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。
Gold surfaces coated with monolayers of alkyl thiols are significant in the field of biosensors and chromatography. There is a general concern about the quality of coatings in terms of surface density and voids. The self-assembly of the short-chain hexane (C 6 ) thiol and long-chain dodecane (C 12 ) and hexadecane (C…
Abstract The LO and TO phonon frequencies and dampings have been measured by near‐infrared Raman spectroscopy both in bulk GaAs and InP. The phonon damping of the LO phonon in InP is much smaller than the LO phonon damping in GaAs. The experimentally obtained temperature dependences were compared with a theory includi…
We report first- and higher-order Raman scattering from the surface and confined optic phonons in ${\mathrm{CdS}}_{0.65}$${\mathrm{Se}}_{0.35}$ and pure CdS nanoparticles embedded in glass matrix. The average particle sizes and size distribution have been estimated from the quantitative comparison of the blue-shifted…
Abstract We describe the preparation of telechelic OH‐terminated poly[( R )‐3‐hydroxybutyric acid] (PHB) and poly{[( R )‐3‐hydroxybutyric acid]‐ co ‐[( R )‐3‐hydroxyvaleric acid]} (PHB/HV), on a semi‐preparative scale, by a transesterification procedure from the high‐molecular weight polymers. The oligomers have well‐…
We have attempted to clarify the effects of low and high levels of mechanical agitation on the cellulolytic activity of a pure endoglucanase ( EG ) and a total cellulase mixture (TC) on scoured and bleached cotton fabric, along with the effect of EG pretreatment on subsequent treatments with TC. Methods used to follow…
A plastic columnar discotic phase is reported for an asymmetrically substituted triphenylene. It is characterized by a three-dimensional crystal-like registry of ordered columns in a hexagonal lattice while the disc molecules within the columns are able to rotate. At the phase transition from the normal discotic hexag…
The distribution of thermophilic marine sulfate reducers in produced oil reservoir waters from the Gullfaks oil field in the Norwegian sector of the North Sea was investigated by using enrichment cultures and genus-specific fluorescent antibodies produced against the genera Archaeoglobus, Desulfotomaculum, and Thermod…
The polyhydroxybutyrate (PHB) synthase gene of the bacterium Alcaligenes eutrophus was used to construct a yeast plasmid which enabled expression of the functional synthase enzyme in Saccharomyces cerevisiae. Cells transformed with the synthase plasmid accumulated up to 0.5% of cell dry weight as PHB, with accumulatio…
This paper concerns a revision of some Achnanthes subsection Achnanthidium or genus Achnanthidium species, common on sand grains in freshwaters. The taxonomy of the species required a scanning electronmicroscopy study of new and old material and examination of some type material. The SEM study has provided illustratio…
Single crystal MnO(100) substrates can be selectively oxidized to produce Mn2O3- and Mn3O4-like surfaces under mild oxidation/reduction conditions readily accessed under ultrahigh vacuum (UHV). MnO(100) yields a characteristic Mn 2p x-ray photoelectron spectroscopy (XPS) satellite structure and appropriate O/Mn concen…
Abstract A new processing system for the extrusion of microcellular polymer sheets is presented. Specifically, the detailed design of a shaping and cell growth control system is discussed in the context of an overall extrusion system design with particular emphasis on the system level functional requirements of cell n…
Many different processing techniques are currently being used to produce tissue regeneration devices from polyesters in the polylactide/polyglycolide family. While it is generally well recognized that processing techniques influence bulk mechanical and degradation properties of these materials, the effects on surface…
Abstract This paper describes the diagenetic evolution of clay minerals in the Rotliegend sandstone reservoir under contrasting burial histories in the Broad Fourteens basin (Dutch sector, Southern North Sea). The diagenetic modifications affecting the crystal structure of clay minerals (both kaolin-group and illitic…
The use of lime to improve the behavior of marine clays has been in practice in several parts of the world over a long period. In this paper, the beneficial changes occurred in a marine clay due to the diffusion of lime from lime column and lime injected points have been studied using XRD and SEM techniques. The new c…
Cadmium is one of the most toxic trace metals and induces high concentrations of the metal-binding polypeptide phytochelatin, (γ-Glu-Cys) n Gly where n ≥ 2, in the marine diatom Thalassiosira weissflogii . Here we show that at high inorganic cadmium concentrations there is an efflux of cadmium from T. weissflogii so l…
The oxidation state of nickel in a nickel oxide battery has been examined using x‐ray absorption spectroscopy. Chemically synthesized β‐NiOOH and were used as reference standards for the Ni(III) and Ni(IV) oxidation states of nickel, respectively. The shift of the Ni K‐edge absorption in both a completely charged nick…
Evidence of intergranular attack (IGA) in the absence of stress, together with dissolution kinetics, indicates that intergranular stress corrosion cracking (IGSCC) of ferritic steels in various environments is by a dissolution mechanism. Film rupture can play an important role in the rate of growth of cracks, but film…
Abstract Microcellular semicrystalline polymers such as poly(ethylene terephthalate) show great promise for engineering applications because of their unique properties, particularly at higher densities. Recent studies have shown that some high density microcellular polymers have longer fatigue lives and/or equivalent…
The ferroic phase‐transition behavior of two (Na 1/2 Bi 1/2 )TiO 3 (NBT) crystals grown by flux and by the Czochralski method has been investigated in the present study. Although both the tetragonal and the rhombohedral phases of NBT are expected to be ferroelastic, these crystals exhibit different ferroelastic behavi…
Two new diglycidyl ester compounds containing preformed imide rings for better thermal stability were prepared to be used as chain extenders for PET and PBT. The preparation of these compounds was carried out in two steps. In the first step, diimidodiacids were prepared from pyromellitic anhydride and 3-aminopropanoic…