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81.
82.
D. Boettle M. Burzio P. Cinato G. Eilenberger J. -B. Jacob T. Martinson F. Masetti A. Mcguire M. Sotom P. Vogel J. Benoit 《Fiber and Integrated Optics》1996,15(4):267-279
The expected traffic growth from new broadband services will require network capacities that can be beneficially provided by optical WDM transport networks. Optical packet techniques are essential for large networks to provide flexibility and granularity. A layered network architecture with a transparent optical layer and optical packet layers has been elaborated. Four switching concept options for large optical ATM switch fabrics in the public network and small access nodes are presented. The technology for the related key functions of space and wavelength switching was developed in the RACE ATMOS project and the feasibility of concepts and technologies was verified in four system demonstrators. 相似文献
83.
84.
Hanane Belghit Cyril Colas Sébastien Bristeau Benoit Maunit 《International journal of environmental analytical chemistry》2015,95(2):93-105
Chlordecone (CLD) is a persistent toxic chlorinated pesticide which contaminates different ecosystems in French West Indies. A soil remediation process including zero-valent iron (ZVI) has produced promising results but failed to completely degrade CLD, and the analytical procedures used yielded little information on the transformation products. To fill these gaps, dechlorination of aqueous CLD by micrometric particles of ZVI has been investigated. Aliquots of water with 25% (v/v) of acetone spiked with 100 ppm CLD were taken at different times during a 30-day ZVI treatment and directly analysed by ultra-high-performance liquid chromatography in negative electrospray ionisation mode. CLD has been totally transformed after 14 days into 14 dechlorinated degradation products, including 9 isomeric compounds. The maximum chloride concentrations appearing in the medium represent 44% of that which would result from total dechlorination of CLD. The CLD transformation products identified by accurate mass measurements on an ultra-high-resolution Q-TOF mass spectrometer (Q-TOF-MS) were C10H3Cl9O2, C10H4Cl8O2, C10H5Cl7O2, C10H6Cl6O2 and C10H7Cl5O2. The results show the interest of LC-Q-TOF-MS for identifying transformation products of organic contaminants, and the effectiveness of micrometric ZVI particles to totally transform CLD into less chlorinated products. 相似文献
85.
86.
Maxit B Giermanska J Ly I Bendejacq D Mondain-Monval O Ponsinet V 《Langmuir : the ACS journal of surfaces and colloids》2011,27(5):1990-1995
We report on the structures exhibited by two different diblock poly(styrene)-b-poly(acrylic acid) (PS-b-PAA) copolymers in water, a selective solvent. Using a combination of X-ray scattering and freeze fracture-transmission electron microscopy (FF-TEM), we show that these structures can be widely swollen while retaining their initial morphology and a high degree of long-range order. The analysis of the FF-TEM pictures also evidences the presence of water crystallites of regular size and shape within the confined water domains. We relate the growth of these crystallites to the high local ionic strength of the water swelling the PAA brushes. Moreover, the confinement of the crystallites growth shows that the swollen phases have a very robust structure, potentially useful for confining colloidal particles. 相似文献
87.
Modular natural products are biosynthesized by series of enzymes that activate, assemble, and process a nascent chain of building blocks. Adenylation domains are gatekeepers in nonribosomal peptide biosynthesis, providing the entry point for assembly of typical peptide-based natural products. We report the directed evolution of an adenylation domain based on a strategy of using a weak, promiscuous activity as a springboard for reprogramming the biosynthetic assembly line. Randomization of residues invoked in a "specificity-conferring code" and selection for a non-native substrate lead to mutant G2.1, favoring smaller amino acids with a specificity change of 10(5): a 170-fold improvement for L-alanine corresponds to a 10(3)-fold decrease for its original substrate (L-phenylalanine). These results establish directed evolution as a method to change gatekeeper domain specificity and suggest that adaptation of modules in combinatorial biosynthesis is achievable with few mutations during evolution. 相似文献
88.
Benoit Enaux Victor Granet Olivier Vermorel Corine Lacour Ludovic Thobois Vincent Dugué Thierry Poinsot 《Flow, Turbulence and Combustion》2011,86(2):153-177
This paper describes a compressible Large Eddy Simulation (LES) used to investigate cyclic variations for nonreacting flow
in an optical single cylinder engine setup. The simulated operating point is part of a large experimental database designed
to validate LES for cycle-to-cycle prediction, and constitutes a first step towards the realization of fired operating points.
The computational domain covers almost the whole experimental setup (intake and exhaust plenums, intake and exhaust ducts,
cylinder) to account for acoustic phenomena. The assessment of the computation is performed in two regions of the domain:
the intake and exhaust duct predictions are compared to the results of a Helmholtz solver and the experiment (pressure transducers
and Particle Image Velocimetry (PIV)) while the in-cylinder dynamics are compared to PIV measurements. The ability of the
developed methodology to capture the correct level of cycle-to-cycle variations is demonstrated considering in-cylinder pressure
and velocity fields predictions. Cycle-to-cycle variations in velocity are highlighted and localized using a proper orthogonal
decomposition analysis. 相似文献
89.
Ohne Zusammenfassung 相似文献
90.
Benoit Bachand Mohamed Atfani Bita Samim Sophie Lévesque Daniel Simard Xianqi Kong 《Tetrahedron letters》2007,48(49):8587-8589
A practical synthetic route to various 2-alkylpropane-1,3-sultones, the key intermediates for the preparation of 2-substituted homotaurines as analogs of tramiprosate, was developed. 相似文献