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Ohne Zusammenfassung 相似文献
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Observations of the molecular cloud G1.6-0.025 in the 2K-1K and J0-J?1E series and 5?1-40E line of CH3OH, the (2-1) and (3-2) lines of SiO, and the 7?7-6?6 line of HNCO are described. Maps of the previously observed extended cloud with Vlsr~50 km/s and high-velocity clump with Vlsr~160 km/s, as well as a newly detected clump with Vlsr~0 km/s, have been obtained. The extended cloud and high-velocity clump have a nonuniform structure. The linewidths associated with all the objects are between 20 and 35 km/s, as is typical of clouds of the Galactic center. In some directions, emission at velocities from 40 to 160 km/s and from ?10 to +75 km/s is observed at the clump boundaries, testifying to a connection between the extended cloud and the high-velocity clump and clump at Vlsr~0 km/s. Compact maser sources are probaby contributing appreciably to the emission of the extended cloud in the 5?1-40E CH3OH line. Non-LTE modeling of the methanol emission shows that the extended cloud and high-velocity clump have a relatively low hydrogen density (<104 cm?3). The specific column density of methanol in the extended cloud exceeds 6×108 cm?3s, and is 4×108?6×109 cm?3s in the high-velocity clump. The kinetic temperatures of the extended cloud and high-velocity clump are estimated to be <80 K and 150–200 K, respectively. Possible mechanisms that can explain the link between the extended cloud with Vlsr~50 km/s and the clumps with Vlsr~0 km/s and ~160 km/s are briefly discussed. 相似文献
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Much of the authors' knowledge of kin interaction and exchange in Britain is partial, in that it is based on studies of co-resident groups and excludes consideration of kin "beyond the household". It is known that there have been large declines in intergenerational co-residence, raising fears that family bonds have weakened. It is also commonly assumed that family members are less likely to live in close proximity than in the past. In this paper the authors examine one important aspect of kin relationships--proximity of adult children to their parents--using nationally representative data from 1986, 1995, and 1999. The analyses presented focus on: differences between 1986, 1995, and 1999 in proximity of adults to their parents; sociodemographic characteristics associated with variations in proximity, and temporal differences in the pattern of these variations. The paper concludes with an assessment of some of the policy implications of the findings. 相似文献
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Camps A. Skou N. Torres F. Corbella I. Duffo N. Vall-llossera M. 《Geoscience and Remote Sensing Letters, IEEE》2006,3(2):259-261
Accurate measurement of the antenna voltage patterns of large-aperture synthesis radiometers is critical in order to achieve good radiometric accuracy, and a very time consuming and expensive task. Measurement requirements and a tradeoff study relating radiometric accuracy degradation and number of elements to be measured are presented. 相似文献