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。
Abstract A number of mineralogical and synthetic precipitates undergo solid to solid phase changes via a solution phase. A review of the literature reveals a lack of both experimental data and a framework for its interpretation. A model is developed, for the case of a polymorphic phase transformation, which involves t…
A simple natural Landau theory of two- or three-component systems is described, which appears to give a region of the phase diagram in which quasicrystalline ordering is the state of lowest free energy. The quasicrystals are stabilized by special geometric relations between the length scales characterizing the compone…
Theories for elasticity and dislocation defects in two-dimensional pentagonal and three-dimensional icosahedral quasicrystals are presented.Received 4 February 1985DOI:https://doi.org/10.1103/PhysRevLett.54.1520©1985 American Physical Society
The crystal structure with icosahedral point-group symmetry and long-range orientational order observed by Shechtman et al. in Mn-Al alloys can be explained as a multiple-q density-wave structure with only one length scale. Its existence and stability can be understood from a simple Landau theory. The diffraction spot…
Influence de la composition du caoutchouc, des systemes vulcanisants, de la teneur en oxyde de zinc, du polyethylene chlorosulfone, des antioxygenes, des coagents
Abstract A method is proposed for solving the problem of temperature optimal control in tubular fixed‐bed reactors with reaction systems described by Langmuir‐Hinshelwood‐Hougen‐Watson kinetic equations. The optimization problem is formulated by N state differential equations corresponding to the N differential fixed‐…
Abstract Polarization measurements of two‐phonon absorption spectra in TISe and TlInSe 2 , and of the second‐order Raman scattering spectrum in TISe are carried out in the range of overtone and combination frequencies at room temperature. The observed peaks in the absorption and scattering spectra are interpreted by t…
Radon-222, a naturally occurring radioactive noble gas, is often a contaminant in natural gas. During fractionation at processing plants, Radon tends to be concentrated in the Liquified Petroleum Gas (LPG) product stream. Radon-222 decays into a number of radioactive metallic daughters which can plate out on the inter…
Abstract Poly[1‐(2‐oxazoline‐2‐yl)ethylene] ( 2a ), poly[1‐(5‐methyl‐2‐oxazoline‐2‐yl)ethylene] ( 2b ), poly[1‐(4,4‐dimethyl‐2‐oxazoline‐2‐yl)ethylene] ( 2c ), poly[1‐(4,4‐dimethyl‐5,6‐dihydro‐4 H ‐1,3‐oxazine‐2‐yl)ethylene] ( 2d ), and poly[1‐(4,4,6‐trimethyl‐5,6‐dihydro‐4 H ‐1,3‐oxazine‐2‐yl)ethylene] ( 2e ) were sy…
A description is given of detailed analyses of neutron powder diffraction data on Nd2Fe14B at several temperatures, and relationships between the crystal structure and the magnetic properties via comparison with other rare earth-transition metal systems, Nd2Fe17 in particular, are discussed. Diffraction studies have a…
Synopsis Substantivity of various (125)I-labelled collagen hydrolysates to virgin or bleached and dyed European hair or human callus was tested under conditions which simulated actual application of such hydrolysates in shampoos or foam baths. Factors which most strongly influence protein substantivity were identified…
The influence of acidity on the thermochemical stability of molten sodium nitrate‐nitrite mixtures used as heat‐transfer fluids (as in the case of the French electrosolar power system called Thémis) has been demonstrated by considering the diagram relative to redox systems corresponding to these mixtures and been esta…
The method for determining of optical constants of weakly absorbing plane-parallel films from the fringe pattern of the transmittance spectra is extended. The model supposes that the film thickness varies slowly but that the surface of the film is smooth, so that scattering of the beam can be neglected. A simple appro…
The systematics of [001] twist boundary structure is presented formally in terms of a structural unit/grain boundary dislocation hierarchical model and the earlier model of Sutton is generalized. By comparison with experimental observation and atomistic calculation using pair-potential models the physical significance…
An energy transfer from 5D3 and 5D4 levels of Tb3+ to 2D3/2 state of Ce3+ in Ce3+:Tb3+:YAG was studied using time resolved spectroscopy. It was found that the transfer from the Tb3+(5D3) level proceeds via (d–d) interaction and the critical distance is 18 Å. The transfer from Tb3+(5D4) state was consistent with the (d…
Electrochemical corrosion rates of 70Cu-30Ni alloy have been measured in oxygenated 0.5M NaCl and in synthetic seawater by the Tafel extrapolation procedure using a rotating disk electrode system. The rotation rate was varied from 500 to 6000 rpm. A log-log plot of the corrosion current vs rotation rate was linear, wi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIsothermal growth of low molecular weight polyethylene single crystals from solution. 2. Melting and dissolution behaviorW. M. Leung, R. St. John Manley, and A. R. PanarasCite this: Macromolecules 1985, 18, 4, 753–759Publication Date (Print):April 1, 1985Publication History…
This paper is a brief review of the relationship between the structure and the mechanical properties of grain interfaces. Early work had inferred that such a correlation exists from experiments with bicrystals of different orientations. More recently, the advances in the understanding of grain boundary structure have…
A plausible model is used to derive formulas for the expected number of fibers with zero, one, or two ends in a given length segment of a random assembly of aligned fibers. These results are then combined to form the expectation of the number of ends and various related quantities. By making a stronger assumption, an…
Abstract The uptake of 137-Cs and 90-Sr on to synthetic zeolite A has been studied. The use of a combined barium exchange followed by a relatively mild heat treatment has been shown to fix the isotopes within a collapsed zeolite structure. Leaching experiments using deionized and simulated sea and pond waters were car…