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。
A dramatic increase of the clearing temperatures of liquid crystals based on bis(cyclohexyl)ethane 1 by 50 to 70 K can be achieved by the perfluorination of the central ethylene link. Conformational analysis indicates that this effect is due to the increased rigidity of the mesogenic core structure and to the suppress…
A highly efficient algorithm for the reconstruction of microstructures of heterogeneous media from spatial correlation functions is presented. Since many experimental techniques yield two-point correlation functions, the restoration of heterogeneous structures, such as composites, porous materials, microemulsions, cer…
The strontium bismuth tantalate vanadate, SrBi2Ta1.8V0.2O9, (SBTV) layered perovskite ferroelectrics were made by solid state powder sintering. It was found that the SBTV ferroelectrics had the same crystal structure as that of strontium bismuth tantalate, SrBi2Ta2O9 (SBT), but an increased paraferroelectric transitio…
Transparent optical nonlinear crystallized glasses with the composition of 25La2O3 25B2O3 50GeO2, stoichiometric to ferroelectric stillwellite-type LaBGeO5 crystalline phase, have been prepared by a two-step heat-treatment (first heat treatment: T1=670 °C, t1=10 h, second heat-treatment: T2, t2), and their second harm…
In this paper we present fundamental studies elucidating the role of entropy in particle suspensions. We focus on systems composed of large colloidal particles along with a second, usually smaller species such as a particle or polymer. We describe direct measurements of these interactions in suspension, and we systema…
In this article, the Jiles–Atherton model is modified to elucidate the variation of magnetic properties with grain size and dislocation density. The modified model predicts generally that coercive field increases with increasing dislocation density and inverse grain size and that remanent flux density and permeability…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSupramolecular Assembly of Amide DendronsChulhee Kim, Kyoung Taek Kim, Youngkyu Chang, Hyun Hoon Song, Tai-Yon Cho, and Hye-Jin JeonView Author Information Department of Polymer Science and Engineering Inha University, Inchon 402-751, Korea Department of Polymer Scienc…
Among various magnetic orderings exhibited by transition-metal compounds, ferromagnetism is the most important particularly in technological aspects. Recent intensive studies on the colossal magnetoresistance (CMR) have given even another reason for the importance of ferromagnetism. It would be very useful if one coul…
We have prepared a homologous series of filamentous viruses with varying contour length using molecular cloning techniques. These viruses are monodisperse enough to form a stable smectic phase. Two systems are studied. The first system consists of viruses to the surfaces of which the polymers are covalently bound. Thr…
An ultraviolet light-emitting diode (UV-LED) was realized using a p-n heterojunction composed of the transparent oxide semiconductors p-SrCu2O2 and n-ZnO. A Ni/SrCu2O2/ZnO/ITO multilayered film was epitaxially grown on an extremely flat YSZ (111) surface by a pulsed-laser deposition technique. SrCu2O2 (112) was prefer…
Features in the Raman and infrared (IR) spectra of highly sp3 bonded hydrogenated amorphous carbon nitride films are assigned. The Raman spectra show three main features all found in a-C itself, the G and D peaks at 1550 and 1350 cm−1, respectively, and the L peak near 700 cm−1. The intensity ratio of the D and G peak…
The subunit compositions of skin and muscle type I collagens from rainbow trout were found to be alpha1(I)alpha2(I)alpha3(I) and [alpha1(I)](2)alpha2(I), respectively. The occurrence of alpha3(I) has been observed only for bonyfish. The skin collagen exhibited more susceptibility to both heat denaturation and MMP-13 d…
We propose that the boson peak originates from the (quasi-) localized vibrational modes associated with long-lived locally favored structures, which are intrinsic to a liquid state and are randomly distributed in a sea of normal-liquid structures. This tells us that the number density of locally favored structures is…
We have studied the remanent magnetic flux distribution in bulk melt-textured YBa2Cu3O7 (YBCO) crystals after their magnetization in quasi-static and pulsed magnetic fields up to 6T. It has been shown that, provided that the magnetic pulse is sharp enough and its amplitude much exceeds the twice penetration magnetic f…
Samples of aligned MgB2 crystallites have been prepared, allowing for the first time the direct identification of an upper critical field anisotropy Hc2^{ab}/Hc2^{c}= xi_{ab}/xi_{c} ~ 1.73; with xi_{o,ab} ~ 70 A, xi_{o,c} ~ 40 A, and a mass anisotropy ratio m_{ab}/m_{c} ~ 0.3. A ferromagnetic background signal was ide…
Weak localization corrections to conductivity of ferromagnetic systems are studied theoretically in the case when spin-orbit interaction plays a significant role. Two cases are analyzed in detail: (i) the case when the spin-orbit interaction is due to scattering from impurities, and (ii) the case when the spin-orbit i…
Convective effects on free dendritic crystal growth into a supercooled melt in two dimensions are investigated using the phase-field method. The phase-field model incorporates both melt convection and thermal noise. A multigrid method is used to solve the conservation equations for flow. To fully resolve the diffuse i…
The topotactic transformation of boehmite (AlOOH) taking place under calcination and leading to γ-alumina (γ-Al 2 O 3 ) has been investigated theoretically and a step-by-step mechanism for the structural transformation is proposed. This mechanism reveals two major steps. First, the structural collapse of boehmite occu…
The magnetic and transport properties, under magnetic field and hydrostatic pressure, of a ${\mathrm{La}}_{0.8}{\mathrm{Ba}}_{0.2}{\mathrm{MnO}}_{3}$ single crystal are studied. On cooling down, the signatures of the rhombohedral (R) to orthorhombic (O) structural phase transition at ${T}_{S}\ensuremath{\approx}175\ma…
Si 29 magic-angle-spinning nuclear-magnetic resonance has been measured on spinel-type cubic silicon nitride (c-Si3N4). c-Si3N4 shows two Si29 resonances at −50.0±0.2 and −225.0±0.2 ppm, corresponding to the tetrahedron SN4 and the octahedron SiN6, respectively. Integration of the spectrum gives SN4/SiN6 about one hal…