Nucleated Nanoparticles Research Articles

Microstructure refinement and mechanical properties enhancement of Mg[sbnd]Al alloys via a novel of MgO nanoparticles modified graphene nanoplates refiner by in-situ synthesis

Grain refinement by inoculation treatment is one of the simplest and most efficient ways to improve the mechanical properties of MgAl alloys. In this study, a novel GNP@MgO grain refiner was designed by an in-situ reaction of CO2 gas and Mg melt. It can significantly reduce the average grain sizes of Mg9Al alloys from 126.9 μm to 12.7 μm. The mechanical properties of Mg9Al alloys were significantly enhanced, and its ultimate compressive strength was increased from 370 MPa to 436 MPa. HRTEM characterization and atomic interface analyses have shown that the Al4C3 phase has an orientation relationship with α-Mg as (009)Al4C3//(002)Mg, and [11−20]Al4C3//[11–20]Mg, which has a low degree of lattice mismatch of 5.79%. Besides, these MgO nanoparticles can adsorb on the surface of α-Mg grains and play a role in hindering growth and solute diffusion. The ultra-high grain refinement efficiency of 90% is achieved through the synergistic effects of GNP promoting heterogeneous nucleation and MgO nanoparticles inhibiting grain growth. This work sheds new light on designing innovative and effective grain refiners for Mg alloys.

Customizing nanoparticle characteristics in Ba-rich nanoparticle-doped optical fibers to tune Rayleigh scattering

Rayleigh scattering enhanced nanoparticle-doped silica-based optical fibers have recently emerged for distributed sensing applications. To date, Ca-, Sr- and Mg-based nanoparticles have been demonstrated to be very promising for it. In this work, we add in situ growth Ba-rich nanoparticles to alkaline earth-based compositions suitable to fabricate tunable Rayleigh scattering enhanced nanoparticle-doped optical fibers. Preform fabrication conditions allow largely customizing the features of the nucleated nanoparticles in the preform core. Fiber drawing process further impact on their size and composition due to a possible reaction with the silica-based glass and allows large customization, which is translated into an optimized trade-off between Rayleigh scattering enhancement of 35.4–44.9 dB, regarding a SMF-28, and two-way optical losses, 1.2–6.9 dB/m. Sensing lengths from 6.5 to 28.7 m become possible. The possibility of easily tailoring Ba-rich nanoparticle characteristics strengthen the potential of in situ grown alkaline earth nanoparticles for future distributed optical fiber sensors.

Experimental Evaluation of Pilot and Main Injection Strategies on Gasoline Compression Ignition Engine—Part 2: Performance and Emissions Characteristics

<div>Internal combustion (IC) engines play an important role in the global economy by powering various transport applications. However, it is a leading cause of urban air pollution; therefore, new combustion strategies are being developed to control emissions. One promising advanced low-temperature combustion (LTC) technology is gasoline compression ignition (GCI). This experimental study assesses the performance of a two-cylinder engine, emissions, and exhaust particulate characteristics using G80 (80% v/v gasoline and 20% v/v diesel) blend operating in GCI mode vis-à-vis baseline conventional diesel combustion (CDC) mode using diesel. The effects of double pilot injection, Pilot-1 proportion (10–30%), and main injection timing were investigated on the GCI combustion. Experiments were performed at different engine loads (3, 4, and 5 bar brake mean effective pressure [BMEP]) at a constant engine speed (2000 rpm). GCI combustion showed higher brake thermal efficiency (BTE) than CDC mode at medium loads. Hydrocarbon (HC) and carbon monoxide (CO) emissions increased in GCI mode, but oxides of nitrogen (NOx) were reduced than the baseline CDC mode. High pilot ratio and late main injection timing tests showed higher HC and CO emissions in the GCI mode at low engine loads. The GCI mode engine emitted higher nucleation mode particles and nanoparticles than baseline CDC mode at high engine loads. Using a triple injection strategy, GCI engines simultaneously reduced NOx and particulate matter (PM) emissions, especially at high loads. Controlling these emissions in baseline CDC mode engines is otherwise quite challenging.</div>

Catalytically proficient ceria nanodots supported on redox-active mesoporous hosts for treatment of inflammatory bowel disease via efficient ROS scavenging.

Ceria nanozyme-based ROS scavengers have shown great potential in the treatment of inflammatory bowel disease (IBD) through microenvironment regulation. However, the currently developed nanotherapeutics suffer from difficulties in concomitantly achieving small sizes and stable interparticle dispersion which is pivotal to sufficient oxygen vacancies facilitating electron transfer and oxygen storage in the dynamic cycling of Ce3+/Ce4+ redox pairs. Herein, a hybrid nanosystem consisting of ceria nanodots supported on redox-active mesoporous hosts was developed to address the challenge of ROS scavenging, in particular the efficient downregulation of the readily renewable, highly concentrated H2O2 species. Specifically, Ce4+ ions oxidized from Ce3+ in weakly basic solution were captured and reduced in time by the abundant catechols on the mesoporous polydopamine nanoparticles. This led to strong restriction of ceria growth (∼2.8 nm) in the ion precipitation process and efficient maintenance of the Ce3+/Ce4+ ratio at a high value of 1.59 which is 4.8 fold higher than that of homogeneously nucleated ceria nanoparticles. Through this design, the nanohybrid showed an attractive catalytic performance in scavenging multiple ROS species, particularly the fast and recyclable conversion of H2O2. Thereby, significant suppression of the inflammatory cytokine/chemokine secretion was achieved by inhibiting the activation of NF-κB signaling pathways (5.1 fold higher as compared to those of pristine ceria nanoparticles), upregulating the Nrf2 signaling pathway, and reducing the proportion of M1 macrophages at IBD sites. Therapeutic efficiency was also demonstrated by the effective repair of the intestinal mucosal barrier by recovering the tight junction integrity in vivo. This study sheds light on the employment of redox-active hosts to support ceria catalysts for advancing anti-inflammation applications by boosting ROS scavenging performance.

CTAB-mediated lithium disilicate branched structures as superb adsorbents to remove Mn2+ in water

Removal of heavy metal Mn2+ ions in water is of great importance for human health and it is urgently needed to develop efficient adsorption materials. Here, a green and effective strategy to prepare mesoporous micro/nanostructured lithium disilicates (LDs) by employing the cation surfactant hexadecyltrimethyl-ammonium bromide (CTAB) as morphology control agent in hydrothermal environment, and investigated its adsorption behavior toward Mn2+ ions. The LDs possessed branched structures that were consisted of scattering pyramidal rods bestrewn with secondary nucleated and aggregated nanoparticles. Due to the mesoporous structures and negatively charged surfaces, LDs exhibited a high adsorption capacity up to 346.84mgg−1 with corresponding removal efficiency up to 99.82% when initial Mn2+ concentration was 82mgL−1, and their maximum adsorption capacity reached up to 785.25mgg−1 toward Mn2+ of 250mgL−1. Results indicated that the isotherm adsorption behavior of LDs was well described by mono-layer Langmuir model and kinetic adsorption fitted well with pseudo-second-order model, implying them the excellent chemical adsorbent to remove Mn2+ from wastewater. We believe this CTAB-modified approach could be extended to prepare other lithium silicates with mesoporous structures, rendering them wider applications in environmental protection.

Heterostructured Functional Materials through Molten Salt Synthesis for Solid Oxide Fuel Cells and Electrolysis Cells

La0.6Sr0.4Co0.2Fe0.8O3 (LSCF)−La0.8Sr0.2MnO3 (LSM) heterostructure crystalline materials have been synthesized in a simple, one-step via reaction-deposition process using a molten salt. Two-phase perovskite composites can be synthesized in times as short as 10 minutes in a molten salt solvent. X-ray diffraction and S/TEM energy dispersive X-ray spectroscopy have been utilized to confirm the formation of an LSM shell on LSCF cores in all samples when adjusting dwell time, core size, weight ratio between core and shell precursors, and weight ratio of powder to salt. Specifically, decreasing the LSCF core size increases core−shell yield. Smaller cores result in a greater density of facets on the crystal surface and provide more favorable sites for LSM heterogeneous nucleation. By decreasing the weight ratio of shell precursor to core decreases shell thickness, and reduces the number of homogeneously nucleated LSM nanoparticles, and thereby increases core−shell yield. Increasing the amount of molten salt solvent relative to precursors decreases supersaturation in the melt and results in less uniform, and isolated shell deposition on the cores. The synthesized heterostructred nanoparticles have been functionalized into electrodes for solid oxide fuel cells and electrolysis cells. Symmetrical cells fabricated from baseline LSCF electrodes are compared with symmetrical cells fabricated from the molten salt-synthesized heterostructred electrodes. The heterostructured electrodes are shown to have significantly lower polarization resistance compared to baseline LSCF electrodes, showing the promise of the molten salt process to achieve heterostructured electrodes with substantially reduced polarization resistance.

Nucleation and growth of iron pebbles explains the formation of iron-rich planets akin to Mercury

The pathway to forming the iron-rich planet Mercury remains mysterious. Its core makes up 70% of the planetary mass, which implies a significant enrichment of iron relative to silicates, while its mantle is strongly depleted in oxidised iron. The high core mass fraction is traditionally ascribed to evaporative loss of silicates, for example following a giant impact, but the high abundance of moderately volatile elements in the mantle of Mercury is inconsistent with reaching temperatures significantly above 1000 K during its formation. Here we explore the nucleation of solid particles from a gas of solar composition that cools down in the hot inner regions of the protoplanetary disc. The high surface tension of iron causes iron particles to nucleate homogeneously (i.e. not on a more refractory substrate) under very high supersaturation. The low nucleation rates lead to depositional growth of large iron pebbles on a sparse population of nucleated iron nanoparticles. Silicates in the form of iron-free MgSiO3 nucleate at similar temperatures but obtain smaller sizes because of the much higher number of nucleated particles. This results in a chemical separation of large iron particles from silicate particles with ten times lower Stokes numbers. We propose that such conditions lead to the formation of iron-rich planetesimals by the streaming instability. In this view, Mercury formed by accretion of iron-rich planetesimals with a subsolar abundance of highly reduced silicate material. Our results imply that the iron-rich planets known to orbit the Sun and other stars are not required to have experienced mantle-stripping impacts. Instead, their formation could be a direct consequence of temperature fluctuations in protoplanetary discs and chemical separation of distinct crystal species through the ensuing nucleation process.

Molten Salt Synthesis of Core-Shell Heterostructure Cathode Materials for Solid Oxide Fuel Cells

Core-shell La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) – La0.8Sr0.2MnO3 (LSM) heterostructure crystalline materials have been synthesized in a simple, one-step feeding method via a KNO3 molten salt solvent. Two-phase perovskite composites can be synthesized in times as short as 10 minutes, and is demonstrated for the first time in a molten salt. A combination of X-ray diffraction and S/TEM energy dispersive X-ray spectroscopy has been utilized to confirm the formation of an LSM shell on LSCF cores in all samples when adjusting dwell time, core size, weight ratio between core and shell precursors, and weight ratio of powder to salt. Specifically, decreasing the LSCF core size increases core-shell yield. Smaller cores introduce a greater density of facets on the crystal surface, and provide more favorable sites for LSM heterogeneous nucleation. Decreasing the weight ratio of shell precursor to core decreases shell thickness, reduces the number of homogeneously nucleated LSM nanoparticles, and increases core-shell yield. Increasing the amount of salt relative to powder decreases supersaturation in the melt and results in less uniform, isolated shell deposition on the cores. Overall, the molten salt synthesis of core-shell perovskite oxides is investigated and demonstrated as an expeditious method to synthesize core-shell composites for energy applications. Considering the parameters of molten salt synthesized LSCF-LSM, optimized core-shell cathodes are then fabricated and used as electrodes in symmetric cells as a preliminary insight into their efficacy for solid oxide fuel cells.

Sono-chemical synthesis of Fe3O4 nanostructures and its application in acrylonitrile-butadiene-styrene polymeric nanocomposite

Sono-chemical is a fast procedure for preparing monodisperse nanoparticles. Magnetite nanoparticles were prepared via a sono-chemical reaction at a room temperature. Fe3O4 nanostructures were then added to acrylonitrile-butadiene-styrene (ABS) copolymer. Nanocomposites are very attractive due to the fact that small amount of nanostructure can lead to great improvement in many properties, such as mechanical and thermal property. Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The XRD pattern of nanoparticles is indexed as a cubic phase (space group: Fd-3m). Fe3O4 nanostructures exhibit a super paramagnetic behaviour with a saturation magnetization of 54 emu/g and a coercivity of 11 Oe at room temperature. The effect of ultrasonic power on the shape and particle size was investigated and the result showed at 150W by increasing power growth stage overcome to nucleation stage and nanoparticles with bigger diameters were obtained. The flame retardancy behavior of ABS-Fe3O4 was studied by UL-94 analysis.

Stabilization of Size-Controlled BaTiO3 Nanocubes via Precise Solvothermal Crystal Growth and Their Anomalous Surface Compositional Reconstruction.

Crystal growth of barium titanate (BaTiO3) using a wet chemical reaction was investigated at various temperatures. BaTiO3 nanoparticles were obtained at an energy-efficient temperature of 80 °C. However, BaTiO3 nanocubes with a preferred size and shape could be synthesized using a solvothermal method at 200 °C via a reaction involving titanium tetraisopropoxide [(CH3)2CHO]4Ti for nucleation and fine titanium oxide (TiO2) nanoparticles for crystal growth. The BaTiO3 nanocubes showed a high degree of dispersion without the use of dispersants or surfactants. The morphology of BaTiO3 was found to depend on the reaction medium. The size of the BaTiO3 particles obtained using water as the reaction medium was the largest among the particles synthesized using various reaction media. In the case of alcohol reaction media, the BaTiO3 particle size increased in the order methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol. Furthermore, BaTiO3 powder obtained using alcohol reaction media resulted in cubic shapes as opposed to the round shapes obtained when water was used as the medium. We found that the optimal condition for the synthesis of BaTiO3 nanocubes involved the use of 1-butanol as the reaction medium, resulting in an average particle size of 52 nm, which is the average distance of the cubes measured diagonally from corner to corner, and gives an average side length of 37 nm, and a tetragonal crystal system as evidenced by the powder X-ray diffraction pattern obtained using high-energy synchrotron X-rays. The origin of the spontaneous polarization of the BaTiO3 tetragonal crystal structure was clarified by a pair distribution function analysis. In addition, surface reconstruction of BaTiO3 nanocubes led to an outermost surface comprising two layers of Ti columns.

Counting Nanoplastics in Environmental Waters by Single Particle Inductively Coupled Plasma Mass Spectroscopy after Cloud-Point Extraction and In Situ Labeling of Gold Nanoparticles.

The globally raising concern for nanoplastics (NPs) pollution calls for analytical methods for investigating their occurrence, fates, and effects. Counting NPs with sizes down to 50 nm in real environmental waters remains a great challenge. Herein, we developed a full method from sample pretreatment to quantitative detection for NPs in environmental waters. Various NPs of common plastic types and sizes (50-1200 nm) were successfully labeled by in situ growth of gold nanoparticles and counted by single particle inductively coupled plasma mass spectrometry. Sucrose density gradient centrifugation enables the isolation of gold-labeled NPs from homogeneously nucleated Au nanoparticles, enhancing the particle number detection limit to 4.6 × 108 NPs/L for 269 nm spherical polystyrene NPs. For real environmental water samples, the pretreatment of acid digestion with a mixture of 5 mM HNO3 and 40 mM HF eliminates the coexisting inorganic nanoparticles, while the following dual cloud-point extraction efficiently isolates NPs from various matrices and thus improves the Au-labeling efficiency. The high spiked recoveries (72.9%-92.8%) of NPs in different waters demonstrated the applicability of this method in different scenarios.

Time of Flight Size Control of Carbon Nanoparticles Using Ar+CH4 Multi-Hollow Discharge Plasma Chemical Vapor Deposition Method

As the application of nanotechnology increases continuously, the need for controlled size nanoparticles also increases. Therefore, in this work, we discussed the growth mechanism of carbon nanoparticles generated in Ar+CH4 multi-hollow discharge plasmas. Using the plasmas, we succeeded in continuous generation of hydrogenated amorphous carbon nanoparticles with controlled size (25–220 nm) by the gas flow. Among the nanoparticle growth processes in plasmas, we confirmed the deposition of carbon-related radicals was the dominant process for the method. The size of nanoparticles was proportional to the gas residence time in holes of the discharge electrode. The radical deposition developed the nucleated nanoparticles during their transport in discharges, and the time of flight in discharges controlled the size of nanoparticles.

Production of TiO2 coated α-Al2O3 platelets by flame spray pyrolysis and their characterization

In this study, the applicability of the flame spray pyrolysis (FSP) method in the production of α-Al2O3 based TiO2 coatings was investigated. Plate-like α-Al2O3 particles, with a particle size of 8–30 μm, were dispersed in a solution of titanium tetraisopropoxide-xylene, a low solids suspension was prepared, and then a TiO2 coating was obtained on α-Al2O3 platelets by feeding the precursor suspension into a pre-mixed methane/oxygen flame in a FSP reactor. Obtained coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) methods. While the presence of heterogeneous nucleated TiO2 coating on α-Al2O3 platelet surfaces was revealed by the characterization process performed, it was also observed that homogeneously nucleated TiO2 nanoparticles were obtained during the process.

Detection of Chemical Compositions of Ultrafine Nanoparticles by a Vacuum Ultraviolet Photoionization Nucleation Aerosol Mass Spectrometer

Abstract A vacuum ultraviolet photoionization nucleation aerosol mass spectrometer (VUVPI-AMS) was developed for detection of chemical compositions of ultrafine nanoparticles with size of less than 100 nm. A commercial nano-scanning mobility particle sizer (Nano-SMPS) was employed for size-selection of ultrafine nanoparticles, as well as the size distribution was measured. A special aerodynamic lens was designed to transfer and focus the ultrafine nanoparticles into the vacuum. On arriving on the hot surface of the heater, the ultrafine nanoparticles were vaporized and changed into gas-phase molecules, which were then softly photoionized at their ionization energy thresholds by the VUV photons emitted from a commercial 10.6 eV krypton discharge lamp. A home-made orthogonal acceleration reflectron time-of-flight mass analyzer was adopted to measure the mass of ions. As representative examples, the dioctyl phthalate (DOP) ultrafine nanoparticles and the nucleation nanoparticles from the ozonolysis reaction of α-pinene were measured and their chemical compositions were obtained with molecular information.

Facile Synthesis of Calcium Hydroxide Nanoparticles onto TEMPO-Oxidized Cellulose Nanofibers for Heritage Conservation.

Calcium hydroxide is used in diverse applications including heritage conservation where supplying it in the form of nanoparticles allows easy carbonation with atmospheric air contacts. The effects of cellulose nanofibers on the precipitation of calcium hydroxide nanoparticles were investigated by varying the reaction time, concentration, and carboxylation content of cellulose nanofibers. Cellulose nanofibers were very effective in producing calcium hydroxide nanoparticles with less than 50 nm sizes out of calcium nitrate–sodium hydroxide precipitation reactions. The formation of smaller-size calcium hydroxide nanoparticles is believed to be the result of heterogeneous nucleation and growth of calcium hydroxide particles on cellulose nanofibers. The liquid-phase nucleated and grown calcium hydroxide nanoparticles were also deposited onto cellulose nanofibers. The resulting calcium hydroxide nanoparticles were carbonized and generated calcite under atmospheric carbon dioxide in an efficient way.

New Particle Formation in the Atmosphere: From Molecular Clusters to Global Climate

AbstractNew particle formation (NPF) represents the first step in the complex processes leading to formation of cloud condensation nuclei. Newly formed nanoparticles affect human health, air quality, weather, and climate. This review provides a brief history, synthesizes recent significant progresses, and outlines the challenges and future directions for research relevant to NPF. New developments include the emergence of state‐of‐the‐art instruments that measure prenucleation clusters and newly nucleated nanoparticles down to about 1 nm; systematic laboratory studies of multicomponent nucleation systems, including collaborative experiments conducted in the Cosmics Leaving Outdoor Droplets chamber at CERN; observations of NPF in different types of forests, extremely polluted urban locations, coastal sites, polar regions, and high‐elevation sites; and improved nucleation theories and parameterizations to account for NPF in atmospheric models. The challenges include the lack of understanding of the fundamental chemical mechanisms responsible for aerosol nucleation and growth under diverse environments, the effects of SO2 and NOx on NPF, and the contribution of anthropogenic organic compounds to NPF. It is also critical to develop instruments that can detect chemical composition of particles from 3 to 20 nm and improve parameterizations to represent NPF over a wide range of atmospheric conditions of chemical precursor, temperature, and humidity.

Revealing the nucleation mechanism of diamond film deposited on steel by high resolution transmission electron microscopy

Diamond nucleation on iron and iron alloy substrates is comparatively investigated by high resolution transmission electron microscopy (HRTEM). A unique interfacial microstructure is observed between diamond film and iron substrate. Besides a graphite interlayer formed on the substrate surface, many unique clusters are observed to distribute randomly in the transitional zone from the graphite interlayer to the continuous diamond film. These clusters present a complex structure containing polycrystalline diamond, amorphous carbon, iron carbide particles and graphite, which are all closely associated with the nucleation sites for the diamond phase. The findings reveal that diamond is unlikely to directly nucleate and grow on a pure graphite interlayer. Meanwhile, diamond nucleation nanoparticles are observed at the surfacial grooves through the study of the very early stage of diamond nucleated on iron alloy substrate. These diamond nuclei are elongated about 10–15 nm (about 5 nm in width) and surrounded by the amorphous carbon, suggesting the mechanism that the diamond nucleates spontaneously from the amorphous carbon.

Role of stabilizers on agglomeration of debris during micro-electrical discharge machining

Micro-electrical discharge machining (µ-EDM) as an advanced mechanical micro-machining method has been widely used in the generation of micro-features by removing debris through melting and evaporation phenomena, and during this time some amount of debris is dispersed in the dielectric medium. These debris are treated as unwanted materials and later will be disposed of from the system. But, after critical evaluation of the debris through transmission electron microscope (TEM), it is found that the debris are agglomerated and in the size range of 40–600 nm (mean size: 242 nm). This makes curious to search for any alternatives to overcome the agglomeration to result into ultrafine particles in the range of nanometres. In the present article, an attempt has been made to incorporate ultrasonication during machining process and also resorted to use stabilizers. As per chemistry aspect of metallic aluminium particles, Poly Ethylene Glycol (PEG), Bael Gum (BG) and ACacia Gum (ACG) stabilizers are used along with deionized (DI) water and studied their effect individually on the interaction between the nucleated nanoparticles. The characterization results reveal that using PEG, BG and ACG, the debris of aluminium generated are in the size range of 45–500 nm (mean size: 196 nm), 25–70 nm (mean size: 45 nm) and 3–30 nm (mean size: 10 nm), respectively. ACG stabilizer was found to be strongly reduce the agglomeration resulting in excellent stable dispersion of the colloidal aluminium nanoparticles. The nature of colloidal samples was studied by ultraviolet–visible (UV–vis) spectroscopy after 2 weeks of their generation. Furthermore, thermal conductivity and viscosity properties are ascertained, and the heat transfer effect has also been studied experimentally using a developed thermal management system. The obtained results are presented in the article.

Effect of alkali ions (Na+, K+, Cs+) on reaction mechanism of CZTS nano-particles synthesis

The control of morphology, elemental composition and phase composition of Cu2ZnSnS4 (CZTS) nano-crystals depends on the control of complex formation and surface stabilization of nano-particles in solution-based synthesis in oleylamine. At temperatures ≥280 °C, the control of nano-crystal's morphology and homogenous growth is difficult because of fast poly-nuclear growth occurring at higher temperatures. In the present work the effect of oleylamine complex formation with different alkali ions (Na+, K+ and Cs+) on nano-crystals growth at synthesis temperature of 280 °C was studied. It was found that nano-powders synthesized in the presence of Na+ and K+ ions showed the formation of crystals of different sizes - small nano-particles (18 nm-30 nm), large aggregated crystals (few nm to 1 μm) and large single crystals (1 μm - 4 μm). The presence of Cs+ ions in the nano-powder synthesis in oleylamine-metal precursor-CsOH solution promoted growth of nano-crystals of homogenous size. It is proposed that the formed oleylamine-Cs complexes a) enhance the formation and stabilization of oleylamine–metal (Cu, Zn and Sn) complexes before the injection of sulphur precursor into the oleylamine–metal precursor solution and b) after addition of sulphur stabilize the fast nucleated nano-particles and promote diffusion limited growth.

КОСМІЧНІ ПРОМЕНІ Й АЕРОЗОЛІ В ЗЕМНІЙ АТМОСФЕРІ

КОСМІЧНІ ПРОМЕНІ Й АЕРОЗОЛІ В ЗЕМНІЙ АТМОСФЕРІ