Lower Oxidation States of <Emphasis Type="Italic">f</Emphasis> Elements: III. Properties of Low-Valence Lanthanide and Actinide Compounds in the Solid State and in Various Solvents

Properties of low-valence f-element compounds in the solid state and in protic, aprotic, and mixed solvents are discussed, including the solubility of low-valence f-element compounds, hydration of Ln²⁺ and An²⁺, and their complexation in aqueous and organic solutions with various anions (I^?, Br^?, Cl^?, ClO ₄ ^? , BF ₄ ^? , BPh ₄ ^? and polycyclic crown ethers.     

Synthesis of a MoSi2-Based Powder Material Under the Influence of Pressure and Shearing

Refractories and Industrial Ceramics - The SHS-grinding method was employed to prepare molybdenum disilicide powder material through the reduction of molybdenum oxide by aluminum and silicon. It is...     

Effect of carbon nanotubes on structure and properties of the antifriction coatings produced by plasma cladding

Abstract

Due to their high antifriction characteristics, the Sn-Sb-Cu alloys (referred to as babbits) are widely used to coat sliding bearings. However, some limitations of the present techniques for applying such coating materials cause a decrease in their fatigue strength because of the reinforcing phase particles growth. As a technique for restricting the increasing of the reinforcing particle sizes, this paper proposes plasma surface cladding with multiwall carbon nanotubes (MWNTs) as modifiers. The dry sliding friction tests performed according to the “pin-on-disk” scheme using as a counterface a steel 100Cr6 (DIN 17230) disk have shown that adding to the coating 0.25%wt of CNTs significantly improves the friction stability (the coefficient of friction process stability decreases twice with reducing the friction coefficient and wear resistance by 5% on the average). An attempt to reveal the mechanism for the MWNT influence on the structure and performance of the babbit-based coatings was undertaken. Studies of the coatings metal structure by soft X-ray absorption spectroscopy and also by the metallographic and fractographic analysis involving electron-microscopy have shown that MWNTs remain stable during plasma cladding process and save into the coating.     

Solid-Phase Transformations in Se/Cu Nanosized Film Structures Fabricated by the Vacuum Thermal Evaporation Method

Technical Physics Letters - Experimental results of studying the solid-phase transformations in Se/Cu nanosized film structures fabricated by vacuum thermal evaporation method are presented. It is...     

A device for testing a fast nanographite photodetector at high temperatures

The results of tests of a fast photodetector based on a nanographite film grown on a silicon substrate are presented. The temperature dependence of the optoelectric signal from the photodetector in the range 300–800 K has been studied under the vacuum conditions. It has been shown experimentally that, when the temperature increases from 300 to 625 K, the photodetector’s sensitivity decreases by approximately 30%. When the temperature increases to higher values, the optoelectric-signal amplitude drops linearly and is halved at T = 740 K as compared to room temperature. Extrapolation of the experimental data shows that the optoelectric response of the photodetector disappears at T > 1000 K.