Influence of addition of nanosize barium cerate on the microstructure and properties of top-seeded melt growth YBCO bulk superconductors

Barium cerate (BaCeO₃) is one of the possible additions to bulk YBa₂Cu₃O₇ single-grain superconductors to suppress the growth of Y₂BaCuO₅ (Y211) particles. This paper investigates the synthesis of barium cerate powder and its use in YBa₂Cu₃O₇ bulk superconductors. Crystalline barium cerate was synthesized by solid-state reaction, by co-precipitation of oxalates and by sol-gel method. Final calcination was held in air or in vacuum. It is shown that the most efficient in refining Y211 is nanocrystalline barium cerate prepared by sol-gel method calcined in vacuum. The effective refinement of Y211 particles occurred over the entire interval of nanocrystalline BaCeO₃ addition from 0.38 to 1.90 wt%. The optimal concentration of nanosize barium cerate was determined, microstructure and superconducting properties were characterized. The effect of Y211 content on trapped field in YBCO bulks with addition of nanocrystalline barium cerate is shown.     

Ultrasonic-Assisted Exfoliation of Graphitic Carbon Nitride and its Electrocatalytic Performance in Process of Ethanol Reforming

Semiconductors - Graphitic carbon nitride was synthesized via thermolysis of urea and then ultrasonic exfoliated from colloidal solution to obtain phase pure ultrafine powder of g-C3N4. It was...     

On the problem concerned with the statistical nature of fatigue damage of steels and alloys

Conclusions The distribution of the logarithm of the number of, cycles to destruction (logN) at a constant amplitude of the variable stress _-1, in accordance with the proposed hypothesis about independence of the two fatigue damage mechanisms being realized in the metal, can be represented by a mixture of two normal distributions with the weighting coefficients P₁ and P₂. Processing of results of fatigue tests, by means of separating the two constituents, from an empirical distribution, is expedient in three cases: 1) for moderlate probabilities 0.05-1 into the region of large life values in the case of probabilities of failure P0.05; 3) for extrapolation of experimental data with respect to log N into the region of small and very small probabilities P0.01.Translated from Problemy Prochnosti, No. 4, pp. 17–23, April, 1974.     

Spinning of a chemisorptive sulfonic acid fibre

Conclusions Special features of spinning a fibre by the wet method from a copolymer based on acrylonitrile and sodium methallylsulfonate which are connected with dissociation and solvation of the sulfonate groups have been examined.It has been found that, to obtain a fibre with satisfactory physico-mechanical properties which assure processing into textile articles from a sulfonate-containing copolymer, it is necessary to carry out the spinning either into nonaqueous baths or into aqueous baths which contain lyophilic salts.Translated from Khimicheskie Volokna, No. 3, pp. 10–12, May–June, 1988.     

Photoluminescence spectra of thin films of ZnTPP–C<Subscript>60</Subscript> and CuTPP–C<Subscript>60</Subscript> molecular complexes

The results of studies of thin composite films of zinc and copper tetraphenylporphyrins with different fractions of fullerene C₆₀ are reported. The photoluminescence spectra are recorded, and the composition and surface morphology are analyzed by means of scanning electron microscopy. The results show a difference in the structure of films with two types of metals (Zn, Cu) entering into the complex of the porphyrin macrocycle. An additional long-wavelength photoluminescence band at 1.4 eV is detected for the first time, which is evidence of the formation of ZnTPP–C₆₀ molecular complexes from a gas-dynamic vapor flow upon condensation. In CuTPP thin films, the processes of self-assembly into nanowires 20 nm in diameter and up to 50 µm in length and the formation of nanoheterojunctions upon the addition of fullerene C₆₀ are observed. Quantum-chemical calculations in the context of density-functional theory are carried out to interpret the experimental data.     

Complex Transposon Insertion as a Novel Cause of Pompe Disease

Pompe disease (OMIM#232300) is an autosomal recessive lysosomal storage disorder caused by mutations in the GAA gene. According to public mutation databases, more than 679 pathogenic variants have been described in GAA, none of which are associated with mobile genetic elements. In this article, we report a novel molecular genetic cause of Pompe disease, which could be hardly detected using routine molecular genetic analysis. Whole genome sequencing followed by comprehensive functional analysis allowed us to discover and characterize a complex mobile genetic element insertion deep in the intron 15 of the GAA gene in a patient with infantile onset Pompe disease.     

Design of conduction band structure of TiO2 electrode using Nb doping for highly efficient dye‐sensitized solar cells

A barrier layer of undoped TiO₂ was deposited on the Nb‐doped TiO₂ electrode to suppress the recombination at the Nb‐doped TiO₂/dye–electrolyte interface for highly efficient dye‐sensitized solar cells (DSCs). The Nb content in TiO₂ was varied in a range of 0.7–3.5 mol% to modify the TiO₂ energy‐band structure. Nb‐doped TiO₂/dye interfaces were characterized by a combination of ultraviolet photoemission spectroscopy and optical absorption spectroscopy measurements, allowing the determination of the conduction band minimum (CBM) of the TiO₂ electrode and the lowest unoccupied molecular orbital of the N719 dye. The lowering of TiO₂ CBM by Nb doping induced the increase in short‐circuit current of DSCs. However, open‐circuit voltage and fill factor are decreased, and this result was ascribed to the enhanced recombination at the Nb‐doped TiO₂/dye–electrolyte interface. The effect of doping on charge transport in DSCs was analyzed using electrochemical impedance spectroscopy. We have shown that by introducing of TiO₂ barrier layer, the Nb doping content, which results in DSC highest efficiency, can be increased because of the suppression of the dopant‐induced recombination. The energy conversion efficiency of the solar cells increased from 7.8% to 9.0% when undoped TiO₂ electrode is replaced with electrode doped with 2.7 mol% of Nb because of the improvement of the electron injection and collection efficiencies. The correlation between the electronic structure of the TiO₂ electrode, charge transfer characteristics, and photovoltaic parameters of DSCs is discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

溶胶-凝胶法制备V2O5为基体的薄膜材料及其应用

综述了以V2O5为基体的薄膜材料的制备方法、结构及其特性,介绍了该材料在湿度传感器、电压开关和锂电池等领域的应用。     

Mechanism of displacement of electrolyte solutions from metal surface by inhibited oils

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 5, 11–13, May, 1991.