The Isa smelting furnace discharges the matte and slag in the same tapping hole. As a result, an electric furnace needs to clean the slag. In the present study, the copper slag cleaning in an ...electric furnace, particularly the separation of the matte from the slag during the reduction process, was investigated. For Fe3O4 to FeO, the foaming slag in the melt disappeared when the Fe3O4 content was less than 10%. With the formation of the metallic iron, the foaming slag formed again, hindering the sedimentation of the matte. When the anthracite dosage increased to 2.61%, the copper content in the slag increased to 9.46%. The microstructure of the slag and the existence of the metallic iron found in the slag were analyzed in detail. The results obtained in this study provide a theoretical basis for the reasonable control of the transformation of Fe3O4 during the copper slag cleaning.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Synthetic antiferromagnets (SAF) have been proposed to replace ferromagnets in magnetic memory devices to reduce the stray field, increase the storage density, and improve the thermal stability. ...Here, we investigate the spin-orbit torque in a perpendicularly magnetized Pt/Co/Pd/Ru/Co/Pd SAF structure, which exhibits completely compensated magnetization and an exchange coupling field up to 2100 Oe. The magnetizations of two Co/Pd layers can be switched between two antiparallel states simultaneously by spin-orbit torque. The magnetization switching can be read out due to much stronger spin-orbit coupling at the bottom Pt/Co/Pd interface compared to its upper counterpart without Pt. Both experimental and theoretical analyses unravel that the torque efficiency of antiferromagnetically coupled stacks is significantly higher than the ferromagnetic counterpart, making the critical switching current of SAF comparable to the conventional single ferromagnet. Besides adding an important dimension to spin-orbit torque, the efficient switching of completely compensated SAF might advance magnetic memory devices with high density, high speed, and low power consumption.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Display omitted
A sphere impacting a plate is different from impacting a half-space bulk, because energy in the former case can be dissipated in a form of flexural wave propagating on the plate. Such ...energy loss by the elastic wave can be explained by the Zener model; however, this model is only valid for low-velocity impact with elastic Hertzian contact law. For high-velocity impact with contact plasticity, the Zener model is not valid any ore because energy dissipation by plasticity may take a large fraction, so that the Zener model, which ignores plasticity, will overestimate the coefficient of restitution (COR). In order to study how much the plasticity affects the sphere impacting the plate, we developed a modified Zener model by employing the contact plasticity into the controlling equation. Using the developed model, we firstly presented a thickness-dependent yielding velocity (yielding impact velocity depends on the thickness of the plate), above which the contact plasticity should be taken into account. What is more, we presented a semi-analytical solution to predict the COR over a large range of plate thickness. Meanwhile, finite element simulations were carried out to prove that the present model can give enough accuracy for the high velocity impact.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Shaping the light emission characteristics of laser systems is of great importance in various areas of science and technology. In a typical lasing arrangement, the transverse spatial profile of a ...laser mode tends to remain self-similar throughout the entire cavity. Going beyond this paradigm, we demonstrate here how to shape a spatially evolving mode such that it faithfully settles into a pair of bi-orthogonal states at the two opposing facets of a laser cavity. This was achieved by purposely designing a structure that allows the lasing mode to encircle a non-Hermitian exceptional point while deliberately avoiding non-adiabatic jumps. The resulting state transfer reflects the unique topology of the associated Riemann surfaces associated with this singularity. Our approach provides a route to developing versatile mode-selective active devices and sheds light on the interesting topological features of exceptional points.
Tunable spin correlations are found to arise between two neighboring trapped exciton-polariton condensates which spin polarize spontaneously. We observe a crossover from an antiferromagnetic to a ...ferromagnetic pair state by reducing the coupling barrier in real time using control of the imprinted pattern of pump light. Fast optical switching of both condensates is then achieved by resonantly but weakly triggering only a single condensate. These effects can be explained as the competition between spin bifurcations and spin-preserving Josephson coupling between the two condensates, and open the way to polariton Bose-Hubbard ladders.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
The geochemical characteristics of melt inclusions and their host olivines provide important information on the processes that create magmas and the nature of their mantle and crustal source regions. ...We report chemical compositions of melt inclusions, their host olivines and bulk rocks of Xindian basalts in Chifeng area, North China Craton. Compositions of both bulk rocks and melt inclusions are tholeiitic. Based on petrographic observations and compositional variation of melt inclusions, the crystallizing sequence of Xindian basalts is as follows: olivine (at MgO > ~5.5 wt%), plagioclase (beginning at MgO = ~5.5 wt%), clinopyroxene and ilmenite (at MgO < 5.0 wt%). High Ni contents and Fe/Mn ratios, and low Ca and Mn contents in olivine phenocrysts, combining with low CaO contents of relatively high MgO melt inclusions (MgO > 6 wt%), indicate that Xindian basalts are possibly derived from a pyroxenite source rather than a peridotite source. In the CS-MS-A diagram, all the high MgO melt inclusions (MgO > 6.0 wt%) project in the field between garnet + clinopyroxene + liquid and garnet + clinopyroxene + orthopyroxene + liquid near 3.0 GPa, further suggesting that residual minerals are mainly garnet and clinopyroxene, with possible presence of orthopyroxene, but without olivine. Modeling calculations using MELTS show that the water content of Xindian basalts is 0.3–0.7 wt% at MgO = 8.13 wt%. Using 20–25 % of partial melting estimated by moderately incompatible element ratios, the water content in the source of Xindian basalts is inferred to be ≥450 ppm, much higher than 6–85 ppm in dry lithospheric mantle. The melting depth is inferred to be ~3.0 GPa, much deeper than that of tholeiitic lavas (<2.0 GPa), assuming a peridotite source with a normal mantle potential temperature. Such melting depth is virtually equal to the thickness of lithosphere beneath Chifeng area (~100 km), suggesting that Xindian basalts are derived from the asthenospheric mantle, if the lithospheric lid effect model is assumed.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
499.
The core-like nature of HST-1 in the M87 jet Chen, Y. J.; Zhao, G.-Y.; Shen, Z.-Q.
Monthly notices of the Royal Astronomical Society. Letters,
09/2011, Volume:
416, Issue:
1
Journal Article
Peer reviewed
Open access
Abstract
We investigate the total flux density, spectral, polarization and Faraday rotation variability of HST-1 in the M87 jet during the outburst from 2003 to 2007 through multi-epoch Very Large ...Array observations at 8, 15 and 22 GHz. Contrary to the general case for blazars, the flux densities of HST-1 rise earlier at lower frequencies from radio to X-ray, and the spectra are softening with the growth of outburst, indicating that the newly emerging subcomponents within HST-1 have relatively steep spectra. In particular, the intrinsic optical electric vector positional angle varies monotonically by ∼90° at the three wavebands during the period, and all but the stationary subcomponent in the eastern end of HST-1 move downstream superluminally deviating divergently from the overall jet direction, with the motion of the outmost subcomponent bending from one side of the jet axis to another. These strongly argue for the presence of helical magnetic fields around HST-1, which is also supported by the fact that the subcomponents might be accelerated in this region. The fractional polarization is relatively low in the rising stage, and in the decaying stage the polarization levels are almost comparable at the three wavebands. In view of the quite large rotation measure (RM) values, Faraday rotation is expected to occur dominantly external to HST-1 in the decaying stage, which is well supported by the presence of diffuse emission around HST-1, and consistent with the scenario that RM decrease gets slower with time.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The Omicron (B.1.1.529) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was initially identified in November 2021 in South Africa and Botswana, as well as in a sample from a ...traveller from South Africa in Hong Kong
. Since then, Omicron has been detected globally. This variant appears to be at least as infectious as Delta (B.1.617.2), has already caused superspreader events
, and has outcompeted Delta within weeks in several countries and metropolitan areas. Omicron hosts an unprecedented number of mutations in its spike gene and early reports have provided evidence for extensive immune escape and reduced vaccine effectiveness
. Here we investigated the virus-neutralizing and spike protein-binding activity of sera from convalescent, double mRNA-vaccinated, mRNA-boosted, convalescent double-vaccinated and convalescent boosted individuals against wild-type, Beta (B.1.351) and Omicron SARS-CoV-2 isolates and spike proteins. Neutralizing activity of sera from convalescent and double-vaccinated participants was undetectable or very low against Omicron compared with the wild-type virus, whereas neutralizing activity of sera from individuals who had been exposed to spike three or four times through infection and vaccination was maintained, although at significantly reduced levels. Binding to the receptor-binding and N-terminal domains of the Omicron spike protein was reduced compared with binding to the wild type in convalescent unvaccinated individuals, but was mostly retained in vaccinated individuals.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
You have reached the maximum number of search results that are displayed.
For better performance, the search offers a maximum of 1,000 results per query (or 50 pages if the option 10/page is selected).
Consider using result filters or changing the sort order to explore your results further.
PDF
