Exchange bias (EB) and magnetic properties of ferrimagnetic (FI) Fe3O4 and antiferromagnetic (AFM) Cr2O3 nanocomposites prepared by mechanical alloying have been investigated. A large EB field of 2.2 kOe at 10 K is observed in one of the nanocomposites, which may be related to the uncompensated and pinned AFM spins at the interface between FI and AFM phases of the nanocomposites. The EB field varies with the strength of cooling field and the content of the Cr2O3 phase, the phenomena observed are explained in terms of interfacial exchange interaction between the two phases.

A large magnetoresistance (MR) is observed in a double helical CoMnSi compound over the entire temperature region from 5 K to the maximum measuring temperature of 380 K, with the largest MR ratio of −18.3% at 245 K and the smallest MR ratio of −5.5% at 85 K at 5 T. This phenomenon is ascribed to two different mechanisms in different temperature regions. The suppressed spin fluctuations of the double helical structure are responsible for the MR below 110 K. However, in consideration of the natural multilayer superstructure of CoMnSi, the larger MR above 110 K is ascribed to the decrease in K-space restrictions when the change in magnetic structure from double helical order to fan order occurs.

It is shown that the superconductivity in Ce 1−x Gd x FeAsO 0.84 F 0.16 compounds can be modulated by internal (chemical) pressure. The internal pressure is induced by Gd substitution for Ce in CeFeAsO 0.84 F 0.16 , which compresses the crystal lattice. The temperature dependences of resistivity and magnetization show that the superconducting-transition temperature T c is enhanced from 40 K for CeFeAsO 0.84 F 0.16 to 47.5 K for Ce 0.6 Gd 0.4 FeAsO 0.84 F 0.16 . The increase and subsequent decrease of T c upon application of external pressure, as observed previously in LaFeAsO 0.89 F 0.11 , is entirely confirmed by the modulation of T c of the Ce 1−x Gd x FeAsO 0.84 F 0.16 superconductors by internal pressure.

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Aminoglycoside antibiotics affect protein translation fidelity and lead to protein aggregation and an increase in intracellular oxidative stress level as well. The overexpression of the chaperonin GroEL/GroES system promotes short-term tolerance to aminoglycosides in Escherichia coli. Here, we demonstrated that the coexpression of prefoldin or Hsp60 originating from the hyperthermophilic archaeon Pyrococcus furiosus in E. coli cells can rescue cell growth and inhibit protein aggregation induced by streptomycin exposure. The results of our study show that hyperthermophilic chaperones endow E. coli with a higher tolerance to streptomycin than the GroEL/GroES system, and that they exert better effects on the reduction of intracellular protein misfolding, indicating that these chaperones have unique features and functions.

We report detection of radio recombination line (RRL) H40α toward 75 sources, with data obtained from ACA observations in the ATOMS survey of 146 active Galactic star forming regions. We calculated ionized gas mass and star formation rate with H40α line emission. The mass of ionized gas is significantly smaller than molecular gas mass, indicating that ionized gas is negligible in the star forming clumps of the ATOMS sample. The star formation rate (SFR$_{\rm H_{40\alpha }}$) estimated with RRL H40α agrees well with that (SFR$_{\rm L_{\rm bol}}$) calculated with the total bolometric luminosity (Lbol) when SFR ≥ 5 M⊙ Myr−1, suggesting that millimeter RRLs could well sample the upper part of the initial mass function (IMF) and thus be good tracers for SFR. We also study the relationships between Lbol and the molecular line luminosities (L$^{^{\prime }}_{\rm mol}$) of CS J=2-1 and HC3N J=11-10 for all the 146 ATOMS sources. The $L_{\rm bol} - L^{\prime }_{\rm mol}$ correlations of both the CS J=2-1 and HC3N J=11-10 lines appear approximately linear and these transitions have success in predicting Lbol similar to that of more commonly used transitions. The Lbol-to-$L^{\prime }_{\rm mol}$ ratios or SFR-to-mass ratios (star formation efficiency; SFE) do not change with galactocentric distances (RGC). Sources with H40α emission (or H ii regions) show higher Lbol-to-$L^{\prime }_{\rm mol}$ than those without H40α emission, which may be an evolutionary effect.

Hydrogen radio recombination lines (RRLs) are one of the major diagnostics of the physical properties of H ii regions. We use RRL H40α, He40α, and 3 mm continuum emission to investigate the properties of a large sample of resolved UC H ii regions identified in the ATOMS survey. In total, we identify 94 UC H ii regions from H40α emission. The basic parameters for these UC H ii regions, such as electron density, emission measure, electron temperature, ionic abundance ratio (n$_{\rm He^+}$/n$_{\rm H^+}$), and line width are derived. The median electron density and the median n$_{\rm He^+}$/n$_{\rm H^+}$ ratio of these UC H ii regions derived from RRLs are ∼9000 cm−3 and 0.11, respectively. Within UC H ii regions, the n$_{\rm He^+}$/n$_{\rm H^+}$ ratios derived from the intensity ratio of the He40α and H40α lines seems to be higher in the boundary region than in the centre. The H40α line width is mainly broadened by thermal motion and microturbulence. The electron temperature of these UC H ii regions has a median value of ∼6700 K, and its dependence on galactocentric distance is weak.