Materials Literature

文献浏览

按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。

清除
第 198898 / 204929 页 · 当前展示 3,977,941–3,977,960 / 4,098,577 条匹配结果 · 摘要仅作预览

Mid-infrared Hall effect in thin-film metals: Probing the Fermi surface anisotropy in Au and Cu

J. Cerne、D. C. Schmadel、M. Grayson 等 6 位作者1999-07-14arXiv

A sensitive mid-infrared (MIR, 900-1100 cm-1, 112-136 meV) photo-elastic polarization modulation technique is used to measure simultaneously Faraday rotation and circular dichroism in thin metal films. These two quantities determine the complex AC Hall conductivity. This novel technique is applied to study Au and Cu t…

Materials Science

Physics of rapidly expanding supercritical solutions: A first approach

Shirish M. Chitanvis1999-07-14arXiv

We consider the case when a supercritical fluid emerges at sonic speed from a small orifice in a high pressure chamber. The subsequent expansion causes a pressure drop and the fluid then enters a regime where its equation of state in $P-V$ space becomes concave towards the origin. This is the signal for an expansion s…

Materials ScienceSoft Condensed Mattercond-mat.stat-mechphysics.flu-dyn

Transmission FT-IR and Knudsen Cell Study of the Heterogeneous Reactivity of Gaseous Nitrogen Dioxide on Mineral Oxide Particles

G. M. Underwood、T. Miller、Vicki H. Grassian1999-07-14The Journal of Physical Chemistry A

The heterogeneous reactivity of gaseous nitrogen dioxide on mineral oxide particles was investigated. In particular, spectroscopic and kinetic measurements have been made to investigate surface reactions of NO 2 on Al 2 O 3, Fe 2 O 3, and TiO 2 at 298 K. Both gas-phase and surface-bound products are formed from the re…

Atmospheric chemistry and aerosolsCatalytic Processes in Materials ScienceIndustrial Gas Emission Control

Quantitative Analysis of Pyroglutamic Acid in Peptides

Yoshio Suzuki、Hirofumi Motoi、Kenji Sato1999-07-13Journal of Agricultural and Food Chemistry

A simplified and rapid procedure for the determination of pyroglutamic acid in peptides was developed. The method involves the enzymatic cleavage of an N-terminal pyroglutamate residue using a thermostable pyroglutamate aminopeptidase and isocratic HPLC separation of the resulting enzymatic hydrolysate using a column…

Glycosylation and Glycoproteins ResearchEnzyme Structure and FunctionBiochemical and Molecular Research

Molecular Dissection of the Folding Mechanism of the α Subunit of Tryptophan Synthase: An Amino-Terminal Autonomous Folding Unit Controls Several Rate-Limiting Steps in the Folding of a Single Domain Protein

Jill A. Zitzewitz、C. Robert Matthews1999-07-13Biochemistry

The alpha subunit of tryptophan synthase (alphaTS) from Escherichia coli is a 268-residue 8-stranded beta/alpha barrel protein. Two autonomous folding units, comprising the first six strands (residues 1-188) and the last two strands (residues 189-268), have been previously identified in this single structural domain p…

Protein Structure and DynamicsGenetic Neurodegenerative DiseasesEnzyme Structure and Function

Metal Pyrazolato Complexes. Synthesis, Characterization, and X-ray Powder Diffraction Studies of Group 12 Coordination Polymers

Norberto Masciocchi、G. Attilio Ardizzoia、Angelo Maspero 等 5 位作者1999-07-13Inorganic Chemistry

A number of polymeric pyrazolato complexes have been prepared and characterized by spectroscopy, thermal analyses (DSC and TGA), and X-ray powder diffraction (XRPD) methods. Ab initio XRPD studies showed that the (isomorphous) [Zn(pz)(2)](n)() and [Cd(pz)(2)](n)() species (Hpz = pyrazole) are 1-D polymers containing t…

Crystallography and molecular interactionsCrystal Structures and PropertiesX-ray Diffraction in Crystallography

Polyaniline−Dodecylbenzene Sulfonic Acid Polymerized from Aqueous Medium: A Solid State NMR Characterization

Shifra Kababya、M. Appel、Y. Haba 等 5 位作者1999-07-13Macromolecules

The characterization of the product of a novel polymerization procedure of aniline in aqueous medium in the presence of dodecylbenzene sulfonic acid (DBSA) as a dopant is reported. This polymerization yields stable dispersions of the emeraldine salt, which are attractive starting material for the preparation of conduc…

Organic Electronics and PhotovoltaicsAdvanced Sensor and Energy Harvesting MaterialsConducting polymers and applications

Magnetic Transitions in the Cyano-Bridged Bimetallic Ferromagnet Mn2(H2O)5Mo(CN)7·4.75H2O (β Phase)

Joulia Larionova≠、Olivier Kahn、Stéphane Golhen 等 5 位作者1999-07-13Inorganic Chemistry

Slow diffusion of two aqueous solutions containing K(4)[Mo(CN)(7)].2H(2)O and [Mn(H(2)O)(6)](NO(3))(2), respectively, has afforded two kinds of single crystals whose formulas are Mn(2)(H(2)O)(5)Mo(CN)(7)].4H(2)O (alpha phase) and Mn(2)(H(2)O)(5)Mo(CN)(7)].4.75H(2)O (beta phase). This paper is devoted to the latter com…

Magnetic properties of thin filmsMagnetism in coordination complexesAdvanced NMR Techniques and Applications

Synthesis and Characterization of TiO2−MgO Mixed Oxides Prepared by the Sol−Gel Method

Tomás López、Jose G. Hernandez、R. Gómez 等 8 位作者1999-07-13Langmuir

Titania−magnesia mixed oxides, with magnesia concentrations between 10 and 90 wt %, were prepared by using the sol−gel method with titanium n -butoxide and magnesium ethoxide as precursors. The mixed oxides were characterized with X-ray powder diffraction, BET nitrogen adsorption isotherms, electron spin resonance (ES…

Zeolite Catalysis and SynthesisLayered Double Hydroxides Synthesis and ApplicationsMagnesium Oxide Properties and Applications

pH-Dependent Adsorption of Gold Nanoparticles on p-Aminothiophenol-Modified Gold Substrates

Tao Zhu、Xiaoyi Fu、Tao Mu 等 5 位作者1999-07-13Langmuir

Colloidal Au nanoparticles were assembled on a gold substrate via a p -aminothiophenol coupling layer. The surface coverage of Au nanoparticles was found to be closely related to the pH value of gold colloids. In alkaline solution, where the amino group was not protonated, Au nanoparticles could not be adsorbed on the…

Gold and Silver Nanoparticles Synthesis and ApplicationsQuantum Dots Synthesis And PropertiesMolecular Junctions and Nanostructures

Synthesis and Photophysical Properties of Nonaggregated Phthalocyanines Bearing Dendritic Substituents

Anthony C. H. Ng、Xiyou Li、Dennis K. P. Ng1999-07-13Macromolecules

A series of phthalocyanines containing four dendritic substituents with terminal ester or carboxylate functionalities have been synthesized. These compounds having bulky substituents are essentially nonaggregated in organic solvents (for the ester series) or water (for the [G 1 ] and [G 2 ] carboxylate series) as demo…

Porphyrin and Phthalocyanine ChemistryPhotochemistry and Electron Transfer StudiesLuminescence and Fluorescent Materials

Crystal Structure of a Zinc Sorption Complex of Cd2+-Exchanged Zeolite X Containing Tetrahedral Cd2+4(μ3-Zn0Cd2+Zn0)4 Clusters

Shenyan Zhen、Karl Seff1999-07-13The Journal of Physical Chemistry B

The sorption of Zn vapor at 480 °C onto fully dehydrated fully Cd 2+ -exchanged zeolite X (Cd 46 Si 100 Al 92 O 384 per unit cell) has been studied at 23 °C by single-crystal X-ray diffraction in the cubic space group Fd 3̄ ( a 0 = 24.895(3) Å). In this structure, Cd 46 Si 100 Al 92 O 384 ·20Zn, Cd 2+ ions are found a…

Nanocluster Synthesis and ApplicationsInorganic Chemistry and MaterialsX-ray Diffraction in Crystallography

Collective charge-density excitations of non-circular quantum dots in a magnetic field

C. A. Ullrich、G. Vignale1999-07-13arXiv

Recent photoabsorption measurements have revealed a rich fine structure in the collective charge-density excitation spectrum of few-electron quantum dots in the presence of magnetic fields. We have performed systematic computational studies of the far-infrared density response of quantum dots, using time-dependent den…

Mesoscale and Nanoscale PhysicsMaterials Science

Physical Aging of Polycarbonate: Enthalpy Relaxation, Creep Response, and Yielding Behavior

John M. Hutchinson、Stefan J. D. Smith、B. Horne 等 4 位作者1999-07-13Macromolecules

The effect of annealing polycarbonate at 125 °C (≈ T g − 20 K) for aging times up to almost 2000 h has been investigated by differential scanning calorimetry, and the kinetics of the enthalpy relaxation process are compared with the effects of aging at the same temperature on the creep response and on the yield behavi…

Polymer crystallization and propertiesMaterial Dynamics and PropertiesPolymer Nanocomposites and Properties

Na-site substitution effects of the thermoelectric properties of NaCo_2O_4

T. Kawata、Y. Iguchi、T. Itoh 等 5 位作者1999-07-13arXiv

The resistivity and thermopower of Na$_{1+x}$Co$_2$O$_4$ and Na$_{1.1-x}$Ca$_x$Co$_2$O$_4$ are measured and analyzed. In Na$_{1+x}$Co$_2$O$_4$, whereas the resistivity increases with $x$, the thermopower is nearly independent of $x$. This suggests that the excess Na is unlikely to supply carriers, and decreases effect…

Materials ScienceStrongly Correlated Electrons

Ein stark lumineszierender vierkerniger Silber(I)-Cluster und seine ligandeninduzierte Clusterkernumlagerung

Vincent J. Catalano、Heidi M. Kar、Joanna Garnas1999-07-12Angewandte Chemie

Die Umlagerung der Ag4-Clusterkerne der lumineszierenden Silber(I)-Komplexe mit Bis(diphenylphosphanyl)bipyridin (P2-bpy), die bei der Bindung von zusätzlichen Liganden an die Ag-Zentren erfolgt (siehe Bild), führt zur Löschung der Emission. Die Löschung tritt mit O2, CO, NO und mit koordinierenden Lösungsmitteln wie…

Organometallic Complex Synthesis and CatalysisMagnetism in coordination complexesNanocluster Synthesis and Applications

<title>Magnetic shape memory (MSM) effect in textured polycrystalline Ni<formula><inf><roman>2</roman></inf></formula>MnGa</title>

Y. Ezer、A. Sozinov、G. Kimmel 等 9 位作者1999-07-12Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Materials that develop large shape changes in the magnetic field at a short response time provide a new method of producing motion and force in electromechanical devices. The strains are based on the magnetic-field-induced reorientation of the twin variants of the material. This effect is called magnetic shape memory…

Shape Memory Alloy TransformationsMagnetic Properties and Applications

Synthese von Porphomethenen und Porphodimethenen durch Zwei- und Vier-Elektronen-Oxidation vonmeso-Octaethylporphyrinogen

Jean-Marc Bénech、L. Bonomo、Euro Solari 等 5 位作者1999-07-12Angewandte Chemie

Die stufenweise Desalkylierung von meso-Octaethylporphyrinogen 1 liefert Porphomethen 2 und Porphodimethen 3, wodurch große Mengen dieser wertvollen Zwischenprodukte zugänglich werden. Die Synthesesequenz beruht auf der Reaktion mit SnCl4⋅2 THF, Li und H2O; das Ausmaß der Desalkylierung hängt von der eingesetzten Meng…

Molecular Sensors and Ion DetectionSupramolecular Chemistry and ComplexesPorphyrin and Phthalocyanine Chemistry

The First Determination of Eu−H Distances by Neutron Diffraction on the Novel Hydrides EuMg2H6 and EuMgH4

Holger Kohlmann、F. Gingl、Thomas C. Hansen 等 4 位作者1999-07-12Angewandte Chemie International Edition

Despite the high neutron absorption of natural europium, the crystal structures of two Eu hydrides could be solved from powder diffraction data. EuMg2D6 crystallizes in a novel AB2X6 structure type (see picture), EuMgD4 is isotypic to BaZnF4. The mean Eu−D distances are 258 and 253 pm, respectively.

Rare-earth and actinide compoundsHydrogen Storage and MaterialsInorganic Chemistry and Materials