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1.
Dasgupta (2015) has recently put forward a novel argument, which he calls the ‘curvature argument’, that aims to show that Galilean spacetime is not an ideal setting for our classical theory of motion. This paper examines the curvature argument and argues that it is not sound. The discussion yields a remark about the conditions under which a ‘symmetry argument’ demonstrates that a particular spacetime is a non-ideal setting for our theory of motion.  相似文献   
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Contemporary developments in economicmethodology have produced a vibrant agenda ofcompeting positions. These include, amongothers, constructivism, critical realism andrhetoric, with each contributing to the Realistvs. Pragmatism debate in the philosophies of thesocial sciences. A major development in theneo-pragmatist contribution to economicmethodology has been Quine's pragmatic assaulton the dogmas of empiricism, which are nowclearly acknowledged within contemporaryeconomic methodology. This assault isencapsulated in the celebrated Duhem-Quinethesis, which according to a number ofcontemporary leading philosophers of economics,poses a particularly serious methodologicalproblem for economics. This problem, asreflected in Hausman's analysis, consists ofthe inability of economics to learn fromexperience, thereby subverting the capacity totest economic theories. In this paper wedispute this position. Our argument is basedon a combination of Quine's holism with VanFraassen's constructive empiricism, especiallythe latter's analysis of empirical adequacy andhis pragmatic approach to explanation. Theresulting reorientation of economic methodologyrestores the capacity of economics to learnfrom experience and reinstates the imperativeof developing alternatives to orthodoxtheorizing in economics.  相似文献   
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Summary A random distribution of the Y-chromosome at somatic metaphase was found in 50 patients with Ph' positive chronic myelogenous leukemia (CML). Thus, it is concluded that the positive of the Y-chromosome at somatic metaphase does not appear to influence the loss from bone marrow cells.  相似文献   
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Summary 2 populations of rat fleas,Xenopsylla astia, collected from (A) Bombay and (B) Trivandrum, were found to differ in chromosome number as follows; (A) 2n=10 in both sexes; (B) 2n=18 (male) and 20 (female). Preliminary observations have further shown that the 2 populations differ in certain morphological characters and that their reciprocal hybrids are sterile in the male and partially sterile in the female sex.Acknowledgments. We wish to express our deepest gratitude to Dr Robert E. Lewis, Professor of Entomology, Iowa State University, USA, for confirming our identification of the 2 samples of rat fleas. We are indebted to Dr N.R. Prabhoo, Reader in Zoology, University of Kerala, Trivandrum, for his advice and helpful suggestions. We are also indebted to Prof. K.M. Alexander, for encouragement and providing facilities. Financial help of the University Grants Commission, India, to one of us (C.T.) is also gratefully acknowledged.  相似文献   
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The aim of the work was to investigate the fate of injectant coal in blast furnaces and the origin of extractable materials in blast furnace carryover dusts. Two sets of samples including injectant coal and the corresponding carryover dusts from a full sized blast furnace and a pilot scale rig have been examined. The samples were extracted using 1-methyl-2-pyrrolidinone (NMP) solvent and the extracts studied by size exclusion chromatography (SEC). The blast furnace carryover dust extracts contained high molecular weight carbonaceous material, of apparent mass corresponding to 107?108 u, by polystyrene calibration. In contrast, the feed coke and char prepared in a wire mesh reactor under high temperature conditions did not give any extractable material. Meanwhile, controlled combustion experiments in a high-pressure wire mesh reactor suggest that the extent of combustion of injectant coal in the blast furnace tuyeres and raceways is limited by time of exposure and very low oxygen concentration. It is thus likely that the extractable, soot-like material in the blast furnace dust originated in tars is released by the injectant coal. Our results suggest that the unburned tars were thermally altered during the upward path within the furnace, giving rise to the formation of heavy molecular weight (soot-like) materials.  相似文献   
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Channel capacity, system versatility and ease of maintenance are factors of prime concern in future generations of wireless communication systems. As a result, millimeter-wave can offer considerable advantages in providing broadband interface. Nonlinearity and noise effects, including parametric fluctuations, are two significant causes for signal degradation in broadband communication systems. Two methods to assess the performance of an RF channel in a multi-carrier system are described. By measuring the forward transfer function from transmitter IF to receiver IF as the frequency is swept across the channel bandwidth, characteristics such as gain flatness, channel dispersion, and saturation effects are revealed. To evaluate the ability of the communication link in preserving the synchronization between two carriers, their heterodyned spectrum at the receiver IF output is studied. Both measurement methods employ standard equipment and have been found to be effective when applied to a multi-carrier millimeter-wave system with over 1 GHz instantaneous bandwidth.  相似文献   
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音乐作为一种纯粹的文化制度,有其固有的结构和强加的结构。音乐结构原理的应用有力地说明,音乐有其明确规定的数字人类学根据。  相似文献   
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1INTRODUCTIONChina is a country using the most variety of non-wood fiber raw material and is the largest country producing non-wood fiber pulp and paper in the world[1]. Bamboo is one kind of the main non-wood species for papermaking in China. Although the structure of raw materials for papermaking has being adjusted through increasing the proportion of wood pulp and by effectively utilizing waste paper source, non-wood species will still remain an important fiber resource[1,2].At present…  相似文献   
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