检索结果-南通市图书馆

Classification of Sandstone-Related Uranium Deposits

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2022年第2期33卷 236-256页

作者： michel Cuney Julien Mercadier Christophe Bonnetti Universitéde Lorraine GéoRessourcesCNRSCREGUNancy F54500France 2.State Key Laboratory of Nuclear Resources and EnvironmentEast China University of TechnologyNanchang 330013China

Sandstone type deposits are the most common type of uranium deposits in the world.A large variety of sub-types have been defined,based either on the morphology of the deposits(e.g.,tabular,roll front,etc),or on the sedimentological setting(e.g.,paleovalley,paleochannel,unconformity),or on tectonic or lithologic controls(e.g.,tectonolithologic,mafic dykes/sills),or still on a variety of others characteristics(phreatic oxidation type,interlayer permeable type,multi-element stratabound infiltrational,solution front limb deposit,humate type,etc.),reflecting the diversity of the characteristics of these deposits,but making it difficult to have a clear overview of these ***,uranium deposits occurring in the same sedimentological setting(e.g.,paleochannel),presenting similar morphologies(e.g.,tabular),may result from different genetic mechanisms and thus can be misleading for exploration *** aim of the present paper is to propose a new view on sandstone-related uranium deposits combining both genetic and descriptive *** dual view is indeed of primordial importance because all the critical characteristics of each deposit type,not limited to the morphology/geometry of the ore bodies and their relationships with depositional environments of the sandstone,have to be taken into account to propose a comprehensive classification of uranium *** this respect,several key ore-forming processes,like the physical-chemical characteristics of the mineralizing fluid,have to be used to integrate genetic aspects in the *** a succession of concentration steps,potentially temporally-disconnected,are involved in the genesis of some uranium mineralization,the classification here proposed will focus on the main mechanisms responsible for the formation and/or the location of ore *** objective of this paper is also to propose a robust and widely usable terminology to define and categorize sandstone uranium deposits,considering

关键词： sandstone uranium genetic classification redox control depositional environment fluids ore deposit geology

Rankin-Selberg coefficients in large arithmetic progressions

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2023年第12期66卷 2767-2778页

作者： Emmanuel Kowalski Yongxiao Lin Philippe michel Department of Mathematics ETH ZurichZurich CH-8092Switzerland Data Science Institute Shandong UniversityJinan 250100China EPFL/MATH/TAN Lausanne CH-1015Switzerland

Let(λ_f(n))_(n≥1)be the Hecke eigenvalues of either a holomorphic Hecke eigencuspform or a Hecke-Maass cusp form *** prove that,for any fixedη>0,under the Ramanujan-Petersson conjecture for GL_(2)Maass forms,the Rankin-Selberg coefficients(λ_f(n)^(2))_(n≥1)admit a level of distributionθ=2/5+1/260-ηin arithmetic progressions.

关键词： arithmetic progressions Rankin-Selberg L-functions δ-method

Immunotoxic effects of an industrial waste incineration site on groundwater in rainbow trout (Oncorhynchus mykiss)

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2014年第5期26卷 981-990页

作者： Nadjet Benchalgo Franois Gagn michel Fournier INRS-Institut Armand-Frappier Emerging Methods Aquatic Contaminant Research Division

The discharge of organic waste from the petrochemical industry into the Mercier lagoons caused major groundwater contamination. The objective of this study was to determine the immunotoxic potential of three groundwater wells at increasing distance from the incinerator dumping site （1.17, 2.74 and 5.40 km）. Rainbow Trout were exposed to increasing concentrations of water from three groundwater wells for 14 days. Immunocompetence was characterized by phagocytosis, mitogen-stimulated proliferation of lymphocytes, cell cycle analysis and apoptosis. A significant increase in innate （phagocytosis） and specific immune response （B lymphocyte proliferation） was observed in trout exposed to water collected from the well at 2.74 km. However, phagocytosis activity was suppressed in groups at 1.17 and 5.40 km. The proportion of lymphocytes in S phase was significantly increased in groups at 2.74 and 5.40 kin, while lymphocytes in G0/G1 phase were decreased in all three exposure groups. Additionally, dexamethasone （DEX）-induced apoptosis of lymphocytes was significantly reduced in the group at 2.74 km, which suggests decreased lymphocyte turnover. Furthermore, the ratio of DEX- induced apoptosis/apoptosis was lower in the groups at 2.74 and 5.40 km. In summary, our experiments have shown that exposure to the mixture of organic compounds present in Mercier groundwater modulates phagocytosis and cell proliferation, disrupts the cell cycle and reduces the ratio of DEX- induced apoptosis/apoptosis. It is concluded that groundwater collected in the vicinity of an incinerator containment field could impact immunocompetence in fish.

关键词： groundwater phagocytosis lymphocyte proliferation cell cycle apoptosis rainbow trout

Numerical micro-texture optimization for lubricated contacts-A critical discussion

在线全文

学校读者我要写书评

暂无评论

Friction 2022年第11期10卷 1772-1809页

作者： Max MARIAN Andreas ALMQVIST Andreas ROSENKRANZ michel FILLON Department of Mechanical and Metallurgical Engineering Pontificia Universidad Católica de ChileSantiago 690411Chile Division of Machine Elements LuleåUniversity of TechnologyLuleåSE-97187Sweden Department of Chemical Engineering Biotechnology and MaterialsFCFMUniversity of ChileSantiago 8370456Chile Institut Pprime CNRSUniversity of PoitiersPoitiers Cedex TSA 4112386073France

Despite numerous experimental and theoretical studies reported in the literature,surface micro-texturing to control friction and wear in lubricated tribo-contacts is still in the trial-and-error *** tribological behaviour and advantageous micro-texture geometries and arrangements largely depend on the contact type and the operating *** scale implementation is hampered by the complexity of numerical *** substantiates the urgent need to numerically design and optimize micro-textures for specific *** these aspects have not been covered by other review articles yet,we aim at summarizing the existing state-of–the art regarding optimization strategies for micro-textures applied in hydrodynamically and elastohydrodynamically lubricated *** analysis demonstrates the great potential of optimization strategies to further tailor micro-textures with the overall aim to reduce friction and wear,thus contributing toward an improved energy efficiency and sustainability.

关键词： micro-texturing hydrodynamics elastohydrodynamics tribo-simulation optimization

The exercise-cognition relationship:A virtuous circle

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2019年第4期8卷 339-347页

作者： michel Audiffren Nathalie André Research Institute on Cognition and Learning (UMR CNRS 7295) University of PoitiersSport Sciences Faculty

Exercise and health psychology have generated 2 sets of empirical studies guided by separate theory-driven *** first axis focuses on the causal relationship between chronic exercise and cognition and,more particularly,high-level cognitive functions such as executive functions(EFs).The second axis examines factors influencing the adherence process to physical activity(PA).Research conducted during the past decade shows that these 2 topics are closely linked,with EFs and effortful control playing a pivotal role in the bidirectional relationship linking PA and mental/brain *** present article supports the idea that an individual engaged in the regular practice of effortful PA initiates a virtuous circle linking PA and effortful control in a bidirectional *** the one hand,chronic exercise leads to an improvement of EFs and effortful *** the other hand,gains in EFs and effortful control effectiveness lead to a reciprocal facilitation of the maintenance of PA over *** limitations and perspectives to this effort hypothesis are proposed in the last part of the article.

关键词： Adherence Effort Executive functions Physical activity Salience network

High Order Compact Schemes in Projection Methods for Incompressible Viscous Flows

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2011年第4期9卷 994-1019页

作者： michel Fournie Alain Rigal Institut de Mathematiques de Toulouse Universite de Toulouse et CNRS(UMR 5219)France

Within the projection schemes for the incompressible Navier-Stokes equations(namely"pressure-correction"method),we consider the simplest method(of order one in time)which takes into account the pressure in both steps of the splitting *** this scheme,we construct,analyze and implement a new high order compact spatial approximation on nonstaggered *** approach yields a fourth order accuracy in space with an optimal treatment of the boundary conditions(without error on the velocity)which could be extended to more general *** prove the unconditional stability of the associated Cauchy problem via von Neumann *** we carry out a normal mode analysis so as to obtain more precise results about the behavior of the numerical *** we present detailed numerical tests for the Stokes and the Navier-Stokes equations(including the driven cavity benchmark)to illustrate the theoretical results.

关键词： Incompressible Navier-Stokes fractional step method high order compact scheme boundary conditions

An improved method to assess the required strength of cemented backfill in underground stopes with an open face

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2014年第4期24卷 549-558页

作者： Li Li michel Aubertin Department of Civil Geological and Mining Engineering Ecole Polytechnique de MontréalMontreal H3C 3A7 Canada

Backfill is increasingly used in underground mines to reduce the surface impact from the wastes produced by the mining operations. But the main objectives of backfilling are to improve ground stability and reduce ore dilution. To this end, the backfill in a stope must possess a minimum strength to remain self-standing during mining of an adjacent stope. This required strength is often estimated using a solution proposed by Mitchell and co-workers, which was based on a limit equilibrium analysis of a wedge exposed by the open face. In this paper, three dimensional numerical simulations have been performed to assess the behavior of the wedge model. A new limit equilibrium solution is proposed, based on the backfill displacements obtained from the simulations. Comparisons are made between the proposed solution and experimental and numerical modeling results. Compared with the previous solution, a better agreement is obtained between the new solution and experimental results for the required cohesion and factor of safety. For large scale(field) conditions, the results also show that the required strength obtained from the proposed solution corresponds quite well to the simulated backfill response.

关键词： Underground mines Backfill Required strength Analytical solutions Numerical modeling Mitchell's solution

Biomarkers for detection of alcohol consumption in liver transplantation

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2016年第14期22卷 3725-3734页

作者： Katharina Staufer michel Yegles Division of Transplantation Department of Surgery Medical University of Vienna 1090 Vienna Austria Laboratoire National de Sante Service de Toxicologie medico-legale 1 rue Louis Rech L-3555 Dudelange Luxembourg

Alcoholic liver disease is an established, yet controversial, indication for liver transplantation. Although an abstinence period of up to 6 mo prior to transplantation is mandatory, alcohol relapse after transplantation is a common event. In case of recurrence of heavy drinking, graft survival is significantly impaired. Guidelines on detection and surveillance of alcohol consumption in this patient cohort are lacking. This review summarizes the challenge of patient selection as well as the current knowledge on established and novel alcohol biomarkers with special focus on liver transplant candidates and recipients.

关键词： Ethyl glucuronide Liver cirrhosis Short-term alcohol markers Long-term alcohol markers Psychological support

Substitutional doping in 2D transition metal dichalcogenides

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2021年第6期14卷 1668-1681页

作者： Leyi Loh Zhepeng Zhang michel Bosman Goki Eda Department of Physics National University of Singapore2 Science Drive 3Singapore117551Singapore Department of Materials Science and Engineering National University of Singapore9 Engineering Drive 1Singapore117575Singapore Department of Chemistry National University of Singapore3 Science Drive 3Singapore117543Singapore Centre for Advanced 2D Materials National University of Singapore2 Science Drive 2Singapore117542Singapore

Two-dimensional(2D)van der Waals transition metal dichalcogenides(TMDs)are a new class of electronic materials offering tremendous opportunities for advanced technologies and fundamental *** to conventional semiconductors,substitutional doping is key to tailoring their electronic properties and enabling their device ***,we review recent progress in doping methods and understanding of doping effects in group 6 TMDs(MX2,M=Mo,W;X=S,Se,Te),which are the most widely studied model 2D semiconductor *** and theoretical studies have shown that a number of different elements can substitute either M or X atoms in these materials and act as n-or p-type *** review will survey the impact of substitutional doping on the electrical and optical properties of these materials,discuss open questions,and provide an outlook for further studies.

关键词： substitutional doping transition metal dichalcogenide two-dimensional semiconductor acceptor donor