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The physical mechanisms of metallic nanoparticles formation by laser technology were studied. The system air/Au film/glass was irradiated by laser at the conditions of surface plasmon resonance. A surface electromagnetic wave was excited in Kretchmann configuration by the fundamental and second harmonics of the Q-switched YAG/Nd laser with pulse power density close to the threshold of melting. Nanostructuring of Au film was observed only for the second harmonic ( λ = 0.532 μm) irradiation at the surface plasmon polariton resonance (SPR) conditions. Estimations were done using the interference model of the differently directed plasmon polariton waves excited by a surface electromagnetic wave on the metal surface. It was shown that a regular pattern of locally heated spots can be formed in a metallic film by pulsed laser irradiation. The spatial distribution of this pattern is close to the period of interference. The observed effect of laser nanofragmentation is explained by the self-organization of plasmon polariton subsystem in the process of Au nanoparticles formation at high laser intensity levels. These methods open new possibilities for nanostructured surfaces formation utilizing simple self-organization processes. [ABSTRACT FROM AUTHOR]

We show that creation of a p–n junction in p-Si and p-InSb involve so-called donor laser centres (LCs). Analysis of our experimental data and other authors on p–n junction formation in p-InSb and p-Si using of laser radiation (LR) allowed us to conclude that a thermogradient effect plays the main role in this process. The following methods have been used in experiments: four-probe method and magnetoconcentration effect (MCE) (I–V characteristics in an external perpendicular magnetic field). A temperature gradient was created by YAG:Nd laser in the Q-modulation regime. Experiments on p-Si have shown that the LCs are n-type and they are created in materials doped with B and O only. Three types of LC were found: one type is stable at room temperature and two types are unstable. The effect of LC accumulation and saturation takes place in Si. The calculated distribution of O atoms in temperature gradient field and experiment are in qualitative agreement. Experiments on p-InSb have been carried out at 200 and 290 K. Generation of stable and unstable LC at room temperature was shown. Threshold intensities of LC generation are 1.5 MW/cm2 at 200 C and 2 MW/cm2 at 290 C. We conclude that generation of LC occurs in solid state. [Copyright &y& Elsevier]

Aquaculture's role in addressing food security has grown, with a spotlight on Asian carp species. Polyculture, i.e. cultivating multiple fish species in a single system, is being increasingly adopted for its resource efficiency and economic benefits. This practice for Asian fish for food and ornamental purposes is gaining traction in Europe despite their invasive potential. Rising temperatures due to climate change offer an opportunity for thermophilic Asian carps (Hypophthalmichthys molitrix and Aristichthys nobilis). Using GIS modeling (Maxent), we identified the possible settlement of Asian carp in Northern Europe amidst climate change. We analyzed carp global distribution centers, assessed the potential carp spread in Europe, and evaluated their potential suitability for polyculture systems. By 2050, H. molitrix may extend its range to 58–62° N latitude, with a potential 1.7-fold habitat increase, while A. nobilis, which are more heat-tolerant, may move north to 52–58° N latitude, with a 1.3-fold potential increase. Despite the slight ecological differences in their native habitats, niche modeling indicates that these carp can occupy similar niches in Europe (proven statistically). The eventuality of using Asian species for polyculture in Europe presents both opportunities and challenges in the face of a changing climate as long as invasion risks are prevented. Envisaging such polyculture, yet very carefully for the protection of ecosystems, can help food security. [ABSTRACT FROM AUTHOR]

Abstract: Simple, easy to use and selective method of Al(III) sorption–spectroscopic (SS) determination was proposed. For this purpose, silica modified with tridecyloctadecylammonium chloride(SGII) using adsorption technique and glass slide modified with thin silica–poly(dimethyldiallyl-ammonium chloride) (SGI) composite film obtained by sol–gel technique were worked out. It was shown that lumogallion (LG) easily absorbs on SGI and SGII. Obtained sorbents SGIII and SGIV, respectively, were used for aluminum(III) determination by diffuse reflectance and spectrophotometric methods. The ranges of determination were (mgL−1): (0.08–0.54), s r ≤0.13, n =4 for SGIII and (0.05–2.0), s r ≤0.11, n =4 for SGIV. The detection limits (blank+3σ) for aluminum were 70 and 30μgL−1 using SGIII and SGIV, respectively, where σ is the standard deviation of blank estimation. The accuracy of the developed spectrophotometric method was examined by the determination of standard addition of aluminum in alcohol-free beverages. The relative error did not exceed 9%. SGIII can be regenerated by 0.05M EDTANa2H2 solution and reused. SGIV was shown to be perspective for determination of aluminum in solution in the range of 0.01–0.13mgL−1 by solid phase luminescent technique. [Copyright &y& Elsevier]

A mechanism for formation of a potential barrier at the interface of p-CdTe(Cl)-SiO2 structure using the second harmonic of a Q-switched YAG:Nd laser radiation (LR) is proposed which involves thermogradient effect (TGE). According to the TGE in CdTe(Cl) the interstitial atoms of Cd (Cdi) move along a temperature gradient, towards increasing temperature, but Cd vacancies (VCd) and atoms—in the opposite direction, into the bulk of the semiconductor, where temperature is a minimum. Since, the Cl atoms and VCd are localized in the same place of the semiconductor and have opposite charges they are aggregate as A-centres. Result of investigation of the photoluminescence (PL) spectra at 5 K shows that the concentration of the A-centres is increased owing to aggregation of the VCd with Cl after laser irradiation. Investigation of the current–voltage characteristic in crossed magnetic field Bz=0.3 T showed that at the interface of CdTe(Cl)-SiO2 a potential barrier arises after irradiation by the YAG:Nd laser at intensity larger than the threshold intensity Ith=0.2 MW/cm2. Investigation of the morphology of an irradiated surface using the Atomic Force Microscope has shown that generation and redistribution of point defects in CdTe(Cl) is possible in solid state at room temperature. [Copyright &y& Elsevier]