Galactose, glucose, xylose and corresponding itol derivatives with the general formula Su—ZR in which Z is an amido group either NHCO (type I) or NR'CO (type II) were synthetized and their mesophasic behaviour studied. It was shown that the thermotropic and lyotropic phase transition temperatures are influenced by the following structural parameters: alkyl or perfluoroalkyl chain length, Z junction, free OH group number, cyclic or acyclic Su structure.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
This Note proposes a new methodology for function classification with Support Vector Machine (SVM). Rather than relying on projection on a truncated Hilbert basis as in our previous work, we use an implicit spline interpolation that allows us to compute SVM on the derivatives of the studied functions. To that end, we propose a kernel defined directly on the discretizations of the observed functions. We show that this method is universally consistent. To cite this article: N. Villa, F. Rossi, C. R. Acad. Sci. Paris, Ser. I 343 (2006).相似文献
In this paper we develop a heuristic algorithm, based on Scatter Search, for project scheduling problems under partially renewable
resources. This new type of resource can be viewed as a generalization of renewable and non-renewable resources, and is very
helpful in modelling conditions that do no fit into classical models, but which appear in real timetabling and labor scheduling
problems. The Scatter Search algorithm is tested on existing test instances and obtains the best results known so far. 相似文献
The synthesis, crystal and electronic structures, and one‐ and two‐photon absorption properties of two quadrupolar fluorenyl‐substituted tetraphenyl carbo‐benzenes are described. These all‐hydrocarbon chromophores, differing in the nature of the linkers between the fluorenyl substituents and the carbo‐benzene core (C?C bonds for 3 a , C?C?C?C expanders for 3 b ), exhibit quasi–superimposable one‐photon absorption (1PA) spectra but different two‐photon absorption (2PA) cross‐sections σ2PA. Z‐scan measurements (under NIR femtosecond excitation) indeed showed that the C?C expansion results in an approximately twofold increase in the σ2PA value, from 336 to 656 GM (1 GM=10?50 cm4 s molecule?1 photon?1) at λ=800 nm. The first excited states of Au and Ag symmetry accounting for 1PA and 2PA, respectively, were calculated at the TDDFT level of theory and used for sum‐over‐state estimations of σ2PA(λi), in which λi=2 hc/Ei, h is Planck’s constant, c is the speed of light, and Ei is the energy of the 2PA‐allowed transition. The calculated σ2PA values of 227 GM at 687 nm for 3 a and 349 GM at 708 nm for 3 b are in agreement with the Z‐scan results. 相似文献
An adhesive yet easily removable burn wound dressing represents a breakthrough in second‐degree burn wound care. Current second‐degree burn wound dressings absorb wound exudate, reduce bacterial infections, and maintain a moist environment for healing, but are surgically or mechanically debrided from the wound, causing additional trauma to the newly formed tissues. We have developed an on‐demand dissolvable dendritic thioester hydrogel burn dressing for second‐degree burn care. The hydrogel is composed of a lysine‐based dendron and a PEG‐based crosslinker, which are synthesized in high yields. The hydrogel burn dressing covers the wound and acts as a barrier to bacterial infection in an in vivo second‐degree burn wound model. A unique feature of the hydrogel is its capability to be dissolved on‐demand, via a thiol–thioester exchange reaction, allowing for a facile burn dressing removal. 相似文献
This work aims at deriving analytical solutions for the molecular architecture of multi‐block polymer synthesized in a dual‐catalyst single CSTR. While the relevant equations are developed for homopolymerization, they can easily be extended to copolymerization. Special emphasis is placed on the quantities associated with each catalyst rather than the overall ones. However, if all rate parameters are available, the expressions can be used to calculate the properties of the material made by each catalyst as well as the overall ones under various process conditions. Given the reasonable assumption of large residence time, the solutions are simplified to elucidate the kinetics of chain‐shuttling involving two catalysts. It is shown that systems with low chain‐shuttling ability, if DPPn,0 ≠ DPQn,0, may exhibit significant deviation from Flory's most probable distribution. Furthermore, systems with high chain‐shuttling ability produce macromolecules with more uniform architecture and polydispersity index close to 2.
We present a new method for detecting a lowdimensional deterministic character of very short discrete time series. The algorithm depends on two parameters, that can be selected according to a simple criterion. Experiments show that the method is sensitive to noise levels as low as 2%. In addition, our technique allows us to estimate the value of the largest Lyapunov exponent.Sommario: In questo articolo si presenta un nuovo metodo per stabilire il carattere deterministico di serie tempodiscrete molto corte. L'algoritmo dipende da due parametri che possono essere selezionati secondo un semplice criterio. Gli esperimenti mostrano che il metodo è sensibile a livelli di rumore del 2%. Inoltre, tale tecnica consente di stimare il valore del massimo esponente di Lyapunov. 相似文献