Nanostructured CoFe2O4 particles were prepared by a sonochemical approach, first by preparation of the amorphous precursor powders, followed by heat treatment at relatively very low temperatures. The ...precursor was prepared by sonochemical decomposition of solutions of volatile organic precursors, Fe(CO)5 and Co(NO)(CO)3, in Decalin at 273 K, under an oxygen pressure of 100−150 kPa. The amorphous nature of these particles was confirmed by various techniques, such as scanning and transmission electron microscopy (SEM and TEM), electron microdiffraction, and X-ray diffractograms. Magnetic measurements, Mössbauer, and electron paramagnetic resonance (EPR) spectral studies indicated that the as-prepared amorphous particles were superparamagnetic. The Mössbauer parameters and the significantly low (45 emu/g) observed saturation of magnetization of the annealed sample, compared to that of the bulk sample (72 emu/g), reflected its nanocrystalline nature.
A new species of the genus Pheosia Hübner, 1819, Pheosia mayri sp. n., from Sichuan and Gansu Provinces in China is described. The new species is compared with Chinese Pheosia gelupka Gaede, 1934 and ...Pheosia buddhista (Püngeler, 1899). The two differ in wing coloration, male and, especially, female genitalia. Adults of both sexes, their genitalia and map of collecting sites are illustrated.
Despite its increasing prominence in critical political and IR theory, the significance of the Foucauldian problematic of biopolitics remains underestimated. The frequent conflation of ...paradigmatically distinct sovereign and biopolitical forms of power, inspired by influential readings of Agamben and Hardt and Negri, results in increasingly incoherent applications of the concept of biopolitics. This is particularly evident in the attempts to theorise resistance to bio-power, which remains cast in conventional 'emancipatory' terms of resisting transcendent and exterior power. Critically engaging with Hardt and NegriÕs attempt to theorise resistance to biopolitics in terms of the liberation of the domain of biopolitical production, this article offers an alternative pathway of resistance that consists of the refusal of biopolitical 'care of the living' and the creation of autonomous forms of life outside the terrain of biopolitical governmentality. The example of such resistance is offered by the social practices of the late-Soviet period, whereby the alienation from and subversion of the socialist biopolitics and the concomitant experimentation with alternative forms of life in the 'shadow society' reduced Soviet power to its pure form of sovereignty. The article concludes with outlining the implications of this mode of resistance in the contemporary context of the global neoliberal Empire.
Transformation of metallic or bimetallic (BM) nanoparticles (NPs) from one shape to another desired shape is of importance to nanoscience and nanotechnology, where new morphologies of NPs lead to ...enhancement of their exploitable properties. In this report, we present the shape transformation of Au octahedral NPs to Au–Pd core–shell nanocubes, followed by their transformation to nanostars and finally to multilayered Au–Pd–Au core–shell hexagonal platelets in the presence of T30 DNA. The weaker binding affinity of T30 DNA directs the growth to favor the formation of lower energy {111} facets, changing the morphology from nanocubes to nanostar. The nanostars, exhibiting unusual intermediate morphologies, are comprised two sets of shell layers and have Au core, Pd intermediate shell, and Au outer shell. Similarly, the hexagonal platelets, which also have Au core and inner Pd shell, are encased in an external gold shell. The formation of multilayered Au–Pd–Au core–shell hexagonal platelets from Au–Pd core–shell nanocubes via the multilayered nanostars is monitored using scanning/transmission electron microscopy analysis.
The article presents methods based on probability theory and mathematical statistics for solving a number of basic problems: formation and evaluation of the current flight safety level; forecasting ...the level of flight safety; ranking the objects (planes, pilots) in terms of flight safety; evaluation of the presence (or absence) of control actions arising in the context of the organization of corporate safety management system. At the same time as the main source of information are considered forward-looking events received from flight data.
We report measurements of electrical resistivity under pressure to 5.8 GPa, magnetization to 6.7 GPa, and ac susceptibility to 7.1 GPa in KFe2As2. The previously reported change of slope in the ...pressure dependence of the superconducting transition temperature Tc(p) at a pressure p*~1.8 GPa is confirmed, and Tc(p) is found to be nearly constant above p* up to 7.1 GPa. The T-p phase diagram is very sensitive to the pressure conditions as a consequence of the anisotropic uniaxial pressure dependence of Tc. Across p*, a change in the behavior of the upper critical field is revealed through a scaling analysis of the slope of Hc2 with the effective mass as determined from the A coefficient of the T2 term of the temperature-dependent resistivity. We show that this scaling provides a quantitative test for the changes of the superconducting gap structure and suggests the development of a kz modulation of the superconducting gap above p* as a most likely explanation.
Although challenging, assembling and orienting non-spherical nanomaterials into two- and three-dimensional (2D and 3D) ordered arrays can facilitate versatile collective properties by virtue of their ...shape-dependent properties that cannot be realized with their spherical counterparts. Here, we report on the self-assembly of gold nanorods (AuNRs) into 2D films at the vapor/liquid interface facilitated by grafting them with poly(ethylene glycol) (PEG). Using surface sensitive synchrotron grazing incidence small angle X-ray scattering (GISAXS) and specular X-ray reflectivity (XRR), we show that PEG-AuNRs in aqueous suspensions migrate to the vapor/liquid interface in the presence of salt, forming a uniform monolayer with planar-to-surface orientation. Furthermore, the 2D assembled PEG functionalized AuNRs exhibit short range order into rectangular symmetry with side-by-side and tail-to-tail nearest-neighbor packing. The effect of PEG chain length and salt concentration on the 2D assembly are also reported.
The effects of 2.5-MeV electron irradiation were studied in the superconducting phase of single crystals of LaNiGa2, using measurements of electrical transport and radio-frequency magnetic ...susceptibility. The London penetration depth is found to vary exponentially with temperature, suggesting a fully gapped Fermi surface. The inferred superfluid density is close to that of a single-gap weak-coupling isotropic s– wave superconductor. Superconductivity is extremely robust against nonmagnetic point-like disorder induced by electron irradiation. Our results place strong constraints on the previously proposed triplet pairing state by requiring fine-tuned impurity scattering amplitudes and are most naturally explained by a sign-preserving, weak-coupling, and approximately momentum-independent singlet superconducting state in LaNiGa2, which does not break time-reversal symmetry. Finally, we discuss how our findings could be reconciled with previous measurements that indicated magnetic signatures in the superconducting phase.
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