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The Circum-Bohai-Sea Region is an important economic zone of China. The sea ice, which occurs at each winter, is the major marine hazard of the Bohai Sea. As a result, it is very important to evaluate the damage effects quantitatively in this region, which is seldom studied and analyzed systematically using long-time-series data. In this paper, the sea-ice disaster in the Bohai Sea is evaluated quantitatively based on the Sentinel-1 and GOCI. For different hazard-bearing bodies of the marine transportation and the offshore constructions, different sea-ice-hazard indexes are defined, which can be applied to analyze the sea-ice disaster quantitatively in the Bohai Sea, including the annual and inter-annual variations in the period from 2011 to 2017. The analysis results can provide the reference of the sea-ice monitoring in the Bohai Sea.

To study the characteristics of nitrogen (N) loss on slopes, different vegetation (bare soil, alfalfa), slopes (5°, 10°, 15°), and rainfall intensities (40, 60, 80 mm/h) were set as variable factors in simulated rainfall experiments. Surface runoff accounts for 60.38–96.16% of total runoff and most N loss (57.69–88.67% of NO3−-N). Alfalfa can reduce average concentrations of N loss in runoff and reduce N loss in surface runoff by more than 48.29%, as well as subsurface runoff by 3.8%. Average N loss in subsurface runoff exceeds that of surface runoff. Rainfall intensity most affects N loss from surface runoff in bare soil conditions, and slope most affects N loss in subsurface runoff. Rainfall intensity in alfalfa treatments most influences runoff volume and N loss. The comprehensive effects of rainfall intensity, slope, and vegetation cover on the total loss of various forms of nitrogen in surface runoff can be described using a linear correlation equation, with a correlation coefficient between 0.84 and 0.91. [ABSTRACT FROM AUTHOR]

Two-dimensional semiconductors, such as MoS2, have demonstrated great potential applications in post-Moore electronic and optoelectronic devices, and organic cations intercalation has been widely utilized to modulate their physical properties. However, the correlation between the conductivity, carrier mobility, carrier density, and structure of organic cations intercalated MoS2 is still unclear. In this Letter, we systematically investigated the structural and electrical transport properties of pristine MoS2 and MoS2 intercalated with various organic cations such as tetradecyltrimethyl-ammonium, tetraheptyl-ammonium, and cetyltrimethyl-ammonium. Semimetal bismuth (Bi) was used as electrodes to make Ohmic contact with MoS2, and four-probe measurements were employed to obtain the intrinsic conductivity of MoS2. The intercalated organic cations greatly expand interlayer spacing and strongly dope MoS2 up to an electron concentration of 6.1 × 1013 cm−2 depending on the size and intercalation amount of organic cations. The severe electron doping constrains the out-of-plane A 1 g vibration mode and screens the Coulomb scattering, such that the intercalated MoS2 has enhanced Hall mobility of >50 cm2 V−1 s−1 at room temperature and even >1700 cm2 V−1 s−1 at 5 K. The intercalated MoS2 responds much faster than pristine MoS2 when functioning as a phototransistor. Our work provides insight for understanding the electrical transport properties of MoS2 and designing more efficient electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

The gas flow temperature signal simulation system (ATSSS) plays a crucial role in the hardware-in-the-loop simulation of hypersonic aircraft. The accuracy of gas flow temperature measurements is of paramount importance for the ATSSS. This system comprises a high-temperature plasma heater, a gas flow mixing chamber, and thermocouples. The ATSSS exhibits specific characteristics such as high temperatures, rapid temperature changes, and fast flow rates. However, due to the large measurement time constant of high-temperature thermocouples, significant dynamic errors are introduced into the measurement results. To address this issue and enhance the dynamic measurement accuracy of gas flow temperature, this study establishes a thermocouple heat transfer model for the ATSSS. It also analyzes the mechanism behind the generation of dynamic errors in the ATSSS and proposes a three-thermocouple coupled temperature measurement dynamic compensation method (TTCTMDC). This method compensates for errors caused by thermal convection, thermal radiation, and thermal conduction under high-temperature conditions. Simulation results demonstrate that the proposed method can reduce errors by 50% to 80%. In addition, an experimental platform for the ATSSS is constructed, and the TTCTMDC method is employed to compensate for measurement errors. The results indicate that the dynamic measurement error can be reduced to 1/4 to 1/2 of the original value using the TTCTMDC method. This research lays a foundation for the successful development of the ATSSS and provides a novel approach to dynamically measuring high-temperature gas flow, thereby advancing scientific research in the field of measurement. [ABSTRACT FROM AUTHOR]

The pylon of the Xinshougang Bridge, a welded steel box arch with a variable cross-section, exhibits asymmetrical design and unevenly inclined limb ends. The segmented assembly of this uniquely shaped steel pylon necessitates precise splicing. In this paper, a novel three-point method for segment attitude positioning is proposed based on the local coordinate system. This method facilitates accurate coordinate translation and attitude alignment between the section preparation facility and the construction site. Furthermore, a predictive methodology for segment posture during erection is introduced, aiming to minimize misalignments at the connection interfaces. This approach accounts for potential deviations arising in manufacturing and erection phases. The synergistic application of these methods effectively ensures the precise geometric shape of the bending and twisting steel tower throughout its phased construction. [ABSTRACT FROM AUTHOR]

Accurate target prediction, especially bounding box estimation, is a key problem in visual tracking. Many recently proposed trackers adopt the refinement module called IoU predictor by designing a high‐level modulation vector to achieve bounding box estimation. However, due to the lack of spatial information that is important for precise box estimation, this simple one‐dimensional modulation vector has limited refinement representation capability. In this study, a novel IoU predictor (IoUNet++) is designed to achieve more accurate bounding box estimation by investigating spatial matching with a spatial cross‐layer interaction model. Rather than using a one‐dimensional modulation vector to generate representations of the candidate bounding box for overlap prediction, this paper first extracts and fuses multi‐level features of the target to generate template kernel with spatial description capability. Then, when aggregating the features of the template and the search region, the depthwise separable convolution correlation is adopted to preserve the spatial matching between the target feature and candidate feature, which makes their IoUNet++ network have better template representation and better fusion than the original network. The proposed IoUNet++ method with a plug‐and‐play style is applied to a series of strengthened trackers including DiMP++, SuperDiMP++ and SuperDIMP_AR++, which achieve consistent performance gain. Finally, experiments conducted on six popular tracking benchmarks show that their trackers outperformed the state‐of‐the‐art trackers with significantly fewer training epochs. [ABSTRACT FROM AUTHOR]

Ballast fouling occurs when the voids of granular particles are wholly or partially filled by fine particles. Railway ballast fouling is always an inevitable issue related to railway performance and safety in ballasted tracks. This paper presents an overview of the railway ballast fouling mechanism, current works, perspective, and innovation. The paper first reviews the fouling mechanism with different fouling sources and their influence, followed by the fouling indices. Then, fouling inspection methods are reviewed, and the ground penetrating radar is highlighted due to its high efficiency and accuracy. The proposed solutions, including rehabilitation, prevention, reinforcement, and stabilization in the ballasted track, are introduced. Additionally, several perspectives and works for the future are mentioned. Ballast cleaning is a thorough and effective treatment. Ground-penetrating radar inspection and proper evaluation can provide a preview and perspective on ballast cleaning determination. [ABSTRACT FROM AUTHOR]