A scheme for generating high-flux angularly uniform proton beams with high laser-to-proton energy conversion efficiency is proposed. Three laser beams are focused on a microwire array attached to a solid-density hemispheric target. The laser-driven hot electrons from the front of the microwire hemisphere generate a hot-electron sheath in the hollow behind it, so that the protons on its back are accelerated by target normal sheath acceleration. The accelerated protons are of high flux, as well as angularly and energetically uniform. The scheme should be useful for applications involving warm dense matter, such as isochoric heating and modification of materials, as well as for proton therapy and inertial confinement fusion.

Vessel trajectories from the Automatic Identification System (AIS) play an important role in maritime traffic management, but a drawback is the huge amount of memory occupation which thus results in a low speed of data acquisition in maritime applications due to a large number of scattered data. This paper proposes a novel online vessel trajectory compression method based on the Improved Open Window (IOPW) algorithm. The proposed method compresses vessel trajectory instantly according to vessel coordinates along with a timestamp driven by the AIS data. In particular, we adopt the weighted Euclidean distance (WED), fusing the perpendicular Euclidean distance (PED) and synchronous Euclidean distance (SED) in IOPW to improve the robustness. The realistic AIS-based vessel trajectories are used to illustrate the proposed model by comparing it with five traditional trajectory compression methods. The experimental results reveal that the proposed method could effectively maintain the important trajectory features and significantly reduce the rate of distance loss during the online compression of vessel trajectories.

A novel wide 3-dB axial ratio (AR) circularly polarized 2 × 2 array antenna is proposed in this paper. The spindle-shaped coupling cavity with tilted waveguide is capable of generating circular polarization waves from incident linear waves, which improves the AR bandwidth (ARBW) of the antenna. With this structure, a similar amplitude of the two orthogonal transmitted wave components and a stable phase difference of nearly 90° can be generated. The circularly polarized antenna proposed herein has been fabricated. According to the measurement results, the operating bandwidth from 5.32 to 6.13 GHz is <−10 dB. In addition, the measured ARBW, which is below 3 dB, can cover the range of 5.41–6.02 GHz. The maximum gain of the antenna can attain 15.65 dBi, and the efficiency is better than 80%.

A mathematical model of variable inclination continuous transverse stub (VICTS) antenna for low sidelobe design is proposed in this paper. VICTS antenna is an antenna with continuous transverse stubs on the parallel-plate waveguide and additional branches attached to the transverse stubs to generate radiation. The antenna using this technique has high aperture efficiency and keeps a significant solution for high-gain antenna. However, the sidelobe level (SLL) of this antenna is relatively high and increases continuously as the pitch angle decreases. This paper presents a fast calculation model for the SLL of VICTS antennas using leaky-wave theory and antenna array theory. The full-wave simulation results and model calculation results are in good agreement, so this model can be used for SLL suppression of VICTS antennas in different frequency bands. By controlling the aperture field distribution to be tapered, the SLL is suppressed to − 23.7 dB using this mathematical model.

An Electronic Navigational Chart (ENC) is a two-dimensional abstraction and generalisation of the real world and it limits users' ability to obtain more real and rich spatial information of the navigation environment. However, a three-dimensional (3D) chart could dramatically reduce the number of human errors and improve the accuracy and efficiency of manoeuvring. Thus it is important to be able to visualize charts in 3D. This article proposes a new model for future Electronic Chart Display and Information Systems (ECDIS) and describes our approach for the construction of web-based multi-resolution future ECDIS implemented in our system Automotive Intelligent Chart (AIC) 3D ECDIS, including multi-resolution riverbed construction technology, multi-layer technology for data fusion, Mercator transformation of the model, rendering and web publishing methods. AIC 3D ECDIS can support global spatial data and 3D visualization, which merges the 2D vector electronic navigational chart with the three-dimensional navigation environment in a unified framework and interface, and is also published on the web to provide application and data service through the network.

The driving mechanism of solar flares and coronal mass ejections is a topic of ongoing debate, apart from the consensus that magnetic reconnection plays a key role during the impulsive process. While present solar research mostly depends on observations and theoretical models, laboratory experiments based on high-energy density facilities provide the third method for quantitatively comparing astrophysical observations and models with data achieved in experimental settings. In this article, we show laboratory modeling of solar flares and coronal mass ejections by constructing the magnetic reconnection system with two mutually approaching laser-produced plasmas circumfused of self-generated megagauss magnetic fields. Due to the Euler similarity between the laboratory and solar plasma systems, the present experiments demonstrate the morphological reproduction of flares and coronal mass ejections in solar observations in a scaled sense, and confirm the theory and model predictions about the current-sheet-born anomalous plasmoid as the initial stage of coronal mass ejections, and the behavior of moving-away plasmoid stretching the primary reconnected field lines into a secondary current sheet conjoined with two bright ridges identified as solar flares.