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The Integrated Sachs-Wolfe Effect in Time Varying Vacuum Model

The integrated Sachs-Wolfe (ISW) effect is an important implication for dark energy. In this paper, we have calculated the power spectrum of the ISW effect in the time varying vacuum cosmological model, where the model parameter $\beta=4.407$ is obtained by the observational constraint of the growth rate. It's found that the source of the ISW effect is not only affected by the different evolutions of the Hubble function $H(a)$ and the dimensionless matter density $\Omega_m(a)$, but also by the different growth function $D_+(a)$, all of which are changed due to the presence of matter production term in the time varying vacuum model. However, the difference of the ISW effect in $\Lambda(t)\textmd{CDM}$ model and $\Lambda \textmd{CDM}$ model is lessened to a certain extent due to the integration from the time of last scattering to the present. It's implied that the observations of the galaxies with high redshift are required to distinguish the two models

Unified nonequilibrium dynamical theory for exchange bias and training effects

We investigate the exchange bias and training effects in the FM/AF heterostructures using a unified Monte Carlo dynamical approach. This real dynamical method has been proved reliable and effective in simulating dynamical magnetization of nanoscale magnetic systems. The magnetization of the uncompensated AF layer is still open after the first field cycling is finished. Our simulated results show obvious shift of hysteresis loops (exchange bias) and cycling dependence of exchange bias (training effect) when the temperature is below 45 K. The exchange bias fields decrease with decreasing the cooling rate or increasing the temperature and the number of the field cycling. With the simulations, we show the exchange bias can be manipulated by controlling the cooling rate, the distributive width of the anisotropy energy, or the magnetic coupling constants. Essentially, these two effects can be explained on the basis of the microscopical coexistence of both reversible and irreversible moment reversals of the AF domains. Our simulated results are useful to really understand the magnetization dynamics of such magnetic heterostructures. This unified nonequilibrium dynamical method should be applicable to other exchange bias systems.Comment: Chin. Phys. B, in pres

Cooling rate calculation and microstructure evolution of Sm-Fe alloy powder prepared by high pressure gas atomization

The Sm2Fe17 alloy powder was prepared by high-pressure gas atomization technology, and its morphology and size distribution were analyzed. The relationship between the micro-structure evolution of the Sm-Fe alloy powder and the cooling rate was calculated. Besides, the relationship between the cooling rate of the high-pressure aerosolized alloy powder and the change of secondary dendrite arm spacing (SDAS) was verified. The cooling rate of the powder was indirectly determined according to the empirical relationship between the dendritic spacing of the rapidly solidified alloy and the cooling rate. After comparison, the results are consistent with the theoretical calculation

Resonances in Ferromagnetic Gratings Detected by Microwave Photoconductivity

We investigate the impact of microwave excited spin excitations on the DC charge transport in a ferromagnetic (FM) grating. We observe both resonant and nonresonant microwave photoresistance. Resonant features are identified as the ferromagnetic resonance (FMR) and ferromagnetic antiresonance (FMAR). A macroscopic model based on Maxwell and Landau-Lifschitz equations reveals the macroscopic nature of the FMAR. The experimental approach and results provide new insight in the interplay between photonic, spintronic, and charge effects in FM microstructures.Comment: 4 pages, 4 figure

KLJUČNI ČIMBENICI U UROĐENOM IMUNOLOŠKOM PREPOZNAVANJU VIRUSNE INFEKCIJE U SISAVACA I RIBA

Viral infection of mammalian cells activates an innate antiviral immune response characterized by production of interferon and subsequent enhanced transcription of interferon–stimulated genes important for antiviral defense. Cells recognize viral infection through various pathogen–associated molecular patterns, of which dsRNA seems to be the most important. In mammals, several gene products are important in recognition of dsRNA: RIG–I, TLR3, PKR and mda–5. Recent research proved that fish possess most of the key elements in recognition of viral infection which indicates that these mechanisms are very similar and evolutionary conserved in vertebrates.Virusna infekcija u stanicama sisavaca potiče urođeni odgovor karakteriziran proizvodnjom interferona i posljedičnom pojačanom transkripcijom interferonima stimuliranih gena, bitnih u obrani organizma od virusa. Stanice prepoznaju virusnu infekciju preko određenih molekularnih uzoraka povezanih s patogenima, od kojih je najvažnija dvolančana RNK. U organizmu sisavaca ključnu ulogu u prepoznavanju dvolančane RNK ima nekoliko gena: RIG–I, TLR3, PKR i mda–5. Dosadašnja su istra‘ivanja pokazala da ribe posjeduju većinu ključnih elemenata zaduženih za prepoznavanje virusne infekcije, što upućuje na veliku sličnost i evolucijsku očuvanost spomenutih mehanizama