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 Changes in the fast dynamics of polybutadiene (PB) with molecular weight and molecular architecture have been investigated by light and neutron scattering spectroscopy. Differences observed in the fast dynamics of various molecules correlate with differences seen in the value of the glass‐transition temperatu…
Crystalline phases of monoglyme:NaCF 3 SO 3, diglyme:NaCF 3 SO 3, and tetraglyme:NaCF 3 SO 3 have been characterized by DSC, X-ray diffraction, and vibrational spectroscopy. Comparison of the structures allows for the investigation of the effect of the number of ethylene oxide units on local structure in these systems…
The bimetallic trinuclear complexes, [{(tpa)Cu(NC)}2Fe(CN)4]ClO4·6H2O (1), [{(tren)Cu(NC)}2Fe(CN)4]ClO4·4H2O (2), [{Cu(tpa)NC}2Cr(CN)4]ClO4·8H2O (3) and [{Cu([15]aneN4)NC}2Cr(CN)4]ClO4·4H2O (4) [tpa = tris(2-pyridylmethyl)amine, tren = tris(2-aminoethyl)amine, ([15]aneN4 = 1,5,9,12-tetraazacyclopentadecane] were prepa…
The problem of asymmetric X-ray diffraction peak broadening caused by dislocations is investigated. The leading term responsible for the asymmetry of the intensity distribution is calculated for randomly distributed polarized dipoles and dipole walls. It is found that the polarization structure of a dislocation ensemb…
Aggregation kinetics and cluster-size distributions are studied with off-lattice, diffusion-limited cluster-cluster simulations. With increased cluster crowding (occurring at late times) as measured by the normalized free volume, Omega, both the kinetics speeds up and the size distribution broadens. The exponents char…
A high-resolution X-ray diffractometer devoted to the study of imperfect materials (mainly oxides and ceramics) is presented. It is based on a rotating anode generator, a four-bounce monochromator, a five-movement sample holder and a curved position-sensitive detector (PSD). This setup allows rapid acquisition of a re…
Abstract A selective dissolution/reprecipitation technique was applied for the effective recovery of Polyamide 6 (PA 6) and Polyamide 6 6 (PA 6 6) from their mixtures. The proposed process comprises mainly selective polyamide dissolution in an appropriate solvent at a specific temperature, reprecipitation of the polym…
Structural and thermal expansion studies of Li 2 ZrO 3 were carried out by recording X-ray powder diffraction patterns at five temperatures, 82, 198, 300, 423 and 573 K. The Rietveld refinement method was used for the analysis. There were large anisotropic changes in the lattice parameters as a function of temperature…
The present paper aims to clarify some of the still controversial aspects of the chemistry of copper in Cu-based catalytic systems active for de-NO x processes by using hydrocarbons as reductants. Reactivity tests, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) experiments have been carr…
Nanosized polycrystalline samples of (Er 1− u Gd u ) 2 O 3 (0 ≤ u ≤ 1.0) were synthesized by a sol–gel technique. X-ray diffraction data were collected and the crystal structures were refined by the Rietveld method. All samples are found to have the same crystal system and formed solid solutions over the whole range o…
Crystals of Yb 3+ doped Rb 2 MnCl 4 exhibit very intense yellow-orange Mn 2+ 4 T 1g → 6 A 1g upconversion luminescence under near-infrared 2 F 7/2 → 2 F 5/2 Yb 3+ excitation around 1 μm at 15 K. Excitation with 10 ns pulses indicates that the upconversion process consists of a sequence of ground-state and excited-stat…
Abstract Interpenetrating polymer network (IPN) hydrogels based on poly(vinyl alcohol) (PVA) and 1‐vinyl‐2‐pyrrolidone (VP) were prepared by radical polymerization using 2,2‐dimethyl‐2‐phenylacetophenone (DMPAP) and methylene bisacrylicamide (MBAAm) as initiator and crosslinker, respectively. The thermal characterizat…
A new class of volatile, low-melting, fluorine-free lanthanide metal-organic chemical vapor deposition (MOCVD) precursors has been developed. The neutral, monomeric Ce, Nd, Gd, and Er complexes are coordinatively saturated by a versatile, multidentate ether-functionalized beta-ketoiminato ligand series, the melting po…
High-quality colloidal mercury sulfide quantum dots (QDs) are synthesized at room temperature using a strategy combining the effects of strongly binding Hg(II) ligands and metal/chalcogen precursor phase separation. This combination prevents both the rapid precipitation of bulk HgS in preparations involving only weak…
Abstract Recycling of polycondensation polymers can give rise to secondary materials with good mechanical properties only if a careful drying is carried out before the melt reprocessing operations. The presence of humidity provokes the hydrolytic chain scission of the macromolecules and the consequent decrease of mole…
Abstract The thermal properties of Bombyx mori silk fibers subjected to heat treatment were examined by thermogravimetry, differential thermal analysis, Fourier transform infrared absorption spectrometry (TG‐DTA‐FTIR) and scanning electron microscopy (SEM). The color, size, and shape of B . mori cocoon shells were obs…
Abstract The effect of the compatibilizers, P(LLA‐ co ‐ϵCL) and P(LLA‐ b ‐ϵCL), on the morphology and hydrolysis of the blend of poly(ϵ‐caprolactone) (PCL) and poly( L ‐lactide) (PLLA) was investigated. An addition of P(LLA‐ co ‐ϵCL) or P(LLA‐ b ‐ϵCL) into the blend could enhance the compatibility between the disperse…
The phase transformation kinetics of high-energy ball-milled monoclinic ZrO 2 have been studied in detail by Rietveld powder structure refinement analysis. In the present study, no stabilizing compound was required to obtain the cubic phase. The fine-grain powder was milled in a planetary ball mill for up to several h…
The paper presents polarized Raman scattering study on a few-micron-size crystallite of LiBC with natural faces. The experiment on as grown sample has revealed a four lattice modes with frequencies at 1276 cm^-1, 830 cm^-1, 546 cm^-1 and 170 cm^-1, respectively. The number of observed Raman lines and their selection r…
First principles calculations using the full-potential linearized augmented plane wave (FLAPW) method including intra-atomic noncollinear magnetism have been performed to determine the magnetic structures of RuSr$_{2}$GdCu$_{2}$O$_{8}$. The magnetism clearly arises from the RuO$_{6}$ octahedra where the moments on nei…