检索结果-南通市图书馆

foF2 Diurnal Variability at African Equatorial Stations:Dip Equator Secular Displacement Effect

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 Geosciences 2013年第8期4卷 1145-1150页

作者： Doua A.Gnabahou Frederic Ouattara Emmanuel Nanema Francois Zougmore Laboratoire d’Enseignement et de Recherche en Sciences Experimentales et Mathematiques Ecole Normale Superieure de l’Universite de KoudougouKoudougouBurkina Faso Laboratoire des materiaux et Environnement Universite de OuagadougouOuagadougouBurkina Faso institut de Recherches en Sciences Appliquées et Technologies/Centre National de la Recherche Scientifique et Technologique OuagadougouBurkina Faso

The paper goal is to analyze the variability of foF2 at African equatorial stations and the effect of dip angle on this variability. The gap between the dip angle of Dakar and Ouagadougou is superior to that between Djibouti and Ouagadougou. The trend of the dip angle at Ouagadougou and Dakar decreases while that of Djibouti increases. The relative position of the station with respect to the equator and the trend sign explains the difference observed in foF2 variability at Dakar station and at the two other stations. At Djibouti and Ouagadougou, foF2 exhibits noon bite out profile during all solar cycle phases while at Dakar observed profile is dome or plateau during the maximum and the predominance afternoon peak for the other solar cycle phases.

关键词： Dip Angle foF2 Diurnal Variability Solar Cycle Phase

Encapsulating segment-like antimony nanorod in hollow carbon tube as long-lifespan,high-rate anodes for rechargeable K-ion batteries

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 2019年第5期12卷 1025-1031页

作者： Wen Luo Feng Li Weiran Zhang Kang Han Jean-Jacques Gaumet Hans-Eckhardt Schaefer Liqiang Mai department of Physics School of ScienceWuhan University of TechnologyWuhan 430070China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230000China Division of Materials Science and Engineering Boston UniversityMA 02215USA State Key Laboratory of Advanced Technology for Materials Synthesis and Processing International School of Materials Science and Technology Wuhan University of TechnologyWuhan 430070China Laboratoire de Chimie et physique: Approche Multi-echelles des Milieux Complexes Institut Jean BarriolUniversite de LorraineMetz 57070France institute for Functional Matter and Quantum Technologies Stuttgart UniversityPfaffenwaldring 57Stuttgart 70569Germany

K-ion battery (KIB) is a new-type energy storage device that possesses potential advantages of low-cost and abundant resource of *** develop advanced electrode materials for accommodating the large size and high activity of potassium ion is of great ***,a segment-like antimony (Sb) nanorod encapsulated in hollow carbon tube electrode material (Sb@HCT) was *** from the virtue of abundant nitrogen doping in carbon tube,one-dimensional and hollow structure advantages,Sb@HCT exhibits excellent potassium storage properties:in the case of potassium bis(fluorosulfonyl)imide (KFSI) electrolyte,Sb@HCT displays a reversible capacity of up to 453.4 mAh·g^-1 at a current density of 0.5 A·g^-1 and good rate performance (a capacity of 211.5 mAh·g^-1 could be achieved at an ultrahigh rate of 5 A·g^-1).Additionally,Sb@HCT demonstrates excellent long-cycle stability at a current density of 2 A·g^-1 over 120 ***,electrolyte optimization is an effective strategy for greatly improving electrochemical *** ex-situ characterizations,we disclosed the potassiation of Sb anode is quite reversible and undergoes multistep processes,combining solid solution reaction and two-phase reaction.

关键词： K-ion battery antimony anode hollow carbon tube encapsulation electrolyte optimizati on potassium storage mechanism

New Petrological and Geochemical Data of the Nephelinitic Lavas and Geodynamic Implications of Mount Etinde (Cameroon)

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 Geosciences 2016年第12期7卷 1452-1470页

作者： Mama Ntoumbé Bernard Déruelle Isaac Bertrand Gbambié Mbowou Ismaila Ngounouno Département des Sciences de la Terre Faculté des Sciences The University of Ngaoundere Ngaoundere Cameroon Laboratoire de Magmatologie et Géochimie Inorganique et Expérimentale (MAGIE) Institut de Physique du Globe de Paris Université Pierre et Marie Curie Paris France Département de Mines Geologie School of Geology and Mining Engineering The University of Ngaoundéré Meiganga Cameroun

Mount Etinde is a Recent (2).

Mount Etinde is a Recent (de lavas are distinguished on the basis of the mineralogical compositions of their phenocrysts: olivine-pyroxene, olivine-melilite and clinopyroxene-nepheline. Some magnetite and ilmenite occur as inclusions in these early phases. Mafic mineral composition indicates that fractionation involved only limited Fe-enrichment. Oscillatory, normal and sectorial zoning in clinopyroxene relates to the differentiation and fractional crystallization of the magma. Based on the primitive mantle-normalized trace and rare earth element patterns, all nephelinites have high abundances of incompatible elements (103 derivation from a similar source. Textural characteristics and mineral chemical data, as well as whole-rock compositions, suggest that the nephelinitic lavas may have been derived from basaltic magma from a heterogeneous lithospheric mantle. Geochemical modeling of major and trace element variations indicates that the Etinde lavas could not have been produced by only fractional crystallization. Pneumatolytic reaction probably affected the pyromagmas (basaltic magma composition) and was responsible for the nephelinite rocks at lower oxygen fugacity (fO2).

关键词： Petrogenesis Nephelinite Fugacity Geodynamic Mount Etinde

Enhanced Electrochemical Properties of LiFePO_(4)as Positive Electrode of Li-Ion Batteries for HEV Application

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Chemical Engineering and Science 2012年第3期2卷 321-329页

作者： Christian M.Julien Karim Zaghib Alain Mauger Henri Groult Physicochimie des Electrolytes Colloides et Systèmes AnalytiquesUniversitéPierre et Marie CurieParisFrance institut de Recherche d’Hydro-Québec VarennesCanada institut de Minéralogie et physique de la Matière Condensée UniversitéPierre et Marie CurieParisFrance

LiFePO4 materials synthesized using FePO4(H2O)2 and Li2CO3 blend were optimized in view of their use as positive electrodes in Li-ion batteries for hybrid electric vehicles. A strict control of the structural properties was made by the combination of X-ray diffraction, FT-infrared spectroscopy and magnetometry. The impact of the ferromagnetic clus-ters (γ-Fe2O3 or Fe2P) on the electrochemical response was examined. The electrochemical performances of the opti-mized LiFePO4 powders investigated at 60℃ are excellent in terms of capacity retention (153 mAh·g-1 at 2C) as well as in terms of cycling life. No iron dissolution was observed after 200 charge-discharge cycles at 60℃ for cells containing Li foil, Li4Ti5O12, or graphite as negative electrodes.

关键词： Olivine Nanostructured Compounds Local Structure Magnetometry Lithium-Ion Batteries

Predominance of non-adiabatic effects in zero-point renormalization of the electronic band gap

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2020年第1期6卷 297-304页

作者： Anna Miglio Véronique Brousseau-Couture Emile Godbout Gabriel Antonius Yang-Hao Chan Steven G.Louie Michel Côté Matteo Giantomassi Xavier Gonze institute of Condensed Matter and Nanosciences UCLouvainB-1348 Louvain-la-NeuveBelgium Département de physique et Regroupement Québécois sur les Matériaux de Pointe Universitéde MontrealC.P.6128Succursale Centre-VilleMontréal H3C 3J7Canada department of Physics University of California at BerkeleyBerkeleyCA 94720USA Materials Sciences Division Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA Département de Chimie Biochimie et PhysiqueInstitut de recherche sur l’hydrogèneUniversitédu QuébecàTrois-RivièresTrois-Rivières G8Z 4M3Canada Skolkovo institute of Science and Technology Skolkovo Innovation CenterNobel St.3Moscow 143026Russia

Electronic and optical properties of materials are affected by atomic motion through the electron–phonon interaction:not only band gaps change with temperature,but even at absolute zero temperature,zero-point motion causes band-gap *** present a large-scale first-principles evaluation of the zero-point renormalization of band edges beyond the adiabatic *** materials with light elements,the band gap renormalization is often larger than 0.3 eV,and up to 0.7 *** effect cannot be ignored if accurate band gaps are *** infrared-active materials,global agreement with available experimental data is obtained only when non-adiabatic effects are taken into *** even dominate zero-point renormalization for many materials,as shown by a generalized Fröhlich model that includes multiple phonon branches,anisotropic and degenerate electronic extrema,whose range of validity is established by comparison with first-principles results.

关键词： adiabatic renormalization phonon

Biochemical Methane Potential of Food Wastes from Akouedo Landfill, Côte d’Ivoire

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green and Sustainable Chemistry 2018年第3期8卷 288-293页

作者： Kouadio Marc Cyril Kouakou Adjoumani Rodrigue Kra Essi Trokourey Albert Akichi Agboue Laboratoire de Chimie physique Université Félix Houphou&euml t Boigny Abidjan C&ocirc te d’Ivoire Laboratoire de mécanique et des sciences des matériaux Institut National Polytechniques Felix Houphou&euml t Boigny (INPHB) Yamoussoukro C&ocirc te d’Ivoire

The determination of biochemical methane potential (BMP) is very important for the valorization of food wastes. This study is focused on the evaluation of the theoretical methane production from chemical oxygen demand (COD) of some food wastes, coming out Akouedo landfill. Almost all of the considered samples exhibited methane theoretical yields equal to about 402.5 - 507.8 mLCH4/gVS. These results indicate the suitability of all the studied food wastes from Akouedo landfill to be converted into energy.

关键词： Biochemical Methane Potential Food Wastes Akouedo Landfill Chemical Oxygen demand

Stability of M13 Phage in Organic Solvents

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 Biomaterials and Nanobiotechnology 2016年第2期7卷 72-77页

作者： Pouya Moghimian Vesna Srot Benoit P. Pichon Sandra J. Facey Peter A. van Aken Stuttgart Center for Electron Microscopy Max Planck Institute for Solid State Research Stuttgart Germany institut de physique et Chimie des Matériaux de Strasbourg UMR 7504 CNRS—Université de Strasbourg Strasbourg France institute of Technical Biochemistry University of Stuttgart Stuttgart Germany

The effect of different types of organic solvents on the structural integrity of M13 phages has been directly visualized by transmission and scanning electron microscopy. The exposure of M13 phages to apolar hexane had no effect on the structure of the phages for up to 8 h. In contrast, phages showed ~10-fold contraction into rod-like I-forms and to flattened spheroids with ~12 nm diameter upon exposure to polar organic solvents. We show that this finding can be beneficial for the macromolecular self-assembly and in broader aspects, to enhance the spatial arrangement of desired inorganic nanoparticles in the rapidly developing field of virotronics.

关键词： M13 Phage Organic Solvent Structural Integrity Self-Assembly Electron Microscopy

CO2-induced destabilization of pyrite-structured FeO2Hx in the lower mantle

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2018年第6期5卷 870-877页

作者： Eglantine Boulard Franois Guyot Nicolas Menguy Alexandre Corgne Anne-Line Auzende Jean-Philippe Perrillat Guillaume Fiquet Synchrotron SOLEIL Sorbonne Universit Musum National d’Histoire Naturelle Sorbonne Universit Musum National d’Histoire Naturelle instituto de Ciencias de la Tierra Universidad Austral de Chile ISTerre Universit Grenoble Alpes Laboratoire de Gologie de Lyon UMR CNRS 5276Universit Claude Bernard Lyon 1—ENS de Lyon

Volatiles, such as carbon and water, modulate the Earth’s mantle rheology, partial melting and redox state,thereby playing a crucial role in the Earth’s internal dynamics. We experimentally show the transformation of goethite FeOOH in the presence of CO2into a tetrahedral carbonate phase, Fe4C3O12, at conditions above 107 GPa—2300 K. At temperatures below 2300 K, no interactions are evidenced between goethite and CO2, and instead a pyrite-structured FeO2Hx is formed as recently reported by Hu et al.(2016; 2017)and Nishi et al.(2017). The interpretation is that, above a critical temperature, FeO2Hx reacts with CO2and H2, yielding Fe4C3O12and H2O. Our findings provide strong support for the stability of carbon-oxygen-bearing phases at lower-mantle conditions. In both subducting slabs and lower-mantle lithologies, the tetrahedral carbonate Fe4C3O12would replace the pyrite-structured FeO2Hx through carbonation of these phases. This reaction provides a new mechanism for hydrogen release as H2 O within the deep lower mantle. Our study shows that the deep carbon and hydrogen cycles may be more complex than previously thought, as they strongly depend on the control exerted by local mineralogical and chemical environments on the CO2and H2thermodynamic activities.

关键词： deep carbon cycle FeOOH high pressure

N-Methylcarbamoyl Azide:Spectroscopy,X-ray Structure and decomposition via Methylcarbamoyl Nitrene

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

N-Methylcarbamoyl Azide:Spectroscopy,X-ray Structure and Dec...