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 hexa-(p-n-dodecyloxybenzoyl) derivatives (1b), (2b), and (3b) of the macrocyclic polyamines [18]-N6, [24]-N6O2, and [27]-N6O3 display a liquid crystal phase in which the macrocyclic units are stacked, forming a tubular mesophase.
X-ray photoelectron and X-ray-induced Auger electron spectra of silicate minerals have been measured. The systematic shifts of the photoelectron binding energies of Si, O and tetrahedrally coordinated Al ions in the silicate framework suggest that the negative charge on the framework is delocalized over these ions. On…
Allium is a genus of some 500 species belonging to the family Liliaceae. However, only a few of these are important as food plants, notably onion, garlic, chive, leek, and rakkyo. Such plants have been used for many centuries for their pungency and flavoring value, for their medicinal properties, and in some parts of…
Abstract The buffering relationships of a wide variety of Vermont soils were investigated by adding either acid (H 2 SO 4 ) or base (CaCO 3 ). Soils were found to be very well buffered above pH 7 and below pH 4. When amendment added is expressed on an organic matter (OM) basis [mmol (H + or 1/2 CaCO 3 ) g −1 OM] and t…
The existence of various crystalline forms in drugs is a phenomenon frequently encountered (about 40% of the USP XX tablet monographs with dissolution tests are concerned with such compounds). Some studies concerning trituration or grinding of polymorphs have been published; surprisingly little information is availabl…
In this paper we review both photorefractive and nonlinear optical materials for optoelectronic applications. The material requirements for nonlinear optical laser-frequency conversion using the electronic hyperpolarizabilities and optical signal processing using the photorefractive effect will be discussed. Some repr…
Etude, par spectroscopie RMN de 29 Si et 27 Al dans le systeme CaO-Al 2 O 3 -SiO 2 , d'une serie de 50 verres environ dont les compositions chimiques variaient systematiquement le long de sept lignes selectionnees du diagramme de composition ternaire. Les donnees sont discutees d'apres un modele de structure base sur…
Composites of Al 2 O 3 and Y 2 O 3 partially‐stabilized ZrO 2 were isostatically hot‐pressed using submicrometer powders as the starting material. The addition of Al 2 O 3 resulted in a large increase in bending strength. The average bending strength for a composite containing 20 wt% Al 2 O 3 was 2400 MPa, and its fra…
Two hexa-alkoxy derivatives (7a and 7b) of terephthal-bis-[4-benzoyloxyaniline] are described. They exhibit two new types of mesophase for which the term phasmidic is proposed : one has an hexagonal 2D lattice and the second an oblique 2D lattice.
abstract Carbonate concretions occur commonly in organic-rich clastic sediments of ancient coastal floodplains and deltas. They consist of calcite, dolomite, or siderite or combinations of these. The influence of marine, mixed or non-marine depositional waters is seen in early cements; solute sources from decompositio…
On a procédé à l'examen des données existantes sur la composition chimique et les propriétés structurales de columbite-tantalite, ferrotapiolite-manganotapiolite, ixiolite, wodginite, rutile tantalifère et niobifère, cassitérite niobo-tantalifère, et du groupe de pyrochlore. La compréhension de la cristallochimie de c…
Materials transparent to infrared radiation are becoming more and more important with the increasing sophistication and exacting requirements of their diverse applications. Although books have appeared on different aspects of this subject, Dr Savage is the first to collect all the relevant topics in one volume. His wo…
Very comprehensive text for physiology (algae) and/or limnology (freshwater biology) courses at the junior/senior/grad level.
The yield of hydrogen peroxide in the sonication of argon-saturated water was studied in the presence of various solutes. The efficiency of OH radical scavenging is expressed by the reciprocal value of C 1/2, the solute concentration at which the H2O2 yield is decreased by 50 per cent. C 1/2 ranges over several orders…
Polylactide (PLA) microcapsules with an average diameter of 1.5μm were prepared by an interfacial deposition technique. The degree of degradation of PLA microcapsules was estimated by determination of the amount of lactic acid as a final product in bulk solution and from the molecular weight distribution of PLA of the…
The gene encoding subtilisin Carlsberg from Bacillus licheniformis has been isolated by molecular cloning using a mixture of synthetic oligonucleotides. The entire nucleotide sequence of the coding sequence as well as 5' and 3' flanking sequences have been determined. The deduced amino acid sequence reveals an N-termi…
A survey is given of magnetic excitations in metallic 4f systems when the crystal-field splitting is comparable to or larger than the magnetic interaction between different sites. Particular emphasis is put on the interaction of crystal-field split rare-earth ions with conduction electrons. A number of physical effect…
We present results for the splay and bend constants, K11 and K33, in two homologous series of nematic compounds, the alkyl- and alkoxy-cyanobiphenyls, and in PAA. They have been obtained in two laboratories using different methods, and the extent to which they agree gives confidence that neither set is significantly a…
Stoichiometric mullite powder (3Al 2 O 3 ·2SiO 2 ) prepared by spray pyrolysis and sintered at 1650°C attained 95% of theoretical density. The flexural strength was 360 MPa at room temperature and decreased slightly at 1400°C. A fairly high K Ic value (2.8 MN/m 3/2 ) was obtained. These mechanical properties can be at…
Following the discovery of a first-order phase transition in annealed KOH-doped ice at 72 K, which was identified as the order–disorder transition associated with the proton positions, a structural study has now been made. Powder neutron diffraction measurements on KOD-doped D2O above and below the phase transition, t…