摘要:

The reaction of active nitrogen with hydrogen bromide was found to produce bromine and ammonium bromide as the main products, along with traces of compounds tentatively identified as bromamine, NH2Br, and bromimine, NHBr2. Hydrogen abstraction from hydrogen bromide by nitrogen atoms, imine and amine radicals can account for ammonia formation. Considerable catalysis of nitrogen atom recombination by hydrogen bromide appears to occur. A resonance transfer of the electronic energy responsible for the nitrogen afterglow to bromine with a resultant bromine emission spectrum is proposed to account for the orange reaction flame.

ISSN:0008-4042    

DOI:10.1139/v59-088

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Measurement of Ni63, a β−emitter with very low maximum energy, is described. External absorption curves were determined in aluminum and a range 8.5 ± 0.5 mg/cm2was found. This corresponds to a maximum energy of the β radiation of 72.7 ± 2.5 kev, in reasonably good agreement with values obtained by other methods. Self-absorption curves of electrolytically deposited samples were obtained and attempts made to compare these with the theoretical predictions of Gora and Hickey.

ISSN:0008-4042    

DOI:10.1139/v59-089

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Hydrogen cyanide was the main nitrogen-containing product of all three reactions, but whereas only about one-half the available active nitrogen was converted to product in the acetylene reaction, the conversion by methyl- and dimethyl-acetylene was substantially complete. A faster-than-linear increase of HCN production with acetylene flow rate was observed at low flow rates. Similar behavior was just perceptible in the corresponding curve for methylacetylene, while no observable inflection was present with dimethylacetylene. Polymer formation was pronounced with acetylene, less so with methylacetylene, and practically absent with dimethylacetylene. Small amounts of cyanogen resulted from all three reactions, while condensable hydrocarbons were obtained in significant yields from the methyl- and dimethyl-acetylene reactions only at higher flow rates of the alkynes.

ISSN:0008-4042    

DOI:10.1139/v59-090

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Relative yields of Sr89, Sr91, Ba139, Ba140, and La141have been measured for U233and Pu239thermal neutron fission. Ion exchange separations and 4π beta-counting methods were used. The following relative values were obtained for the nuclides as listed: 1.05, 1.00, 1.00, 1, and 1.10 in U233fission and 0.301, 0.431, 1.07, 1, and 1.01 in Pu239fission.

ISSN:0008-4042    

DOI:10.1139/v59-091

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The basicities of seven meta- and para-substituted benzaldehydes have been determined by a spectrophotometric method in sulphuric acid media. The simple Hammett relation does not hold for these bases but a good correlation exists betweenand σ+. The effects of substitution on the wavelengths of maximal ultraviolet absorption in benzaldehyde are compared with those in acetophenone.The basicity ofo-tolualdehyde was determined in an attempt to estimate the steric effects of ortho substitution. The effects of symmetrical trisubstitution on the basicity of benzaldehyde and acetophenone are compared and discussed.

ISSN:0008-4042    

DOI:10.1139/v59-092

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Azomethane was photolyzed in the presence of up to 30 mole per cent formaldehyde and formaldehyde-d2at temperatures from 80 °C to 180 °C. The value of the activation energy for the abstraction reaction with methyl radicals was found to be 6.2 kcal mole−1for CH2O and 7.9 kcal mole−1for CD2O. The results indicated that the formyl radical was stable over the temperature range studied.

ISSN:0008-4042    

DOI:10.1139/v59-093

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The stable alkylation products of alkyl and aryl nitrosohydroxylamines seem to exist in a hitherto unknown structure, the diimide dioxide linkage. The alternative possibility is the alkyl diazotate monoxide structure, but the latter cannot account for the pure methane evolved when the substances are treated with methyl halide Grignard reagent. The principal products of this reaction with Grignard reagents are diimide monoxides formed subsequently by addition of an equivalent of reagent with elimination of the original alkoxy group as its magnesium salt. Nitration of N-methyl-N′-phenyldiimide dioxide shows that in salt-forming media (nitric-sulphuric) the N2O2R group is electrically negative, but dipole moment studies show that it is highly degenerate. This resonance stabilization is not unexpected in view of the high stability of the diimide dioxides in acidic media.

ISSN:0008-4042    

DOI:10.1139/v59-094

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The electronic energy levels ofcis- andtrans-bent planar centrosymmetric acetylene molecules, withandrcc = 1.383 Å, have been calculated by the LCAO/ASMO/CI procedure. The lowest energy state that can spectroscopically combine with the linear ground state is found to be of symmetry classAubelonging to thetrans-bent molecule and to lie at 4.58 ev above the ground state. This compares favorably with the experimentally observed electronic transition of lowest energy which is of type (1Au−1∑g+) and at 5.24 ev. The lowest-energy allowed transition to acis-bent state of these dimensions is at 9.39 ev, and hence this may not form part of the unanalyzed system of bands in the 2000–1500 Å region, as has been suggested. However, a transition to atrans-bent state of type (1Bu−1∑g+) is predicted to fall in this region. The energies of other electronic states are discussed in relation to the observed absorption systems of acetylene.

ISSN:0008-4042    

DOI:10.1139/v59-095

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

A simple two-stage gas chromatograph is described which employs only one detector for both effluent streams. It was designed specifically for the routine quantitative analysis of mixtures of ethylene oxide, carbon dioxide, and ethylene in the presence of water vapor and a large excess of air, and for concentrations down to 0.2% by volume of individual components.

ISSN:0008-4042    

DOI:10.1139/v59-096

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The total surface energy (or surface enthalpy) of a calcium silicate hydrate, tobermorite, having the composition of Ca3Si2O7•2H2O, was determined at 23.5 °C. The tobermorite was obtained from the room-temperature hydration of tricalcium silicate, Ca3SiO5, or β-dicalcium silicate, β-Ca2SiO4, two of the most important constituents of portland cements. The hydration reactions were carried out in three different ways, and 14 preparations were obtained. For each preparation the heats of solution in a mixture of nitric acid and hydrofluoric acid were measured at 23.5 °C, and the surface areas were determined by the B.E.T. method, using water vapor at 25 °C as the adsorbate. The cross-sectional area of the adsorbed water molecule was taken to be 11.4 Å2. The surface energy of tobermorite at 23.5 °C was found to be 386 ± 20 ergs/cm2. It is close to the geometric mean of the surface energies of calcium hydroxide and hydrous amorphous silica, previously reported.Nitrogen adsorption did not measure the true surface area of most tobermorite preparations. This was indicated by negative surface energy values in a number of instances.

ISSN:0008-4042    

DOI:10.1139/v59-097

出版商:NRC Research Press    

年代:1959

数据来源: NRC