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。
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.
A template-directed mechanism of crystal growth is demonstrated for urea inclusion compounds (UICs). For UICs containing n -alkanone or α+1,ω−1-alkanedione guests, x-ray diffraction revealed superstructure relations between host and guest repeats along the channel axis for guests containing 8 to 14 carbons. For a favo…
In spite of the very great progress made in ceramic science, and the elegance and excitement of the research which has been performed, the real driving force for developments in ceramics remains their potential applications. The opportunity for dramatic scientific advances was certainly one reason for the "ceramic fev…
SF6 gas breakdown and spacer surface flashover volt–time characteristic curves were established for a GIS of D/d = 55/25 (15 mm gap) and D/d = 45/25 (10 mm gap) for 1.2/50, 0.5/50, 0.2/50 and osc/50 (1.64 MHz) µs impulse and disconnector induced VFT voltages. VFT volt–time curves established using actual breakdown vol…
It is believed that the polymorphism observed in calcium carbonate crystals, such as aragonite and calcite in mollusk shells, is controlled by organic matrix proteins secreted from the mantle epithelia. However, the fine structures of these proteins are still unknown, and to understand the molecular mechanisms of mine…
We present in situ scanning tunneling microscopy (STM) images with the resolution of isolated $\ensuremath{\equiv}\mathrm{Si}---\mathrm{O}X$ groups on H-Si(111) in NaOH solutions with or without isopropyl alcohol $[X=H\mathrm{or}---\mathrm{CH}(\mathrm{CH}{}_{3}{)}_{2}]$. The comparison of STM with geometric contours s…
A surface under stress is morphologically unstable. In normal step-flow growth, this is manifested as a step-bunching instability. Here it is shown that for alloy growth the resulting inhomogeneous strain drives decomposition of the alloy. At the same time, this decomposition ``screens'' the inhomogeneous strain, part…
Special features of atomic vacancies in oxides of the perovskite family have been studied within the framework of the Green function method. It has been shown that, in accordance with experiments, the oxygen vacancy has both shallow and comparatively deep levels corresponding to different charge states. The single-cha…
Ellipsometric measurements of a nematic drop spreading on a rough surface are reported. The thickness profile of the drop shows two typical lengths belonging to the microscopic and to the mesoscopic scales (a few tens and some hundreds of \AA{}, respectively). No intermediate thicknesses are observed during the spread…