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False data injection attack is one of the important factors that threaten the safe and stable operation of power systems. The research on the methods of the attack against power systems can provide decision-making basis for the improvement of power system defense measures. Considering the operation characteristics of high voltage direct current (HVDC) converter station and AC-DC coupling characteristics, a false data injection attack method for AC-DC hybrid system is proposed. Firstly, the basic principle of state estimation of AC-DC hybrid systems is analyzed. Secondly, the attack strategy in AC-DC hybrid systems is proposed, and the attack model is constructed. Finally, the improved IEEE 30-bus system is taken as an example for simulation verification. The results show that the false data injection attack against AC-DC hybrid system can bypass the bad data detection algorithm and endanger the safe and stable operation of the system, which verifies the effectiveness of the proposed model and method.

Naturally occurring granular uranium particles are typically fine and are often found as accessory minerals. However, reports of megacrystalline uraninite are rare. The discovery of megacrystalline uraninite is a significant achievement in uranium prospecting and mineralogy in the Kangdian region and China. Our team's research and review of previous studies have led to a systematic summary of the formation age, genetic types, relationship with migmatization, and metallogenic dynamic background of megacrystalline uraninite in the Kangdian region. The key findings are as follows: (1) the formation age of megacrystalline uraninite is Neoproterozoic (790–770 Ma); (2) migmatization preceded uranium mineralization; (3) the formation of megacrystalline uraninite is linked to high-temperature, low-pressure metamorphism caused by partial melting; (4) and the formation of megacrystalline uraninite may be associated with the Rodinia rifting event. This review aims to enhance our understanding of uranium mineralization during the Neoproterozoic in China and worldwide. [ABSTRACT FROM AUTHOR]

A flame retardant rigid polyurethane foam (FR-RPUF) boasting good mechanical properties is developed by integrating phosphorus-based compounds (DBHP/DMMP) and organically modified microcrystal muscovite (OM-MCM). During foaming, OM-MCM undergoes in-situ exfoliation, yielding RPUF nanocomposites with heightened mechanical strength. The combined deployment of OM-MCM and DBHP/DMMP enables FR-RPUF to achieve an excellent flame retardancy (such as UL94 V-0 rating). This flame retardant effect stems from a bi-phase mechanism: trapping effect of phosphorus-containing radicals in the gas phase and enhanced charring of nanominerals in the condensed phase. Overall, this accessible method enhances flame resistance in RPUF using conventional processes and available materials. [ABSTRACT FROM AUTHOR]

As intrinsically stretchable materials for flexible electronics construction, liquid metal (LM) based composite conductors face challenges to achieve a high conductivity with minimum resistance increase due to the large dimensional change and poor wettability under a large tensile strain. To address this issue, a super-stretchable eutectic gallium indium (EGaIn) foamed elastomer composite is prepared with the assistance of a sugar template and O2 plasma treatment, and displays a marginal resistance change of only ∼31.3% under a large strain of 500% due to the reorientation and elongation of the conductive network. The EGaIn conductor exhibits superior properties of a high uptake of LM and conductivity enhancement from ∼2.38 × 104 (0% strain) to ∼2.97 × 105 S m−1 (500% strain) due to the strong capillary force during stretching. This work is a significant step toward high-performance stretchable conductors, demonstrating great potential in multifunctional device development including self-powered nanogenerators, electromagnetic interface (EMI) shielding, and thermal regulators. [ABSTRACT FROM AUTHOR]