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。
We present an inelastic neutron scattering study of the relationship between lattice dynamics and the phase transition sequence for the proper ferroelectric Sn2P2Se6, which demonstrates a type II incommensurate phase. The dynamics in the phase transition sequence paraelectric-incommensurate-ferroelectric shows the fol…
A new technique for transmission electron microscope (TEM) observation of grown-in defects has been developed. The grown-in defects beneath the surface, at the “origin of crystal originated particles (COPs)”, are detected using a laser particle counter combined with an atomic force microscope (AFM). Subsequently, the…
The oxides A 2 B 2 O 7 and A 2 B 2 O 6 with the pyrochlore structure and nonferroelectric phase transitions are suitable materials for capacitors. Their behavior, including their dielectric behavior, can be explained on the assumption that they are improper antiferroelectrics. An approximate calculation gives a reason…
Complexes of yttrium (III) and lanthanide(III) ions with an axial macrobicycle derived from the 2+3 Schiff-base condensation of tris(2-aminoethyl)amine with 2,6-diformylpyridine have been prepared in high yields using a one-step procedure. The complexes, with formula [M 2 L](NO 3 ) 6 · xH 2 O · ySolv, (M = Y, La - Lu,…
Polyamides (4a-b and 5a-b) were synthesized from interfacial polycondensation of novel diamine containing phosphatidylcholine analogous moiety, hexamethylene diamine with adipoyl chloride, or sebacoyl chloride in the interface of water and carbon tetrachloride at room temperature. The characterizations of synthesized…
Long‐term potassium (K) fertilization practices are likely to affect the K content of soils. This study assessed the effect of long‐term K fertilization strategies for corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotations on extractable K in the soil profile of a major Iowa soil type at two locations. The…
The state and the elastic dilatational properties of a mixed spiropyran (with attached hydrocarbon)−octadecanol (1:5, mol/mol) spread monolayer was studied. A localized photochemical excitation was used to generate dilatational motion along the elastic monolayer. The surface pressure variations at various distances fr…
SmI2-catalyzed polyaddition of 1,12-dodecanedial followed by treatment with benzaldehyde gives a polyester (1) containing three structural units, [OCH2-(CH2)10-CH2O], [OCH2-(CH2)10-CO], and [CO-(CH2)10-CO], in the main chain and an OCH2Ph end-capping group. GPC analysis of 1 shows molecular weights of Mn = 5.5 × 103 a…
Conformal optical elements offer the promise of enhanced aircraft and missile performance, as well as the potential of improved commercial applications such as microlithography and precision illumination. To turn potential into reality, a number of technical issues must be understood and solved in the areas of optical…
Abstract We give here a model for the pressure dependent, biaxial mechanical behavior of glassy polymers based on the thermally activated growth of deformation zones (Somigliana dislocation loops). The Coulomb criterion of plasticity, σ c = S − m σ n , is found as the critical threshold needed to propagate Somigliana…
A variety of plasma etching chemistries were examined for patterning NiMnSb Heusler alloy thin films and associated barrier layers. Chemistries based on , and were all found to provide faster etch rates than pure Ar sputtering. In all cases the etch rates were strongly dependent on both the ion flux and ion energy. Se…
Two new layered compounds, Pb2BaCuFeO5X (X = Cl, Br), have been prepared by a solid-state reaction. The structure of these compounds is an intergrowth of a defective perovskite BaCuFeO5 block unit and a cesium chloride type Pb2X layer. The structure is related to that of the mineral hematophanite by removing the centr…
Mineral crystals with specific surface texture have been grown by a templating mechanism from a lyotropic liquid-crystalline phase. This experimental system is important in understanding mineralization in ordered organic media, a phenomenon of importance in biology and possibly in biomaterials technology as well. The…
A simplified method for planarizing liquid-crystal-on-silicon (LCOS) backplanes is presented. The method relies on the planarizing capability of spin-cast benzocyclobutene (BCB) polymeric resin. BCB planarization shows a sixfold reduction in step height on the surface of a typical LCOS backplane. Contact with the unde…
Nanoporous Si layers have been investigated by photoacoustic (PA) spectroscopy. The optical absorption spectra for porous Si on p-type Si substrates were obtained in the region of 300 to 1500 nm. The absorptivity became remarkable at 600 nm and increased drastically up to the saturation value while the wavelength decr…
Article SYNTHESIS, CHARACTERIZATION AND THERMAL BEHAVIOUR OF CALCIUM AND STRONTIUM 2, 2, 6, 6-TETRAMETHYL-3,5-HEPTANEDIONATE COMPLEXES. CRYSTAL STRUCTURE OF [Sr(μ, η2-thd)(η2-thd)(η2-MeOC2H4OH)]2 was published on October 1, 1997 in the journal Main Group Metal Chemistry (volume 20, issue 10).
Pigeon liver malic enzyme has an N-terminal amino acid sequence of Met-Lys-Lys-Gly-Tyr-Glu-. In this work, various mutants of the enzyme with individual or combinational deletion (delta) or substitution at these amino acids were constructed and functionally expressed in Escherichia coli cells. A major protein band cor…
The energy distribution of the electrons backscattered in the direction of the surface normal of polycrystalline silver samples was studied using reflected electron energy loss spectroscopy (REELS) at 200 eV and 2 keV primary beam energies. For modeling the electron scattering processes, the Monte Carlo simulation tec…
The influence of poly(octadecyl acrylate) (PODA), which is a comb-like polymer with ethylenic side chains, on the crystallization and morphological behavior of high-density polyethylene (HDPE) in a binary blend was investigated. The studied parameters were the cooling rate, degree of crystallinity, spherulite size, an…
In this work, confirmation of the molecular formula and investigation of the structural stability of the prepared various types of heteropoly acids and their salts by TGA are reported. Specific surface areas of the samples were determined by the BET-single point N2 adsorption method. Scanning electron microscopy (SEM)…