Formation of chiral CO polyhedral crystals on icy interstellar grains

The crystallinity and morphology of solid CO on icy interstellar grains were examined by observing the deposition, crystallisation, and UV and electrons irradiation of solid CO using transmission electron microscopy. Herein, we found that solid CO deposited in molecular clouds was crystalline, and that even if amorphous CO was deposited amorphous CO crystallised within 103 years at 10 K. Conversely, crystalline CO was not amorphised by UV rays or electron beam at 10 K. These results indicated the occurrence of chiral crystalline CO instead of amorphous CO in space. Furthermore, the large surface diffusion coefficients of CO on amorphous H2O and crystalline CO at 10 K facilitated the morphological equilibration of crystalline CO. Bad wetting of crystalline CO with amorphous H2O proved that the morphology of the ice grains was not spherical with an onion-like structure, as hitherto assumed, but rather it was a polyhedral crystalline CO attached to amorphous H2O. This has important implications for phenomena associated with the collision and subsequent sticking between ice grains, surface chemical reactions, non-thermal desorption of molecules and the origin of homochirality in interstellar biomolecules.

Real-time imaging of surface chemical reactions by electrochemical photothermal reflectance microscopy

The potential-dependent photothermal signal, which is sensitive to the free electron density, map the evolution of surface species on the electrode in real time.

Surface chemical reactions on self-assembled silane based monolayers

Developments in the chemical surface reactions performed on hydroxyl-terminated substrates are reviewed. This comprehensive overview illustrates the importance of the highly dynamic field of surface functionalization utilizing self-assembled monolayers.

ILLUMINATION EFFECT ON RECOGNITION ABILITY OF MULTISENSOR MICROSYSTEMS BASED ON TIN OXIDE NANOWHISKERS

С помощью стандартных методов классификации данных показана возможность распознавания газовых смесей с помощью мультисенсорной микросистемы с газочувствительным слоем на основе нитевидных нанокристаллов. Проведенный статистический анализ экспериментальных результатов показал, что освещение светодиодом в ультрафиолетовом диапазоне газочувствительного слоя диоксида олова значительно увеличивает медианное расстояние Евклида-Махаланобиса между классами (распознавательная способность) различных газовых проб по сравнению с результатами измерений в темноте. Высказана гипотеза о том, что повышение распознавательной способности мультисенсорной микросистемы связано с селективным влиянием освещения на поверхностные химические реакции активных форм кислорода и частицами анализируемых газов. Using standard methods of data classification, the possibility of recognizing gas mixtures using a multisensor microsystem with a gas-sensitive layer based on whisker nanocrystals is shown. The statistical analysis of the experimental results showed that the illumination of a gas-sensitive layer of tin dioxide with a LED in the ultraviolet range significant increases the median Euclidean-Mahalanobis distance between the classes (recognition ability) of various gas samples compared to the results of measurements in the dark. Suggested that the increase in the recognition ability of a multisensor microsystem is associated with the selective effect of illumination on surface chemical reactions of oxygen species and particles of analyzed gases.