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 rate of water evaporation in the exposed surfaces plays an important part in the development of cracks in fresh concretes and mortars before hardening is completed. This rate of evaporation depends on the drying power of the wind sweeping such surfaces as a function of the relative humidity, temperature and speed…
The application of the zeta potential technique in the area of construction materials and Portland cement is quite recent. The initial research work involved the study of cement suspensions or suspensions of one of the components of cement, such as alite, tricalcium alumínate, in the presence of additives and, more sp…
Precursors to highly conducting polypyrrole (Ppy) are formed in the lipophilic channels of 1 subsequent to a spontaneous, strictly stoichiometric [N(Ppy)/Fe = 1/1] redox reaction. In view of the diameter of the channel (6.8 Å) the entrapped Ppy should be free of cross-linking (thus approximating a “molecular wire”).
Abstract The strength of high-performance filaments is a complex parameter which can not be fully described with a single value. The Weibull model is used to describe the intrinsic statistical nature of the fracture strength. Possibilities and limitations of the Weibull model are illustrated. The relationship between…
Vibrational spectroscopic methods are widely used to characterize semicrystalline polymers in terms of crystallinity. The temperature coefficient of crystallinity, an important and fundamental quantity, is seldom determined for lack of a sensitive method. In this paper, we describe an infrared approach to the measurem…
A neutron powder diffraction investigation confirms that, in tough magnesiapartially‐stabilized zirconia cooled to 30 K, most of the tetragonal zirconia transforms to an orthorhombic phase. This phase is retained on heating to room temperature; the lattice parameters at 295 K are a = 0.5068, b = 0.5260, and c = 0.5077…
Reported studies indicate that the association of potassium monopersulfate with [Mn(TMPyP)](OAc)5, a water-soluble manganese porphyrin complex, leads to an efficient reagent for the oxidative cleavage of DNA. Single-strand breaks (SSBs) are observed on double-stranded DNA at manganese porphyrin concentrations as low a…
The crevice model for heterogeneous nucleation of bubbles in water in response to a decreasing liquid pressure is studied. The model neglects gas-diffusion effects and is therefore more suited for acoustic than for flow cavitation. It is argued that previous work has overlooked the essential requirement of unstable gr…
The poly-beta-hydroxybutyrate biosynthetic thiolase gene from Zoogloea ramigera was used as a hybridization probe to screen restriction digests of Alcaligenes eutrophus H16 DNA. Specific hybridization signals were obtained and two fragments (a 2.3-kilobase PstI fragment and a 15-kilobase EcoRI fragment) cloned in the…
Corrosion behavior of mold-cast Mg alloy AZ91 is investigated in as-cast (F), homogenized (T4), and artificially-aged (T6) conditions in chloride media. Heat treatment influences mainly the distribution of intermetallic β-phase (Mg17Al12) in the alloy. Aging to T6 temper causes precipitation of the phase as a nearly c…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStabilization of a liquid-crystalline phase through noncovalent interaction with a polymer side chainTakashi Kato and Jean M. J. FrechetCite this: Macromolecules 1989, 22, 9, 3818–3819Publication Date (Print):September 1, 1989Publication History Published online1 May 2002Pub…
Abstract Synthesis, mesomorphism, orientation and photo‐initiated chain crosslinking of the liquid‐crystalline diacrylate 1,4‐phenylene bis{4‐[6‐(acryloyloxy)hexyloxy]benzoate} ( 1 ) are studied. Monomer 1 exhibits a broad nematic phase between 108 and 155°C and a monotropic smectic phase below 88°C. The monomer is un…
The phbC gene encoding the third enzyme of the poly-beta-hydroxybutyrate biosynthetic pathway, poly-beta-hydroxybutyrate polymerase, in Alcaligenes eutrophus H16 has been identified by the complementation of poly-beta-hydroxybutyrate negative mutants of A. eutrophus H16. These results demonstrate that the three enzyme…
The dynamics of laser-produced cavitation bubbles near a solid boundary and its dependence on the distance between bubble and wall are investigated experimentally. It is shown by means of high-speed photography with up to 1 million frames/s that jet and counterjet formation and the development of a ring vortex resulti…
Active transport across the vacuolar components of the eukaryotic endomembrane system is energized by a specific vacuolar H+-ATPase. The amino acid sequences of the 70- and 60-kDa subunits of the vacuolar H+-ATPase are approximately equal to 25% identical to the beta and alpha subunits, respectively, of the eubacteria…
A review is given of the experimental investigations of the magnetocaloric effect (MCE) in rare-earth magnetic materials of different classes: heavy rare-earth metals and their alloys, iron garnets, and intermetallic compounds. The results of measurements of the MCE near phase transitions are given for the vicinity of…
The gene coding for nitrite reductase of Pseudomonas aeruginosa has been cloned and its sequence determined. The coding region is 1707 bp long and contains information for a polypeptide chain of 568 amino acids. The sequence of the mature protein has been confirmed independently by extensive amino acid sequencing. The…
Crystals of hen egg white lysozyme soaked in 15% (v/v) dimethyl sulfoxide have been studied with single-crystal neutron diffraction to determine the effect of the solvent molecules on the protein configuration. A total of 9423 statistically significant Bragg reflections to a resolution of approximately 1.8 A were used…
The dynamics of ultra-thin wetting films has been studied experimentally under a controlled atmosphere using a dynamic ellipsometric technique. The spreading fluid was PDMS and the substrates were oxide covered silicon wafers. The situations of capillary rise up a vertical wall, and the spreading of 'nanoscopic' drops…