High-resolution neutron spectrum regulation for promoting transuranic isotope production
Peer-Reviewed Publication
Updates every hour. Last Updated: 27-Jul-2025 18:10 ET (27-Jul-2025 22:10 GMT/UTC)
A method is proposed for high-resolution neutron spectrum regulation across the entire energy domain, which helps to determine the optimal neutron spectrum for transuranic isotope production and a regulation scheme to establish this optimal neutron spectrum within the irradiation channels. The state-of-the-art production schemes for 252Cf and 238Pu in the High Flux Isotope Reactor were optimized, improving the yield of 252Cf by 12.16% and that of 238Pu by 7.53% to 25.84%.
Deflagration-to-Detonation Transition (DDT) process is the most common technique for obtaining stable detonation propagation. Although the detonation initiation appearances are different, the essential physical characteristic is the same: the local hot spot created by the energy focus. One or more bow shocks created by Mach reflection remain as strong transverse shocks after the detonation front. The corresponding numerical simulations show that the strong transverse shock propagation behavior strongly depends on the location where the hot spot forms. This work provides some fresh new insights into the DDT process, which may improve the understanding of DDT formation mechanisms.
For multi-vehicle networks, Cooperative Positioning (CP) technique has become a promising way to enhance vehicle positioning accuracy. Especially, the CP performance could be further improved by introducing Sensor-Rich Vehicles (SRVs) into CP networks, which is called SRV-aided CP. However, the SRV-aided CP system may split into several sub-clusters that cannot be connected with each other in dense urban environments, in which the sub-clusters with few SRVs will suffer from degradation of CP performance. In this work, a new locally-centralized CP method based on the clustering optimization strategy, aiming to fully utilize potential available information from high precision node, has been proposed.
Safe and feasible path planning is crucial for achieving autonomous navigation of fixed-wing Unmanned Aerial Vehicles (UAVs) in complex environments. However, due to the high-speed flight and complex control requirements of fixed-wing UAVs, ensuring the feasibility and safety of planned paths in complex environments remains challenging. Researchers at Beihang University have developed a feasible path planning algorithm named Closed-loop Radial Ray A* (CL-RaA*). The core components of the CL-RaA* include an adaptive variable-step-size path search and a just-in-time expansion primitive. By integrating these two components and conducting safety checks on the trajectories to be expanded, the CL-RaA* can rapidly generate safe and feasible paths that satisfy the differential constraints of fixed-wing UAVs.
Modern flight control demands faster response, greater adaptability, and resilience against unknowns—challenges traditional control systems struggle to meet. Incremental Nonlinear Dynamic Inversion (INDI) has emerged as a compelling solution, shifting control logic away from models toward real-time measurements. In a sweeping two-part review, researchers chart the path of INDI from its mathematical roots to its growing role inapplications. With its modular structure and built-in robustness, INDI is no longer just an academic concept.
A servicing spacecraft equipped with a compliant flexible rod has emerged as an innovative solution for detumbling defunct satellites, but the contact-induced vibrations of the flexible rod and severe disturbance pose significant challenges to operational accuracy and safety. Despite the extensive research on vibration suppression and detumbling control for tumbling satellites, the combined application of nonlinear energy sink with active varying stiffness (NES-AVS) for flexible rod vibration suppression in servicing spacecraft has yet to be comprehensively studied, and addressing this research gap is crucial as existing methods struggle to achieve both vibration reduction and guaranteed control performance under contact-induced disturbance.
Nowadays, the prevailing of 5G communication era has greatly stimulated a tremendous progress in microwave devices and has also made a demand of more stringent dielectric characteristics. Therefore, it is important to develop ceramics with excellent microwave dielectric properties.Vanadate dielectrics are attracting attention due to their relatively low sintering temperatures. But their large and negative τf values still limit practical applications, just as most of low εr ceramics. Adding those materials with positive τf values into low εr ceramics is an effective method to adjust τf to the near-zero value. However, this method will inevitably pose the decline in the Q×f value. Consequently, one key challenge facing low εr ceramics is how to adjust τf to the near-zero value without deteriorating Q×f.
The global antibiotic resistance crisis necessitates alternatives like bacteriophage therapy. However, bacterial phage resistance remains challenging. The authors developed a phage cocktail targeting carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKp) that exploits the dual-layered collateral sensitivity to suppress resistance evolution. The first layer leveraged overlapping capsular polysaccharide (CPS) and lipopolysaccharide (LPS) coverage: CPS-binding phage resistance increased susceptibility to LPS-binding phages. The second layer exploited an O serotype switch (O1→O2): resistance to O1-binding phages increased susceptibility to O2-binding phages. This dual-mechanism cocktail effectively constrained phage resistance development and mitigated CR-hvKp infection in mice. This research highlights collateral sensitivity's importance in countering phage resistance and provides a sophisticated phage cocktail design strategy to overcome bacterial resistance.
Artificial intelligence (AI) is emerging as a powerful catalyst for transforming enterprise productivity.
In an era of growing demand for real-time precision navigation, researchers have unveiled a powerful leap forward in satellite-based positioning.