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Enhancing the efficiency of charge carrier separation is crucial for improving the performance of photocatalysts, thereby offering more effective solutions to energy and environmental pollution challenges. In this study, a carbon‐deficient ultra‐thin porous g‐C3N4 (Vc‐UPCN) was synthesized and subsequently was integrated with Bi2Fe4O9 (BFO) using a sonochemical self‐assembly technique, a Bi2Fe4O9/Vc‐UPCN (BC) photocatalyst featuring a Z‐scheme heterojunction. The BC catalyst was subjected to corona poling treatment to obtain BCp, which possesses an intrinsic electric field. Compared with pure BFO and Vc‐UPCN, the BC heterojunction exhibited higher photo‐generated electron–hole separation efficiency and photodegradation ability. Upon introduction of corona polarization, the photocatalytic performance of BC was further enhanced. Specifically, BCp‐15 (BFO/BC mass fraction = 15) achieved complete degradation of methylene blue (MB) within 30 min. BCp‐15 demonstrated that its degradation efficiency for MB was 1.28 times higher than that of BC‐15, 1.85 times higher than that of Vc‐UPCN, and impressive 7.69 times higher than that of pure BFO. The coupling effect of the heterojunction and ferroelectric polarization significantly improved the separation efficiency of photo‐generated carriers in BCp. This study is expected to provide a reference for the synergistic application of heterojunction and ferroelectric polarization in traditional semiconductor photocatalysis. [ABSTRACT FROM AUTHOR]

A high speed/high flow test facility was designed and implemented to study experimentally the supercavitating flow behind a projectile nose in a controlled laboratory setting. The simulated projectile nose was held in position in the flow and the cavity interior was made visible by having the walls of the visualization facility 'cut through' the supercavity. Direct visualization of the cavity interior and measurements of the properties of the cavity contents were made. Transducers were positioned in the test section within the supercavitation volume to enable measurement of the sound speed and attenuation as a function of the flow and geometry parameters. These characterized indirectly the content of the cavity Photography, high speed videos, and acoustic measurements were used to investigate the contents of the cavity A side sampling cell was also used to sample in real time the contents of the cavity and measure the properties. Calibration tests conducted in parallel in a vapor cell enabled confirmation that, in absence of air injection, the properties of the supercavity medium match those of a mixture of water vapor and water droplets. Such a mixture has a very high sound speed with strong sound attenuation. Injection of air was also found to significantly decrease sound speed and to increase transmission. [DOI: I 0.1115/1.2409356]

Cooperative guidance and control design of multiple vehicles plays an important role in obtaining benefits of cooperation for enhancement of combat effectiveness in modern military. A number of efficient cooperative strategies have been developed in literature within this context. This paper aims to provide a detail overview of the theoretical advances toward multi‐vehicle coordination for cooperative attack and defense. With a focus on the pertinent literature published in the past two decades, this topic is divided into two categories, namely, terminal‐time coordination and multiplayer pursuit‐evasion. The recent progress of these two categories is systematically reviewed, and a short discussion on future research perspectives is also presented. [ABSTRACT FROM AUTHOR]

This paper investigates an adaptive gradient‐based online convex optimization problem over decentralized networks. The nodes of a network aim to track the minimizer of a global time‐varying convex function, and the communication pattern among nodes is captured as a connected undirected graph. To tackle such optimization problems in a collaborative and distributed manner, a weight decay distributed adaptive online gradient algorithm, called WDDAOG, is firstly proposed, which incorporates distributed optimization methods with adaptive strategies. Then, our theoretical analysis clearly illustrates the difference between weight decay and L2 regularization for distributed adaptive gradient algorithms. The dynamic regret bound for the proposed algorithm is further analyzed. It is shown that the dynamic regret bound for convex functions grows with order of O(n(1+logT)+nT), where T and n represent the time horizon and the number of nodes associated with the network, respectively. Numerical experiments demonstrate that WDDAOG works well in practice and compares favorably to existing distributed online optimization schemes. [ABSTRACT FROM AUTHOR]