Thermal Effects in Up-Conversion Luminescence NaYF: Tm, Yb Core-Shell Nanoparticles in the Temperature Range of 18-312 K.

This work demonstrates the temperature (18-312 K) impact on Tm up-conversion luminescence in core-shell structured NaYF:Tm, Yb nanoparticles excited at 976 nm. As the temperature decreases from room temperature to 18 K, Tm up-conversion luminescence bands intensities greatly increase, an average of 60-fold, emitting intense blue and ultraviolet radiation. Tm up-conversion luminescence spectra measurements at different temperatures reveal that three thermal quenching mechanisms are responsible for observed variations in Tm up-conversion luminescence spectra.

High-order harmonics generation in Cd and Pd laser-induced plasmas.

We demonstrate the generation of high-order harmonics of laser pulses in palladium and cadmium plasmas. We adjusted the wavelength of driving pulses to investigate the resonance enhancement in different ranges of extreme ultraviolet region. The summation of incommensurate waves during the two-color pump of Pd and Cd plasmas allowed the generation of a broader range of harmonics.

Fast-Response Single-Nanowire Photodetector Based on ZnO/WS Core/Shell Heterostructures.

The surface plays an exceptionally important role in nanoscale materials, exerting a strong influence on their properties. Consequently, even a very thin coating can greatly improve the optoelectronic properties of nanostructures by modifying the light absorption and spatial distribution of charge carriers. To use these advantages, 1D/1D heterostructures of ZnO/WS core/shell nanowires with a-few-layers-thick WS shell were fabricated.

Low-friction nanojoint prototype.

High surface energy of individual nanostructures leads to high adhesion and static friction that can completely hinder the operation of nanoscale systems with movable parts. For instance, silver or gold nanowires cannot be moved on silicon substrate without plastic deformation. In this paper, we experimentally demonstrate an operational prototype of a low-friction nanojoint.

Some aspects of formation and tribological properties of silver nanodumbbells.

Unlabelled: In this paper, metal nanodumbbells (NDs) formed by laser-induced melting of Ag nanowires (NWs) on an oxidized silicon substrate and their tribological properties are investigated. The mechanism of ND formation is proposed and illustrated with finite element method simulations. Tribological measurements consist in controllable real-time manipulation of NDs inside a scanning electron microscope (SEM) with simultaneous force registration.

Manipulation of nanoparticles of different shapes inside a scanning electron microscope.

In this work polyhedron-like gold and sphere-like silver nanoparticles (NPs) were manipulated on an oxidized Si substrate to study the dependence of the static friction and the contact area on the particle geometry. Measurements were performed inside a scanning electron microscope (SEM) that was equipped with a high-precision XYZ-nanomanipulator. To register the occurring forces a quartz tuning fork (QTF) with a glued sharp probe was used.

Toluidine blue test for sperm DNA integrity and elaboration of image cytometry algorithm.

Background: Sperm DNA integrity is of paramount importance in the prognosis of fertility. We applied image cytometry to a toluidine blue (TB) test we recently proposed.

Methods: Sperm samples from 33 men were assayed for standard sperm parameters and classified as normal or abnormal.