排序方式: 共有38条查询结果,搜索用时 218 毫秒
1.
P. Giangiacomo V. Michelassi 《International Journal of Computational Fluid Dynamics》2013,27(1):15-26
The paper describes a domain decomposition strategy which allows high efficiency parallel simulations of turbomachinery flows. The implicit ADI parallel solver is based on the scalar approximate factorisation. The Navier-Stokes (NS) and turbulence model equations are discretised by centred finite differences. The results prove that the parallel calculations with domain decomposition, in which each sub-domain explicitly communicates with the adjacent ones at the end of each implicit iteration, may suffer from a considerable deterioration of the convergence rate. A simple sub-iterative domain recoupling strategy allows recovering the convergence rate of a single processor computation. The strategy is carefully analysed and optimised in terms of inter-processor data communication rate and algorithm memory requirements. The span-wise domain decomposition is particularly suited for turbomachinery flows and is applied to a radial impeller and to an axial turbine stator and stage to prove the validity and the accuracy of the proposed approach. The results indicate that the parallel recoupled algorithm usually reach efficiencies of 0.8, with peaks over 0.9 with up to 16 processors, thereby allowing a considerable speed-up of design and verification calculations. 相似文献
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In this paper we present several results about local MV-algebras, extending existing results given for MV-chains. The role
of local MV-algebras in sheaf representation and weak boolean product is stressed and the relationship of local MV-algebras
with varieties of MV-algebras is analyzed.
Presented by S. Pulmannova.
Received November 11, 2005; accepted in final form December 20, 2005. 相似文献
4.
A short and efficient synthesis of novel tetracyclic Kynurenic acid analogues, isolated from chestnut honey, is described. The crucial step of the strategy was a MW-assisted cyclization of enamines of ethyl dioxohexahydropyrrolizine and 2,3-dioxooctahydroindolizine carboxylates to obtain 2,3,6,11b-tetrahydro-1H-pyrrolizino[2,1-b]quinoline-5,11-dione and 5,8,91,011,11a-hexahydroindolizino[2,1-b]quinoline-6,12-dione, respectively. Because of its modular nature, the synthetic strategy can have value as a general method for the preparation of compounds containing these new heterocyclic scaffolds. 相似文献
5.
Giangiacomo Beretta Fabrizio Gelmini Fabrizio Fontana Roberta Manuela Moretti Marina Montagnani Marelli Patrizia Limonta 《Natural product research》2018,32(10):1130-1135
In this work, we report a rapid and convenient HPLC-UV-DAD method for the isolation of δ-T3 on semi-preparative scale from two different vitamin E rich processed, commercially available products obtained from the fruits of Elaeis guineensis Jacq. (oil palm) and from the seeds of Bixa orellana L. (achiote tree). Chromatography was run using reverse phase (RP) C-18 columns and HPLC-grade acetonitrile as mobile phase. The purity of the isolated δ-T3, assessed by GC–MS and 1H NMR was above 98%. The δ-T3 cytotoxic activity found in vitro against the proliferation of human A375 melanoma cells compared to that of the other δ-T3 free tocols mixture suggest its primary role in the experimental anticancer activity observed for palm oil derived products. Taken altogether, the results of this study highlight the importance of the application of suitable purification systems for the preparations of tocotrienols prior to their experimental or clinical testing. 相似文献
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Lawrence P. Belluce Antonio Di Nola Brunella Gerla 《Applied Categorical Structures》2007,15(1-2):135-151
In this paper, after recounting the basic properties of perfect MV-algebras, we explore the role of such algebras in localization
issues. Further, we analyze some logics that are based on Łukasiewicz connectives and are complete with respect to linearly
ordered perfect MV-algebras.
相似文献
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Beretta G Artali R Caneva E Maffei Facino R 《Magnetic resonance in chemistry : MRC》2011,49(3):132-136
1,2,3,4,6-Penta-O-galloyl-β-D-glucopyranose (PGG) is a polyphenolic compound found in substantial amounts in a number of medicinal herbs. We report (i) its conformational analysis by solution NMR and molecular dynamics calculation and (ii) theoretical study of its interaction with a model membrane bilayer. The galloyl groups B and E appear to play important roles in the interaction with the phospholipid bilayer. 相似文献
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Alberti A Fuochi P Guerra M Macciantelli D Torri G Valerio A Vismara E 《Organic & biomolecular chemistry》2011,9(9):3199-3204
Irradiation of a number of different sutures largely employed in the clinical practice with either high energy electrons or with γ-rays followed by quenching with glycidyl methacrylate (GMA) conveniently led to derivatization through a radical-based process. The radicals involved were detected by means of ESR spectroscopy and were characterized on the basis of their ESR spectral parameters which were also found to be consistent with the hfs constants predicted by DFT calculations. Evidence of the GMA derivatization of the sutures was obtained via(13)C CP-MAS NMR spectroscopy, while its extent was evaluated gravimetrically. 相似文献
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Gemma Carotenuto Giangiacomo Gerla 《International Journal of Approximate Reasoning》2013,54(8):1066-1086
In this exploratory paper we propose a framework for the deduction apparatus of multi-valued logics based on the idea that a deduction apparatus has to be a tool to manage information on truth values and not directly truth values of the formulas. This is obtained by embedding the algebraic structure V defined by the set of truth values into a bilattice B. The intended interpretation is that the elements of B are pieces of information on the elements of V. The resulting formalisms are particularized in the framework of fuzzy logic programming. Since we see fuzzy control as a chapter of multi-valued logic programming, this suggests a new and powerful approach to fuzzy control based on positive and negative conditions. 相似文献
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In this review, some well-established assays and more recent markers developed for the understanding of the biological activity
of pharmaceutical drugs belonging to different pharmacological classes (nonsteroidal anti-inflammatory drugs, cardiovascular
drugs, and central-nervous-system-acting drugs) are considered. The results of in vitro studies are reviewed and critically
compared with those available from clinical trials, and their relevance for the elucidation of the mechanism of action of
the drugs is discussed. Although from this examination a positive correlation between the in vitro and in vivo data seems
to emerge, the small number of clinical trials available, their low number of patients enrolled, and sometimes the arbitrary
or inappropriate choice of the biomarker(s) used highlight the need for (1) more standardized protocols to allow a reliable
comparison of the results from different studies and (2) the development of new and more appropriate and specific biomarkers
for the evaluation of oxidative stress before and after drug intervention. 相似文献