Adaptive Probabilistic Flooding for Multipath Routing

In this work, we develop a distributed source routing algorithm for topology discovery suitable for ISP transport networks, that is however inspired by opportunistic algorithms used in ad hoc wireless networks. We propose a plug-and-play control plane, able to find multiple paths toward the same destination, and introduce a novel algorithm, called adaptive probabilistic flooding, to achieve this goal. By keeping a small amount of state in routers taking part in the discovery process, our technique significantly limits the amount of control messages exchanged with flooding -- and, at the same time, it only minimally affects the quality of the discovered multiple path with respect to the optimal solution. Simple analytical bounds, confirmed by results gathered with extensive simulation on four realistic topologies, show our approach to be of high practical interest.Comment: 6 pages, 6 figure

Novel D–A chromophores with condensed 1,2,4-triazine system simultaneously display thermally activated delayed fluorescence and crystallization-induced phosphorescence

Control of photophysical properties is crucial for the continued development of electroluminescent devices and luminescent materials. Preparation and study of original molecules uncovers design rules towards efficient materials and devices. Here we have prepared 7 new compounds based on the popular donor–acceptor design used in thermally activated delayed fluorescence emitters. We introduce for the first time benzofuro[3,2-e]-1,2,4-triazine and benzothieno[3,2-e]-1,2,4-triazine acceptors which were connected to several common donors: phenoxazine, phenothiazine, carbazole and 3,6-di-tert-butylcarbazole. DFT calculations, and steady-state and time-resolved photophysical studies were conducted in solution and in solid states. While derivatives with azine moieties are non-emissive in any form, the compounds comprising 3,6-di-tert-butylcarbazole display TADF in all cases. More interestingly, the two derivatives substituted with a carbazole donor are TADF active when dispersed in a polymer matrix and phosphorescent at room temperature in neat films (microcrystalline form)

Excited State Intramolecular Proton Transfer Based Fluorophores with Circularly Polarized Luminescence Emission

International audienceAbstract Herein, the first molecular design allowing the combination of circularly polarized luminescence (CPL) and excited state intramolecular proton transfer (ESIPT) fluorescence is described. In this novel class of emitters, the chiroptical activity originates from a chiral excitonic coupling induced by the tethering of two ESIPT fluorophores via a readily accessible trans ‐1,2‐diaminocyclohexane scaffold. This approach has notably allowed the synthesis in a single step of a CPL‐active molecule displaying a very large Stokes shift (up to 12 087 cm −1 in toluene solution) and the synthesis in three steps of one of the rare examples of CPL‐active purely organic dual‐emission materials

Cross‐Dehydrogenative Homocoupling of 2‐Aryl‐N‐heterocycles and Application to the Synthesis of Phenylpyridine Borane Dimers

Abstract A method for the synthesis of 2‐aryl‐N‐heterocyclic dimers via a cross‐dehydrogenative homocoupling (homo‐CDC) has been developed using commercially available Ruthenium on charcoal as catalyst and iron trichloride as oxidant. A large variety of heterocyclic scaffolds and functional groups are tolerated and a complete regioselectivity resulting from the activation of the less sterically hindered C−H bonds was observed for meta ‐substituted substrates. Starting from several homocoupling products obtained, a series of pyridine‐borane complexes was synthesized and the impact of the dimerization on their photophysical properties was studied and rationalized using theoretical calculations

Silafluorene as a promising core for cell-permeant, highly bright and two-photon excitable fluorescent probes for live-cell imaging

International audienceIn this study, we report the synthesis, linear and non-linear photophysical studies and live cell imaging of two two-photon activatable probes based on a silafluorene core: SiFluo-V and SiFluo-L. Thanks to their quadrupolar (A-π-D-π-A) design, these probes exhibit respectively good to impressive two-photon cross sections (from 210 GM to 2150 GM). TD-DFT calculations support the experimental evidence that SiFluo-L displays far better two-photon absorption properties than SiFluo-V. Moreover, SiFluo-L possesses all requirements for bioimaging as it is water soluble, cell-permeant and and presents a low cytotoxicity (IC80≥10 µM). It labels mitochondria in live-cell imaging at low laser power with high brightness, contrast and photostability. This study demonstrates that silafluorene is a promising core to develop new two-photon fluorophores for live cell imaging

High-temperature behavior of dicesium molybdate Cs2MoO4: Implications for fast neutron reactors

International audienceDicesium molybdate (Cs 2 MoO 4)'s thermal expansion and crystal structure have been investigated herein by high temperature X ray diffraction in conjunction with Raman spectroscopy. This first crystal-chemical insight at high temperature is aimed at predicting the thermostructural and thermomechanical behavior of this oxide formed by the accumulation of Cs and Mo fission products at the periphery of nuclear fuel rods in sodium-cooled fast reactors. Within the temperature range of the fuel's rim, Cs 2 MoO 4 becomes hexagonal P6 3 /mmc, with disordered MoO 4 tetrahedra and 2D distribution of Cs-O bonds that makes thermal axial expansion both large (50 rα l r 70 10 À 6 1C À 1 , 500-800 1C) and highly anisotropic (α c À α a ¼ 67 Â 10 À 6 1C À 1 , hexagonal form). The difference with the fuel's expansion coefficient is of potential concern with respect to the cohesion of the Cs 2 MoO 4 surface film and the possible release of cesium radionuclides in accidental situations

FIB Aplasia through Probabilistic Routing and Autoforwarding

In this work, we propose Aplasia, an holistic architecture with a radical design. Aiming at simplifying the inner network devices (and so their cost), we tradeoff node architecture- and algorithmic-complexity for an increased (but tunable) communication cost. The main ingredients of our recipe are (i) the use of complete paths directly in the frames header, that allows core devices to perform data-plane switching functions without lookup and (ii) the use of a greedy probabilistic routing algorithm to quickly discover multiple, near optimal, paths in the control plane. We extensively simulate, analyze and implement our proposal to testify its soundness

Site-Selective Arylation of Naphthalenes: a Key Entry towards Extended Fluorenones and Phenanthridinones

International audienceThe development of an oriented arylation process dedicated to the naphthalene core is presented. Our approach is based on dual role of N-tosyl carboxamides acting jointly as a directing group in a first C-H arylation step and as a "CO" or "CO-NH" fragment precursor in a further construction step of naphthalene-based fluorenone or phenanthridinone derivatives. The presence of the directing group in position 1 and 2 of the naphthalene platform allowed selective arylations in position 2 and 3 respectively. Our study represents a first synthetic and general entry of C-H arylation at naphthalene platforms towards the preparation of extended fluorenones as well as benzo-fused phenanthridinones. Further, the C-H arylation and cyclisation sequence represents a useful way to the preparation of novel extended tetra-and pentacyclic fluorenones bearing both electron donating as well as electron withdrawing groups in various substitution patterns. Additionally, both the regioselectivity and the reaction paths of the cyclization leading to the fluorenone architectures was studied by DFT calculations which fully complement experimental observations

Rational design of visible and NIR distyryl-BODIPY dyes from a novel fluorinated platform.

International audienceA new series of distyryl-BODIPY has been rationally designed and synthesised from a novel fluorinated platform, 8-pentafluorophenylBODIPY, which has enhanced reactivity in the presence of both electron rich, and for the first time, electron deficient aldehydes. The pentafluorobenzene leads to larger red shifts of absorption and emission compared to previously reported analogues. The reactivity and spectroscopic results have been rationalised with quantum mechanics calculation. The fluorescence sensitivity of one derivative to acidity is also presented