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101.
102.
The gas-phase high-resolution spectrum is reported for v1 of the linear molecule thioborine (HBS) from 2775 cm?1 to 2720 cm?1. Band centers and rotational constants are given for the 1000-0000 transitions of H11B32S, H10B32S, H11B34S and H10B34S and for the 1110-0110 transitions of H11B32S and H10B32S. A valence force field is determined from measured values of v1, Do (the centrifugal distortion) and q (the l-doubling constant). The remaining unobserved vibrational fundamentals are calculated from the force constants. 相似文献
103.
From measurement of the heat of hydrolysis, at 25°C , the enthalpy of formation of rubidium tetrafluoroiodate is derived: ΔH°f [RbIF4, cryst.]298= ?191.12±4.43 kJ mol?1. Heat capacity measurements for RbIF4 over the range 273–303 K are also reported. 相似文献
104.
A systematic presentation of the quasi-linear first order symmetric hyperbolic systems of Friedrichs is presented. A number of sharp regularity and smoothness properties of the solutions are obtained. The present paper is devoted to the case ofR
n
with suitable asymptotic conditions imposed. As an example, we apply this theory to give new proofs of the existence and uniqueness theorems for the Einstein equations in general relativity, due to Choquet-Bruhat and Lichnerowicz. These new proofs usingfirst order techniques are considerably simplier than the classical proofs based onsecond order techniques. Our existence results are as sharp as had been previously known, and our uniqueness results improve by one degree of differentiability those previously existing in the literature.Partially supported by AEC Contract AT(04-3)-34.Partially Supported by NSF Contract GP-8257. 相似文献
105.
A smog chamber and modeling study of the gas phase NOx–air photooxidation of toluene and the cresols
Roger Atkinson William P. L. Carter Karen R. Darnall Arthur M. Winer James N. Pitts 《国际化学动力学杂志》1980,12(11):779-836
An experimental and modeling study of irradiated toluene–NOx–air, toluene–benzaldehyde–NOx–air, and cresol–NOx–air mixtures at part-per-million concentrations has been carried out. These mixtures were irradiated at 303 ± 1 K in a 5800-liter Teflon-lined, evacuable environmental chamber, with temperature, humidity, light intensity, spectral distribution, and the concentrations of O3, NO, NO2, toluene, PAN, formaldehyde, benzaldehyde, o-cresol, m-nitrotoluene, and methyl nitrate beingmonitored as a function of time. For the toluene and toluene–benzaldehyde–NOx–air runs a variety of initial reactant concentrations were investigated. Cresol–NOx–air runs were observed to be much less reactive in terms of O3 formation and NO to NO2 conversion rates than toluene–NOx–air runs, with the relative reactivity of the cresol isomers being in the order meta » ortho > para. The addition of benzaldehyde to toluene–NOx–air mixtures decreased the reactivity, in agreement with previous studies. Alternative mechanistic pathways for the NOx photooxidations of aromaticsystems in general are discussed, and the effects of varying these mechanistic alternatives on the model predictions for the toluene and o-cresol–NOx–air systems are examined. Fits of the calculations to most of the experimental concentration–time profiles could be obtained to within the experimental uncertainty for two of the mechanistic options considered. In both cases it is assumed that (1) O2 adds to the OH–toluene adduct ~75% of the time forming, after a further addition of O2, a C7 bicyclic peroxy radical, and (2) this C7 bicyclic peroxy radical reacts with NO ~75% of the time to ultimately form α-dicarbonyls and conjugated γ-dicarbonyls (e.g., methylglyoxal + 2-butene-1,4-dial) and ~25% of the time to form organic nitrates. The major uncertainties in the mechanisms concern (1) the structure of the bicyclicperoxy intermediate, and (2) the γ-dicarbonyl photooxidation mechanism. Good fits to the o-cresol concentration–time profiles in the toluene–NOx runs are obtained if it is assumed that o7-cresol reacts rapidly with NO3 radicals. However, it is observed that the model underpredicts nitrotoluene yields by a factor of ~10, but this is in any case a minor product. It is concluded that further experimental work will be required toadequately validate the assumptions incorporated in the aromatic photooxidation mechanisms presented here. 相似文献
106.
107.
The preparation of standard specifications at national and international level on pH measurement has stimulated new experimental work on this important subject, which is reviewed here against the background of continuing international deliberations and controversy about the definition of the pH scale in terms of a single primary standard or multi-primary standards. 相似文献
108.
Arthur T. Mattick 《Journal of Quantitative Spectroscopy & Radiative Transfer》1980,24(4):323-334
Coupled radiative and convective heat transfer is investigated for an absorbing gas flowing in a finite length channel and heated by blackbody radiation directed along the flow axis. The problem is formulated in one dimension and numerical solutions are obtained for the temperature profile of the gas and for the radiation escaping the channel entrance, assuming both gray and nongray absorption spectra. Due to radiation trapping, the flowing gas is found to have substantially smaller radiation losses for a given peak gas temperature than a solid surface that is radiatively heated to this temperature. A greenhouse effect is also evident whereby radiation losses are minimized for a gas having stronger absorption at long wavelengths. 相似文献
109.
Arthur W. Apter 《Israel Journal of Mathematics》1980,35(3):225-233
We prove that under the assumption of a supercompact cardinal κ which is a limit of supercompact cardinals, for any increasing
Σ2 function φ the set {∂<κ:∂ is at least φ(∂) supercompact, is strongly compact, yet is not fully supercompact} is unbounded
in κ. We then use ideas of Magidor to show that under the hypotheses of a supercompact cardinal which is a limit of supercompact
cardinals it is consistent for the least strongly compact cardinal κ0 to be at least φ(κ0) supercompact yet not to be fully supercompact, where φ is again an increasing Σ2 function which also meets certain other technical restrictions.
The author wishes to thank Menachem Magidor for helpful conversations and suggestions in method which were used in the proof
of Theorem 2. 相似文献
110.
A DuPont 950 TG has been modified to permit operation at up to 30 atm, 1100°C, with corrosive atmospheres, and steam partial pressures up to 20 atm.The major areas of instrument development included: weight and temperature measurement at high pressures in a dynamic flow system; modification of a TG to accept corrosive gas atmospheres containing high partial pressures of steam; design of a pressure balanced flow system for safe introduction of corrosive gas atmospheres; design of a working steam generation system for low flows.Process studies illustrating the utility of the high presure thermobalance include the cyclic CO2-acceptor reaction for half-calcined dolomite and the cyclic H2S absorption and regeneration reaction for half-calcined dolomite 相似文献