Plasmonic nanosponges filled with silicon for enhanced white light emission.

Plasmonic nanosponges are a powerful platform for various nanophotonic applications owing to extremely high local field enhancement in metallic nanopores. The filling of the nanopores with high-refractive index semiconductors (e.g. Si, Ge, GaP, etc.) opens up opportunities for the enhancement of nonlinear effects in these materials. However, this task remains challenging due to the lack of knowledge on the integration process of metal and high-index semiconductor components in such nanoobjects. Here, we investigate metal-dielectric nanoparticles fabricated from bilayer Si/Au films by the laser printing technique via a combination of theoretical and experimental methods. We reveal that these hybrid nanoparticles represent the Au sponge-like nanostructure filled with Si nanocrystallites. We also demonstrate that the Au net provides strong near-field enhancement in the Si grains increasing the white light photoluminescence in the hybrid nanostructures compared to uniform Si nanoparticles. These results pave the way for engineering the internal structure of the sponge-like hybrid nanoparticles possessing white light luminescence and control of their optical properties on demand.

Room temperature self-assembled growth of vertically aligned columnar copper oxide nanocomposite thin films on unmatched substrates.

In this work, we report the self-assembled growth of vertically aligned columnar Cu2O + Cu4O3 nanocomposite thin films on glass and silicon substrates by reactive sputtering at room temperature. Microstructure analyses show that each phase in nanocomposite films has the columnar growth along the whole thickness, while each column exhibits the single phase characteristics. The local epitaxial growth behavior of Cu2O is thought to be responsible for such an unusual microstructure. The intermediate oxygen flow rate between those required to synthesize single phase Cu2O and Cu4O3 films produces some Cu2O nuclei, and then the local epitaxial growth provides a strong driving force to promote Cu2O nuclei to grow sequentially, giving rise to Cu2O columns along the whole thickness. Lower resistivity has been observed in such kind of nanocomposite thin films than that in single phase thin films, which may be due to the interface coupling between Cu2O and Cu4O3 columns.

[Behaviour of asbestos fibres in the respiratory system as revealed by animal experiments (author's transl)]. / Etude expérimentale du devenir des fibres d'amiante dans l'appareil respiratoire.

By comparing the evolution of chrysotile and amosite fibres in rat lungs, more rapid clearance was found in the case of chrysotile. The rate of chrysotile clearance is strongly influenced by the size factor. The two varieties of asbestos also differ in their chemical behaviour in the lung. The evolution of chrysotile fibers in vivo is characterized by progressive decrease in magnesium content, while silicium retained in the fibre skeleton is practically not eliminated. Transport of fibers from the lungs to the lymph-nodes, the parietal pleura and the diaphragm also differs with the two asbestos varieties. From fibre counts with the electron microscope, chrysotile was more rapidly eliminated from the lungs than amosite. The concentration is higher with amosite in the lymph-nodes, and with chrysotile in the diaphragm. This last result confirms observations made on human lungs.

[Variation in the toxicity of various silicas in relation to the duration of presence in the body]. / Variation de la nocivité de certaines silices en relation avec leur temps de séjour dans l'organisme.

The toxic effect of two forms of sand on the lung was investigated by tracheal injection in Rats. After a latent period with low toxicity, more and more extensive pulmonary lesions, comparable to typical silicotic lesions, appear progressively. On the basis of some observations, the hypothesis is put forward that the impurities present in the dust have a retardative effect.