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。
Various magnesium oxide catalysts have been prepared by thermal treatment of two different precursors: Mg(OH)2 and Mg5(OH)2(CO3)4. An additional system based on MgO and doped with B2O3 was also prepared. The textural and acid–base properties of the catalysts were investigated. The synthesized solids were characterized…
Cut-off frequencies of all TE and TM modes of a ridged rectangular waveguide are accurately determined using a coupled-integral equations technique (CIET). The technique analyzes both symmetric and asymmetric situations in one step. Basis functions, which include the edge conditions and mirror images in the waveguide…
Several computational aspects of the fracture energy based softening plasticity model for plain concrete are considered. A need for a more robust stress return strategy is identified, as the basic closest point projection algorithm leads to regions of nonconvergence, associated with zones of high curvature near the co…
Recent literature has drawn a distinction between charging across the surface (lateral differential charging) and charging with depth (vertical differential charging) for insulating samples. In this study, differential charging in a bulk insulator was investigated using imaging and small-area spectra acquired with a m…
The effects of Tween 20 on the desorption of proteins from polyethylene and polyurethane were studied, using single protein solutions of the human proteins fibrinogen (Fb), immunoglobulin G (IgG), serum albumin (HSA), high density lipoproteins (HDL), and plasma. The surfactant may partly or even completely desorb the…
The incorporation of titanium oxide into the interlayers of a myristic acid exchanged lithium aluminum layered double hydroxide was done by partitioning of titanium butoxide into the interlayer, followed by hydrolysis under ambient conditions. Upon excitation with near-ultraviolet radiation in the presence of viologen…
We studied the high temperature decomposition mechanism for the Fe/sub 17/Sm/sub 2/N phase using several different experimental techniques, as thermomagnetic and thermogravimetric analyses. Our results show that the decomposition occurs in a two step scheme. In the first reaction we hare the formation of SmN and a sol…
Bisphenol A polycarbonate (PC) and PET/0.6PHB polymer liquid crystal (PLC), where PET is poly(ethylene terephthalate), PHB is p -hydroxybenzoic acid, and 0.6 is the mole fraction of PHB in the copolymer, were studied along with their blends from the PC side up to 20 wt % PLC. Dielectric relaxation in the range 10 -2 −…
The fracture toughness of Zircaloy-2 cladding has been estimated by means of the recently developed pin-loading (PL) tension test. Axially notched ring specimens, cut directly from different cladding (annealed, cold-worked, hydrided, and irradiated), have been tested in a way similar to that used for compact tension s…
The effect of continuous-wave ultrasound on the viability of Escherichia coli HB101 was assessed using a 20 kHz ultrasonic processor. A standardised cell suspension of fixed concentration was used to investigate the influence of different physical and environmental conditions on ultrasound susceptibility. Cell viabili…
Block copolymers of the ABA type, where B is polybutadiene (PBD) and A is poly(ethyl methacrylate) (PEMA), poly( tert -butyl methacrylate) (P-t-BMA), poly(methyl methacrylate) (PMMA), or poly(isobornyl methacrylate) (PIBMA), have been successfully synthesized by sequential anionic polymerization of butadiene and metha…
Abstract Polyacrylamide‐starch composite was prepared by polymerization of maize or rice starch with acrylamide (Aam) using potassium permangante/citric acid initiation system. Major factors affecting the polymerization reaction were studied with a view to discover appropriate conditions for preparation of the composi…
Treatment of 4-acetylstyrene (an AB 2 monomer) with dihydridocarbonyltris(triphenylphosphine)ruthenium leads to hyperbranched poly(4-acetylstyrene) whose structure has been determined by 1 H and 13 C NMR spectroscopy. The hyperbranched material has been characterized by GPC, IR, UV, TGA, DSC, and elemental analysis. P…
A series of new FePS 3 layered intercalation compounds having the general formula Fe 1 - x PS 3 G 2 x (where G stands for a monocation) has been prepared by cation exchange with several pyridinium derivatives. The occurrence of intralayer Fe 2+ vacancies is evidenced by 57 Fe Mössbauer spectroscopy. The magnetic prope…
The goal of this work was to synthesize new molecular bricks which could be used as precursors of heterobimetallic low-dimensional compounds. Along this line, four compounds have been synthesized and structurally characterized, namely (NBu(4))(2)[Ni(Cl(2)opba)] (1), (NBu(4))(2)[Cu(Cl(2)opba)] (2), (NBu(4))(5)[Mn(Cl(2)…
Annealed interfaces between high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene (PP) and some ethylene- co -vinyl acetate (EVA) and ethylene- co -acrylic acid (EAA) copolymers were examined using optical microscopy, scanning electron microscopy (SEM), and electron microprobe analysis.…
The pressure-induced iron(II) high-spin (HS) → low-spin (LS) conversion has been investigated, by near-edge X-ray absorption (XANES) spectroscopy at room temperature, in a number of parent six-coordinate complexes of the type FeL n L‘ m (NCS) 2, viz. Fe(phen) 2 (NCS) 2 form I ( 1 ) and form II ( 2 ), Fe(py) 2 bpym(NCS…
Abstract A new type of inorganic‐organic composite has been developed using organic monomeric or polymerizable silanes (with appropriate organic groupings like double bonds or epoxides) as monomers or in situ prepared or separately added nano‐scale ceramic or metal particles. Due to the small size of the particulate p…
A method for the preparation of poly(aryl ether benzimidazoles) has been developed where the generation of an ether linkage is the polymer-forming reaction. We found that 2-(4-fluorophenyl)benzimidazoles were activated toward nucleophilic aromatic substitution with phenoxides. Facile displacement occurred at this posi…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTHeterocycle-Activated Aromatic Nucleophilic Substitution of AB2 Poly(aryl ether phenylquinoxaline) Monomers. 3S. Srinivasan, R. Twieg, J. L. Hedrick, and C. J. HawkerView Author Information IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 951…