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[en] Bulk superconductors of Pb-doped Bi-oxide system (BSCCO) dominated with the high-Tc phase have the critical transition temperature, Tc of 110 K, and the upper critical fields, Hc2 of 140 T at OK and 60 T at 77 K. A highly dense and a highly oriented microstructure is obtained by inserting an intermediate uniaxial pressing process. The critical current density, Jc at 77 K in zero field, Jc (77K,OT) of some 5000 A/cm2 can be easily obtained by this process, and the field dependence of Jc is also improved. Flexible high-Tc BSCCO ribbons with a Jc (77K,Ot) of 1850 A/cm2 have been successfully prepared by the combined process of doctor blade casting, cold rolling and sintering. Aq-sheeted multifilamentary wires with 1330 filaments and tapes with 30 filaments have also been successfully fabricated and the 36-filament tape shows a Jc(77K,OT) of 1050 A/cm2. (Auth.). 7 refs.; 7 figs
[en] Organic–inorganic hybrid material, aniline-functionalized bismuth oxide nanoparticles, has been synthesized using a two-step wet-chemical synthesis method and characterized by different optical, microscopy and surface analysis techniques. The material was applied as an active device component to demonstrate the electrical property of the device. The device exhibited a nonvolatile, resistive switching performance with a constant ON–OFF current ratio. The nonvolatile behaviour was confirmed by applying a 6 V of read pulse for 0.1 s after every 60 s with the duty-cycle of 0.16% for 2 × 103 s. To check the endurance of ‘ON’ and ‘OFF’ states of the system, a bias of 6 V (read pulse) was applied to the device for 0.2 s with a duty-cycle of 50% for 103 cycles and the device showed the potential for storing and processing the data in a binary approach and differentiate between the ON and OFF states with the ratio of ~ 102. The current–voltage characteristics of the device in both the ON and OFF states are fitted with the Poole–Frenkel emission.
[en] Here in this paper, a full-spectrum responsive vacancy-rich monolayer BiO2-x has been synthesized. The increased density of states at the conduction band (CB) minimum in the monolayer BiO2-x is responsible for the enhanced photon response and photo-absorption, which were confirmed by UV/Vis-NIR diffuse reflectance spectra (DRS) and photocurrent measurements. Compared to bulk BiO2-x, monolayer BiO2-x has exhibited enhanced photocatalytic performance for rhodamine B and phenol removal under UV, visible, and near-infrared light (NIR) irradiation, which can be attributed to the vacancy VBi-O' as confirmed by the positron annihilation spectra. The presence of VBi-O' defects in monolayer BiO2-x promoted the separation of electrons and holes. This finding provides an atomic level understanding for developing highly efficient UV, visible, and NIR light responsive photocatalysts.
[en] The solid ionic conductor cell Bi2O3Y2O3 was used to study the current-voltage behaviour under different temperatures and voltage scan rate, as is usually done in cyclic voltammetry in three-electrode cells using liquid electrolytes. The result shows that the reactions are different at the electrodes and a hysteresis effect is presented at low temperature and high voltage scanning rates
[en] Highlights: • The hole doping enhanced after the metal on graphene is completely oxidized. • O-species adsorbates absorbed after exposing the graphene in air. • The short-range scattering center induced by Bi2O3 and O-species adsorbates. • The influence of O-species adsorbates from the air is restorable with annealing at 350 K. In this work, we have studied the oxidation process of the bismuth doped graphene in the ambient air. Complete oxidation of the bismuth clusters and that of the graphene are firmly confirmed. The influence of oxygen on the graphene is characterized by means of Hall measurement and SdH oscillation. All transport measurements demonstrate a hole-type doping behavior. Our work also demonstrates that the short-range scattering mechanism is enhanced in doped graphene due to accumulated O-species adsorbates after being exposed in the atmosphere for 40 days and is suppressed after annealing. This investigation may open a new perspective for fabricating the graphene metal oxide devices.
[en] We have prepared aluminophosphate glass samples differing in bismuth oxide content and demonstrating broadband near-IR photoluminescence. Analysis of their photoluminescence spectra leads us to conclude that they contain two main types of emission centres, one of which seems to be a bismuth monocation and the other is a cluster ion. In addition to these luminescence centres, the aluminophosphate glasses contain a nonluminescent bismuth-containing centre responsible for the broad, strong optical absorption band peaking at 450 nm. (active media)
[en] A mixture of α-Bi2O3 and α-Bi5O7I is a condidate material for immobilization of radioactive iodine. This report discusses factors that affect the reaction of α-Bi2O3 with aqeous iodide to form α-Bi5O7I. In order to achieve high decontamination factors in short reaction times, it is necessary to nucleate Bi5O7I on the Bi2O3 surface by pretreatment with a 10-2 mol·dm-3, using a dilute slurry of Bi2O3 (5 g in 100 cm3), in contact times of the order of a minute at 20-25 degrees Celsius. Several other common ions, e.g., carbonate/bicarbonate, chloride, borate and sulfate, can interfere with this reaction. Effects of varying pH (9-11), temperature (20-50 degrees Celsius), iodide concentration, and quantity of Bi2O3 are discussed. There is also some variation in the rate and extent of reaction with Bi2O3 samples from different sources. At high iodide concentrations (≥ 5 x 10-2 mol·-3), products other than Bi5O7I, possible Bi4O5I2 and Bi7O9I3, are formed. X-ray diffraction data for these compounds are included. 17 refs