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371.
Patrizia Ciminiello Carmela Dell'Aversano Martino Forino Paola Di Meglio Roberto Poletti 《Tetrahedron》2004,60(33):7093-7098
A detailed analysis of toxic shellfish collected in the Adriatic sea in October 2000 allowed us to isolate a new cytotoxic chlorosulfolipid (3). Its gross structure has been elucidated through an extensive NMR analysis including various 2D techniques; the relative stereochemistry has been solved by applying the Murata's method. Compound 3 showed to posses cytotoxic activity against WEHI 164 and J774 cells. The presence of chlorosulfolipids in toxic mussels from the northern Adriatic sea has not to be considered incidental as we have been detecting these cytotoxic compounds since 1998. Their simultaneous and constant presence together with typical marine biotoxins represents a further risk both to consumers' health and aquacultures economic proceeds. 相似文献
372.
S. Galvagno S. Casu M. Martino E. Di
Palma Sabrina Portofino 《Journal of Thermal Analysis and Calorimetry》2007,88(2):507-514
The world production of tyre waste amounts to 5·106
ton year–1, 2·106
tons of which are produced in Europe, but the final destination of nearly
65–70% of them is the landfill, despite the high added value materials
lost and the consequent environmental impact.
Treatments alternative
to landfilling take into account reconstruction and reuse of the tyres or
the matter and/or energy recovery by means of thermal treatment processes
(incineration, gasification and pyrolysis). Among these, pyrolysis seems to
be a promising and realistic alternative to attain the conversion of tyre
waste into valuable and reusable products.
Present work relates
to experimental tests and results obtained for the study of tyre waste pyrolysis,
conducted by means of thermo-gravimetric analysis (TG) of the material and
the simultaneous determination, through Fourier transform infrared (FTIR)
and mass spectrometry (MS), of the decomposition products. The analysis of
the volatile fraction allows to isolate, within the thermograms, the evolution
of products referable to specific tyre components and therefore it suggests
the application of a multi-component decomposition model. The kinetic model
consequently developed agrees fairly well with the experimental data. 相似文献
373.
E. Fort B. Lescop A. De Martino H. Vach M. Châtelet F. Pradère 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(3):331-334
In this paper, we show how the use of a third non-condensable species gives both new insight and control on the binary nucleation
process during supersonic expansion of gas mixtures. We present the case of an oxygen-nitrogen mixture diluted in various
proportions of helium. Using beam diagnostics, we determine the mean cluster composition and size as well as the percentage
of uncondensed matter present in the beam. The presence of helium permits us to understand the cooling and clustering role
played by each species during the expansion process. We discuss, in particular, its influence on the dramatic composition
change observed at the nucleation onset.
Received 18 April 2001 相似文献
374.
Corrado Berti Enrico Binassi Annamaria Celli Martino Colonna Maurizio Fiorini Paola Marchese Elisabetta Marianucci Massimo Gazzano Francesco Di Credico Daniel J. Brunelle 《Journal of Polymer Science.Polymer Physics》2008,46(6):619-630
A series of poly(1,4‐cyclohexylenedimethylene 1,4‐cyclohexanedicarboxylate) (PCCD) samples, characterized by different cis/trans ratio of the 1,4‐cyclohexanedicarbonyl unit, have been synthesized and analyzed by thermogravimetry (TGA), calorimetry (DSC), and X‐ray diffraction (WAXD). The thermal stability results are good and are not affected by the stereochemistry of the 1,4‐cyclohexylene units. On the other hand, the thermal transitions are notably influenced by the cis/trans content. With the increment of the trans content the polymer changes from completely amorphous to semicrystalline material. Tg, Tm, and crystallinity increase. These results suggest that the trans configuration induces a better chain packing and higher symmetry, improving the crystallizability of the samples. The effect of the molecular structure on the thermal properties is analyzed by using a statistical approach. From the effective correlations found between stereochemistry of the C6 rings and transition temperatures it is possible to extrapolate that the configuration of 1,4‐cyclohexylene ring deriving from 1,4‐cyclohexanedicarboxylic acid or dimethyl 1,4‐cyclohexanedicarboxylate results to be the main element responsible for the thermal properties. This is due to the high rigidity of the 1,4‐cyclohexanedicarbonyl unit with respect to 1,4‐cyclohexanedimethyleneoxy unit, deriving from the diol. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 619–630, 2008 相似文献
375.
We present a numerical method for the resolution of a bidimensional blood flow problem and more generally for a fluid flow surrounded by a time dependent domain. Our approach is based on an ALE formulation which is solved using a Galerkin method with an eigenvectors basis set on the initial fixed domain. 相似文献
376.
377.
Machine learning and pattern recognition techniques are being increasingly employed in functional magnetic resonance imaging (fMRI) data analysis. By taking into account the full spatial pattern of brain activity measured simultaneously at many locations, these methods allow detecting subtle, non-strictly localized effects that may remain invisible to the conventional analysis with univariate statistical methods. In typical fMRI applications, pattern recognition algorithms "learn" a functional relationship between brain response patterns and a perceptual, cognitive or behavioral state of a subject expressed in terms of a label, which may assume discrete (classification) or continuous (regression) values. This learned functional relationship is then used to predict the unseen labels from a new data set ("brain reading"). In this article, we describe the mathematical foundations of machine learning applications in fMRI. We focus on two methods, support vector machines and relevance vector machines, which are respectively suited for the classification and regression of fMRI patterns. Furthermore, by means of several examples and applications, we illustrate and discuss the methodological challenges of using machine learning algorithms in the context of fMRI data analysis. 相似文献
378.
D. Valerini A. P. Caricato M. Lomascolo F. Romano A. Taurino T. Tunno M. Martino 《Applied Physics A: Materials Science & Processing》2008,93(3):729-733
We report the use of PLD to grow different ZnO nanostructures. Very different film morphologies have been observed using different
laser wavelengths to ablate the target. The influence of substrate temperature and oxygen background pressure on the film
morphology has been investigated too. Smooth and rough films, hexagonal pyramids and columns have been obtained by using a
KrF excimer laser (248 nm) for the target ablation, while hexagonal hierarchical structures and pencils have been obtained
by using ArF (193 nm). Photoluminescence and X-ray diffraction measurements revealed the good quality of the samples, in particular
of those deposited using the ArF laser beam. 相似文献
379.
Razvigor Ossikovski Makrina Anastasiadou Antonello De Martino 《Optics Communications》2008,281(9):2406-2410
We show that the product decomposition of a depolarizing Mueller matrix (S.-Y. Lu, R.A. Chipman, J. Opt. Soc. Am. A 13 (1996) 1106) as well as the recently proposed reverse decomposition (R. Ossikovski, A. De Martino, Opt. Lett. 32 (2007) 689) need to be extended in order to account for Mueller matrices with negative determinants. The necessity of such an extension of the formalism is illustrated on experimentally determined Mueller matrices. The procedure of the modified decomposition formalism is explicitly described. 相似文献
380.
Alessandro Chiolerio Edvige Celasco Federica Celegato Salvatore Guastella Paola Martino Paolo Allia Paola Tiberto Fabrizio Pirri 《Journal of magnetism and magnetic materials》2008
A specific technique of numerical treatment of atomic force microscopy (AFM) and magnetic force microscopy (MFM) signal has been developed to enhance the quality of raw images, in order both to improve their contrast and to gain better insight on the sample topography and on the local arrangement of the magnetisation vector. Basically, the technique consists in computing the optimum conformal transformation that allows one to superimpose two AFM images of the same area, acquired performing subsequent scans whose fast scan axis were mutually perpendicular, and applying the inverse transform to the second image. After MFM image superposition, the two datasets were either summed or subtracted, in order to improve the magnetic contrast. Computations have been done in a Matlab® workspace with the help of Image Processing Toolbox 4.2. Improved MFM images obtained on both dots and antidots thin evaporated Co arrays in the demagnetised state (after performing alternate field demagnetisation parallel and perpendicular to the array plane) have been interpreted. Samples consisting of large-size patterns (1×1 mm) of circular dots/antidots with square/hexagonal lattices and minimum diameters of 1 μm were prepared by optical lithography. The magnetic film thickness was chosen depending on resist thickness, and varied between 25 and 150 nm, with a fixed ratio 1:4 between metal/resist film thickness. MFM was exploited to obtain images of either intra-dot or inter-antidot magnetic structures. 相似文献