Benzothiazinones by addition of o-Mercaptobenzamides to acetylene esters

The condensation of o-mercaptobenzamides with methyl acetylenedicarboxylate or methyl propiolate occurs with trans addition of the SH to the alkyne linkage. The resulting vinyl sulfide adducts can be ring closed to 1,3-benzothiazin-4-ones in excellent yield.     

Adsorption and solution of H2, D2, N2, O2 and CO by (100) Ta

Sticking coefficients, saturation densities, and solution rates of gases on (100) Ta are obtained by comparing with results on (100) W using Auger electron spectroscopy and flash desorption. Hydrogen has a lower sticking coefficient on (100) Ta than on polycrystalline Ta, but solution occurs readily even at 78°K. Differences between H₂ and D₂ are observed for both adsorption and solution. Nitrogen is confined to the surface of Ta for T < ≈500°K, and adsorbed nitrogen dissolves with an activation energy of ≈2.5 kcal mole^?1 upon heating to higher temperatures. The saturation density of O₂ at 300° K is approximately twice that on (100) W. The first monolayer dissolves at ≈500°K but the second dissolves or desorbs only at much higher temperatures. Carbon monoxide adsorbs without solution of either species at 300°K. At ≈500°K carbon dissolves completely leaving oxygen which desorbs at much higher temperature.     

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Содержания работ, выш едших толъко в чешско м издании настояшего ж урнала (Československý časopis pro fysiku)

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Abstracts of papers which have appeared only in the czech edition of this journal (eskoslovenský asopis pro fysiku)

     

Responses of teachers to aircraft noise

Acoustic measurements of aircraft noise in 139 schools in Hong Kong have been carried out. The schools are located under and very near the flight-paths of aircraft coming in and leaving the international airport, Kai Tak. Coupled with the acoustic measurements, measurements of the subjective responses to this aircraft noise of 2100 Chinese teachers in these schools have been made. It is found that the subjective responses of the teachers correlate well with the Noise and Number Index. Besides the effect of annoyance, it is further found that the more serious effect of aircraft noise is the disruption of verbal communication, resulting in speech and teaching interference during lessons.     

Spectral Theory of Diffraction

In this paper we present an overview of the spectral domain approach for solving a variety of high frequency diffraction problems. We demonstrate via a number of examples that the fields derived from the use of the Spectral Theory of Diffraction (STD) remain uniformly valid for all observation angles, including the shadow boundary, the reflection boundary and the caustic direction where the conventional Geometrical Theory of Diffraction (GTD) breaks down. Furthermore, we show how the accuracy of STD can be improved and its range extended by combining it with integral equation methods in the spectral domain. This work was supported in part by U.S. Army Research Grant DAHC04-74-G0113 and in part by Office of Naval Research Grant N00014-75-C-0293.     

Intensity measurements in freon bands of atmospheric interest

The absolute intensities of the i.r. absorption bands, which are located in the atmospheric window region, of CFCl₃ (“Freon-11”) and CF₂Cl₂ (“Freon-12”) have been measured at 300°K. Our best estimates for these parameters are: for CFCl₃ (“Freon-11”), S_v = 635±36 cm^-2atm^-1 (9.2μ band), S_v = 1536±45 cm^-2atm^-1 (11.8μ band); for CF₂Cl₂ (“Freon-12”), S_v = 718±14 cm^-2atm^-1 (8.7μ band), S_v = 1136±22 cm^-2atm^-1 (9.1μ band), and S_v = 1302±40 cm^-2atm^-1 (10.9μ band).     

Study of the decay D0 --> K+pi-

Using a large sample of photoproduced charm mesons from the FOCUS experiment at Fermilab (FNAL-E831), we observe the decay D0-->K+pi- with a signal yield of 149+/-31 events compared to a similarly cut sample consisting of 36 760+/-195 D0-->K-pi+ events. We use the observed ratio of D0-->K+pi- to D0-->K-pi+ (0.404+/-0.085+/-0.025)% to obtain a relationship between the D0 mixing and doubly Cabibbo suppressed decay parameters.     

Biscopper complexes of meso-aryl-substituted hexaphyrin: gable structures and varying antiferromagnetic coupling

The copper metalation into the hexaphyrins is accompanied by large structural changes to give four complexes exhibiting gable structures and varying antiferromagnetic couplings.