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。
1,3-Dibromo-2,4,6-trinitrobenzene (DBTNB), a two-dimensional charge transfer hyperpolarisable chromophore, crystallizes in the non-centrosymmetric space group C2 in perfect polar order leading to an intense powder SHG signal at 1.06 microns.
Energy increments for van der Waal effects are determined by bond-energy measurements on over 50 guest compounds (see diagram) and can be used for prediction. Hydrophobic effects can be discounted on the basis of comparison measurements with alkylated derivatives.
In einem einzigen Schritt erhält man ausgehend von Bipyrrol-Vorstufen in über 70 % Ausbeute Cyclo[8]pyrrole. Diese verkörpern eine neue Klasse von Porphyrin-Analoga und weisen die charakteristische scheibenartige Struktur der Porphyrine auf. Aus der Struktur eines solchen Cyclo[8]pyrrols im Kristall (siehe Bild) geht…
Abstract Colored fibers can be intimately blended in suitable proportions to achieve a specific color. This kind of formulation suffers from a lack of computer‐aided tool to assist the colorist attempting to find a good recipe to reproduce a target color. In this article a color‐matching system based on the theoretica…
Extremely thin titanium nitride (TiN) barrier layers for Cu based interconnects were deposited using metal organic chemical vapor deposition. The effect of the subsequently performed nitrogen/hydrogen plasma treatment on the microstructure, composition, and electrical properties of these films is studied using convent…
Fractal growth of nanofiber networks from a small-molecule organic gel has been identified and measured in situ for the first time by a new rheological method. The unique nucleation and growth mechanism promises the manipulation of the fractal structure and rheological properties of functional supramolecular materials…
The effect of changing the N2/CH4 feedgas ratio on the structure and mechanical properties of microwave plasma chemical vapor deposited diamond films grown on Ti–6Al–4V alloy substrates was investigated. The relative concentration of CH4 and N2 (in a balance of H2) was shown to strongly influence film structure, hardn…
Ab initio total-energy density functional theory is used to investigate the low temperature (LT) monoclinic form of Mg2NiH4. The calculated minimum energy geometry of LT Mg2NiH4 is close to that determined from neutron diffraction data, and the NiH4 complex is close to a regular tetrahedron. The enthalpies of the phas…
The deformation mechanisms of crystalline (100) Ge were studied using nanoindentation, cross sectional transmission electron microscopy (XTEM) and Raman microspectroscopy. For a wide range of indentation conditions using both spherical and pointed indenters, multiple discontinuities were found in the force–displacemen…
Sm 3+ -doped cadmium–aluminum–silicate glasses (CdO–Al2O3–SiO2) have been fabricated and characterized optically. Intense visible lights and near-infrared emissions were observed under ultraviolet light and 488 nm laser excitation. The density, refractive index, optical absorption, Judd–Ofelt parameters, and spontaneo…
The effects of fluorine (F) doping on silica glass structure, structural relaxations, and vacuum ultraviolet (VUV) absorption edge were investigated by the infrared and vacuum ultraviolet absorption measurements. Linewidth of 2260 cm−1 absorption band, which is one of the good indicators of structural disorder, decrea…
The electric permittivity of the sodium niobate ceramic was investigated in the temperature range from 15 up to 900 K, at frequencies from 100 Hz to 1 MHz. Three anomalies were found in the permittivity curve. A phase transition for NaNbO3 was assigned to anomaly at around 280 K, while other two ones have previously b…
Abstract The effect of the starting polymer on the reaction of sulfonation of polysulfones was investigated. When concentrated sulfuric acid is used as the sulfonation reagent in an organic solvent‐free reaction, a polymer degradation equally occurs, leading to a decrease in the yield of product recovery. Poly(ether s…
The objective of this study was to gain insight into the electronic structure of silver-silver chloride cluster composites and especially into the metal-semiconductor interface. For this purpose a theoretical study of (AgCl)(n) (n=4, 32, 108, 192, and 256), of Ag(m) (m=1-9, 30, 115, 276, and 409), and of the cluster c…
Perfekt in Position gebracht für die [2+2]-Photodimerisierung werden Olefine in selbstorganisierten Koordinationskäfigen aus sechs Metallionen und vier dreizähnigen Liganden. In diesen gefäßartigen Nanokäfigen ließ sich die Dimerisierung von Acenaphthylenen und Naphthochinonen quantitativ, schnell und mit sehr hoher R…
A back-to-front synthesis of azuliporphyrins from an azulitripyrrane (1) has been developed. This methodology has allowed the first rational synthesis of the dicarbaporphyrinoid system 2.
The effect of particle size on the transport properties (resistivity and thermopower) of La0.5Pb0.5MnO3 has been investigated both in the presence and in the absence of magnetic field B=0.0–1.5 T (maximum). Grain size, dc conductivity; and the metal–insulator transition temperature Tp of the sample increase with incre…
In this paper we report the development of a family of polymerizable urea derivatives that are gelators for organic solvents. The design involves amino-acid-based urea derivatives containing methacrylate functional groups. Several of the bis-ureas show excellent gelation properties in a variety of organic solvents at…
Abstract Measurements of the thermal expansion coefficients (TECs) of cellulose crystals in the lateral direction are reported. Oriented films of highly crystalline cellulose I β and III I were prepared and then investigated with X‐ray diffraction at specific temperatures from room temperature to 250 °C during the hea…
Abstract The structural characterization and transport properties of blends of a commercial high molecular weight poly(ϵ‐caprolactone) with different amounts of a montmorillonite‐poly(ϵ‐caprolactone) nanocomposite containing 30 wt % clay were studied. Two different vapors were used for the sorption and diffusion analy…