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1.
Under a one-sided dissipative Lipschitz condition on its drift, a stochastic evolution equation with additive noise of the
reaction-diffusion type is shown to have a unique stochastic stationary solution which pathwise attracts all other solutions.
A similar situation holds for each Galerkin approximation and each implicit Euler scheme applied to these Galerkin approximations.
Moreover, the stationary solution of the Euler scheme converges pathwise to that of the Galerkin system as the stepsize tends
to zero and the stationary solutions of the Galerkin systems converge pathwise to that of the evolution equation as the dimension
increases. The analysis is carried out on random partial and ordinary differential equations obtained from their stochastic
counterparts by subtraction of appropriate Ornstein-Uhlenbeck stationary solutions. 相似文献
2.
A simple procedure for the determination of manganese in different sections of human brain samples by graphite furnace atomic absorption spectrometry has been developed. Brain sections included cerebellum, hypothalamus, frontal cortex, vermix and encephalic trunk. Two sample preparation procedures were evaluated, namely, slurry sampling and microwave-assisted acid digestion. Brain slurries (2% w/v) could be prepared in distilled, de-ionized water, with good stability for up to 30 min. Brain samples were also digested in a domestic microwave oven using 5 ml of concentrated HNO3. A mixed palladium+magnesium nitrate chemical modifier was used for thermal stabilization of the analyte in the electrothermal atomizer up to pyrolysis temperatures of 1300 °C, irrespective of the matrix. Quantitation of manganese was conducted in both cases by means of aqueous standards calibration. The detection limits were 0.3 and 0.4 ng ml−1 for the slurry and the digested samples, respectively. The accuracy of the procedure was checked by comparing the results obtained in the analysis of slurries and digested brain samples, and by analysis of the NIST Bovine Liver standard reference material (SRM 1577a). The ease of slurry preparation, together with the conventional set of analytical and instrumental conditions selected for the determination of manganese make such methodology suitable for routine clinical applications. 相似文献
3.
Isidoro Izquierdo María T. Plaza Rafael Robles Concepcin Rodríguez 《Tetrahedron: Asymmetry》1996,7(12)
Bishydroxylation of methyl
1 with osmium tetraoxide proceeded with extremed high diastereoselectivity to give only methyl
2. Configurations of the new stereogenic centers (C-2,3) in 2 were determined by degradation of the C-5,6,7,8 fragment to the well-known methyl
7. Transformation of 2 into the required
10, was achieved by a methodology that implied, protection to 8, reduction of the ester group in 8 to a hydroxymethyl group in 9, and finally deprotection to the free
10. On the other hand, epoxidation reaction on
11 afforded only the corresponding 2,3-anhydro derivative 12 with
configuration, as could be demonstrated by degradation to (S)-1,2,4-trimetoxybutane 16, which synthesis is reported herein. 相似文献
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4.
A new synthesis for (+)-casuarine (1) and its 6,7-diepi isomer (15) in a stereocontrolled manner, is reported herein. An appropriately protected polyhydroxylated pyrrolidine, such as (2R,3R,4R,5R)-3,4-dibenzyloxy-2′-O-tert-butyldiphenylsilyl-2,5-bis(hydroxymethyl)pyrrolidine (3, protected DMDP), easily available from d-fructose, was chosen as the chiral starting material. Compounds 1 and 15 were obtained from 3, in seven steps, in a 23.2 and 20.5% overall yields, respectively. 相似文献
5.
Xu Jiaohui Zhang Zhengce Caraballo Tomás 《Journal of Dynamics and Differential Equations》2022,34(1):583-603
Journal of Dynamics and Differential Equations - In this paper, the well-posedness of stochastic time fractional 2D-Stokes equations of order $$\alpha \in (0,1)$$ containig finite or infinite delay... 相似文献
6.
An absolute method to obtain molecular weight averages is theoretically proved and experimentally applied to size exclusion chromatographic data. The method is based on stoichiometric relationships and uses labelled polymer molecules. 相似文献
7.
8.
In this Note we first introduce the concept of pullback asymptotic compactness. Next, we establish a result ensuring the existence of a pullback attractor for a non-autonomous dynamical system under the general assumptions of pullback asymptotic compactness and the existence of a pullback absorbing family of sets. Finally, we prove the existence of a pullback attractor for a non-autonomous 2D Navier–Stokes model in an unbounded domain, a case in which the theory of uniform attractors does not work since the non-autonomous term is quite general. To cite this article: T. Caraballo et al., C. R. Acad. Sci. Paris, Ser. I 342 (2006). 相似文献
9.
Najwa Sbei Belen Batanero Fructuoso Barba Beya Haouas Mohamed Lamine Benkhoud Isidoro Barba 《Tetrahedron》2018,74(16):2068-2072
A new series of 3,4-disubstituted quinazolin-2-ones, with potential T-type calcium channel antagonist activity, and new 4-methylene-quinazolin-2-ones, promising catalysts as N-heterocyclic olefins, have been prepared in good yield by a simple reaction between 2-aminobenzophenone, or 2-aminoacetophenone, and cyanomethyl anion electrogenerated by acetonitrile reduction at a graphite electrode, followed by the addition of different organic isocyanates and subsequent heterocyclization. 相似文献
10.