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 report novel odd-even layering effects in freely suspended films of the chiral liquid crystal MHPOBC in its antiferroelectric smectic phase. Films with an odd number of smectic layers are characterized by transverse ferroelectricity (molecular tilt plane perpendicular to applied electric field E), while films with…
Zwischen 2 und 44 g L −1 des Diamids 1 werden nur benötigt, um mit einer großen Vielfalt organischer Lösungsmittel stabile Gele zu erhalten. Der Circulardichroismus der Gele läßt sich auf die Bildung chiraler Aggregate aus 1 zurückführen, die durch Wasserstoffbrückenbindungen und van‐der‐Waals‐Wechselwirkungen zusamme…
Porous GaAs was formed electrochemically on n-type GaAs(100) in a 0.1 M HCl electrolyte. Scanning electron microscopy revealed feature sizes of the porous structure in the micrometer to nanometer range. The optical properties of the porous material were characterized by photoluminescence (PL) measurements at 295 K. Co…
A model for ferroelectric relaxors such as PMN, PSN and PLZT giving a quantitative description of their properties and phase diagrams is proposed within the framework of the random field theory. In this model, the relaxors are considered as systems with random sites and orientations of electric dipoles, lattice vacanc…
A simple globular-shaped liquid (octamethylcyclotetrasiloxane, OMCTS) was placed between two solid plates at variable spacings comparable to the size of this molecule and the linear shear viscoelasticity of the confined interfacial film was measured. Strong monotonic increase of the shear relaxation time, elastic modu…
An antiparallel ferroelectric domain in LiNbO3 doped with 5 mol % MgO (MgO:LN) was inverted at room temperature by applying a step-like electric field. The lowest electric field was about one fifth of that for undoped LN, but a high field compared to that for BaTiO3 was found to be necessary from the analysis of the s…
The valence photoemission spectra of alkali metals exhibit multiple plasmon satellite structure. The calculated spectral functions within the GW approximation show only one plasmon satellite at too large binding energy. In this Letter we use the cumulant expansion approach to obtain the spectral functions of Na and Al…
Brillouin scattering spectra of water from T=30 °C down to supercooling temperatures of about T=−26 °C have been measured, at different scattering angles and for different exciting wavelengths, covering exchanged wave vector values from 0.0137 to 0.0351 nm−1. A fit of the spectra using the hydrodynamic line shape for…
The temperature dependence of infrared absorption spectra of CH and CD on diamond nanocrystal surfaces has been investigated. Phase relaxation was closely examined by analyzing frequency shifts and line broadening in the spectra. Based on the model of Persson and Ryberg [Phys. Rev. B 40, 10 273 (1989)], coupling phono…
Hyper-Rayleigh light scattering measurements at incident wavelengths of 1064 and 1319 nm are reported for several organic nonlinear optical chromophores in solution with approximately 5%–10% uncertainty in the relative first hyperpolarizabilities. The measured chromophores include representatives from C1, Cs, C2V, and…
We present in this paper a computer simulation study of the phase behavior of the Gay–Berne liquid crystal model. The effect of the anisotropic attractive interactions on stabilizing orientationally ordered phases is analyzed by varying the anisotropy parameter κ′ at fixed values of the molecular elongation parameter…
The application of advanced polycondensed fused polynuclear aromatic (COPNA) resin to a material for flexible printed wiring boards was studied in this work. To give flexibility to the advanced COPNA resin, a polymer blend technology was introduced. Nylon 6 was selected from the nominated blend polymers with advanced…
Self-assembly of new tetranuclear (1) and octanuclear (2) manganese carboxylate clusters is controlled by the bis(bipyridine) ligands L1 and L2, respectively, which are shown on the right. The cation 1 consists of two Mn2O complex fragments, each of which contains one MnII and one MnIII center; 2 contains two butterfl…
Two distorted Fe6O6 hexagonal prisms with a common rectangular face form the core (shown on the right) of the decanuclear iron complex 1. Magnetic studies indicate a high-spin ground state of around S = 11 or 12. Hchp = 6-chloro-2-pyridone.
The titanium-mediated coupling of NiII and ZnII pyrophaeophorbides results in formation of planar ethenefused bisphaeophorbides 1, M = Ni, Zn. Absorption spectroscopy indicates that the two chlorin units are highly conjugated, and the X-ray crystal structure shows the two phaeophorbide rings to be almost coplanar.
Trigonal-bipyramidal and octahedral coordination is found in transition metal complexes 1 and 2 (M = Co, Ni, Cu, Zn; X = Cl, NO3, NCS (or SCN)) with dendrimeric ethyleneimine ligands of the first (1 = H; R2 = CH2-3,4-C6H3[O(CH2)9CH3]2) and second generation (R1 = R2 = CH2CH2NHCO-3,4-C6H3[O(CH2)9CH3]2). These complexes…
Manganese( II ) nitrate, sodium azide, and 2,2′‐bipyrimidine (bpym) react to give 1 in which the azido groups function as end‐on bridging ligands and the bpym as a bis(bidentate) ligand. The structure of 1 can be described as a honeycomb sheet formed by Mn 6 hexagons. Magnetic susceptibility data reveals the existence…
The scanning tunneling microscope (STM) has been used to observe threefold symmetric electron scattering from point defects on a graphite surface. These theoretically predicted electronic perturbations could not be observed with a bare metal tip but could only be imaged when a fullerene (C 60 ) molecule was adsorbed o…
The role of aminopropyltriethoxysilane in the interaction between ISAF carbon black and carboxylated nitrile rubber was studied by measurements of bound rubber, physical and dynamic mechanical properties of the vulcanizates, and Monsanto Rheometric studies on the rubber-filler mixes. It is believed that NH2 groups o…
A link has been forged between porphyrins and annulenes by carbaporphyrins 1 (R = H and CH3), in which one nitrogen atom of the porphyrin framework is replaced by a carbon atom. These novel compounds are 18π arenes like porphyrins and have similar spectroscopic properties.