Paolo Ghigna、Andrea Campana、Alessandro Lascialfari 等 7 位作者2000-07-06arXiv
The first X-ray magnetic circular dichroism (XMCD) spectra on the title compounds are presented. In Mn12 the Mn(III) and Mn(IV) contributions are clearly apparent and evidence the opposite spin arrangement of the two ions. For Fe8 the typical two peak structure of Fe(III) compounds is found. Quantitative analysis yiel…
Mesoscale and Nanoscale PhysicsMaterials Science
C. Gilles、P. Bonville、K. K. W. Wong 等 4 位作者2000-07-06arXiv
The magnetic behaviour of nanoparticles of antiferromagnetic ferritin, with a mean Fe loading of 410 atoms per core, has been investigated by 57Fe Mossbauer absorption spectroscopy down to very low temperature (34mK). In previous experi- ments of frequency dependent magnetic susceptibility and magnetic noise performed…
Materials Science
Silvio Franz、Giorgio Parisi2000-07-06Journal of Physics Condensed Matter
In this paper, we discuss theoretically the behaviour of the four-point non-linear susceptibility and its associated correlation length for supercooled liquids close to the mode-coupling instability temperature T c . We work in the theoretical framework of the glass transition as described by mean-field theory of diso…
Material Dynamics and PropertiesTheoretical and Computational PhysicsLiquid Crystal Research Advancements
Thomas S. Reger、Kim D. Janda2000-07-06Journal of the American Chemical Society
This paper describes the synthesis of both soluble and insoluble polymer-supported chiral (salen)Mn complexes and their use in asymmetric epoxidation reactions. These studies were undertaken to establish whether high enantioselectivities could be achieved with a polymer-bound catalyst and if the complexes could be rec…
Polyoxometalates: Synthesis and ApplicationsChemical Synthesis and ReactionsOxidative Organic Chemistry Reactions
Terry P. Bigioni、Robert L. Whetten、Ömer Dag2000-07-06The Journal of Physical Chemistry B
A novel photoluminescence is reported for small metal nanocrystals in the near-infrared region (1.1−1.6 μm). Near-infrared photoluminescence spectra were measured at room temperature for 1.1 and 1.7 nm Au nanocrystals using a 1.06 μm excitation source. This photoluminescence is attributed to sp to sp-like transitions,…
Nonlinear Optical Materials StudiesLaser-Ablation Synthesis of NanoparticlesGold and Silver Nanoparticles Synthesis and Applications
T. Yong-Jin Han、Ji Man Kim、Galen D. Stucky2000-07-06OpenAlex
We demonstrate a novel preparation method for the formation of metallic nanowires from gold, platinum, and silver using mesoporous silica SBA-15 as a template. SBA-15 controls the size and the growth direction of the nanowires and also prevents bulk aggregation of the metal. Nanowires can be isolated from the silica f…
Catalytic Processes in Materials ScienceAnodic Oxide Films and NanostructuresMesoporous Materials and Catalysis
Wei Dafu、Zhao Tiejun、Xiaosu Yi2000-07-05Journal of Applied Polymer Science
The resistivity and volume expansion of carbon black (CB)/high-density polyethylene (HDPE) composite with different CB volume fractions at different temperatures were measured simultaneously. A model based on Meyer's theory is proposed to explain the positive temperature coefficient resistance (PTCR) effect. The relat…
Polymer Nanocomposite Synthesis and IrradiationPolymer Nanocomposites and PropertiesPolymer crystallization and properties
Xinyuan Zhu、Deyue Yan、Deyue Yan 等 8 位作者2000-07-05Journal of Applied Polymer Science
The origins of the single- and double-melting endotherms of isotactic polypropylene crystallized at different temperatures were studied carefully by differential scanning calorimetry, wide-angle X-ray diffraction, and small-angle X-ray scattering. The experimental data show that spontaneous crystallization occurs when…
Polymer Nanocomposites and Propertiesbiodegradable polymer synthesis and propertiesPolymer crystallization and properties
Xiaodong Wang、Hangquan Li2000-07-05Journal of Applied Polymer Science
A polymeric blend system of nylon 6 and a core–shell impact modifier was studied. The modifier had a poly(butyl acrylate) core and a poly(methyl methacrylate) (PMMA) shell compatibilized with an epoxy resin, diglycidyl ether of bisphenol-A (DGEBA). The compatibilization of DGEBA is achieved by the reaction of its glyc…
Polymer Nanocomposites and PropertiesPolymer crystallization and propertiesbiodegradable polymer synthesis and properties
Kavita Taunk、Kunj Behari2000-07-05Journal of Applied Polymer Science
The graft copolymerization of acrylic acid (AA) onto guar gum (GOH) was carried out by a peroxydiphosphate (PDP)–silver(I) system. Grafting ratio, efficiency, add-on, and conversion increase upon increasing the concentration of PDP and acrylic acid, whereas they decrease upon increasing the concentration of guar gum.…
biodegradable polymer synthesis and propertiesElectrospun Nanofibers in Biomedical ApplicationsAdvanced Polymer Synthesis and Characterization
Yumin Yang、Jian Shao2000-07-05Journal of Applied Polymer Science
This article discusses the preparation of the water-insoluble adsorbent sulfhydryl chitin (s-chitin), by treatment of the chitin with sulfhydryl acetic acid in the presence of sulfuric acid as a catalyst. Its structure was confirmed by elemental analysis, FTIR spectra analysis and near-IR spectra analysis. We also inv…
Advanced Cellulose Research StudiesNanocomposite Films for Food PackagingAdsorption and biosorption for pollutant removal
Rong Guan2000-07-05Journal of Applied Polymer Science
To enhance the compatibility of polypropylene (PP) with sericite–tridymite–cristobalite (STC), polypropylene was irradiated by low-energy ultraviolet (UV) irradiation within 2.5 h to introduce the oxygen-containing groups onto the PP chains. From blending the UV-irradiated polypropylene with STC, the effects of the co…
Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesNatural Fiber Reinforced Composites
Bryan D. Kaushiva、Garth L. Wilkes2000-07-05Journal of Applied Polymer Science
In this study, the viscoelastic and morphological properties of molded foams were investigated to determine the influence of varying the concentration of diethanolamine (DEOA), a commercially utilized crosslinking agent. FTIR and WAXS analyses showed that DEOA had a disrupting effect on the bidentate hydrogen bonding…
Polymer Nanocomposites and PropertiesPolymer composites and self-healingPolymer Foaming and Composites
Yan Feng、Gi Xue、Mingshi Zhou2000-07-05Journal of Applied Polymer Science
Nanoscopic conducting polypyrrole powder was prepared in an oil/water microemulsion with FeCl3 as a dopant. Compared with solution and conventional emulsion polymerizations, a microemulsion polymerization system increases the yield of the resultant polypyrrole. The results of FTIR spectra and thermal analysis studies…
Analytical Chemistry and SensorsConducting polymers and applicationsElectrochemical Analysis and Applications
Chang-Hyeon Kim、Kuk Young Cho、Eui‐Jun Choi 等 4 位作者2000-07-05Journal of Applied Polymer Science
This article describes the compatibility of two semicrystalline polymers, poly(ε-caprolactone) (PCL) and poly(l-lactic acid) (PLLA). The compatibility of the PCL/PLLA blends was enhanced by the compatibilizing effect of the poly(l,l-lactide-co-ε-caprolactone) [P(lLA-co-εCL)]. A discussion details the effect of the con…
Additive Manufacturing and 3D Printing TechnologiesPolymer crystallization and propertiesbiodegradable polymer synthesis and properties
Shin-Ichi Ikeda、Yoshiteru Maeno、Satoru Nakatsuji 等 5 位作者2000-07-05arXiv
We show that single-crystalline Sr3Ru2O7 grown by a floating-zone technique is an isotropic paramagnet and a quasi-two dimensional metal as spin-triplet superconducting Sr2RuO4 is. The ground state is Fermi liquid with very low residual resistivity (3 micro ohm cm for in-plane currents) and a nearly ferromagnetic meta…
Materials ScienceStrongly Correlated Electrons
M. D. Glinchuk、E. A. Eliseev、V. A. Stephanovich 等 4 位作者2000-07-05arXiv
We suggest a random field based model for calculation of physical properties of mixed ferroelectric relaxors. Our model naturally incorporates the different orientations of electric dipoles (related to different solid solution components) as well as the contribution of nonlinear and correlation effects of random field…
Materials Science
Dmitry V. Evtuguin、Carlos Pascoal Neto、João Rocha2000-07-04Holzforschung
Summary The behaviour of lignin in wood delignification by oxygen in acidic media in the presence of the molybdovanadophosphate heteropolyanion [PMO 7 V 5 O 40 ] 8− as studied using wet chemistry methods, solid and liquid state 13C NMR spectroscopy. Lignin is oxidised by [PMO 7 V 5 O 40 ] 8− almost completely to carbo…
Polyoxometalates: Synthesis and ApplicationsVanadium and Halogenation ChemistryLignin and Wood Chemistry
T. del Rio Gaztelurrutia、J. M. Pitarke2000-07-04arXiv
A nonlinear description of the interaction of charged particles penetrating a solid has become of basic importance in the interpretation of a variety of physical phenomena. Here we develop a many-body theoretical approach to the quadratic decay rate, energy loss, and wake potential of charged particles moving in an in…
Materials Science
J. Schwitalla、B. L. Gyorffy、L. Szunyogh2000-07-04arXiv
We present a first principles account of Bloch Walls on the basis of relativistic Spin-Density Functional Theory in the Local Density Approximation (LDA). We argue that calculations based on this description will provide useful and novel informations about the physics of this important element of micro-magnetics. To i…
Materials Science