Eudoxos' planetary theory—the earliest mathematical model?     

J.G. Landels 《Endeavour》1983,7(4):183-188

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Sleuthing in reciprocal space: the search for a charge-density wave in alphauranium     

G. H. Lander Ph.D 《Endeavour》1990,14(4)

This year marks the 50th anniversary of the preparation of the first transuranium elements, neptunium and plutonium though thus losing pride of place in the Periodic Table, uranium still has secrets to reveal. This article describes efforts to characterize the extremely subtle series of distortions that appears at low temperature in the element. Our understanding of these distortions require some of the latest ideas in diffraction physics, so that the story is a continuously evolving one. Uranium is the only element (so far) that has been found to have a spontaneous charge-density wave.  相似文献   

A conceptual model of taste receptors     

Syed Shamil B.Sc.  Ph.D.  C.Chem.  M.R.S.C.  M.I.F.S.T.  Gordon G. Birch B.Sc.  Ph.D.  D.Sc.  F.R.C.S.  F.I.F.S.T. 《Endeavour》1990,14(4)

Of all the senses, that of taste is perhaps the hardest to define and quantify and elucidation of the underlying mechanisms is unrespondingly difficult. This article describes a conceptual model — at the molecular level — for the four basic taste modalities, using apparent specific volume as a fundamental parameter. It also considers possible practical applications.  相似文献   

Optimization of configurations of field problem grids using network models     

G.J. Savage  P.H. Roe  G. Reedel 《Journal of The Franklin Institute》1981,312(1):61-80

Optimization of grid configurations decreases the discretization error in the numerical solution of field problems. In this paper, the theoretical and algorithmic aspects of optimizing configurations of grids used in equilibrium, potential-type field problems is presented. The criterion for establishing the optimum grid and the steps required to move to the optimum grid are given. Sensitivity network modelling is invoked to systematically form matrices required in the algorithm. One-dimensional examples are presented to illustrate the validity of the approach.  相似文献   

Dynamic dictionary updating     

Robert G. Crawford 《Information processing & management》1977,13(4):235-245

A method for updating the dictionary in a dynamic information retrieval system is presented. It is shown that as a collection changes through addition and deletion of documents, the appropriate set of index terms may be determined without complete periodic regeneration of the dictionary. Results are presented for experiments involving a complete change in collection membership, with the dynamic dictionary updating methods shown to be effective.  相似文献   

Polymorphonuclear leukocytic sialic acid and sialidase activity in obesity     

Raj K. Das  M. G. Muddeshwar 《Indian journal of clinical biochemistry : IJCB》1997,12(2):114-118

The level of sialic acid in the obese polymorphonuclear leukocytes (PMNL) was found to be significantly reduced as compared to normal. Activity of sialic acid degrading enzyme, sialidase, was found to be increased in the obese state. Restoration in both sialic acid content and sialidase activity was also evidenced in the PMNL of treated obese patients.  相似文献   

Discoveries, When and By Whom?     

Hudson  Robert G. 《The British journal for the philosophy of science》2001,52(1):75-93

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On preservation of mean square continuity under zero memory non-linear transformation     

G.L. Wise 《Journal of The Franklin Institute》1977,303(2):201-207

Mean square continuity of a random process is of considerable theoretical and practical importance. Mean square continuous random processes passed through zero memory non-linearities are considered. Several conditions are given relating to mean square continuity of the output. Bounded zero memory non-linearities are considered with arbitrary random processes as inputs, and conditions on both the zero memory non-linearity and on the random process are examined. Also, general zero memory non-linearities are considered with Gaussian random processes as inputs.  相似文献   

Warranting scientific belief   总被引：1，自引：0，他引：1  

Gilbert GN  Mulkay M 《Social studies of science》1982,12(3):383-408

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Asymptotic memoryless detection of random signals in dependent noise     

D.R. Halverson  G.L. Wise 《Journal of The Franklin Institute》1981,312(1):13-29

Design of detectors for strong mixing signals in strong mixing noise is considered, where a large degree of dependency may occur between the signal and noise. Under the criterion of asymptotic relative efficiency, it is shown that this design reduces to determining the solution of an integral equation, where only knowledge of the second order statistics of the randon processes involved is required. In particular, if the signal is independent of the noise and has nonzero mean, the optimal detector is the same as in the known constant signal case. It is also shown that it is possible to delete several regularity conditions which may be difficult to check in practice in the slightly more restrictive case where the maximal correlation coefficients of the signal and noise tend to zero.  相似文献