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91.
92.
Albert Padwa Mitsuo Akiba Leslie A. Cohen J.Gavin MacDonald 《Tetrahedron letters》1981,22(26):2435-2438
Thermolysis and photolysis of several allyl substituted oxazolin-5-ones results in a sigmatropic rearrangement in accord with orbital symmetry predictions. 相似文献
93.
Terrence J Brown 《Journal of Combinatorial Theory, Series A》1974,17(3):290-298
We characterize the matroid dual to a transversal matroid. We also show that Richard Rado's condition for the existence of an independent transversal can be weakened. 相似文献
94.
Travasso RD Buxton GA Kuksenok O Good K Balazs AC 《The Journal of chemical physics》2005,122(19):194906
Through a combination of simulation techniques, we determine both the structural evolution and mechanical properties of blends formed from immiscible ternary mixtures. In this approach, we first use the lattice Boltzmann method to simulate the phase separation dynamics of A/B/C fluid mixtures for varying compositions within the spinodal region. We also investigate the effect of an imposed shear on the phase ordering of the mixture. We assume that the fluid is quenched sufficiently rapidly that the phase-separated structure is preserved in the resultant solid. Then, the output from our morphological studies serves as the input to the lattice spring model, which is used to simulate the elastic response of solids to an applied deformation. These simulations reveal how the local stress and strain fields and the global Young's modulus depend on the composition of the blend and the stiffness of the components. By comparing the results for the sheared and unsheared cases, we can isolate optimal processing conditions for enhancing the mechanical performance of the blends. Overall, the findings provide fundamental insight into the relationship between structure, processing, and properties for heterogeneous materials and can yield guidelines for formulating blends with the desired macroscopic mechanical behavior. 相似文献
95.
Pribil PA Patton E Black G Doroshenko V Fenselau C 《Journal of mass spectrometry : JMS》2005,40(4):464-474
New and improved strategies are eagerly sought for the rapid identification of microorganisms, particularly in mixtures. Mass spectrometry remains a powerful tool for this purpose. Small acid-soluble proteins (SASPs), which are relatively abundant in Bacillus spores, represent potential biomarkers for species characterization. Despite sharing extensive sequence homology, these proteins differ sufficiently in sequence for discrimination between species. This work focuses on the differences in sequence between SASPs from various Bacillus species. Compilation of SASP sequences from protein database searches, followed by in silico trypsin digestion and analysis of the resulting fragments, identified several species-specific peptides that could be targeted for analysis using mass spectrometry. This strategy was tested and found to be successful in the characterization of Bacillus spores both from individual species and in mixtures. Analysis was performed using an ion trap mass spectrometer with an atmospheric pressure MALDI source. This instrumentation offers the advantage of increased speed of analysis and accurate precursor ion selection for tandem mass spectrometric analysis compared with vacuum matrix-assisted laser desorption/ionization and time-of-flight instruments. The identification and targeting of species-specific peptides using this type of instrumentation offers a rapid, efficient strategy for the identification of Bacillus spores and can potentially be applied to different microorganisms. 相似文献
96.
Maspoch D Domingo N Ruiz-Molina D Wurst K Hernández JM Vaughan G Rovira C Lloret F Tejada J Veciana J 《Chemical communications (Cambridge, England)》2005,(40):5035-5037
A metal-organic open-framework with an unprecedented (6,3)-helical topology, large channels and mixed ferro- and antiferromagnetic interactions has been synthesized using a three-connecting tricarboxylic polychlorotriphenylmethyl radical and Co(ii) ions. 相似文献
97.
Bernard Vittoz et Paul Gavin 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1964,15(3):319
Résumé Un réseau non régulier permet une utilisation plus rationnelle du combustible, par un applatissement possible du flux. On dispose les barres de combustibles de façon à obtenir des variations continues des paramètres nucléaires. On utilise la théorie de la diffusion, qui suppose un milieu homogène mais non uniforme. Dans le cas stationnaire, on représente la répartition du flux par une somme infinie de fonctions de Bessel, dont les coefficients sont déterminés grâce aux propriétés d'orthogonalité. En cinétique, on suppose que chaque harmonique de l'espace décroit dans le temps selon une somme d'exponentielles. La période stable de chaque harmonique s'obtient par identification avec l'équation de diffusion. 相似文献
98.
99.
Gavin R. Thomson 《Applicable analysis》2013,92(3):349-361
The Hölder continuity and differentiability are investigated of Newtonian potentials arising in the theory of bending of elastic plates with transverse shear deformation. These properties play an essential role in the study by means of boundary integral equation techniques of boundary value problems for the equilibrium and harmonic oscillation states, and in the construction of associated boundary element methods. 相似文献
100.
John Gavin Christopher Jennison 《Journal of computational and graphical statistics》2013,22(2):182-201
Abstract In statistical image reconstruction, data are often recorded on a regular grid of squares, known as pixels, and the reconstructed image is defined on the same pixel grid. Thus, the reconstruction of a continuous planar image is piecewise constant on pixels, and boundaries in the image consist of horizontal and vertical edges lying between pixels. This approximation to the true boundary can result in a loss of information that may be quite noticeable for small objects, only a few pixels in size. Increasing the resolution of the sensor may not be a practical alternative. If some prior assumptions are made about the true image, however, reconstruction to a greater accuracy than that of the recording sensor's pixel grid is possible. We adopt a Bayesian approach, incorporating prior information about the true image in a stochastic model that attaches higher probability to images with shorter total edge length. In reconstructions, pixels may be of a single color or split between two colors. The model is illustrated using both real and simulated data. 相似文献