With the wide application of UAVs in modern intelligent warfare as well civil fields, demand for C-UAS technology is increasingly urgent. Traditional detection methods have many limitations dealing with “low, slow, and small” targets. This paper presents a pure laser automatic tracking system based on Geiger-mode avalanche photodiode (Gm-APD). Combining target motion state prediction Kalman filter adaptive Camshift, Cam–Kalm algorithm proposed to achieve high-precision stable moving The also...

In this study, the memory effect of a polymer is investigated with mesomorphic isotactic polypropylene (iPP) melt as initial state. It found that nucleation density and crystallization rate at low temperatures are strongly dependent on melting temperature time, indicating strong effect. High decrease density, while short time causes faster than in its thermal history removed. At 180 °C, it takes about 1 hour for to be restored normal value erasure 220 °C. Further experiments indicate...

In this study, we built a single photon avalanche diode (SPAD) receiver based underwater wireless optical communication (UWOC) system. The bit error rate (BER) and signal-to-noise ratio (SNR) performance of UWOC with different distances data transmission rates were obtained. Based on the water attenuation coefficient 0.12 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> , series neutral density (ND) filters exploited to attenuate light...

Double network structure constructed with filler of carbon black and molecular natural rubber possesses excellent toughness strength. However, due to lack proper in situ imaging techniques detect the structural evolutions under loading, reinforcement mechanism is still debate. Here synchrotron radiation X-ray nano-computed tomography high spatial resolution (100 nm) employed study evolution a large volume matrix. For first time, strain-induced deformation, destruction, reconstruction are...

In order to solve the problem of detecting, tracking and estimating size “low, slow small” targets (such as UAVs) in air, this paper designs a single-photon LiDAR imaging system based on Geiger-mode Avalanche Photodiode (Gm-APD). It improves Mean-Shift algorithm proposes an automatic method that combines weighted centroid realize target extraction, principal component analysis (PCA) adaptive rotating rectangle is realized fit flight attitude target. This uses intensity distance information...

The Geiger-Mode Avalanche Photodiode (Gm-APD) LiDAR system demonstrates high-precision detection capabilities over long distances. However, the of occluded small objects at distances poses significant challenges, limiting its practical application. To address this issue, we propose a multi-scale spatio-temporal object network (MSTOD-Net), designed to associate information across different scales for effective objects. Specifically, in encoding stage, dual-channel feature fusion framework is...

Military settlements along the Ming Great Wall are typical representatives of construction ancient Chinese military defense system. The location fortification is complex, and scattered affected by multiple factors. academic community lacks systematic research on Wall. Existing studies focus local protection, especially regional connectivity overall mechanism in Hexi Corridor. This study incorporates distribution, morphology, function Corridor into a unified analytical framework to explore...

Abstract Novel interpenetrating polymer network membranes were made from poly(vinyl alcohol)/poly(vinyl pyrrolidone) blends of different compositions. The two components independently crosslinked chemically with glutaraldehyde and photochemically 4,4′‐diazostilbene‐2,2′‐disulfonic acid disodium salt. membrane performances studied in pervaporation tetrahydrofuran (THF)/water THF/methanol mixtures. It was found that the excellent THF dehydration, but much less efficient for separation results...

As an indispensible material for modern society, natural rubber possesses peerless mechanical properties such as strength and toughness over its artificial analogues, which remains a mystery. Intensive experimental theoretical investigations have revealed the self-enhancement of due to strain-induced crystallization. However rigorous model on self-enhancement, elucidating rubber's extraordinary properties, is obscured by deficient understanding local hierarchical structure under strain. With...

The effect of flow on crystallization is commonly attributed to entropic reduction, which caused by stretch and orientation polymer chains but overlooks the role final-state free energy. With aid in situ synchrotron radiation wide-angle X-ray diffraction (WAXD) a homemade constrained uniaxial tensile testing machine, polycrystals possessing single-crystal-like rather than are found during natural rubber, whereas c-axis a-axis align direction (SD) (CD), respectively. Molecular dynamics...

The luminescence enhancement effect of different kinds and contents rare earth complexe (RE(DBM)3Phen, RE = Dy, La, Gd, Sm, Y; DBM dibenzoylmethane; Phen 1,10-phenanthroline) sensitized Eu(DBM)3Phen doped in poly(methyl methacrylate) (PMMA) matrix was investigated using the combinatorial method. efficiency increases with a decrease weight percentage an increase molecular PMMA systems. Among these sensitization ion complexes, La(DBM)3Phen shows highest efficiency. At optimal content 5 wt %...

Abstract The memory effect of metastable β form crystals trans ‐1,4‐polyisoprene (TPI) is investigated with its thermodynamically stable α‐TPI as reference. Unexpectedly, β‐TPI exhibits a stronger over α‐TPI. temperature can be 20 °C higher than equilibrium melting point (78 °C), while has lost below the (87 °C). Moreover, ordered structures in memorized melt accelerate spherulite growth, and growth rate depends on time, similar to previous mesomorphic isotactic polypropylene studies,...

The 3D dispersion and breakage of CB aggregates in the natural rubber matrix are obtained by TXM at stain 3.

Let $(X,f)$ be a topological dynamical system and ${\mathcal{F}}$ Furstenberg family (a collection of subsets $\mathbb{N}$ with hereditary upward property). A point $x\in X$ is called an -transitive if for every non-empty open subset $U$ $X$ the entering time set $x$ into , $\{n\in \mathbb{N}:f^{n}(x)\in U\}$ in ; -point transitive there exists some point. In this paper, we first discuss connection between transitivity -transitivity, show that weakly mixing strongly systems can characterized...

Epilepsy is one of the most common neurological disorder diseases all over world, which gives patients a huge burden in seizure-related disabilities. For epileptic seizure detection, encephalography (EEG) commonly used clinical approach. Recently, several Internet Things (IoT)-based wearable monitoring systems using machine learning (ML) approaches have been proposed to assist real-time detection attack scenarios. Among these approaches, convolutional neural networks (CNNs) provide superior...

The influences of Fe/Ni substitution for Co the local atomic structures, glass-forming ability (GFA), and magnetic properties a Co71.5Y3.5B25 metallic glass (MG) have been systematically investigated by utilizing combination experiments ab initio molecular dynamics simulations. It is demonstrated that effectively improves GFA. Specifically, (Co0.7Fe0.3)71.5Y3.5B25 MG exhibits superior GFA with achieving critical diameter 2.0 mm. hightened attractions between B-B, Co-Y, B-Y, Co-Fe, B-Fe pairs...

When using Geiger mode Avalanche Photo Diode (Gm-APD) array lidar for long-distance imaging, the few echo photons make it challenging to get target position. To solve these problems, this paper proposes a spatial correlation extraction algorithm combined with morphological filtering (SCMF), which uses of superposition weight pixel histogram, increasing number statistical frames, improving signal-to-noise (SNR) data and accurately extracting distance value pixel. Spatial also improves...