Materials Literature
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The influence of microstructural variations on the fracture toughness of two tool steels having compositions (wt-%) lC–4Cr–5Mo–2V–6W (AISI M2 high-speed steel) and 0·35C–5Cr–1·5Mo;amp;#x2013;1V (AISI H13 hot-work steel) was investigated. In the as-hardened condition, the H13 steel has a higher fracture toughness than…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA comparison of electron donor and proton abstraction activities of thermally activated pure magnesium oxide and doped magnesium oxidesKenneth J. Klabunde and Hiromi MatsuhashiCite this: J. Am. Chem. Soc. 1987, 109, 4, 1111–1114Publication Date (Print):February 1, 1987Public…
Abstract Resonance Raman spectra (RRS) of azobenzene, 4‐aminoazobenzene, 4‐methylaminobenzene and 4‐dimethylaminoazobenzene in the solid state and in a range of solvents have been recorded. The RRS of the 4‐aminoazobenzenes are much more solvent dependent than those of azobenzene. Their electronic absorption spectra s…
Abstract The influence of composition on the primary nucleation process of poly(ethylene oxide) spherulites in the case of poly(ethylene oxide)/poly(methyl methacrylate) (PEO/PMMA) blends was investigated by optical microscopy and DSC. In the case of isothermally crystallized samples it was found that heterogeneous nu…
The electrical conductivity and dielectric loss of films of polyether ether ketone have been investigated over a wide range of frequencies and electric fields in the temperature range of 40 to 140°C. The volume resistivity of PEEK was found to be 1014 Ωm at temperatures 80°C but decreased significantly above this temp…
We incubated samples of five unfertilized Argentinian soils with phosphate at 4, 25, 40, and 60°C and measured the change in the null-point phosphate concentration through time. There was an initial decrease in this phosphate concentration, but, in some cases, it was followed by an increase in concentration. The incre…
Medium-chain S-acyl fatty acid synthetase thioester hydrolase (thioesterase II), a discrete monomeric enzyme of 29 kDa, regulates the product specificity of the de novo lipogenic systems in certain specialized mammalian and avian tissues, such as mammary and uropygial glands. The amino acid sequence of a 57-residue re…
Abstract The Raman spectrum of commercial "sulfur dichloride" shows strong lines due to SCl 2 and S 2 Cl 2 and weak Cl 2 lines at 25 °C, but strong SCl 2 and SCl 4 signals at -100 °C (the latter are superimposed on the S 2 Cl 2 lines). Thus, the intense Raman effect of SCl 4 can be used to detect small amounts of chlo…
Abstract The di-μ-oxo-tetrakis(2,2′-bipyridine)dimanganese complex was used as a heterogeneous phase catalyst for water oxidation by adsorbing into Kaolin clay. The oxygen evolved was analyzed by gas chromatography and mass spectrometry. The water oxidation reaction involving the four-electron process in a heterogeneo…
Mn 2 O 7 —a long‐known compound, whose crystal structure has finally been elucidated: the Mn atoms are surrounded tetrahedrally by O atoms; the bridging and the terminal Mn–O bonds are, as expected, of different lengths. The Mn 2 O 7 molecules are packed in such a way that an only slightly distorted fcc arrangement re…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHexagonal molybdates: Crystal structure of (Na.2H2O)Mo5.33[H4.5]0.67O18E. M. McCarron III, D. M. Thomas, and J. C. CalabreseCite this: Inorg. Chem. 1987, 26, 3, 370–373Publication Date (Print):February 1, 1987Publication History Published online1 May 2002Published inissue 1…
A comparison of new and traditional methods for stabilizing corroded copper alloy artifacts is presented, using data obtained from a variety of objects from both marine and land-based sites. The data show that there are common parameters that determine the rate at which chloride ions are removed. The choice of methods…
In order to study the physical properties of ${\mathrm{K}}_{3}$${\mathrm{Cu}}_{8}$${\mathrm{S}}_{6}$, we have carefully defined the synthetic conditions for ${\mathrm{KCu}}_{4}$${\mathrm{S}}_{3}$, ${\mathrm{K}}_{3}$${\mathrm{Cu}}_{8}$${\mathrm{S}}_{6}$, and ${\mathrm{KCu}}_{3}$${\mathrm{S}}_{2}$. ${\mathrm{K}}_{3}$${\…
Abstract Ca-K.-, Na-K-, and Ca-Na-exchange isotherms on four reference smectites were studied. The electric charge on the four smectites was due predominantly to cationic substitution in the octahedral layer and varied between 90 and 122 meq/g (cmole(+)/kg) clay. The affinity of the clays for K increased with a decrea…
Abstract The relation between the dynamic mechanical properties and the morphology of polypropylene (PP) block copolymers and polypropylene/elastomer blends was studied by dynamic mechanical analysis (DMA), light‐ and electron microscopy. The latter techniques contributed to an improvement in assignments of relaxation…
The bias‐dependent etching of Si in has been studied in detail. The quantity of Si etched and evolved has been measured at various anodic and cathodic potentials. These quantities have been related to the current flow in the electrochemical cell in such a way as to shed light on the mechanisms responsible for bias‐dep…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAlkylation and silylation of the aluminum enolates generated by hydroalumination of .alpha.,.beta.-unsaturated carbonyl compoundsTetsuo Tsuda, Hiroshi Satomi, Toshio Hayashi, and Takeo SaegusaCite this: J. Org. Chem. 1987, 52, 3, 439–443Publication Date (Print):February 1, 1…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotochemistry of (5,10,15,20-tetraphenylporphyrinato)iron(III) halide complexes, Fe(TPP)(X)David N. Hendrickson, Michael G. Kinnaird, and Kenneth S. SuslickCite this: J. Am. Chem. Soc. 1987, 109, 4, 1243–1244Publication Date (Print):February 1, 1987Publication History Publi…
Solid-state 13 C CPMAS NMR was used to examine organic soils from virgin, 5-yr and 15-yr cultivated sites. In agreement with previous studies using other techniques, the chemical effects of cultivation were essentially confined to the plough layer. Cultivated sites had less carbohydrate, and increased lipid and methox…
In 1979 ICRU recommended the value W=(33.85+or-0.05) eV for the average energy required for electrons to produce an ion pair in dry air. A re-evaluation is presented which is based on recently published stopping-power data. The new result is W/e=(33.97+or-0.05) JC -1 , where all stated uncertainties are estimated stan…