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In this work, electron beam irradiation technology was used to increase the dielectric and energy storage performance of polypropylene (PP) films. Electron beam irradiation makes no difference on the crystal morphology but decreased the crystallinity and crystal size of PP. Besides, irradiation improved the thermal stability and polarity of PP. The irradiated PP films behaved much higher dielectric constant than pure PP films. Actually, the dielectric constant of the irradiated PP with 30 kGy was 3.98, while the dielectric constant of pristine PP was only 2.8. Furthermore, the irradiated PP films still kept low dielectric loss and AC conductivity. Weibull distribution test results proved electron beam irradiation improved the breakdown strength of PP films. The discharged energy storage of PP films increased from 1.3 J/[cm.sup.3] of pristine PP film to 3.6 J/[cm.sup.3] of irradiated PP with 30 kGy film. Moreover, the PP film irradiated with 30 kGy displayed an excellent charge-discharge efficiency of more than 95%. This research provides an easy and practical approach to investigate dielectric PP material for energy storage. KEYWORDS dielectric properties, electron beam irradiation, energy storage, polypropylene, 1 | INTRODUCTION Capacitors play critical roles in various fields such as aerospace, military, telecommunications, electronics, and power in the form of electronic components. [1] The characteristics of capacitors depend [...]

Despite the breadth of scientific literature on micro- and nanoplastics (MNPs), a standardized procedure for detecting MNPs is still lacking so far, leading to incomparable results between published studies. This work innovatively proposed the combination of machine learning with advanced optical photothermal infrared (O-PTIR) spectroscopy to develop an efficient and reliable detection framework for MNPs. Spectra of MPs and non-MPs were first collected and inputted to build a classification model, based on which four important wavenumbers were selected. A simplified support vector machine (SVM) model was subsequently developed using the selected four wavenumbers. Good predictive ability was evidenced by a high accuracy of 0.9133. The developed method can improve speed as well as the reliability of results, having a great potential for routine analysis of MNPs, ultimately leading to the standardization of detection methods.

The joint transmit and receive beamforming algorithm has been envisioned to optimise the target's signal‐to‐interference‐plus‐noise ratio by co‐designing the transmit and receive beamforming vectors simultaneously. However, the traditional design concepts for this algorithm only consider the monostatic radar system, which may not work as well for the multistatic radar system. The authors present a novel transmit and receive beamforming algorithm for the multistatic radar system that includes a common transmitter and multiple receivers. The transmit beamforming vector can directly influence the output signal‐to‐interference‐plus‐noise ratio of each radar subsystem. To ensure the balanced performance of the subsystems, the authors propose a weighted sum of the signal‐to‐interference‐plus‐noise ratio optimisation problem to co‐design the transmit and receive beamforming. The proposed problem is non‐convex, and the authors construct an iterative algorithm to solve it using semi‐definite relaxation and slack‐variable replacement techniques. By using pre‐determined weights, the output performance of each radar subsystem can be effectively regulated. The simulation results confirm that the proposed algorithm can ensure better output signal‐to‐interference‐plus‐noise ratio for the entire multistatic radar system than the conventional joint transmit and receive beamforming algorithm. [ABSTRACT FROM AUTHOR]

It is shown here that the model and empirical equation presented in a previous paper have not been completely qualified in terms of their limitations. Based on a new model developed in this paper, a theoretical expression for joint probability of detection for two overlapping gates is derived and confirms the excellent accuracy of Cann's empirical expression. The general principle can be applied to calculate range gate straddling loss for arbitrary gates with arbitrary correlation coefficients.