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。
A charge-coupled device (CCD)-based detector designed for macromolecular crystallography is described. The detector has an area of 200 × 200 mm, a readout time of 1.6 s, and total noise equivalent to approximately three 12 keV X-ray photons per pixel. The detector is constructed from a 2 × 2 array of four identical un…
Two-dimensional coordination polymer compounds FeL2Ni(CN)4 (L: 2, 3, or 4-methylpyridine) have been synthesized and characterized by single crystal X-ray diffraction method.
A novel experimental technique that employs high-energy synchrotron radiation is used for the investigation of through-thickness texture gradients in two aluminium plates, cold-rolled 40% with either intermediate or small draughts. In these two plates, crystallographic textures are inspected in a large number of layer…
A method is proposed, and preliminary experiments are described, for collection of X-ray data from macromolecular crystals in situ . The usual processes of mounting for either room-temperature or cryogenic X-ray data collection are eliminated by growing crystals, using vapor diffusion, on small supports or films that…
This paper describes the biosynthesis and properties of bacterial poly(hydroxyalkanoate)s (PHA) with predominantly hydroxyl end groups. Hydroxy termination is achieved by the addition of low molecular weight diols to the culture. It is found that low molecular weight diols of various structures can be easily incorpora…
We investigate the well-posedness of a phase-field model for the isothermal solidification of a binary alloy due to Warren–Boettinger [12]. Existence of weak solution as well as regularity and uniqueness results are established under Lipschitz and boundedness assumptions for the non-linearities. A maximum principle ho…
Abstract A polymeric coupling agent acrylic acid grafted polypropylene (AAgPP) was synthesized and its efficiency in CaCO 3 /PP composite was investigated. The grafting of acrylic acid monomer (AA) onto polypropylene was performed using an internal mixer. The effect of peroxyde, acrylic acid monomer content, temperatu…
In a previous static atomistic simulation, it has been shown unambiguously that a surface step is a privileged site for dislocation nucleation. Before dislocation nucleation, an elastic shear, localized in the plane in zone with the step where nucleation will occur, is observed. The real dislocation forms when this lo…
We generalize the earlier theory by Fredrickson [J. Rheol. 38, 1045 (1994)] to study the orientational behavior of the hexagonal phase of diblock copolymer melt subjected to steady shear flow. We use symmetry arguments to show that the orientational ordering in the hexagonal phase is a much weaker effect than in the l…
Crystal structure solution in P 1 may be particularly suitable for complex crystal structures crystallizing in other space groups. However, additional efforts and human intervention are often necessary to locate correctly the structural model so obtained with respect to an allowed origin of the actual space group. An…
We study the effect of the divergence (surfacelike) K24 and K13 terms on stability of the uniform ground state of a nematic phase. It is shown that the K13 term can effectively boost the action of the K24 term. As a result, even if the two Ericksen stability conditions are satisfied, spontaneous deformations can occur…
Low-molecular-weight organic acids (LMWOA's) play an important role in soil genesis and plant physiology. Oxalic acid is one of the more common and abundant LMWOA's in forest soils, where it accumulates especially as salts of Ca. In two soils under silver fir (Abies alba Mill.) from Tuscany, Italy, we measured the oxa…
Controlled coammonolysis of elementalkylamides in aprotic organic solvents at low temperatures have been shown to result in the formation of polyazanes. The synthetic procedure developed may be addressed as “sol-gel-route in the ammono system”. Pyrolysis of these novel polymer precursors gave access to multinary nitri…
The influence of biofilms formed by microorganisms on the corrosion behaviour of stainless steel (SS) in various fresh water environments was studied using electrochemical techniques. Biofilm characterization studies showed an algal-dominated biofilm in the normal dark and light exposures, whereas, in the continuous d…
Analysis using gas chromatography/mass spectroscopy (GC/MS) was performed for evaluation of surface degradation of silicone insulating materials. Silicones are used as coatings for porcelain insulators and shed material for high voltage composite insulators. A comparison between virgin silicone rubber and aged silicon…
Cell ellipticity and non-planar membranes are thought to be dominant degradation factors of cellular metals. The mechanisms operating at the cell/membrane level in both closed and open cell Al alloys have been established by following the evolution of deformation with cell-level resolution using digital image correlat…
We present the experimental framework for the origin of the anomalously large thermoelectric power for Si and Au-doped Ge superlattice thin film. The thermoelectric power of the sample still remains anomalously large even though the superlattice structure begins to collapse. An amorphous Ge thin film displays large th…
We present experimental evidence that the diffusion process close to the boundary is fundamentally different from the bulk diffusion in the sense that it is affected by the scattering properties of the individual centers. Systematic measurements show a nontrivial behavior of the extrapolation length ratio on the scatt…
The metalation of several free base porphyrins by the bismuth salts Bi(NO 3 ) 3 and Bi(SO 3 CF 3 ) 3 in DMF or pyridine is described. The resulting stable Bi(III) porphyrin complexes are characterized by electrochemistry, 1 H NMR and UV-vis spectroscopy. The structure of ( OEP ) Bi ( SO 3 CF 3 ) was also determined by…
The deformation behavior of a hot‐pressed, fine‐grained β‐Si 3 N 4 ceramic was investigated in the temperature range 1450°—1650°C, under compression, and the results for strain rate and temperature dependence of the flow stress are presented here. The present results show that the material is capable of high rates of…