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Discovery of two new millisecond pulsars towards the Galactic bulge
No full textThe mysterious Galactic Center Excess of gamma rays could be explained by a large population of millisecond pulsars hiding in the Galactic bulge, too faint to be detected as individual high-energy point sources by the Fermi Large Area Telescope, as well as too fast and too dispersed to be detected in shallow radio pulsation surveys. Motivated by an innovative candidate selection method, we aim at detecting millisecond pulsars associated with the Galactic Center Excess by carrying deep radio pulsation searches towards promising candidates detected in the inner Galaxy, in X rays by Chandra, and in radio or gamma rays by the Very Large Array or Fermi. We conducted deep radio observation and follow-up campaigns with MeerKAT, the Murriyang and the Green Bank telescopes towards 9 X-ray candidate sources. We here report the detection of two new millisecond pulsars, including a black widow candidate, towards the Galactic bulge: PSRs J1740-2805 and J1740-28. These discoveries double the number of MSPs discovered within the innermost 2 degree from the Galactic center
Structural Heterogeneity in Medium-Entropy AgMnSbPbTe<sub>4</sub> for Glassy Thermal Transport and High Thermoelectric Performance
No full textMedium-entropy semiconductors represent a unique category of entropy-engineered materials. They possess a considerable level of randomness in atomic mixing, although this is not sufficient to conclusively achieve single-phase structure stabilization, in contrast to high-entropy materials. This introduces strong competition between the formation of different phases, which can potentially lead to structural heterogeneity. In this work, we uncover endotaxial nanoprecipitates in the microscopically identified homogeneous medium-entropy semiconductor AgMnSbPbTe4. These nanoprecipitates initially crystallize in a cubic phase (Fm3m) within kinetically stabilized AgMnSbPbTe4, subsequently evolving into a thermodynamically stable monoclinic phase (P21/c) during thermal annealing while maintaining an endotaxial relationship with the matrix lattice. This nanophase segregation and the resultant lattice mismatch at interfaces introduce strain fluctuations up to 5% at intervals of 20 nm across the entire microstructure. Within the matrix phase, atomic displacement of up to 23 pm was observed. This structural heterogeneity results in glass-like thermal transport behavior, achieving an ultralow lattice thermal conductivity kappa L = 0.312 Wm-1 K-1 at 800 K, which is in accordance with the amorphous limit predicted by the Cahill model. The synergy of band convergence effect and well-maintained carrier mobility leads to a maximum ZT of 1.72 at 800 K and an average ZTavg of 1.02 over the temperature range of 300-825 K. This study highlights that the underexplored structural heterogeneity in medium-entropy semiconductors can potentially yield beneficial phenomena, such as the phonon-glass electron-crystal transport behavior in this case, which holds promise for advancing thermoelectric applications
Trait activation in daily life: comparing two perspectives on person-situation interactions
No full textTrait activation theory posits that personality traits are expressed when trait-relevant situational cues—affordances—are present. While prior work has primarily examined how situational affordances moderate trait–behavior associations (an affordance-gradient perspective), comparatively less attention has been given to how multiple traits are differentially activated within affordance-relevant situations (an affordance-configured perspective), especially in ecologically valid settings. We addressed this gap using a retrospective diary design with 224 respondents (Ndiary = 448), combining self- and independently rated assessments of situational affordances and behavioral expressions. Consistent with the affordance-configured perspective, traits showed stronger associations with behavior in affordance-relevant situations relative to other traits. In contrast, interaction effects for the affordance-gradient perspective were mostly absent. These findings extend trait activation theory to everyday life and underscore the value of situational affordances for understanding personality expression
Local fields reveal atomic-scale nonadiabatic carrier-phonon dynamics
No full textUnderstanding nonadiabatic carrier-lattice interactions at the atomic scale remains a fundamental challenge, yet these processes govern energy transfer in materials and ultimately set limits in microelectronics. We combined attosecond core-level transient absorption spectroscopy with many-body theory to uncover how nonadiabatic electron-phonon coupling drives ultrafast relaxations in a titanium-carbide MXene. Phonon-driven changes in carrier localization modulated local field effects (LFEs), yielding carrier-, site-, and orbital-specific absorption signatures. LFEs served as sensitive fingerprints of electron-phonon coupling strength across the phonon spectrum and revealed a breakdown of the Born–Oppenheimer approximation: Electrons lagged lattice oscillations by 32 ± 8 femtoseconds, whereas holes responded almost instantaneously (7 ± 7 femtoseconds). Our results establish a framework for probing and controlling nonadiabatic carrier-phonon interactions with orbital and site specificity
