scholarly journals Online chemical adsorption studies of Hg, Tl, and Pb on SiO2 and Au surfaces in preparation for chemical investigations on Cn, Nh, and Fl at TASCA

2018 ◽  
Vol 106 (12) ◽  
pp. 949-962 ◽  
Author(s):  
Lotte Lens ◽  
Alexander Yakushev ◽  
Christoph Emanuel Düllmann ◽  
Masato Asai ◽  
Jochen Ballof ◽  
...  
Keyword(s):  
Experimental Data ◽  
Chemical Properties ◽  
Relativistic Effects ◽  
Chemical Yield ◽  
Single Atom ◽  
Chemical Adsorption ◽  
Detector Arrays ◽  
Adsorption Studies ◽  
Heaviest Elements ◽  
Fusion Evaporation Reactions

Abstract Online gas-solid adsorption studies with single-atom quantities of Hg, Tl, and Pb, the lighter homologs of the superheavy elements (SHE) copernicium (Cn, Z=112), nihonium (Nh, Z=113), and flerovium (Fl, Z=114), were carried out using short-lived radioisotopes. The interaction with Au and SiO2 surfaces was studied and the overall chemical yield was determined. Suitable radioisotopes were produced in fusion-evaporation reactions, isolated in the gas-filled recoil separator TASCA, and flushed rapidly to an adjacent setup of two gas chromatography detector arrays covered with SiO2 (first array) and Au (second array). While Tl and Pb adsorbed on the SiO2 surface, Hg interacts only weakly and reached the Au-covered array. Our results contribute to elucidating the influence of relativistic effects on chemical properties of the heaviest elements by providing experimental data on these lighter homologs.

Relativity in the electronic structure of the heaviest elements and its influence on periodicities in properties

2019 ◽  
Vol 107 (9-11) ◽  
pp. 833-863 ◽  
Author(s):  
Valeria Pershina
Keyword(s):  
Periodic Table ◽  
Chemical Properties ◽  
Relativistic Effects ◽  
Experimental Investigations ◽  
Close Link ◽  
Chemical Studies ◽  
Heaviest Elements ◽  
Chemical Groups ◽  
Physical And Chemical ◽  
And Chemical Properties

AbstractTheoretical chemical studies demonstrated crucial importance of relativistic effects in the physics and chemistry of superheavy elements (SHEs). Performed, with many of them, in a close link to the experimental research, those investigations have shown that relativistic effects determine periodicities in physical and chemical properties of the elements in the chemical groups and rows of the Periodic Table beyond the 6thone. They could, however, also lead to some deviations from the established trends, so that the predictive power of the Periodic Table in this area may be lost. Results of those studies are overviewed here, with comparison to the recent experimental investigations.

scholarly journals Efficient discrimination of transplutonium actinides by in vivo models

2021 ◽  
Author(s):  
Roger M. Pallares ◽  
Dahlia D. An ◽  
Gauthier J.-P. Deblonde ◽  
Birgitta Kullgren ◽  
Stacey S. Gauny ◽  
...  
Keyword(s):  
Chemical Properties ◽  
In Vivo Models ◽  
Heaviest Elements

Transplutonium actinides are among the heaviest elements whose macroscale chemical properties can be experimentally tested.

scholarly journals Gas chemical properties of heaviest elements

2011 ◽  
Vol 99 (7-8) ◽  
pp. 503-513 ◽  
Author(s):  
H. W. Gäggeler
Keyword(s):  
Chemical Properties ◽  
Heaviest Elements

scholarly journals Modeling the Ternary Chalcogenide Na2MoSe4 from First-Principles

2020 ◽  
Author(s):  
Etienne Palos ◽  
Armando Reyes-Serrato ◽  
Gabriel Alonso-Nuñez ◽  
J. Guerrero Sánchez
Keyword(s):  
Transition Metal ◽  
First Principles ◽  
Inorganic Compounds ◽  
Chemical Properties ◽  
Relativistic Effects ◽  
Equilibrium Structure ◽  
Inorganic Materials ◽  
Metal Chalcogenides ◽  
Energy Storage Devices ◽  
Transition Metal Chalcogenides

In the ongoing pursuit of inorganic compounds suitable for solid-state devices, transition metal chalcogenides have received heightened attention due to their physical and chemical properties. Recently, alkali-ion transition metal chalcogenides have been explored as promising candidates to be applied in optoelectronics, photovoltaics and energy storage devices. In this work, we present a comprehensive theoretical study of sodium molybdenum selenide (Na<sub>2</sub>MoSe<sub>4</sub>). First-principles computations were performed on a set of hypothetical crystal structures to determine the ground state and electronic properties of Na<sub>2</sub>MoSe<sub>4</sub>. We find that the equilibrium structure of Na<sub>2</sub>MoSe<sub>4</sub> is a simple orthorhombic (<i>oP</i>) lattice, with space group Pnma, as evidenced by thermodynamics. Electronic structure computations reveal that three phases are semiconducting, while one (<i>cF</i>) is metallic. Relativistic effects and Coulomb interaction of localized electrons were assessed for the <i>oP</i> phase, and found to have a negligible influence on the band strucutre. Finally, meta-GGA computations were performed to model the band structure of primitive orthorhombic Na<sub>2</sub>MoSe<sub>4</sub> at a predictive level. We employ the Tran-Blaha modified Becke-Johnson potential to demonstrate that <i>oP</i> Na2MoSe4 is a semiconductor with a direct bandgap of 0.53 eV at the <b>Γ</b> point. Our results provide a foundation for future studies concerned with the modeling of inorganic and hybrid organic-inorganic materials chemically analogous to Na<sub>2</sub>MoSe<sub>4</sub>.<br>

scholarly journals Composition and light absorption of nitroaromatic compounds in organic aerosols from laboratory biomass burning

2018 ◽  
Author(s):  
Mingjie Xie ◽  
Xi Chen ◽  
Michael D. Hays ◽  
Amara L. Holder
Keyword(s):  
Experimental Data ◽  
Biomass Burning ◽  
Organic Aerosols ◽  
Chemical Properties ◽  
Nitroaromatic Compounds ◽  
Forest Understory ◽  
Prescribed Fires ◽  
Organic Mass ◽  
Total Contribution ◽  
Mass Spectral

Abstract. This study seeks to understand the compositional details of nitroaromatic compounds (NACs) emitted during biomass burning (BB) and their contribution to light-absorbing organic carbon (OC), also termed brown carbon (BrC). Three laboratory BB experiments were conducted with two U.S. pine forest understory fuels typical of those consumed during prescribed fires. During the experiments, submicron aerosol particles were collected on filter media and subsequently extracted with methanol and examined for their optical and chemical properties. Significant correlations (p < 0.05) were observed between BrC absorption and elemental carbon (EC)/OC ratios for test specific data. However, the pooled experimental data indicated that the BB BrC absorption depends on more than the BB fire conditions as represented by the EC/OC ratio. Fourteen NACs were identified in the BB samples, four of which (C10H11NO4, C10H11NO5, C11H13NO5 and C11H13NO6) have not been observed previously in chamber-based secondary organic aerosols, and are expected to have methoxyphenol-type structure specific to the pyrolized biomass lignin based on mass spectral evidence, suggesting these compounds may be unique to BB aerosols. The average total contribution of NACs to organic mass (0.023 ± 0.0089 to 0.18 ± 0.067 %) was 5–10 times lower than the average contribution to the overall BrC absorption at 365 nm (0.12 ± 0.047 to 2.44 ± 0.67 %). The average contributions (%) of total NACs to organic mass and aqueous extracts absorption correlated significantly (p < 0.05) with EC/OC for both test specific and pooled experimental data. These results suggested that the formation of NACs from BB depended more on burn conditions than the bulk absorptive properties of BB BrC.

scholarly journals Experimental Study on the Energy-Release Characteristics of Fine-Grained Fe/Al Energetic Jets under Impact Loading

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3317
Author(s):  
Li ◽  
Du
Keyword(s):  
Experimental Data ◽  
Energy Release ◽  
Impact Energy ◽  
Impact Loading ◽  
Energetic Materials ◽  
Chemical Properties ◽  
Microscopic Analysis ◽  
Specific Content ◽  
Fine Grained ◽  
The Impact

The energy released by the active metal phase in fine-grained Fe/Al energetic materials enables the replacement of conventional materials in new types of weapons. This paper describes an experiment designed to study the energy-release characteristics of fine-grained Fe/Al energetic jets under impact loading. By means of dynamic mechanical properties analysis, the physical and chemical properties of Fe/Al energetic materials with specific content are studied, and the preparation process is determined. The energy-release properties of fine-grained Fe/Al jets subject to different impact conditions are studied based on experimental data, and energy-release differences are discussed. The results show that for fine-grained Fe/Al energetic materials to remain active and exhibit high strength, the highest sintering temperature is 550 °C. With increasing impact energy, the energy release of fine-grained Fe/Al energetic jets increases. At an impact-energy threshold of 121.1 J/mm2, the chemical reaction of the fine-grained Fe/Al energetic jets is saturated. The experimental data and microscopic analysis show that when the impact energy reaches the threshold, the energy efficiency ratio of Fe/Al energetic jets can reach 95.3%.

Colloid-Chemical Bases on Creation of Multifunctional Modifiers of Concrete Mix and Concrete

2017 ◽  
Vol 265 ◽  
pp. 331-336 ◽  
Author(s):  
M.M. Kosukhin ◽  
N.A. Shapovalov ◽  
A.M. Kosukhin
Keyword(s):  
Experimental Data ◽  
Cement Hydration ◽  
Chemical Properties ◽  
Quality Requirements ◽  
Fungicidal Effect ◽  
Leading Role ◽  
Concrete Mix ◽  
The Given ◽  
Concrete Hardening ◽  
And Chemical Properties

The colloid and chemical bases on creation of highly effective multifunctional modifiers were developed on the basis of the experimental data in the field of chemical modifying of concrete compounds and concrete. The article shows that the leading role in concrete chemicalixation now belongs to the components of the given class, because application of these components supplies the concrete compound and the concrete with a complex of specified properties for operation in different conditions. The article notes that this tendency is true while monolithic concreting, as it is most widely applied when carrying out maintenance operations and it places higher quality requirements upon the concrete compounds and the concrete. The study syntesizes a highly efficient multifunctional modifier for monolithic concretes. This modifier posesses a fungicidal effect and contains a plasticizing component, an accelerator of cement hydration processes, concrete hardening. The article also studies the colloid and chemical properties of the obtained modifier and the properties of the concrete compounds and the concrete with its application.

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