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 synthesis of a new class of high-barrier polymers, poly(hydroxy amide ethers), is described. The polymers are formed by the reactions of bisphenol-A diglycidyl ether, OCH 2 CHCH 2 OC 6 H 4 C(CH 3 ) 2 C 6 H 4 OCH 2 CHCH 2 O, and amide-containing bisphenols of the general formula HOC 6 H 4 NHC(O)RC(O)NHC 6 H 4 OH [R…
Poly(siloxyethylene glycol) (PSEG), which consists of alternating oligo(dimethylsiloxane) and oligo(ethylene glycol) (OEG) units in the main chain, was synthesized through polycondensation reactions between oligosiloxane having two diethylamino groups and OEG. The molecular weight of the polymer was in the range 3500−…
The electronic structure of small clusters forming the inorganic cores in cadmium thiolate complexes is analyzed on the basis of semiempirical quantum chemical calculations. Orbital energies, atom charges, and peculiarities of chemical bond formation are considered for sphalerite lattice fragments Cd x S y ( x ≤ 20, y…
Femtosecond transient absorption and picosecond fluorescence spectra and kinetics have been measured for an ethylene-bridged porphyrin dimer molecule, trans -1,2-bis( meso -octaethylporphyrinyl)ethene (tbis OEP). In part 1 of this work it was shown with the help of absorption and fluorescence spectroscopy that in solu…
Two new copper(I) arenethiolates with ortho -chelating nitrogen donor atoms [Cu(SC 6 H 4 NMe 2 -2)] 3 ( 5 ) and [Cu(S-1-C 10 H 6 NMe 2 -8)] 9 ( 6 ) have been synthesized by reacting Me 3 SiSAr (Ar = C 6 H 4 NMe 2 -2 or 1-C 10 H 6 NMe 2 -8) with copper(I) chloride in a 1:1 molar ratio. Copper(I) arenethiolate 5 is a wh…
Addition of TCNQ to a solution of tetrakis(dimethylamino)ethylene in MeCN produces the salt [TDAE][TCNQ]2; the dipositive cation, [{(CH3)2N}2C–C{N(CH3)2}2]2+, is nonplanar, with a dihedral angle of 63.9°, while the TCNQ anions crystallize as [TCNQ]22– dimers with an interplanar separation of 3.16 Å. The complex [TDAE]…
Stoichiometry dependent hydrolysis of (arylamino)-silyltrichlorides using anhydrous N2H4 as the HCl acceptor and dehydrating agent leads to the formation of the primary and secondary condensation products of silanetriols, tetrahydroxydisiloxanes [Ar(SiMe3)NSi(OH)2]2O and cyclotrihydroxytrisiloxanes [Ar(SiMe3)NSi(OH)O]…
Oxidation of CoII by HSO5– to CoIII in weakly acidic solution, in the presence of molybdate, resulted in the formation of (primarily) the soluble dicobalt species [H4Co2Mo10O38]6–. The kinetics of formation of this species was examined at 15–35 °C over the range pH 4.0–5.5 and found to exhibit three separate kinetical…
Recombination of a PPh2 bridge and a terminal Ph group, originally produced by P–C bond breaking of PPh3 in a Pt complex, is achieved by the two-electron oxidation of the cluster [Pt3(µ-PPh2)3Ph(PPh3)2] 1 with I2, followed by reductive coupling of both fragments, thus restoring a PPh3 ligand in the cationic cluster [P…
The aerobic photocatalysed oxidation of alkanes in the presence of decatungstates Q4W10O32(Q = Na, Me4N, Pr4N, Bu4N, Hex4N) leads to hydroperoxides as primary products. Nitrile solvents and organic counter-ions of the catalyst compete in this photooxidation with alkane substrate. The influence of this competition on q…
The failure rates of synthetic vascular grafts, when placed in low blood flow environments in humans, are not acceptable. Thus, endothelial cell (EC) seeding technology of vascular grafts was developed to prepare prostheses lined with a human monolayer expressing optimal thromboresistant properties. In a clinical sett…
Drainage of the continuous phase liquid from a foam plays a pivotal role in determining its stability to collapse. A theoretical model for the drainage of the liquid during generation of a foam by bubbling and its subsequent collapse is presented. The model accounts for drainage in the films as well as in the plateau…
A small Cyclotella species was abundant in the plankton of Lake Kinneret (Israel). This species showed large phenotypic plasticity with morphological characteristics of several known Cyclotella taxa (C. comensis Grunow, C. ocellala Pantocsek, C. kuetzingiana var. planetophora Fricke and var. radiosa Fricke). It repres…
SiO2/TiO2 multilayers stacks used in optical coatings have been studied by Electron En- ergy Loss Spectroscopy (EELS). The line-spectrum mode has been used: the incident electron probe of the STEM is scanned under digital control on the specimen surface in the direction perpendicular to the layers, while the whole spe…
Crystallographic evidence suggests that there is a large hinged domain motion associated with substrate binding in adenylate kinase. To test this hypothesis, resonance energy transfer measurements of substrate binding were initiated. Adenylate kinase from Escherichia coli consists of three domains: the main body of th…
The hydrogen uptake behavior of two types of Zircaloy-2 specimens containing either fine intermetallic precipitates or coarse ones was studied at 623–723 Kin the pre-transition period of oxidation to clarify the role of the precipitates in the hydrogen transport through the oxide film. In the former case, the amount o…
By applying fluorescence together with DSC and WAXD, structure analysis for a thermotropic liquid-crystalline (LC) polyester (PB-10), prepared from 4,4‘-dihydroxybiphenyl and sebacic acid, containing 10 methylene units, was carried out. The PB-10 shows two enantiotropic transitions: One is the crystal−smectic H transi…
Three iron complexes of the meso-dioxo derivative of octaethylporphryin (trans-H(2)OEPO(2)) were characterized by X-ray diffraction. Green ClFe(III)(trans-OEPO(2)).1.5C(6)H(6) crystallizes in the monoclinic space group P2(1)/c with a = 13.766(3) Å, b = 19.075(3) Å, c = 15.217(3) Å, beta = 99.87(2) degrees at 123 K wit…
A direct current glow discharge mass spectrometer has been used for the analysis of Macor, a nonconducting glass ceramic. To overcome the problem of the conductivity barrier, a tantalum secondary cathode was placed in front of the flat Macor sample. Although the sample characteristics of Macor (the electrical conducti…
The structural and energetic consequences of nonbonded interactions between axial ligands and minimally superstructured borylated iron bis(dioxime) complexes are described. Structural data for 20 low spin axially ligated derivatives are compared. Complexes of Fe((DMG)BPh 2 ) 2 (Py)L, L = NH 3, TCNE, PMePh 2, and Py an…