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The dorsomedial prefrontal cortex (dmPFC) plays a crucial role in social cognitive functions, including perspective-taking. Although perspective-taking has been linked to self-control, the mechanism by which the dmPFC might facilitate self-control remains unclear. Using the multimodal neuroimaging dataset from the Human Connectome Project (Study 1, N =978 adults), we established a reliable association between the dmPFC and self-control, as measured by discounting rate—the tendency to prefer smaller, immediate rewards over larger, delayed ones. Experiments (Study 2, N = 36 adults) involving high-definition transcranial direct current stimulation showed that anodal stimulation of the dmPFC reduces the discounting of delayed rewards and decreases the congruency effect in egocentric but not allocentric perspective in the visual perspective-taking tasks. These findings suggest that the dmPFC promotes self-control by inhibiting the egocentric perspective, offering new insights into the neural underpinnings of self-control and perspective-taking, and opening new avenues for interventions targeting disorders characterized by impaired self-regulation.

Learning of prediction error (PE), including reward PE and risk PE, is crucial for updating the prediction in reinforcement learning (RL). Neurobiological and computational models of RL have reported extensive brain activations related to PE. However, the occurrence of PE does not necessarily predict updating the prediction, e.g., in a probability-known event. Therefore, the brain regions specifically engaged in updating the prediction remain unknown. Here, we conducted two functional magnetic resonance imaging (fMRI) experiments, the probability-unknown Iowa Gambling Task (IGT) and the probability-known risk decision task (RDT). Behavioral analyses confirmed that PEs occurred in both tasks but were only used for updating the prediction in the IGT. By comparing PE-related brain activations between the two tasks, we found that the rostral anterior cingulate cortex/ventral medial prefrontal cortex (rACC/vmPFC) and the posterior cingulate cortex (PCC) activated only during the IGT and were related to both reward and risk PE. Moreover, the responses in the rACC/vmPFC and the PCC were modulated by uncertainty and were associated with reward prediction-related brain regions. Electric brain stimulation over these regions lowered the performance in the IGT but not in the RDT. Our findings of a distributed neural circuit of PE processing suggest that the rACC/vmPFC and the PCC play a key role in updating the prediction through PE processing during decision making.

The development of high-performance aero-engines raises the urgent requirement of coatings deposited on blades, containing both thermal barrier coatings (TBCs) on the external surface and aluminide coatings in the internal winding cooling channels. A TBC system with a low activity aluminizing process before deposition of conventional TBC was developed here to evaluate the feasibility of co-deposition technology. The thermal cyclic oxidation behavior of co-deposited “Al-modified TBC” was examined at 1100 °C and compared to that of conventional TBC. The cross-sectional microstructure evolution and elemental diffusion behavior of the modified TBC were also investigated. Even though the underlying aluminizing layer can serve abundant Al for the upper NiCoCrAlYHf layer to eliminate “Al depletion” in conventional TBC, which is a main reason for spallation, the Al-modified TBC system exhibited shorter thermal cycling life than conventional TBC. The spallation mechanism was discussed. Cracks caused by the fast growth rate of thermally grown oxide (TGO), Cr-rich precipitates resulted from the decreased γ/γ′-phase in the coating, and Re-rich precipitates originated from outward diffusion through the aluminide layer were mainly responsible for the failure.

To substantially prevent electromagnetic threatens, microwave absorbing materials (MAMs) are required to eliminate surplus electromagnetic waves. As a typical MAM, Fe3O4 particles with complex permittivity and permeability have been widely applied due to the coexistence of magnetic loss and dielectric loss. However, the necessary high mass fraction significantly limited its applications, thus Fe3O4 nanostructures have been extensively investigated to overcome this problem. In this work, uniform Fe3O4 nanobelts were prepared by electrospinning and two-step thermal treatment. By controlling the composition and viscosity of the electrospinning precursor solution, Fe3O4 nanobelts with tunable lateral sizes (200 nm–1 μm) were obtained. The samples with low content (only 16.7 wt%) Fe3O4 exhibited wide maximum effective absorbing bandwidths (EAB) over 3 GHz, and Fe3O4 nanobelts with smaller lateral sizes showed a maximum EAB of 4.93 GHz. Meanwhile, Fe3O4 nanobelts with smaller lateral sizes presented superior reflection loss properties, the lowest reflection loss reached −53.93 dB at 10.10 GHz, while the maximum EAB was up to 2.98 GHz. The excellent microwave reflection loss of Fe3O4 nanobelts was contributed to the enhanced synergistic effect of magnetic loss, dielectric loss, and impedance matching, originated from the hierarchically cross-linked networks and shape anisotropies. This study could broaden the practical applications of magnetic absorbers, and provided an approach for the development of shape anisotropic magnetic materials.

Summary: La2Zr2O7 coatings are promising candidates to substitute YSZ coatings in advanced gas turbine engines. In this work, Sm-doped La2Zr2O7 coatings were deposited by physical vapor deposition. This work focuses on the crystal structure, thermal conductivity, thermal expansion coefficient, morphology, composition, and thermal durability of LaSmZrO coatings. The LaSmZrO ceramics exhibit low thermal conductivity (1.69 W/mK at 800°C) and high thermal expansion coefficient (9.72∗10−6 K−1 at 1500°C) compared with La2Zr2O7. The LaSmZrO/YSZ coatings with feathery microstructure show relatively good thermal durability (8183 cycles or 856 h) under high temperature. The broken regions are observed at the ceramic coating/bond coating interface. The failure behaviors are relevant with crack evolution and thermally grown oxide growth. This work might guide the investigation of advanced coatings under high temperature.

Plasma enhanced chemical vapor deposition (PECVD) is considered one of the methods to synthesize graphene with the greatest development potential due to its advantages to operate in low temperatures with high efficiency. However, unlike thermal chemical vapor deposition (TCVD), graphene grown by PECVD usually has smaller grain size with higher nucleation density of graphene films, in which excessive grain boundaries would lead to unsatisfactory electric performance for practical applications. One of the challenges in preparing graphene by PECVD is to improve the quality of graphene by controlling the nucleation and growth of graphene. In this article, the optimal growth of graphene in a Faraday cage by PECVD was studied. The nucleation density and growth rate of graphene in PECVD were decreased significantly with a Faraday cage. Large-sized graphene grains(∼20 µm) were successfully synthesized on polycrystalline copper by rising the growth temperature in the Faraday cage, and showed high quality. Besides, the graphene grown in a Faraday cage exhibits an average current carrier mobility of 309.1 cm2V−1s−1 under room temperature.