Materials Literature
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。
Perturbation of a propagating crack with a straight edge is solved using the method of matched asymptotic expansions (MAE). This provides a simplified analysis in which the inner and outer solutions are governed by distinct mechanics. The inner solution contains the explicit perturbation and is governed by a quasi-sta…
The Gd2Sn2O7 pyrochlore Heisenberg antiferromagnet displays a phase transition to a four sublattice Neel ordered state at a temperature near 1 K. Despite the seemingly conventional nature of the ordered state, the specific heat has been found to be described in the temperature range 350-800 mK by an anomalous T-square…
Using a high speed camera, we study the peeling dynamics of an adhesive tape under a constant load with a special focus on the so-called stick-slip regime of the peeling. It is the first time that the very fast motion of the peeling point is imaged. The speed of the camera, up to 16000 fps, allows us to observe and qu…
We present experiments on the slow growth of a single crack in a fax paper sheet submitted to a constant force $F$. We find that statistically averaged crack growth curves can be described by only two parameters : the mean rupture time $τ$ and a characteristic growth length $ζ$. We propose a model based on a thermally…
We study experimentally the slow growth of a single crack in polycarbonate films submitted to uniaxial and constant imposed stress. The specificity of fracture in polycarbonate films is the appearance of flame shaped macroscopic process zones at the tips of the crack. Supported by an experimental study of the mechanic…
In the patterned vertical alignment (PVA) cell in which multidomains are formed from the perfect vertical alignment through an oblique field only, the formation of disclinations between liquid crystal (LC) molecules is inevitable in the presence of an electric field, which lowers transmittance and the response time. I…
The magnetocaloric properties of polycrystalline Ni50Mn50−xInx (15⩽x⩽16) associated with the second order magnetic transition at the Curie temperature and the first order martensitic transition were studied using magnetization measurements. The refrigeration capacity and magnetic entropy change were found to depend on…
Lilliputian techniques for measuring the mechanical response of microscale specimens are being developed to characterize the performance and reliability of microelectromechanical systems (MEMS) and other small-scale entities. The challenges associated with the preparation, handling, and testing of small volumes of mat…
The authors demonstrate a substantial enhancement in radiation-induced amorphization resistance for single-phased nanocrystalline (NC) versus large-grained polycrystalline MgGa2O4. NC and large-grained MgGa2O4 were irradiated at ∼100K with 300keV Kr++ ions to fluences ranging between 5×1019 and 4×1020Kr∕m2. Large-grai…
In addition to x-ray diffraction, Raman spectrum measurements provide direct evidence of the tetragonal and orthorhombic phases coexistence in lead-free ceramics (1−x)K0.5Na0.5NbO3 (KNN)–xLiTaO3 when x equals 5mol%. This is caused by the phase transition temperature between tetragonal and orthorhombic decreasing to ar…
Magnetoelectric multiferroics is an old but emerging class of materials that combine coupled electric and magnetic dipole order. In these materials, ferroelectric and magnetic (ferromagnetic or antiferromagnetic) states coexist or compete with each other. The interaction leads to a so-called magnetoelectric effect, wh…
A novel type of magnetic origin of ferroelectric polarization is proposed. In crystals with triclinic, monoclinic, or trigonal (rhombohedral) symmetries, the proper screw type of magnetic ordering can induce ferroelectricity through the variation in the metal–ligand hybridization with spin–orbit coupling. The ferroele…
Blutsverwandte: Nanopartikel, die in den Blutstrom eintreten, lagern an ihrer Oberfläche Proteine an. Vier Apolipoproteine wurden mithilfe von Copolymernanopartikeln beim Zentrifugieren vollständig zurückerhalten (siehe Elektropherogramm); ihre Wechselwirkung mit den Nanopartikeln ist stärker als die anderer Plasmapro…
This review describes the mechanisms responsible for low-temperature degradation (LTD) of zirconia ceramics and its detrimental consequences for biomedical devices. Special emphasis is given to the critical issue of zirconia degradation actually observed for hip prostheses. Experimental methods to accurately measure a…
Predictions and measurements of the effect of biaxial strain on the properties of epitaxial ferroelectric thin films and superlattices are reviewed. Results for single-layer ferroelectric films of biaxially strained SrTiO 3 , BaTiO 3 , and PbTiO 3 as well as PbTiO 3 /SrTiO 3 and BaTiO 3 /SrTiO 3 superlattices are desc…
Crystal and magnetic structure analyses have been performed for single crystals of multiferroic materials R Mn 2 O 5 ( R = Y, Ho, Er) using the neutron diffraction technique. For all the compounds, the magnetic structure in the commensurate magnetic phase, where spontaneous electric polarization occurs, was determined…
Recent experiments (F.H.J. Van Der Heyden et al., PRL 96, 224502 (2006)) of streaming currents in silica nanochannels with divalent ions report charge inversion, i.e. interfacial charges attracting counterions in excess of their own nominal charge, in conflict with existing theoretical and simulation results. We revea…
Silica type nanostructured hybrid materials have been prepared by co-assembly of sol−gel materials and an extended amphiphilic dendron consisting of a hydrophilic aliphatic polyether block and hydrophobic docosyl chains. As confirmed by small- and wide-angle X-ray scattering (SAXS and WAXS) experiments, the hybrid pre…
Tubular graphite cones (TGCs) with a single-crystal nanotip have been achieved by means of microwave plasma-assisted chemical vapor deposition using in-situ-evaporated Fe catalysts. The absence of the disorder-induced D band in Raman spectra revealed the single-crystalline feature of the nanotip. TGCs were found to st…
Metal nanoparticles (NPs) are used to catalyze the formation of molecular multielectron transfer products, for example, H 2, from single-electron reductants, such as radicals. Noble metals, like silver and gold, were very instrumental in unraveling the mechanism of this interfacial process. In this study, we explore t…