Laser-Induced Light Absorption in 2D Silver Nanoparticle Array

Nanocomposite comprising planar array of silver nanoparticles in polymer matrix was submitted to Ar laser irradiation at the wavelength of 488 nm. The extinction spectra of the array were measured as a function of the irradiation power density. Two collective surface plasmon modes, namely T and P, associated with particle dipoles parallel and perpendicular to the plane of the layer were identified. The extinction bands of T and P modes exhibit blue spectral shift with the increase of radiation power. P mode band broadens when laser power increases. The observed effects are explained by heating of the nanocomposite by the intense laser radiation

Optical Properties of Multilayered Metal–Dielectric Structures Containing Silver Nanoparticles

In this paper we report on fabrication and optical properties of metal-dielectric nanostructures consisting of stacked monolayers of silver nanoparticles. The extinction spectra of the nanostructures were studied as a function of the angle of incidence and polarization state of the incident light. Two collective surface plasmon modes, namely T and P, associated with particle dipoles parallel and perpendicular to plane of the layer were identified for a single monolayer of the particles. The extinction bands of T and P modes exhibit different intensity and frequency dependences on the angle of incidence. More pronounced angular dependences for P mode band indicate the stronger coupling of dipoles for P mode than for Tone. A new N mode was observed for the structures comprising three nanoparticle layers. This new mode originated from surface plasmon coupling between adjacent layers

Optical Properties of Multilayered Metal–Dielectric Structures Containing Silver Nanoparticles

In this paper we report on fabrication and optical properties of metal-dielectric nanostructures consisting of stacked monolayers of silver nanoparticles. The extinction spectra of the nanostructures were studied as a function of the angle of incidence and polarization state of the incident light. Two collective surface plasmon modes, namely T and P, associated with particle dipoles parallel and perpendicular to plane of the layer were identified for a single monolayer of the particles. The extinction bands of T and P modes exhibit different intensity and frequency dependences on the angle of incidence. More pronounced angular dependences for P mode band indicate the stronger coupling of dipoles for P mode than for Tone. A new N mode was observed for the structures comprising three nanoparticle layers. This new mode originated from surface plasmon coupling between adjacent layers

Analysis of lower limb internal kinetics and electromyography in elite race walking.

The aim of this study was to analyse lower limb joint moments, powers and electromyography patterns in elite race walking. Twenty international male and female race walkers performed at their competitive pace in a laboratory setting. The collection of ground reaction forces (1000 Hz) was synchronised with two-dimensional high-speed videography (100 Hz) and electromyography of seven lower limb muscles (1000 Hz). As well as measuring key performance variables such as speed and stride length, normalised joint moments and powers were calculated. The rule in race walking which requires the knee to be extended from initial contact to midstance effectively made the knee redundant during stance with regard to energy generation. Instead, the leg functioned as a rigid lever which affected the role of the hip and ankle joints. The main contributors to energy generation were the hip extensors during late swing and early stance, and the ankle plantarflexors during late stance. The restricted functioning of the knee during stance meant that the importance of the swing leg in contributing to forward momentum was increased. The knee flexors underwent a phase of great energy absorption during the swing phase and this could increase the risk of injury to the hamstring muscles

Properties Of The Long-Term Ordered Semiconductors

The 45 years monitoring of optical and mechanical properties of different semiconductor crystals grown in the 1960 th shows that the stimuli for long-term improvement of crystal quality prevail over those which lead to its degradation. Evolution of optical and mechanical properties testifies that now in diamond-like gallium phosphide (GaP) doped by nitrogen (N), the impurity is a regular element of the new crystal lattice - it increases the forbidden gap, and at relevant concentration and level of optical excitation creates a bound excitonic crystal. The ternary compound CdIn 2S 4, now having the perfect normal (instead of partly inversed) spinel crystal lattice, as well as GaP with evenly distributed impurities demonstrate new stable and bright luminescent phenomena, including stimulated emission and hot luminescence at room temperature. All chosen semiconductor crystals from different groups of semiconductor compounds demonstrate the long-term ordering and improvement of useful for application properties. Existing technologies help us to reproduce artificially these naturally ordered structures for application in optoelectronics

Structural Characterization Of Long-Term Ordered Semiconductors

We apply investigation of the luminescence, Raman light scattering and mechanical (microhardness, movement of dislocations) properties to the structural characterization of the same representative group of semiconductors as freshly prepared and ordered over 40 years term. Such combination explains new phenomena in luminescence through the data obtained from the other two methods. Systematic monitoring proves that in mono-atomic (Si), binary (GaP, InP) and ternary (Cd-In-S) semiconductors long-term processes lead to the host atoms being placed in their proper equilibrium positions and to a more uniform redistribution of the impurities or structural defects. The results imply that periodic ordering of impurities improved the overall optical and mechanical properties of the material over time. We demonstrate that highly ordered nature of this new crystal lattice facilitates stimulated emission, increases the radiative recombination efficiency of electron-hole pairs and spectral range of luminescence equally at low and at room temperatures

Some practical aspects of the production of high quality tool steel with high carbon and chromium content

Translated from Russian (Probl. Spetsial'noi Elektrometallurgii 1998 (3) p. 62-66)SIGLEAvailable from British Library Document Supply Centre-DSC:9023.190(VR-Trans--8737)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo