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排序方式: 共有1363条查询结果,搜索用时 31 毫秒
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Ricardo Celorrio Vı́ctor Domínguez Francisco-Javier Sayas 《Comptes Rendus Mathematique》2002,334(10):923-926
In this work we study the solution of Laplace's equation in a domain with holes by an iteration consisting of splitting the problem in an exterior one, around the holes, plus an interior problem in the unholed domain. We show the existence of a decomposition of the solution when the exterior problem is represented by means of a single-layer protential. Also, for the three-dimensional case and with some adjustments for the two-dimensional case, we prove convergence of the method by writing the iteration as a Jacobi iteration for an operator equation and studying the spectrum of the iteration operator. To cite this article: R. Celorrio et al., C. R. Acad. Sci. Paris, Ser. I 334 (2002) 923–926. 相似文献
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Tomás Chacón Rebollo Antonio Domı́nguez Delgado Enrique D. Fernández Nieto 《Comptes Rendus Mathematique》2004,338(1):85-90
In this work we introduce a class of balanced numerical schemes, up to second order, for the solution of general non-homogeneous hyperbolic systems of conservation laws. We give a general technique to build such schemes. We also prove that they balance up to second order a large class of steady solutions in the whole domain but some subset whose measure tends to zero as the grid size decreases to zero. We finally present an application to Shallow Water equations that exhibit the good performances of some of the schemes introduced. To cite this article: T. Chacón Rebollo et al., C. R. Acad. Sci. Paris, Ser. I 338 (2004). 相似文献
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Muhammad Faisal Nobuaki Sato Armando T. Quitain Hiroyuki Daimon Koichi Fujie 《国际化学动力学杂志》2007,39(3):175-180
The kinetics and pathway of hydrothermal decomposition of aspartic acid were studied using a continuous‐flow tubular reactor. The reaction was carried out in the temperature range of 200–260°C and at a pressure of 20 MPa. Deamination was the primary reaction, indicated by the presence of significant amount of ammonia, fumaric acid, or maleic acid in the products. Other reaction products were pyruvic acid, malic acid, and traces of succinic and lactic acid. Traces of alanine were also detected, showing the possibility of decomposing high‐molecular weight amino acids to obtain simple amino acids such as glycine or alanine. Results on the effect of reaction parameters demonstrated that decomposition of aspartic acid is highly temperature dependent under hydrothermal conditions. For a slight temperature difference of 60°C (from 200 to 260°C), the first‐order reaction rate constants of 0.003 significantly increased to 0.231 s?1. The activation energy was 144 kJ/mol, as calculated by the Arrhenius equation. No significant effect was exhibited by other reaction parameters such as pH and pressure. The results are useful in controlling the hydrolysis of proteinaceous materials toward high yield of aspartic acid under hydrothermal conditions. © 2007 Wiley Periodicals, Inc. 39: 175–180, 2007 相似文献
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Dimitri Markushevich Vladimir B. Matveev Armando Treibich 《Letters in Mathematical Physics》2006,76(2-3):109-109
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Dore Augusto Clemente Armando Marzotto Giovanni Valle 《Journal of chemical crystallography》1988,18(2):147-156
The crystal and molecular structure of thiamine monochloride (C12H17N4OSCl) was determined by X-ray diffraction and refined to a finalR value of 0.042. The compound crystallizes in the monoclinic system, space groupP21/a, with cell constantsa=18.929(4),b=11.663(2),c=6.376(2) Å and=96.72(8)°. The thiamine molecule is anhydrous and unprotonated, and the torsion angles at the methylene carbon show that it possesses anF conformation. The dihedral angle value of 84.16(6)° between thiazolium and pyrimidine rings is in the normal range found for the thiamine withF conformation, protonated or not, hydrated or not. Thiamine therefore has the same conformation notwithstanding protonation or hydration, with the rings similarly oriented in all the crystal structures containing thiamine. 相似文献
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Shetty Kalidas Korus roger A. Crawford Dom L. 《Applied biochemistry and biotechnology》1989,(1):825-843
Glycine max was used as a model plant cell suspension culture to establish relationships among growth kinetics, phenolics production,
elicitor action, and peroxidase activity. Timing of elictor addition through monitoring of peroxidase provided an excellent
means of optimizing yields of phenolics and reduced the time span during which phenolics were formed, negating the need for
a secondary production medium. We have also determined that calcium and other cellular effectors like polyamines and organic
osmolytes, when used in conjunction with elicitors, enhance phenolics production. Calcium directly enhanced elicitation, whereas
polyamines and other osmolytes such as glycerol and proline extended cell viability. The study also demonstrated potential
for enhancing secondary metabolite production by a combination of elicitation, cell viability stabilizers, and by addition
of nutrients at the time of elicitation. 相似文献