摘要 :
The decomposition of hydrogen peroxide in aerated "pure water" was studied as a function of dose and initial hydrogen peroxide concentra-tion, (H202)o, in the 1 to 100 millimolar concentration region. Irra-diations were performed ...
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The decomposition of hydrogen peroxide in aerated "pure water" was studied as a function of dose and initial hydrogen peroxide concentra-tion, (H202)o, in the 1 to 100 millimolar concentration region. Irra-diations were performed with a 2000-curie Co60 source at a dose rate of 12.8 kilorads per minute. The decomposition of hydrogen peroxide vas found to follow first-order kinetics with respect to peroxide in the 1 to 100 millimolar concentration range. The specific peroxide decom¬position rate constant, K1, was observed to decrease with an increase in initial peroxide concentration. The decomposition yield of hydrogen peroxide, G -(H2O2), at a given dose was found to increase significantly with increasing initial peroxide concentration and to be proportional to the square root of the initial peroxide concentration up to about 40 millimolar peroxide. The peroxide decomposition yield for a given ini¬tial peroxide concentration was observed to decrease continually during irradiation. The rate of decrease was found to be greater for higher initial concentrations of peroxide.
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It is shown that the principal source of electrons in H I regions is the photoionization of vibrationally excited molecular hydrogen by starlight near 1000 A. (Author)
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The mission of the 14th CAB is to provide timely direct and general aviation support to the elements of the Americal Division and selected units within I Corps Tactical Zone.
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Two altitude compensating carburetor modification kits were installed on each of two YH-13H Helicopters at this Board and flown for a period of approximately three months by pilots with varying experience in H-13H Helicopters with...
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Two altitude compensating carburetor modification kits were installed on each of two YH-13H Helicopters at this Board and flown for a period of approximately three months by pilots with varying experience in H-13H Helicopters without altitude-compensated carburetors installed. Two production model H-13H Helicopters with the production-line compensated carburetors installed were flown for a period of approximately 100 hours each by various pilots of this command. Tests were conducted at various gross weights from no payload to maximum takeoff gross weights and from sea level to altitudes of approximately 15,000 feet utilizing all feasible power settings. (Author)
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This report presents Sound Exposure Level (SEL) vs distance curves for eight models of Army rotary-wing aircraft (OH-58, AH-1G, UH-1M, UH1-1H, UH-1B, CH-47B, CH-54, and TH-55) performing dynamic operations, and Equivalent Sound Le...
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This report presents Sound Exposure Level (SEL) vs distance curves for eight models of Army rotary-wing aircraft (OH-58, AH-1G, UH-1M, UH1-1H, UH-1B, CH-47B, CH-54, and TH-55) performing dynamic operations, and Equivalent Sound Level contours for the same aircraft in static operations. The dynamic operations consisted of level fly overs, ascents, descents, turns, taekoffs, and landings; static operations included in-ground and out-of-ground effect hovers. Results are grouped according to model and type of operation and are suitable for use in manual or computerized programs for predicting noise impact from rotary-wing aircraft. (Author)
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摘要 :
We present medium-resolution (R approximately 700) near-infrared (lambda = 1 - 2.5 micrometers) spectra of a sample of planetary nebulae (PNe). A narrow slit was used which sampled discrete locations within the nebulae; observatio...
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We present medium-resolution (R approximately 700) near-infrared (lambda = 1 - 2.5 micrometers) spectra of a sample of planetary nebulae (PNe). A narrow slit was used which sampled discrete locations within the nebulae; observations were obtained at one or more positions in the 41 objects included in the survey. The PN spectra fall into one of four general categories: H1 emission line-dominated PNe, H1 and H2 emission line PNe, H2 emission line-dominated PNe, and continuum-dominated PNe. These categories correlate with morphological type, with the elliptical PNe falling into the first group, and the bipolar PNe primarily in the H2 and continuum emission groups. The categories also correlate with C/O ratio, with the O-rich objects falling into the first group and the C-rich objects in the groups. Other spectral features were observed in all catagories, such as continuum emission from the central star, and warm dust continuum emission towards the long wavelength end of the spectra. H2 was detected in four PNe in this survey for the first time. An analysis was performed using the H2 line ratios in all of the PN spectra in the survey where a sufficient number of lines were observed to determine the ortho-to-para ratio and the rotational and vibrational excitation temperatures of the H-2 in those objects. One unexpected result from this analysis is that the H-2 is excited by absorption of ultraviolet photons in most of the PNe, although there are several PNe in which collisional excitation plays an important role. The correlation between bipolar morphology and H2 emission has been strengthened with the new detections of H2 in this survey.
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