109 research outputs found
Excitation transfer and luminescence in porphyrin-carbon nanotube complexes
Functionalization of carbon nanotubes with hydrosoluble porphyrins (TPPS) is
achieved by "-stacking". The porphyrin/nanotube interaction is studied by
means of optical absorption, photoluminescence and photoluminescence excitation
spectroscopies. The main absorption line of the porphyrins adsorbed on
nanotubes exhibits a 120 meV red shift, which we ascribe to a flattening of the
molecule in order to optimize interactions. The porphyrin-nanotube
complex shows a strong quenching of the TPPS emission while the
photoluminescence intensity of the nanotubes is enhanced when the excitation
laser is in resonance with the porphyrin absorption band. This reveals an
efficient excitation transfer from the TPPS to the carbon nanotube
Pi-stacking functionalization through micelles swelling: Application to the synthesis of single wall carbon nanotube/porphyrin complexes for energy transfer
We report on a new, orginal and efficient method for "pi-stacking"
functionalization of single wall carbon nanotubes. This method is applied to
the synthesis of a high-yield light-harvesting system combining single wall
carbon nanotubes and porphyrin molecules. We developed a micelle swelling
technique that leads to controlled and stable complexes presenting an efficient
energy transfer. We demonstrate the key role of the organic solvent in the
functionalization mechanism. By swelling the micelles, the solvent helps the
non water soluble porphyrins to reach the micelle core and allows a strong
enhancement of the interaction between porphyrins and nanotubes. This technique
opens new avenues for the functionalization of carbon nanostructures.Comment: 6 pages, 5 figure
Optical Investigation of Broadband White-Light Emission in Self-Assembled OrganicâInorganic Perovskite (C 6
24-h variation in soil respiration after a long dry season in a Sudano-Sahelian region
Carbone des sols en Afrique
Les sols sont une ressource essentielle Ă prĂ©server pour la production dâaliments, de fibres, de biomasse, pour la filtration de lâeau, la prĂ©servation de la biodiversitĂ© et le stockage du carbone. En tant que rĂ©servoirs de carbone, les sols sont par ailleurs appelĂ©s Ă jouer un rĂŽle primordial dans la lutte contre lâaugmentation de la concentration de gaz Ă effet de serre. Ils sont ainsi au centre des objectifs de dĂ©veloppement durable (ODD) des Nations unies, notamment les ODD 2 « Faim zĂ©ro », 13 « Lutte contre le changement climatique », 15 « Vie terrestre », 12 « Consommation et production responsables » ou encore 1 « Pas de pauvretĂ© ». Cet ouvrage prĂ©sente un Ă©tat des lieux des sols africains dans toute leur diversitĂ©, mais au-delĂ , il documente les capacitĂ©s de stockage de carbone selon les types de sols et leurs usages en Afrique. Il propose Ă©galement des recommandations autour de lâacquisition et de lâinterprĂ©tation des donnĂ©es, ainsi que des options pour prĂ©server, voire augmenter les stocks de carbone dans les sols. Tous les chercheurs et acteurs du dĂ©veloppement impliquĂ©s dans les recherches sur le rĂŽle du carbone des sols sont concernĂ©s par cette synthĂšse collective. Fruit dâune collaboration entre chercheurs africains et europĂ©ens, ce livre insiste sur la nĂ©cessitĂ© de prendre en compte la grande variĂ©tĂ© des contextes agricoles et forestiers africains pour amĂ©liorer nos connaissances sur les capacitĂ©s de stockage de carbone des sols et lutter contre le changement climatique
State of the art: radiolabeled microspheres treatment for liver malignancies.
Metastatic tumours of the liver are responsible for significant morbidity and mortality, and only a small percentage is resectable with curative intent. Hepatic artery radioembolization (RE) with yttrium-90 ((90)Y)-loaded microspheres is an alternative treatment for patients with unresectable primary or secondary liver tumours, especially in cases of metastatic colorectal cancer (mCRC) and hepatocellular carcinoma (HCC).Journal ArticleReviewSCOPUS: re.jinfo:eu-repo/semantics/publishe
Experimental approaches to studies of soil fauna activity in a hierarchised selection of ecosystems
Behaviours promoting grouping or dispersal of mother and neonates in ovoviviparous cockroaches
WOS:000181930400008International audienceThe nature of early relationships between mother and nymphs and among siblings was compared in four cockroach species belonging to the same ovoviviparous family (Zetoborinae) in order to characterise the behavioural interactions favouring dispersal or maintenance of the group of neonates. Behavioural interactions between mothers and their new-born nymphs and between two sibling neonates were video recorded and analysed with flow charts on factorial maps. In the solitary species Thanatophyllum akinetum, nymphs dispersed a few hours after birth without aggressiveness between siblings or between mother and offspring. In contrast females of Schultesia lampyridiformis displayed a behaviour never previously observed in cockroaches: aggression towards their own neonate nymphs, which could contribute to their dispersal. In Phortioeca nimbata and Lanxoblatta emarginata, nymphs stayed with their mother fo
Transfer dynamics from an interface type-II heavy-hole exciton to a type-I light-hole exciton in a ZnSe/(Zn, Mn) Se heterostructure
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