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In 1914, the physics discipline had reached a very similar stage of development in Australia and Japan. A generation later the paths of development had considerably diverged. A systematic comparison of the evolution of physics in the two countries during these years identifies factors—political, economic and cultural—that led to this divergence, but it also uncovers a number of underlying parallels. 相似文献
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好氧颗粒污泥是一种全新概念的污水生物处理技术。介绍了好氧颗粒污泥技术的理论基础,包括好氧污泥形成机理及理化特性研究,探讨了影响好氧颗粒污泥形成的因素以及工业应用的方向和前景。 相似文献
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R. S. B. Cordeiro J. Assreuy Filho C. A. Flores F. Q. Cunha M. A. Martins H. N. Vasconcelos 《Cellular and molecular life sciences : CMLS》1984,40(3):301-302
Summary Mice inoculated withPlasmodium berghei developed a drastic and significant pulmonary edema. Treatment of animals with phenoxybenzamine rendered mice hyporeactive to this physiopathological alteration.This work was supported by a grant aided by «Conselho Nacional de Desenvolvimento Científico e Tecnológico» (CNPq, Brasil). Presented in preliminary form at the XIX Annual Meeting of the Brazilian Society of Tropical Medicine, Rio de Janeiro, R. J., February 20, 1983.Acknowledgments. We thank Mr Antonio Fernando de P. Oliveira and Solano S. Martins for their excellent technical help. 相似文献
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Social situations, the object of the social sciences, are complex and unique: they contain so many variable aspects that they cannot be reproduced, and it is even difficult to experience two situations that are alike in many respects. The social scientists' past experiences that serve as their background knowledge to intervene in an existent situation is poor compared to what a traditional epistemologist would consider ideal. A way of dealing with the variable and insufficient background of social scientists is by means of models. But, then, how should we characterize social scientific models? This paper examines Otto Neurath's scientific utopianism as an attempt to deal with this problem. Neurath proposes that social scientists work with utopias: broad imaginative plans that coordinate a multitude of features of a social situation. This notion can be used in current debates in philosophy of science because we notice that utopias, in Neurath's sense, are comparable to models and nomological machines in Nancy Cartwright's conception. A model-based view of science lays emphasis on the fact that scientists learn from the repeated operation of such abstract entities, just as they learn from the repetition of experiments in a laboratory. Hence this approach suggests an approximation between the natural and the social sciences, as well as between science and utopian literature. This is exemplified by analyzing the literary dystopia We, written by Yevgeny Zamyatin, to show that reasoning from and debating about utopian writings, even if fictional and pessimistic, creates phenomena of valuation, which are fundamental for constituting a background of experiences in the social sciences. 相似文献
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Walter F Decarli R Carilli C Bertoldi F Cox P Da Cunha E Daddi E Dickinson M Downes D Elbaz D Ellis R Hodge J Neri R Riechers DA Weiss A Bell E Dannerbauer H Krips M Krumholz M Lentati L Maiolino R Menten K Rix HW Robertson B Spinrad H Stark DP Stern D 《Nature》2012,486(7402):233-236
The Hubble Deep Field provides one of the deepest multiwavelength views of the distant Universe and has led to the detection of thousands of galaxies seen throughout cosmic time. An early map of the Hubble Deep Field at a wavelength of 850?micrometres, which is sensitive to dust emission powered by star formation, revealed the brightest source in the field, dubbed HDF?850.1 (ref. 2). For more than a decade, and despite significant efforts, no counterpart was found at shorter wavelengths, and it was not possible to determine its redshift, size or mass. Here we report a redshift of z = 5.183 for HDF?850.1, from a millimetre-wave molecular line scan. This places HDF?850.1 in a galaxy overdensity at z?≈?5.2, corresponding to a cosmic age of only 1.1?billion years after the Big Bang. This redshift is significantly higher than earlier estimates and higher than those of most of the hundreds of submillimetre-bright galaxies identified so far. The source has a star-formation rate of 850 solar masses per year and is spatially resolved on scales of 5 kiloparsecs, with an implied dynamical mass of about 1.3?×?10(11) solar masses, a significant fraction of which is present in the form of molecular gas. Despite our accurate determination of redshift and position, a counterpart emitting starlight remains elusive. 相似文献
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