排序方式: 共有35条查询结果,搜索用时 15 毫秒
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Pfeifer P Aston L Banks M Barker S Burress J Carter S Coleman J Crockett S Faulhaber C Flavin J Gordon M Hardcastle L Kallenborn Z Kemiki M Lapilli C Pobst J Schott R Shah P Spellerberg S Suppes G Taylor D Tekeei A Wexler C Wood M Buckley P Breier T Downing J Eastman S Freeze P Graham S Grinter S Howard A Martinez J Radke D Vassalli T Ilavsky J 《Chaos (Woodbury, N.Y.)》2007,17(4):041108
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James N. Flavin 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1978,29(2):328-332
An energy decay estimate of the Saint-Venant type is obtained for an elastic cylinder whose curved surface is displacement free, and a plane end of which is subjected to tractions which are not necessarily self-equilibrated.
Résumé On obtient une appréciation du type St. Venant pour l'attenuation de l'énergie dans un cylindre élastique dont la surface courbée ne subit pas de déplacement et dont une extremité plane subit des tractions qui ne sont pas forcément en equilibre.相似文献
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S. Pignard H. Vincent E. Flavin F. Boust 《Journal of magnetism and magnetic materials》2003,260(3):437-446
Polycrystalline samples of M-type hexaferrites BaFe12−2xRuxZnxO19 and BaFe12−2xRuxCoxO19 with 0x0.45 have been prepared by a classical sintering method. The evolutions with x of the cell parameters, the saturation magnetization and the magnetic transition temperature have been measured; in this range of small doping ratios, saturation magnetization and Curie temperature of substituted hexaferrites remain close to those of the undoped BaFe12O19. X-ray diffraction measurements on oriented powders show that a change of magnetocrystalline anisotropy from axial to planar occurs in both cases for a small substituting ratio xc=0.375. Microwave electromagnetic characteristics have been studied on the ceramic samples from 0.1 to 10 GHz. The behaviour of the magnetic losses (μ″) corroborates the anisotropy change when doping; a convolution of the dissipation mechanisms (domain wall motions and gyromagnetism) is obtained for xc. The level of the magnetic losses is discussed in relation with others substituted Ba-hexaferrites. 相似文献
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J. N. Flavin R. J. Knops 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1988,39(2):166-176
Summary A rectangular strip, consisting of homogeneous, isotropic, elastic material, is in an equilibrium state of plane stress, due to actions applied to a pair of opposite edges, the remaining pair being traction-free. The convexity of certain cross-sectional measures of stress is established; and a generalized convexity property is also established for one such measure, leading to an explicit decay estimate for the measure in the case of a semi-infinite strip, one end of which is subjected to a self-equilibrated load. 相似文献
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Flavin K Mullowney J Murphy B Owens E Kirwan P Murphy K Hughes H McLoughlin P 《The Analyst》2007,132(3):224-229
The ability to prepare and develop novel pre-concentration media by the sol-gel process, and their integration with mid-infrared transparent waveguides has been demonstrated. This research approach resulted in a mid-infrared sensing methodology in which the properties (porosity, functionality, polarity, etc.) of the recognition layer could be tailored by variation of the sol-gel precursors and processing conditions. Cross-linker type and concentration notably influenced p-xylene absorption and diffusion rate. Unreacted silanol groups appeared to be the dominant factor in the hydrophobicity of sol-gel layers. Variation of sol-gel precursors and thermal treatment altered both film cross-link density and polarity, as demonstrated by variation in the rate of analyte diffusion and equilibrium analyte concentration. The use of a novel 1 : 1 PTMOS : DPDMS material as pre-concentration medium in this analytical sensing approach was validated through the determination of p-nitrochlorobenzene in an aqueous environment. The response demonstrated linearity between 0-30 mg L(-1) with a correlation coefficient of 0.989 and a limit of detection of 0.7 mg L(-1). Sensing times for p-nitrochlorobenzene were also reduced from several hours to 24 minutes, without loss of measurement accuracy or sensitivity, by a 10 degrees C increase in the sensing temperature and the use of a predictive Fickian model previously developed by this research group. 相似文献
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Aye Aye Mar Ali Koohang Nathan D. Majewski Erika L. Szotek David A. Eiznhamer Michael T. Flavin Ze Qi Xu 《中国化学快报》2009,20(10):1141-1144
28-Carboxymethoxy lupane tritepenoids 3 and 4 were synthesized by alkylation of betulin with the THP protected 2-hydroxyethyl iodide followed by oxidation and reduction.Direct reaction of betulin (5) or betulone (10) with ethyl bromoacetate led to 28-O-acylation, instead of 28-O-alkylation.The targeted compounds 3 and 4 were not cytotoxic at the highest concentrationtested (75 mmol/L), suggesting that elongation of the chain length at the 28-position in both betulinic acid (1) and betulonic acid (2)was detrimental to the cytotoxicity.The acylation products 28-O-bromoacetates (8a, 8b and 11) and 28-O-methoxyacetate 13exhibited cytotoxicity against several cancer cell lines tested. 相似文献
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Aye Aye Mar Ali Koohang Nathan D.Majewski Erika L.Szotek David A.Eiznhamer Michael T.Flavin 《中国化学快报》2009,(10)
28-Carboxymethoxy lupane tritepenoids 3 and 4 were synthesized by alkylation of betulin with the THP protected 2- hydroxyethyl iodide followed by oxidation and reduction.Direct reaction of betulin(5) or betulone(10) with ethyl bromoacetate led to 28-O-acylation,instead of 28-O-alkylation.The targeted compounds 3 and 4 were not cytotoxic at the highest concentration tested(75μmol/L),suggesting that elongation of the chain length at the 28-position in both betulinic acid(1) and betulonic acid(2) was detrim... 相似文献
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