In this paper we look at the influence of the Coriolis force on the quasi-geostrophic equations on a domain with islands. We prove that asymptotically we obtain the solution of the Sverdrup equation with homogeneous Dirichlet conditions on the inward boundary plus a corrector function which takes into account the presence of the islands. This work is motivated by the fact that in oceanography most of the surfaces are not simply connected. This is the case for example for the North Pacific with the Japanese islands. At our knowledge, in all the previous mathematical works, just simply connected domains have been considered. Finally we will give some simple numerical simulations related to the Stommel model to see the importance of the corrector. 相似文献
Fino and Amontillado are Sherry wines, produced in Marco de Jerez area (southern Spain), and aged in Criaderas y Solera system. Fino Sherry wine follows a biological aging process, under a veil of flor yeasts, while Amontillado Sherry wine shares the same biological aging firstly, followed by oxidative aging, which gives them special features. Organic acids, esters, higher alcohols, phenolic compounds and total dry extract of Sherries evolve during aging due to evaporation processes, physical-chemical reactions, wood contributions and microbiological activity. During aging, Sherry wines improve their organoleptic profile, as could be proved in the tasting sessions. Hierarchical Cluster Analysis and Factor Analysis with factor extraction using Principal Components of Sherry wines studied were carried out and natural groupings of the wines according to the type of aging and their age were observed. A strong correlation between the parameters analyzed and the aging of each wine has been seen in the Multiple Linear Regression studies, establishing two different models, one for each type of Sherry wine, that, with only four of all the variables studied estimated the wine age with more than 99% of confidence. This constitutes a useful tool to control the age of these Sherry wines in the winery. 相似文献
A rapid, sensitive, and specific method was developed and validated using liquid chromatography-tandem mass spectrometry for
the simultaneous quantitation of atorvastatin (ATV) and its major metabolite ortho-hydroxyatorvastatin (o-HATV) in human plasma. The sample preparation involved a liquid–liquid extraction without chlorinated solvents and an on-line
solid-phase extraction exploring the possibilities that anion exchange offers. The analytical method presented intraday and
day-to-day variation below 10%; intraday and day-to-day accuracy stood between 94% and 105%; the limit of quantification was
0.1 ng/mL for ATV and 0.5 ng/mL for o-HATV; and the recovery was above 75% for both molecules. This method was applied successfully to quantitate ATV and o-HATV concentrations in an unstudied renal transplant recipient cohort treated with an immunosuppressive regime of tacrolimus
and mycophenolic acid and a cohort of hypercholesterolemic patients included in the study as a control group. It can be used
to evaluate patient adherence, drug–drug interactions, and pharmacokinetic/pharmacodynamic relationships. The results in our
study showed that ATV and o-HATV levels in the renal transplant group were significantly increased (p < 0.001), compared to the hypercholesterolemic group. 相似文献
In this paper we prove existence of weak solution with the reproductivity in time property, for a penalized PDE’s system related
to a nematic liquid crystal model.
This problem is relatively explict when time-independent Dirichlet boundary conditions are imposed for the orientation of
crystal molecules. Nevertheless, for the time-dependent case, the treatment of the problem is completely different. The verification
of a maximum principle for weak reproductive solutions is fundamental in the argument.
Finally, the relation between reproductive and periodic in time (regular) solutions will be pointed out, differenting the
2D and 3D cases. Basically, in two-dimensional domains every reproductive solution is regular and time periodic, whereas the problem
remains open for three-dimensional domains. 相似文献
Electrophilic fluorinations of lithiated bis-lactim ethers derived from cyclo-[L-AP4-D-Val] allow a direct access to alpha-monofluorinated phosphonate mimetics of naturally occurring phosphoserine and phosphothreonine, in enantiomerically pure form and suitably protected for solid-phase peptide synthesis. 相似文献
A Poiseuille flow in a 3D cylindrical domain is considered for a non-newtonian fluid of Oldroyd type. We prove existence (and
uniqueness) of a global (in time) weak solution. Moreover, this weak solution is a strong solution when data are more regular.
These results have already been obtained in the case of two concentrical cylinders ([3]). Now, we consider an extension to
an unique cylinder. Then, a mixed parabolic-hyperbolic PDE's system appears but the parabolic equation is of degenerate type.
The key of the proofs is to estimate in appropriate Sobolev weighted spaces (and to obtain strong convergence in weak norms
by means of a Cauchy argument).
Sunto In questo lavoro viene considerato il moto di Poiseuille in un dominio cilindrico tridimensionale per un fluido non-Newtoniano
tipo Oldroyd. Viene dimostrata l'esistenza e l'unicità di una soluzione debole, globale nel tempo. Inoltre, questa soluzione
debole diviene forte quando i dati diventano più regolari. Questi risultati sono già noti nel caso del dominio tra due cilindri
concentrici ([3]). Qui consideriamo l'estensione ad un unico cilindro. Si ottiene, in questo caso, un sistema di equazioni
alle derivate parziali misto parabolico-iperbolico, dove l'equazione parabolica è però di tipo degenere. Il punto chiave delle
dimostrazioni consiste nel fornire delle stime in un appropriato spazio di Sobolev pesato ed ottenere convergenza forte nelle
norme deboli mediante un argomento alla Cauchy.
Our aim was to prepare hybrid electrodes active towards the electrooxidation of thiols by the co‐immobilization of native carbon nanotubes (CNTs) and cobalt phthalocyanine (CoPc) from aqueous solutions. This strategy was adopted to avoid the oxidation of CNTs that can induce a modification of their exceptional properties. To do so, a hydrosoluble pyrrole surfactant was used to get homogeneous aqueous dispersions of CNTs and CoPc and to trap both materials on the electrode via the electropolymerization of the pyrrole surfactant. The hybrid electrodes exhibit a good electrocatalytic activity towards the oxidation of L ‐cysteine and glutathione. Their performances in terms of limit of detection (0.01 mM) are compatible with the detection of these thiols in biological samples. 相似文献
Knowledge of soil–plant transfer of naturally occurring radionuclides can be essential to assure an adequate radiological protection. Available data are mainly for anthropogenic radionuclides and biased for temperate climates. Wheat plantlets were grown using soil collected in Mediterranean regions and transfer factors, TF, for 234,238U, 226Ra, 210Po and stable elements (K, Na, Ca and Mg) were determined. U, Ra and Po were mainly located in roots. Calcium presented the highest TF values, whereas for radionuclides were much lower. Uranium TFs were correlated with total and exchangeable potassium concentration in soil. Calcium and radium TFs were correlated with total calcium concentration in soil.
Density functional theory and molecular dynamics (MD) calculations were used to evaluate electronic structure properties in a series of nanotubes with smallest possible diameters (both types: armchair and zigzag), and the corresponding chiral nanotubes (8,m) for 0 ≤ m ≤ 8. The calculations were performed considering a length of 16.5 Å. We evaluated a set of 26 combinations of dual nanotubes (armchair/armchair, zigzag/zigzag, armchair/zigzag, and zigzag/armchair), where the first label corresponds to the outer tube. We extended our study with nine additional systems of double-walled carbon nanotubes (DWCNT) with semiconductor nature. In this regard, we gave insight into the semiconductive or metallic nature inherited to the dual tubes. DWCNT systems were possible to construct by maintaining a radial distance of 3.392 Å for the armchair/armchair arrangement and 3.526 Å for the zigzag/zigzag type. It was considered as a reference, the interplanar distance of graphite (3.350 Å). Electronic transport calculations were also performed on selected DWCNT systems in order to understand the role played by the different symmetries under study. It was evidenced that the electronic structure nature of the systems rules the ability to transport electrons through the DWCNT interface. 相似文献
We review the construction of generalized integrable hierarchies of partial differential equations, associated to affine Kac-Moody algebras, that include those considered by Drinfel'd and Sokolov. These hierarchies can be used to construct new models of 2D quantum or topological gravity, as well as new W-algebras.Published in Teoreticheskaya i Matematicheskaya Fizika, Vol. 95, No. 2, pp. 258–275, May, 1993. 相似文献