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991.
Nine bedrock and two till samples were analyzed to determine whether their chemical and physical properties could be used to distinguish between bedrock units and to differentiate local bedrock from overlying tills. The bedrock samples came from The North Cliff subsite of the Wellsch Valley Site, and the till samples from Jaw Face subsite. Eight of the nine bedrock samples show great similarity. However, their geochemical differences from the overlying Quaternary tills establish that the tills contain much material entrained, during one or more early Quaternary glaciations, from older bedrock outcrops to the north and northeast. The glaciers that laid down the tills appear to have reworked and concentrated elements compatible with a dry climate, probably formed by weathering during long interglacial, and perhaps preglacial, intervals when the surface was undergoing slow degradation.  相似文献   
992.
The Borel-Weil (BW) construction for unitary irreps of a compact Lie group is extended to a construction of all unitary irreps of the quantum groupU q(n). Thisq-BW construction uses a recursion procedure forU q(n) in which the fiber of the bundle carries an irrep ofU q(n–1)×U q(1) with sections that are holomorphic functions in the homogeneous spaceU q(n)/U q(n–1)×U q(1). Explicit results are obtained for theU q(n) irreps and for the related isomorphism of quantum group algebras.Supported in part by the National Science Foundation, No. PHY-9008007  相似文献   
993.
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995.
Übersicht Ziel der Untersuchung ist es, den Einfluß von Kriechschädigung und Belastungsvorgeschichte auf das weitere Kriechverhalten nach einer Änderung der Belastungsrichtung zu bestimmen. Die ermittelten Kriechbruchzeiten werden stark von der Änderung der Belastungsrichtung beeinflußt. Dieses Verhalten wird mit einer tensoriell nichtlinearen Theorie erklärt, indem man den Einfluß der Vorschädigung mit einem zweistufigen Tensor darstellt.
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996.
A 6.71 kW power tiller was evaluated for draft and drawbar power on tar roads. The effect of mounting 40 kg of wheel ballast was also studied. Polynomial regression analysis was used to establish the relationship between draft and wheel slip, drawbar power and wheel slip, drawbar power and fuel consumption, and drawbar power and specific fuel consumption. The results of the study showed draft values of 2107, 2110 and 2110 N in second low, third low and first high gears at an engine speed of 150o rpm with a 15% wheel slip. The respective draft values at engine speed of 2000 rpm with a 15% wheel slip were 2172, 2189 and 2212 N. With the mounting of 40kg wheel ballast there was an increase in draft of 217, 207 and 291 N at 1500 rpm, and 328, 306 and 344 N at 2000 rpm of the engine with a 15% wheel slip in second low, third low and first high gears, respectively. The increase in drawbar power with 40 kg ballast was 10.88%, 7.83% and 20.13% at 1500 rpm and 18.89%, 16.56% and 14.88% at 2000 rpm of engine over the drawbar power available with zero ballast. The fuel consumption with the use of wheel ballast was slightly more than the fuel consumption without any ballast.  相似文献   
997.
These studies investigated formant frequency discrimination by Japanese macaques (Macaca fuscata) using an AX discrimination procedure and techniques of operant conditioning. Nonhuman subjects were significantly more sensitive to increments in the center frequency of either the first (F1) or second (F2) formant of single-formant complexes than to corresponding pure-tone frequency shifts. Furthermore, difference limens (DLs) for multiformant signals were not significantly different than those for single-formant stimuli. These results suggest that Japanese monkeys process formant and pure-tone frequency increments differentially and that the same mechanisms mediate formant frequency discrimination in single-formant and vowel-like complexes. The importance of two of the cues available to mediate formant frequency discrimination, changes in the phase and the amplitude spectra of the signals, was investigated by independently manipulating these two parameters. Results of the studies indicated that phase cues were not a significant feature of formant frequency discrimination by Japanese macaques. Rather, subjects attended to relative level changes in harmonics within a narrow frequency range near F1 and F2 to detect formant frequency increments. These findings are compared to human formant discrimination data and suggest that both species rely on detecting alterations in spectral shape to discriminate formant frequency shifts. Implications of the results for animal models of speech perception are discussed.  相似文献   
998.
Granular films prepared from well-defined In clusters embedded in Kr (? 10-40 at % Kr) show sharp resistance anomalies very close to the superconducting transition temperature. The observed resistance peak(s), which go(es) above the normal state resistance RN and which can be as high as ? 1.5 RN, can be explained by a “mesoscopic” effect: Superconducting percolation aggregates of size ξρ, larger than the superconducting coherence length ξS, but smaller than the quasiparticle relaxation length λQ*, have a superconducting gap, but are not yet able to carry a supercurrent.  相似文献   
999.
The height distribution of the dayside cusp aurora and the relation between optical emissions and net downward electron energy flux are discussed. These two important characteristics of day-side cusp aurora are still unknown. It is instructive to compare particle flux and optical luminosity because these two quantities should be proportional if the cusp aurora is caused by electron impact, as has been found for nighttime aurora in the oval. Furthermore, there should then be a direct relation between auroral altitudes and particle energy. Based on coordinated auroral observations at Svalbard and Greenland, together with simultaneous, overhead F-9 satellite measurements, these quantities have been evaluated  相似文献   
1000.
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