 14. Tumour necrosis factor a concentration decreased from days 5 to12(all effects were significant at P dy shows that the zinc supplement reduced lipid oxidation and lipopolysaccharide-induced inflammation during the post-weaning period, while the arginine supplementation had only a limited effect.

关键词： Antioxidant Inflammation Zinc Arginine Piglet Weanling

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EXISTENCE OF SOLUTIONS FOR gRAdIENT SYSTEMS WITH APPLICATION TO dIFFUSION PROBLEMS INVOLVINg NONCONVEX ENERgIES

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Acta Mathematica Scientia 2018年第6期38卷 1767-1778页

作者： Sahbi BOUSSANdEL dpartement de Mathmatiques Facult des Sciences de Bizerte

In this paper, we establish the existence of solutions for gradient systems ofevolution under some type （M） and semi-coerciveness conditions. The main result is appliedin order to solve nonlinear diffusion equations... 详细信息

关键词： gradient systems existence of solutions galerkin method type (M) condition semi-coerciveness diffusion equations

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Pseudotachylyte-Induced Weakness of Plate-Boundary Fault:Insight from the Indus-Tsangpo Suture between India and Asia

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Acta geologica Sinica(English Edition) 2019年第1期93卷 1-11页

作者： XU Zhiqin JI Shaocheng ZHOU Xin School of Earth Sciences and Engineering Nanjing University département des génies Civil Géologique et des Mines école Polytechnique de Montréal Institute of geology Chinese Academy of Geological Sciences

Although the Indus-Tsangpo Suture(ITS) is the most spectacular thrust system of continent-continent collision in the world, fundamental questions about its strength evolution and deformation behavior transition remain unanswered. Here we reported, for the first time, frictional melting-induced pseudotachylytes in the intensively deformed felsic rocks along the ITS zone in southern Tibet. This study reveals that pseudotachylytes induced profound weakness of the boundary fault between Indian and Asian plates. The intrinsically low strength of the foliated microlites crystallized from frictional melt or glass(i.e., pseudotachylyte) at seismogenic depths compared with the surrounding coarse-grained quartzofeldspathic rocks in the brittle and semi-brittle regime is sufficient to explain the localization of shear strain, the development of ductile shear zones embedded in strong wall rocks, and the transition from the strong to weak fault behaviors without invoking the presence of high fluid pressure or low friction coefficient metasomatic materials(e.g., smectite or lizardite) within the faults.

关键词： pseudotachylyte mylonite fault strength strain localization Indus-Tsangpo suture Tibet

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Relationship between fracture spacing and bed thickness in sedimentary rocks:Approach by means of Michaelis-Menten equation

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Journal of Rock Mechanics and geotechnical Engineering 2023年第8期15卷 1924-1930页

作者： Shaocheng Ji département des génies Civil Géologique et des MinesÉcole Polytechnique de MontréalMontréalQuébecH3C 3A7Canada

Fractures occur in nearly all rocks at the Earth’s surface and exert essential control on the mechanical strengths of rock masses and *** fractures strongly impact the stability of geological or man-made structures and flow of water and hydrocarbons,CO_(2) and storing *** this,the dependence of opening mode fracture spacing(s)on bed thickness(t)in sedimentary basins(reservoirs)is studied in this *** paper shows that the MichaeliseMenten equation can provide an algebraic expression for the nonlinear s-t *** two parameters have clear geological meanings:a is the maximum fracture spacing which can no longer increase with increasing t,and b is the characteristic bed thickness when s=*** tensile fracture strength(C)of the brittle beds during the formation of tensile fractures can be estimated from the two *** sandstones of 16 areas reported in the literature,C ranges from 2.7 MPa to 15.7 MPa with a mean value of 8 MPa,which lies reasonably within the range of tensile strengths determined *** field-based approach by means of MichaeliseMenten equation provides a new method for estimating the tensile fracture strength of rock layers under natural conditions.

关键词： Fracture spacing Sedimentary rocks Michaelisementen equation Tensile fracture strength Rock fracture mechanics

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A new interpretation for formation of orthogonal joints in quartz sandstone

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Journal of Rock Mechanics and geotechnical Engineering 2021年第2期13卷 289-299页

作者： Le Li Shaocheng Ji département des génies Civil Géologique et des MinesÉcole Polytechnique de MontréalMontréalQuébecH3C 3A7Canada

Two vertical and orthogonal systematic joint sets are generally arrayed in a grid pattern on the bedding surface,which are the significant features of flat-lying sandstone *** extensive researches are reported on this topic,many fundamental problems have still not been *** mutually perpendicular opening-mode fractures are an obvious manifestation of effective tensile stresses in two orthogonal directions in the horizontal bedding plane.A good understanding of these orthogonal joint systems is a key to structural analysis,landscape interpretation,and guidance of resolving a number of very practical problems in engineering,mining and hydrologic *** on an anatomic investigation on the orthogonal joints in the Potsdam sandstone of Cambrian age at Ausable Chasm(New York State,USA)and Beauharnois(Quebec,Canada),we proposed that the orthogonal joints may result from the auxetic effects of quartz-rich sandstone rather than local or regional rotation of the maximum tensile stress(σ_(3))direction by about 90°.The sandstone beds with negative Poisson's ratios are so fascinating that,when placed under vertical burial compression and layer-parallel extension in one direction(σ_(3)),it becomes stretched in the transverse direction(σ_(2)),producing two orthogonal sets of mutual abutting and intersecting joints(J1 and J2 normal toσ_(3) andσ_(2),respectively),and both are normal to the bedding *** set J1 is more closely-spaced than J2 by a factor of∼3.3,which is correlated with an average Poisson's ratio of−0.3 for the Potsdam sandstone at the time of joint formation.

关键词： Rock fractures Orthogonal joints Sandstone Auxetic effects Potsdam group

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Phosphorus Use Efficiency of Bio-Based Fertilizers:Bioavailability and Fractionation

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Pedosphere 2016年第3期26卷 310-325页

作者： Céline VANEECKHAUTE Joery JANdA Peter A.VANROLLEgHEM Filip M.g.TACK Erik MEERS Laboratory for Analytical and Applied Ecochemistry Faculty of Bioscience EngineeringGhent University model EAU Département de Génie Civil et de Génie des EauxFaculté des Sciences et de GénieUniversité Laval

Although to date some technologies producing bio-based phosphorus(P) fertilizers have been proposed and implemented, the efficient use of the recovered products is still limited due to legislative constraints and lack of insights in the P release with time and in the corresponding mechanisms. The aim of this work was to evaluate the fertilizer performance in terms of P release and use efficiency of recovered struvite, FePO_4-sludge, digestate, and animal manure as compared to fossil reserve-based mineral triple superphosphate(TSP). First, product physicochemical characteristics and P fractions in the context of European fertilizer legislation were assessed. Next, a controlled greenhouse experiment was set up to evaluate plant reactions as well as changes of P availability in a sandy soil with high P status and a Rheinsand soil with low P status. Soil P fractions were determined in the extracts with water, ammonium lactate and CaCl_2, and in soil solution sampled with Rhizon soil moisture samplers. Based on all results, it is worth conducting long-term field trials to evaluate the P release effect of struvite and digestate as compared to animal manure and TSP on different soil types with varying P status. These products showed promise as sustainable substitutes for conventional P fertilizers and could contribute to a more efficient use of P in agriculture. A refined classification of P application standards/recommendations in terms of soil P status, soil texture, and fertilizer characteristics, next to the crop P demand, is recommended. Moreover, the additional use of Rhizon samplers for determination of direct available P, including dissolved organic P, is proposed for better understanding and categorization of different P fertilizers in environmental and fertilizer legislations.

关键词： chemical soil analysis digestate nutrient recovery Rhizon samplers struvite

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On the Equivalence of Weyl Theorem and generalized Weyl Theorem

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Acta Mathematica Sinica,English Series 2007年第1期23卷 103-110页

作者： M.BERKANI grouped'Analyse et Théorie des Opérateurs(g.A.T.O.) Département de MathématiquesUniversitéMohammed ⅠFaculté des SciencesOujda 60000Morocco

We know that an operator T acting on a Banach space satisfying generalized Weyl＇s theorem also satisfies Weyl＇s theorem. Conversely we show that if all isolated eigenvalues of T are poles of its resolvent and if T satisfies Weyl＇s theorem, then it also satisfies generalized Weyl＇s theorem. We give also a sinlilar result for the equivalence of a-Weyl＇s theorem and generalized a-Weyl＇s theorem. Using these results, we study the case of polaroid operators, and in particular paranormal operators.

关键词： B-Fredholm operator Weyl's theorem generalized Weyl's theorem a-Weyl's theorem,generalized a-Weyl's theorem poles

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Numerical Modelling Point-to-Plane of Negative Corona discharge in N_2 Under Non-Uniform Electric Field

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Plasma Science and Technology 2015年第6期17卷 469-474页

作者： A.K.FEROUANI M.LEMERINI L.MERAd M.HOUALEF Ecole Préparatoire en Sciences et Techniques Département de Physique LPT Université A.BelkaidFaculté des SciencesDépartement de Physique Ecole Préparatoire en Sciences et Techniques Département de Maths

The paper presents a simulation model of the negative corona discharge in N2 under various pressures. The simulated discharge is of a negative point-to-plane mass type, with an inter-electrode separation distance of 20 mm and a symmetry about the axis of discharge. This simulation investigates the behavior of the neutral density and temperature for different pressures in the range of 0.1-10.0 bar. The spatial and temporal evolution of the neutral gas is analyzed based upon the equations of continuity, momentum and energy in a two-dimensional cylindrical geometry model. For that geometry of the system, the FCT （Flux Corrected Transport） technique was adopted. The results show that the pressure plays a significant role of the neutrals dynamics.

关键词： dC corona discharge FCT method numerical simulation

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