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As we have seen, it was clearly Guyton's intention, in 1808, to supply details of his improved platinum pyrometer, and he did submit a drawing of the instrument at the meeting of the Class in December 1810. It would seem that on that occasion he did not supply those details which are to be found in the fourth, unpublished, part of the ‘Essay’. The existence of a text fit to be sent to the printer, and the execution of a drawing relating to the improved version of his platinum pyrometer, might be taken as evidence that Guyton intended to publish. His paper of 1810 did not appear until 1814, however, so that publication of the fourth part of the ‘Essay’ could scarcely have occurred until 1815 or later. Guyton probably hoped to be able to read it to the Class of Physical and Mathematical Sciences before publishing it in the Annales de Chimie, but his death on 2 January 1816 robbed him of the opportunity.  相似文献   

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The broad analysis made by Home and Watanabe of the development of physics in Australia during the period from 1914 to 1945 is generally accepted; however, details relating to the backgrounds of certain of these developments are questioned.  相似文献   

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In the formative period of London's scientific instrument industry membership of a guild was a necessary step towards owning a business in the City. Through the guilds' formal system of apprenticeship, boys received first-class training in a skilled trade, and learned essential marketing and managerial techniques. By analysing the guilds' records of apprenticeship and subsequent guild life it is possible to determine chains of masters and apprentices by which the knowledge passed from generation to generation. At the same time, dates can be established for the training and subsequent working life of many known makers. The chains of knowledge reveal new and often important masters who were previously unknown because, by chance, their instruments or advertisements have not survived to the present day. Two guilds have been used to illustrate the chains: Broderers' Company and Joiners' Company.  相似文献   

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This paper provides a detailed account of the period of the complex history of British algebra and geometry between the publication of George Peacock's Treatise on Algebra in 1830 and William Rowan Hamilton's paper on quaternions of 1843. During these years, Duncan Farquharson Gregory and William Walton published several contributions on ‘algebraical geometry’ and ‘geometrical algebra’ in the Cambridge Mathematical Journal. These contributions enabled them not only to generalize Peacock's symbolical algebra on the basis of geometrical considerations, but also to initiate the attempts to question the status of Euclidean space as the arbiter of valid geometrical interpretations. At the same time, Gregory and Walton were bound by the limits of symbolical algebra that they themselves made explicit; their work was not and could not be the ‘abstract algebra’ and ‘abstract geometry’ of figures such as Hamilton and Cayley. The central argument of the paper is that an understanding of the contributions to ‘algebraical geometry’ and ‘geometrical algebra’ of the second generation of ‘scientific’ symbolical algebraists is essential for a satisfactory explanation of the radical transition from symbolical to abstract algebra that took place in British mathematics in the 1830s–1840s.  相似文献   

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Summary Twenty-one alkaloids have been identified from the root ofRauwolfia ligustrina R. & S. The more important ones are reserpine, pseudoreserpine and raugustine, a new base which is isomer to pseudoreserpine. The structure of the latter compound is discussed.

Mitteilung über Rauwolfia-Alkaloide

Mitteilung sieheC. F. Huebner undE. Schlittler, J. Amer. chem. Soc.79, 250 (1957).  相似文献   

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Summary Bazzite recently found in Val Strem (Aarmassif, Ct. Graubünden, Switzerland) was investigated by means of X-ray (lattice constants, space group) and spectrographic methods (major and minor constituents). It seems to have a structure of the beryl type.  相似文献   

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