Materials Literature
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A molecular graphics analysis of the features which prevent cytosolic malate dehydrogenase dimers from forming tetramers was evaluated by its success in predicting the synthesis of a version of the LDH framework which is a stable dimer. Surface residues responsible for malate dehydrogenases being dimers were revealed…
The molecular and crystal structure of the classic nematogen 4-methoxybenzylidene-4′-n-butylaniline (MBBA) was determined by X-ray diffraction method at −163°C (diffractometer Nicolet R3m/V, Mo-radiation, 2256 observable reflections, R=0·058). The monocrystal of MBBA was grown from the polycrystalline sample in a thin…
A novel method has been developed to measure the amount of precipitated Fe in a series of (Nd/sub 0.9/Dy/sub 0.1/)/sub x/Fe/sub 93.5-x-y/Nb/sub y/B/sub 6.5/ alloys, where x=13, 14, 15, or 17, and y=0 or 0.5. It has been found that the amount of precipitated Fe decreases significantly with increasing rare earth content…
Clorsulon was measured in plasma and urine of sheep and goats after administration of a single intravenous (i.v.) and after a single oral dose of 7 mg/kg. A three-compartment model with elimination occurring from the central compartment was determined to best describe the i.v. data, whereas a one-compartment model wit…
Single crystals of a-KZnPO 4 , the low-temperature modification of potassium zinc orthophosphate, were obtained from KZnPO 4 powder by high pressure experiments in a modified Belt-type apparatus. The crystals are hexagonal, space group P 6 3 , with a = 18.155(2), c = 8.504(1) Å, c/a = 0.4684 and Z = 24. The crystal st…
Gold plays a dominant role in the jewellery market. This is to a large extent due to the intrinsic value of gold, its beauty and its unique resistance to tarnish and corrosion. In 1990 the amount of gold used in jewellery was about 2000 t worldwide, reaching about 75% of the total demand for gold. The demands on gold…
Abstract The effectiveness of thermal analysis as a technique for screening polymeric candidates for high temperature composite application is described. DSC, DMA, and TGA were employed to measure glass transition temperature, characterize blend phase morphology, and assess thermo‐oxidative stability. The materials st…
New or redefined printed symbols are proposed in the light of the recently accepted redefinition of symmetry elements [de Wolff et al. (1989). Acta Cryst. A45, 494–499]. In particular, the letter e covers certain glide planes which hitherto had no unique symbol, such as those called 'either a or b'. The use of e in th…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn unexpected chiral spiro tetramer offers mechanistic insight into an improved sodium cyanide initiated polymerization of n-hexyl isocyanate in tolueneYoshio Okamoto, Yoshikazu Nagamura, Koichi Hatada, Chetan Khatri, and Mark M. GreenCite this: Macromolecules 1992, 25, 20,…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNew Fatty Acid Esters and Hydroxy Ketones from Fruits of Laurus nobilisS. N. Garg, M. S. Siddiqui, and S. K. AgarwalCite this: J. Nat. Prod. 1992, 55, 9, 1315–1319Publication Date (Print):September 1, 1992Publication History Published online1 July 2004Published inissue 1 Sep…
The minerals constituting the wodfinite group are isostructural oxides, with the general formula ABC20s (Z = 4); A = Mn2+, Fe2+, Li, Q B = Sn +, Ti, Fe3+, Ta; C = Ta, Nb. A classification system based on the chemistry of the A-and B-cation sites has been devised; it uses chemical modifiers in conjunction with the root…
Abstract The crystal structure of klyuchevskite, K 3 Cu 3 (Fe,Al)O 2 (SO 4 ) 4 , was determined in space group I2 using the total of 715 independent reflections up to R 0.12. Klyuchevskite is a structural analogue of piypite (caratiite) K 4 Cu 4 O 2 (SO 4 ) 4 MeCl with the substitution K + + Cu 2+ → (Fe 3+ ,Al) + MeCl…
Oriented thin films of barium hexaferrite, BaFe/sub 12/O/sub 19/, were grown in situ on (0001) sapphire substrates utilizing a pulsed laser deposition technique. X-ray diffraction, elastic backscattering spectrometry, ferrimagnetic resonance, and vibrating sample magnetometry confirm that the structure, composition, a…
Abstract Quasiharmonic equations are derived for stress‐induced vibrational frequency shifts in the infrared and Raman spectra of polymer chains subjected to a tensile stress. The expressions are applied to the helical chains of polyoxymethylene and isotactic polypropylene. Observed frequency shifts can be reproduced…
Abstract A series of multiblock poly(ether‐ester‐amide)s (PEEA) based on polyamide‐6 (PA6) and poly(ethylene glycol) (PEG) is synthesized in a two‐step process. The first step represents the hydrolytic polymerization of ε‐caprolactam (CL) in the presence of adipic acid (AA) to carboxyl‐terminated PA6 oligomers of diff…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStudy of the Stoeber reaction. 1. Properties of colloidal silica spheres prepared via alkoxide hydrolysisL. Jelinek, P. Dong, C. Rojas-Pazos, H. Taibi, and E. S. KovatsCite this: Langmuir 1992, 8, 9, 2152–2164Publication Date (Print):September 1, 1992Publication History Publ…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAnionic polymerization of monomers containing functional groups. 4. Anionic living polymerization of N,N-dialkyl-4-vinylbenzenesulfonamidesTakashi Ishizone, Junji Tsuchiya, Akira Hirao, and Seiichi NakahamaCite this: Macromolecules 1992, 25, 19, 4840–4847Publication Date (Pr…
We have investigated the pressure dependence of the superconducting transition temperature ${\mathit{T}}_{\mathit{c}}$ of elemental arsenic up to 41 GPa both experimentally and theoretically. Our measurements indicate that a peak in ${\mathit{T}}_{\mathit{c}}$ occurs at the rhombohedral--simple-cubic structural phase…
An investigation has been carried out to demonstrate the possibility of using the electrochemical potentiokinetic reactivation (EPR) method for determining the degree of sensitization of 12% Cr ferritic stainless steels. EPR tests were conducted on as-received and thermal-treated samples of a commercial heat of steel…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSteroid moieties attached to macromolecular petroleum fraction via di- or polysulfide bridgesP. Adam, B. Mycke, J. C. Schmid, J. Connan, and P. AlbrechtCite this: Energy Fuels 1992, 6, 5, 553–559Publication Date (Print):September 1, 1992Publication History Published online1…