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In this work, the conformational behaviors of ring polyelectrolyte in tetravalent salt solutions are discussed in detail through molecular dynamics simulation. For simplification, here we have neglected the effect of the twisting interaction, although it has been well known that both bending and twisting interactions play a deterministic in the steric conformation of a semiflexible ring polymer. The salt concentration CS and the bending energy b take a decisive role in the conformation of the ring polyelectrolyte (PE). Throughout our calculations, the b varies from b = 0 (freely joint chain) to b = 120. The salt concentration CS changes in the range of 3.56 × 10−4 M ≤ CS ≤ 2.49 × 10−1 M. Upon the addition of salt, ring PE contracts at first, subsequently re-expands. More abundant conformations are observed for a semiflexible ring PE. For b = 10, the conformation of semiflexible ring PE shifts from the loop to two-racquet-head spindle, then it condenses into toroid, finally arranges into coil with the increase of CS. As b increases further, four phase transitions are observed. The latter two phase transitions are different. The semiflexible ring PE experiences transformation from toroid to two racquet head spindle, finally to loop in the latter two phase transitions. Its conformation is determined by the competition among the bending energy, cation-bridge, and entropy. Combined, our findings indicate that the conformations of semiflexible ring PE can be controlled by changing the salt concentration and chain stiffness. [ABSTRACT FROM AUTHOR]

An increasing number of studies have shown that the seismic response of shield tunnels differs from that of aboveground structures. While the seismic response of aboveground structures is mainly influenced by the peak acceleration and frequency of the earthquake, the seismic response of shield tunnels is more influenced by the ground displacement due to the surrounding soil layers. In this study, it is not appropriate to follow the seismic concept of aboveground structures. Dynamic time-history analysis is a powerful and effective method to study the seismic response of tunnels in the typical subway in this paper. The analysis results show that the overall levelling of the tunnel will not affect the tunnel too much, and the seismic response of the tunnel is mainly related to the relative displacement of the ground around the tunnel. The analysis results show that the internal force of the tunnel and the tunnel inclination have a good linear relationship, and the tunnel inclination can be used to measure the magnitude of the seismic response of the tunnel. In the seismic design of shield tunnels, the inclination of the tunnel can be taken into account to evaluate the change in the internal forces of the tunnel during earthquakes, which avoids the need for complex dynamic time-history analysis and greatly improves the efficiency of the seismic design of shield tunnels. [ABSTRACT FROM AUTHOR]

The identification of stay cable icing is crucial for robot deicing to improve efficiency and prevent damage to stay cables. Therefore, it is significant to identify the areas and degree of icing in the images of stay cables. This study proposed a two-stage model that combines U-Net and ResNet50. In the first stage, this model used U-Net to segment the surface ice and icicles from the stay cable. The image of icing obtained after segmentation was used as the input for the second stage. In the second stage, ResNet50 was used to classify the degree of icing. The experimental results show that the proposed model can successfully segment the icicles and surface ice from the stay cable icing image to complete the classification of the icing degree. The mean pixel accuracy and intersection over the union of icing were 96.65% and 82.10%, respectively. The average accuracy of the icing degree classification was 95.71%. The method proposed in this study meets the requirements of robustness, segmentation accuracy, and classification accuracy for stay cable icing recognition, which provides a research basis for the precise icing recognition of cable-deicing robots. [ABSTRACT FROM AUTHOR]

To achieve wide-gamut and high-efficiency tandem white OLED (WOLED) microdisplays, we propose a new structure leveraging high-order antinodes and patterned microcavities. The color gamut coverages of 95% Rec. 2020 and 92% Rec. 2020 can be achieved in B/G/R tandem WOLED with a moderate microcavity and B/YG tandem WOLED with a strong microcavity, respectively. We have also boosted the optical efficiency by 62% for the tandem B/YG WOLED using the high-order antinodes at optimal conditions. Such a WOLED microdisplay helps reduce the power consumption of virtual reality (VR) and mixed reality (MR) displays while keeping a wide color gamut. [ABSTRACT FROM AUTHOR]

Visual Simultaneous Localization and Mapping (VSLAM) estimates the robot's pose in three-dimensional space by analyzing the depth variations of inter-frame feature points. Inter-frame feature point mismatches can lead to tracking failure, impacting the accuracy of the mobile robot's self-localization and mapping. This paper proposes a method for removing mismatches of image features in dynamic scenes in visual SLAM. First, the Grid-based Motion Statistics (GMS) method was introduced for fast coarse screening of mismatched image features. Second, an Adaptive Error Threshold RANSAC (ATRANSAC) method, determined by the internal matching rate, was proposed to improve the accuracy of removing mismatched image features in dynamic and static scenes. Third, the GMS-ATRANSAC method was tested for removing mismatched image features, and experimental results showed that GMS-ATRANSAC can remove mismatches of image features on moving objects. It achieved an average error reduction of 29.4% and 32.9% compared to RANSAC and GMS-RANSAC, with a corresponding reduction in error variance of 63.9% and 58.0%, respectively. The processing time was reduced by 78.3% and 38%, respectively. Finally, the effectiveness of inter-frame feature mismatch removal in the initialization thread of ORB-SLAM2 and the tracking thread of ORB-SLAM3 was verified for the proposed algorithm. [ABSTRACT FROM AUTHOR]

Problems such as the expansion of impervious areas and changes in underlying surfaces have occurred in cities due to rapid urbanization, along with an increasing probability of extreme rainfall. Based on the normalized building index (NDBI) of underlying surfaces, calculated from remote sensing images in the Pearl River Delta from 1990 to 2020, this study determines the underlying surface changes in the Pearl River Delta. Based on the hourly rainfall data of meteorological stations in the Pearl River Delta region from 1990 to 2020, the extreme rainfall indexes are calculated to analyze the changes in extreme rainfall in the Pearl River Delta. Based on the NDBI of underlying surfaces and extreme rainfall calculated in the Pearl River Delta, the evolution of underlying surfaces and extreme rainfall is analyzed, as is the correlation between them, and the main conclusions are as follows: (1) From 1990 to 2020, the NDBI in highly urbanized areas in the Pearl River Delta was higher than that in non-highly urbanized areas. The NDBI in highly urbanized areas showed an increasing trend, and the growth rate tended to slow down; (2) From 1990 to 2020, extreme rainfall in highly urbanized areas of the Pearl River Delta was higher than in non-highly urbanized areas. Extreme rainfall in both highly urbanized areas and non-highly urbanized areas showed an increasing trend, with that in highly urbanized areas increasing faster; (3) The positive correlation between the NDBI and extreme rainfall indicators in highly urbanized areas is more significant than that in non-highly urbanized areas. [ABSTRACT FROM AUTHOR]

The real-time derivation of the concentration, area, and velocity of river surface ice based on camera imagery is essential for predicting the potential risks related to ice blockages in water routes. The key lies in the continuous tracking and velocity measuring of river ice, and reliable ice motion detection is a prerequisite for the dynamic perception of tracking targets. Previous studies did not utilize motion tracking for measuring ice velocity, and particle image velocimetry and feature point matching were used. This study aimed to use deep learning methods to address the challenging problems of deriving the ice concentration, area, and velocity based on camera imagery, and the focus was on measuring the ice velocity and drawing trajectories using the particle video tracking algorithm. We built a dataset named IPC_RI_IDS and collected information during the ice cover break-up process in the Nenjiang River (China). Our suggested approach was divided into four steps: (1) image preprocessing, where the camera image was calibrated to real-world coordinates; (2) determining the ice and water pixels in the camera image using the lightweight semantic segmentation network and then calculating the ice concentration and area; (3) enhancing and optimizing motion detection using the semantic segmentation results; and (4) adapting the particle video tracking algorithm to measure ice velocity using the proposed tracking points generation strategy. Finally, we analyzed the surface ice data in the study area and attempted to predict the stage of the ice break-up process to provide support for the real-time short-term forecasts of ice floods. [ABSTRACT FROM AUTHOR]

This paper presents an anti-swing control method to prevent situations where inspection robots detach and fall off transmission lines during obstacle crossing due to excessive swing angles caused by the rotation of the robot around the transmission line. Firstly, an obstacle-crossing model for the inspection robot was constructed and the causes of robot swinging phenomena were analyzed, in addition to their impact on obstacle crossing stability. By combining this with the obstacle-crossing model, a moment balance equation was established for the inspection robot. This equation can be used to solve mapping relationships between body offset and the tilt angle of transmission line gripping arms. We propose an anti-swing control strategy by adjusting the angle of the transmission line gripping arm's pitching joint to make the body offset approach zero, and by utilizing the advantages of fuzzy logic in the fuzzy PID algorithm compared with the traditional PID algorithm, it can adaptively avoid the occurrence of robot swinging phenomena. The experimental results of obstacle-crossing experiments under no wind and wind turbulence conditions indicated that the proposed anti-swing control method in this study can effectively keep the body offset to within 3 mm. Compared with the methods of not using anti-swing control and using traditional PID anti-swing control, in the absence of wind effects, the peak values of body offset were reduced by 96.53% and 18.85%, respectively. Under the influence of wind turbulence, the peak values of body offset were reduced by 97.02% and 27.12%, respectively. The effectiveness of the anti-swing control method proposed in this paper has thus been verified. [ABSTRACT FROM AUTHOR]

Silver (Ag) thin films have garnered significant attention due to their unique optical properties. This paper systematically investigates the optical characteristics of Ag films prepared using the electron beam evaporation method. The investigation was conducted using spectroscopic ellipsometry and covers a broad wavelength range of 1679 nm to 36 µm (0.738–0.034 eV), spanning from near-infrared to far-infrared regions. Optical and dispersion models were developed to analyze the impacts of Ag nanostructures on the complex refractive indices, dielectric functions, and reflectance. The results indicate that Ag particles and coalescence films exhibit non-metallic and low absorption properties, while Ag percolation and continuous films present a typical Drude model. The reflectance of Ag films increases as the film coverage ratio increases, and it can reach close to 100% in continuous film. Additionally, a non-destructive, non-contact, and vacuum-free means of confirming the percolation threshold of Ag films was proposed based on the slope of the imaginary part curve. This work is useful to guide simulations and provide a basis for the applications of Ag films in different fields. [ABSTRACT FROM AUTHOR]

Focusing on the problem of low detection precision caused by the few-shot and multi-scale characteristics of air objects, we propose a few-shot air object detection network (FADNet). We first use a transformer as the backbone network of the model and then build a multi-scale attention mechanism (MAM) to deeply fuse the W- and H-dimension features extracted from the channel dimension and the local and global features extracted from the spatial dimension with the object features to improve the network's performance when detecting air objects. Second, the neck network is innovated based on the path aggregation network (PANet), resulting in an improved path aggregation network (IPANet). Our proposed network reduces the information lost during feature transfer by introducing a jump connection, utilizes sparse connection convolution, strengthens feature extraction abilities at all scales, and improves the discriminative properties of air object features at all scales. Finally, we propose a multi-scale regional proposal network (MRPN) that can establish multiple RPNs based on the scale types of the output features, utilizing adaptive convolutions to effectively extract object features at each scale and enhancing the ability to process multi-scale information. The experimental results showed that our proposed method exhibits good performance and generalization, especially in the 1-, 2-, 3-, 5-, and 10-shot experiments, with average accuracies of 33.2%, 36.8%, 43.3%, 47.2%, and 60.4%, respectively. The FADNet solves the problems posed by the few-shot characteristics and multi-scale characteristics of air objects, as well as improving the detection capabilities of the air object detection model. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO)-based solid-state electrolytes for lithium-ion batteries have garnered significant interest due to their enhanced potential window, high energy density, and improved safety features. However, the issues such as low ionic conductivity at ambient temperature, substantial ionic conductivity fluctuations with temperature changes, and inadequate electrolyte interfacial compatibility hinder their widespread applications. Electrospinning is a popular approach for fabricating solid-state electrolytes owing to its superior advantages of adjustable component constitution and the unique internal fiber structure of the resultant electrolytes. Thus, this technique has been extensively adopted in related studies. This review provides an overview of recent advancements in optimizing the performance of PEO solid-state electrolytes via electrospinning technology. Initially, the impacts of different lithium salts and their concentrations on the performance of electrospun PEO-based solid-state electrolytes were compared. Subsequently, research pertaining to the effects of various additives on these electrolytes was reviewed. Furthermore, investigations concerning the enhancement of electrospun solid-state electrolytes via modifications of PEO molecular chains are herein detailed, and lastly, the prevalent challenges and future directions of PEO-based solid-state electrolytes for lithium-ion batteries are summarized. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of different vegetation on the permeability of the shallow soil layers of slopes under rainfall infiltration. Firstly, four large slopes are filled in an outdoor natural environment, and the overburdens of the four slopes are Magnolia multiflora, Cynodon dactylon, Magnolia multiflora mixed with Cynodon dactylon, and no vegetation. Secondly, the four slopes are cultivated in an outdoor natural environment for one year. After the vegetation overburdens are matured, the field artificial rainfall test is carried out through a self-developed artificial rainfall device to monitor the water migration law inside the four slopes in real time. Finally, the unsaturated permeability coefficients of the shallow soil layers of slopes are calculated. The results show that the infiltration rate of rainwater in each overburden slope from fastest to slowest is Magnolia multiflora overburden slope, no vegetation slope, Cynodon dactylon overburden slope, and Magnolia multiflora mixed with Cynodon dactylon overburden slope. In the early stage of rainfall, Magnolia multiflora increases the permeability coefficient of the shallow soil layer of the slope, thus weakening the anti-seepage ability of the slope, but the influence of Magnolia multiflora is not obvious in the later stage. Cynodon dactylon and Magnolia multiflora mixed with Cynodon dactylon can significantly reduce the permeability coefficient of the shallow soil layers of the slopes, thereby increasing the anti-seepage ability of the slopes, and the mixed planting of Magnolia multiflora and Cynodon dactylon can minimize the permeability coefficient of the shallow soil of the slope, resulting in the best anti-seepage effect. [ABSTRACT FROM AUTHOR]

To ensure the safe operation of high-voltage transmission line inspection robots during downhill descents without power and extend their range after a single charge, this paper proposes an energy-saving speed control method for the inspection robot's walking wheel motor on downhill slopes by integrating feedback braking and fuzzy PID control. By combining the parameter equation of the overhead catenary line and the structural characteristics of the overhead transmission line, this paper analyzes the relationship between the driving torque of the inspection robot's wheels and the horizontal displacement along the transmission ground wire before and after descending. Based on this analysis, a speed control and energy recovery scheme is developed for the inspection robot, which combines front-wheel feedback braking with rear-wheel regenerative braking. The fuzzy PID method is utilized to adjust the PWM duty cycle to achieve energy-efficient speed control of the inspection robot's rear walking wheels. Additionally, to improve the energy density and specific power of the robot's energy storage unit, a composite power source consisting of lithium batteries and supercapacitors is employed to recover energy from the front walking wheels through feedback braking. The combined simulation results indicate that, compared to fuzzy control and PID control, fuzzy PID control better regulates the robot's speed under varying slopes, wind resistance, and cable roughness. A downhill speed control system for the inspection of the robot's walking wheel motor was designed, and its effectiveness was validated through simulated high-voltage line experiments. The fuzzy PID control was demonstrated to effectively maintain the rear walking wheel speed within the targeted range during downhill descents. When descending along a fixed 30° angle cable, the fuzzy PID control resulted in an increase of 5.28% and 14.26% in the state of charge (SOC) of the supercapacitor compared to PID control and fuzzy control, respectively. Moreover, when descending along fixed angle cables of 10°, 20°, and 30°, as well as a variable angle cable ranging from 30° to 0°, the SOC of the supercapacitor increased by 17.55%, 26.25%, 38.45%, and 31.29%, respectively. This demonstrates the effective absorption of regenerative braking energy during the robot's downhill movement. [ABSTRACT FROM AUTHOR]

Vehicle displays are becoming more integrated into our daily lives. Achieving a premium driving experience demands the display panel to have high-resolution density and sufficient brightness, particularly when exposed to intense ambient light, as direct sunlight can obscure the displayed images. Combining Barten's model and diffraction theory, the performance of both infotainment displays and head-up displays (HUDs) is evaluated. For infotainment displays, over 800 nit brightness is essential for the driver to discern 55 pixel-per-degree (PPD) patterns under direct sunlight. For HUDs, a delicate balance between resolution density, brightness, transparency, and image quality must be exercised. By slightly reducing the resolution density to 50 PPD, the transparent micro-LED panel can concurrently achieve a reduced background image blur, low required display brightness (~4000 nits), and high background transmittance (~90%). [ABSTRACT FROM AUTHOR]

To make the snake robot crawl quickly along the high-voltage cable, this paper employs the Simulated Annealing Algorithm (SAA) to find the optimal step size for the spiral-winding gait of the snake robot and improve its crawling speed along the high-voltage cable. First, a spiral-winding gait for the robot is designed based on the configuration of the snake robot and the crawling environment along the cable. Next, the double-chain Hopf oscillator is used to generate the spiral-winding gait for the snake-like robot. After that, based on the snake robot's position, the SAA is employed to improve the crawling speed of the snake robot by finding the optimal step size of the spiral-winding gait. Finally, CoppeliaSim 4.0.0 software is used to analyze the optimization effect of the speed of the snake robot crawling along the cable. The results highlight that the maximum crawling speeds of the snake robot are 0.8868 cm/s, 0.8843 cm/s, 0.8598 cm/s, and 0.7971 cm/s, which are 18.01%, 8.16%, 11.01%, and 12.16% lower than the maximum speed obtained using the sampling fit method when the cable friction coefficients are 0.3, 0.4, 0.5, and 0.6. These simulation results verify the effectiveness of the optimized control algorithm. [ABSTRACT FROM AUTHOR]

In order to study the effect of surface roughness on lubrication performance of an elastic support water-lubricated tilting pad thrust bearing, a mixed lubrication (ML) deterministic model is hereby presented based on a unified Reynolds equation model. This very model incorporates the elastic–plastic deformation of asperities and polymer matrix of the thrust pad, as well as the elastic deformation of the rubber support. The randomly distributed surface roughness of the thrust pad is generated by a mathematical model and shares the same distribution characteristics as the measured surface roughness. The Greenwood and Williamson asperity contact model and thin plate deformation model are combined to solve the asperities contact stress and deformation. Meanwhile, the bearing ML performance is compared with the results calculated by a thermohydrodynamic (THD) lubrication model and a thermo-elasto-hydrodynamic (TEHD) lubrication model, while the film thickness is also compared with measurements. The results show that the water film thickness calculated by the ML model is smaller than that by the THD model and the TEHD model, but the water film temperature is higher. The roughness has a great influence on the contact area ratio and the lubrication state, but little effect on the average film thickness. A higher roughness indicates a higher rotational speed required for the bearing to achieve full hydrodynamic lubrication. The film thickness calculated by the mixed lubrication model is closer to the measured results. Overall, it is proved that the mixed lubrication model can more accurately predict the lubrication performance of bearings. Compared to the thin plate deformation model, the elastic deformation simulation based on the half-infinite space model severely overestimates the elastic deformation of the pad surface, making it unsuitable for calculating the elastic deformation of the polymer matrix of the thrust pad under contact force or water film pressure. This ML deterministic model provides an effective means for high-precision prediction of the lubrication performance of the elastic supported water-lubricated thrust bearings coupled with multi-layer soft materials. [ABSTRACT FROM AUTHOR]

Approximate analytical methods have been frequently used in geotechnical engineering to estimate the reliability of geotechnical structures due to their efficiency and simplicity. The main spirit of these methods is using the moments of the limit state function to estimate the reliability index. However, the moments are strongly dependent on the form of the limit state function, resulting in the fact that these methods are sensitive to the form of limit state functions. This study aims to systematically explore how various equivalent forms of limit state functions affect the performance of several commonly used approximate analytical methods, including the first-order second-moment method, the first-order reliability method, and the point estimation method. The applicable conditions of these methods are illustrated through five typical geotechnical examples. The results indicate that the estimated accuracy for the first-order second-moment method and the point estimation method is affected by the form of the limit state functions. Although the form of the limit state function does not affect the accuracy of the first-order reliability method, it affects computational efficiency. The limit state functions with an equivalent logarithmic form are almost always favorable for the investigated examples and are thus recommended in practice. [ABSTRACT FROM AUTHOR]

RGB-D-based technology combines the advantages of RGB and depth sequences which can effectively recognize human actions in different environments. However, the spatio-temporal information between different modalities is difficult to effectively learn from each other. To enhance the information exchange between different modalities, we introduce a SlowFast multimodality compensation block (SFMCB) which is designed to extract compensation features. Concretely, the SFMCB fuses features from two independent pathways with different frame rates into a single convolutional neural network to achieve performance gains for the model. Furthermore, we explore two fusion schemes to combine the feature from two independent pathways with different frame rates. To facilitate the learning of features from independent multiple pathways, multiple loss functions are utilized for joint optimization. To evaluate the effectiveness of our proposed architecture, we conducted experiments on four challenging datasets: NTU RGB+D 60, NTU RGB+D 120, THU-READ, and PKU-MMD. Experimental results demonstrate the effectiveness of our proposed model, which utilizes the SFMCB mechanism to capture complementary features of multimodal inputs. [ABSTRACT FROM AUTHOR]

The icing of bridge pylon crossbeams is a problem that could pose a serious threat to traffic during a cold winter. However, little research has been carried out on the problem and few corresponding countermeasures have been provided. This paper aims to propose a novel heating system, and to study the feasibility of beam de-icing and the related de-icing strategies so as to provide a reference scheme for the practical application of beam de-icing. A number of icing and de-icing tests were carried out on a scale model of Wuhan Yangtze River Second Bridge in the cold chamber. The de-icing effects of the beam in different environments and different de-icing methods were compared, and the recommended pre-heating time, applicable environment range, and heating method were given. The results of the model experiments show that pre-heating the heating system can prevent the surface of the beam from freezing and that the anti-icing method is more suitable for beam de-icing than the passive de-icing method. When the pre-heating time exceeds 7 min, the entire anti-icing process can be ice-free. When the wind velocity exceeds 5 m/s, it is safer to shut down the heating system, and using the passive de-icing method at the end of the icing can also eliminate the hidden danger of beam icing. [ABSTRACT FROM AUTHOR]

Camouflaged object detection (COD), in a broad sense, aims to detect image objects that have high degrees of similarity to the background. COD is more challenging than conventional object detection because of the high degree of "fusion" between a camouflaged object and the background. In this paper, we focused on the accurate detection of camouflaged objects, conducting an in-depth study on COD and addressing the common detection problems of high miss rates and low confidence levels. We proposed a ternary cascade perception-based method for detecting camouflaged objects and constructed a cascade perception network (CPNet). The innovation lies in the proposed ternary cascade perception module (TCPM), which focuses on extracting the relationship information between features and the spatial information of the camouflaged target and the location information of key points. In addition, a cascade aggregation pyramid (CAP) and a joint loss function have been proposed to recognize camouflaged objects accurately. We conducted comprehensive experiments on the COD10K dataset and compared our proposed approach with other seventeen-object detection models. The experimental results showed that CPNet achieves optimal results in terms of six evaluation metrics, including an average precision (AP)50 that reaches 91.41, an AP75 that improves to 73.04, and significantly higher detection accuracy and confidence. [ABSTRACT FROM AUTHOR]

To achieve 60 pixels per degree (PPD) and 100° field of view (FoV) while keeping a reasonably high aperture ratio for active-matrix liquid crystal displays (LCDs), field sequential color (FSC) is a promising approach. We evaluate the physical properties of a high birefringence nematic LC mixture and then use these data to simulate the performance of a fringe-field switching (FFS) LCD. Such an FFS LCD exhibits a fast average gray-to-gray response time (~1.5 ms) to enable FSC operation. By removing the spatial color filters, FSC operation triples the resolution density and optical efficiency, which are critical to high-resolution density and low power consumption virtual reality applications. Wide color gamut (96.2% of the DCI-P3 standard) and superior color uniformity are also demonstrated using such an FSC LCD. [ABSTRACT FROM AUTHOR]

Here, we report an ultracompact angular displacement sensor based on the Talbot effect of optical microgratings. Periodic Talbot interference patterns were obtained behind an upper optical grating. By putting another grating within the Talbot region, the total transmission of the two-grating structure was found to be approximatively in a linear relationship with the relative pitch angle between the two gratings, which was explained by a transversal shift of the Talbot interference patterns. The influence of the grating parameters (e.g., the grating period, the number of grating lines and the gap between the two gratings) was also studied in both a simulation and an experiment, showing a tunable sensitivity and range by simply changing the grating parameters. A sensitivity of 0.19 mV/arcsec was experimentally obtained, leading to a relative sensitivity of 0.27%/arcsec within a linear range of ±396 arcsec with the 2 μm-period optical gratings. Benefitting from tunable properties and an ultracompact structure, we believe that the proposed sensor shows great potential in applications such as aviation, navigation, robotics and manufacturing engineering. [ABSTRACT FROM AUTHOR]

The influence of saturation on the Poisson's ratio v of reservoir sediments has an engineering significance in the field of oil and nature gas exploration. Based on a self-developed combined (BE-EE-RC) test system, under the dehydration path, the Poisson's ratio variation of reservoir silty-fine sand in Hangzhou Bay, China, was investigated. Results show that the P- and S-wave velocities vary non-monotonically with decreasing saturation at different net stresses, and reach a maximum at the optimum saturation Sr(opt); Biot's theory with respect to variation in Vp with Sr matches well with the measured e data. With a small amount of gas intrusion, Poisson's ratio of saturated sand shows a sudden drop and gradually stabilizes; then, it attenuates slowly and reaches the minimum value at Sr(opt). Once the saturation degree decreases to the level lower than Sr(opt), it rapidly increases. Based on the soil–water characteristic curve (SWCC) and mesoscopic evolution of internal pore water morphology, the variation in Poisson's ratio v can be divided into four segments of saturation: the boundary effect stage, the primary transition stage, the secondary transition stage, and the unsaturated residual stage. Ultimately, a prediction model for Poisson ratio's v of the silty-fine sand was proposed to consider the saturation variation. [ABSTRACT FROM AUTHOR]

In recent years, protecting important objects by simulating animal camouflage has been widely employed in many fields. Therefore, camouflaged object detection (COD) technology has emerged. COD is more difficult to achieve than traditional object detection techniques due to the high degree of fusion of objects camouflaged with the background. In this paper, we strive to more accurately and efficiently identify camouflaged objects. Inspired by the use of magnifiers to search for hidden objects in pictures, we propose a COD network that simulates the observation effect of a magnifier called the MAGnifier Network (MAGNet). Specifically, our MAGNet contains two parallel modules: the ergodic magnification module (EMM) and the attention focus module (AFM). The EMM is designed to mimic the process of a magnifier enlarging an image, and AFM is used to simulate the observation process in which human attention is highly focused on a particular region. The two sets of output camouflaged object maps were merged to simulate the observation of an object by a magnifier. In addition, a weighted key point area perception loss function, which is more applicable to COD, was designed based on two modules to give greater attention to the camouflaged object. Extensive experiments demonstrate that compared with 19 cutting-edge detection models, MAGNet can achieve the best comprehensive effect on eight evaluation metrics in the public COD dataset. Additionally, compared to other COD methods, MAGNet has lower computational complexity and faster segmentation. We also validated the model's generalization ability on a military camouflaged object dataset constructed in-house. Finally, we experimentally explored some extended applications of COD. [ABSTRACT FROM AUTHOR]

The enhanced application performance of hollow-structured materials is attributed to their large surface area with more active sites. In this work, the hollow CoSn(OH)6 nanocubes with increased surface area and mesopores were derived from dense CoSn(OH)6 nanocube precursors by alkaline etching. As a result, the hollow CoSn(OH)6 nanocubes-based cathode electrode exhibited a higher area-specific capacitance of 85.56 µF cm−2 at 0.5 mA cm−2 and a mass-specific capacitance of 5.35 mF g−1 at 0.5 mA cm−2, which was more extensive than that of the dense precursor. Meanwhile, the current density was increased 4-fold with good rate capability for hollow CoSn(OH)6 nanocubes. [ABSTRACT FROM AUTHOR]

The small-strain stiffness of soil is significant in the accurate prediction of the deformation caused by interactions between foundation soil and structures. Considering the whole range of small strain (10−6~10−3), a bending element-resonant column (BE-RC) combined test system was developed to conduct continuous tests on the shear modulus of unsaturated soil. Under the dehydration path, it was used to investigate the small-strain shear modulus of unsaturated silty-fine sand in Hangzhou Bay, China. The results show that the shear modulus under different net stresses and matrix suctions appeared to non-linearly decay with the increase in strain until stable values were reached at a large strain. At the beginning from the saturated state, the Gmax value increased slowly with decreasing saturation and reached its maximum value at the optimum saturation (Sr)opt; then, it rapidly decayed to the level in the saturated, once the saturation degree decreased to a level lower than (Sr)opt. Additionally, an improved prediction model was proposed for the Gmax of unsaturated sand, considering different saturations. Based on the mesoscopic evolution of internal pore water morphology and the variation in intergranular stress caused by capillary action, the variation in the Gmax could be divided into three segments of saturation: the boundary effect stage, the transition stage and the unsaturated residual stage. [ABSTRACT FROM AUTHOR]

Germanium selenide (GeSe) thin films were fabricated by employing femtosecond pulsed-laser deposition (fs-PLD) on silicon (100) substrates at various substrate temperatures, ranging from 25 °C to 600 °C. The thin films' surface morphology qualities and optical properties were studied by utilising transmission electron microscopy (TEM) and X-ray diffraction (XRD). The X-ray diffraction result signifies that the thin films deposited on the silicon at a substrate temperature below 400 °C were amorphous Ge-Se. In contrast, those grown at 400 °C and above exhibited crystallised peaks of Ge-Se orthorhombic and tetragonal structures. The deposition growth rate of the thin films was also found to decrease substantially with increasing substrate temperature. These results show that the fs-PLD process has great potential for fabricating good quality Ge-Se thin film. This technique could enable the manufacture of modern optoelectronic devices for applications in optical communication, sensing, and ovonic threshold switching for the high-density crossbar memory array. [ABSTRACT FROM AUTHOR]

This paper deals with the stability characteristics of zeros for sampled-data models with a class of triangle sample and hold realized by a traditional zero-order hold. For any controlled models in the modern industrial system, using a digital control strategy has been shown to provide the means to achieve the assigned objectives. In this process, one must utilize the sample and hold device to obtain the sampled-data models. Previous studies have shown that the triangle sample and hold can improve the stability properties of zeros of a sampled-data control system compared with zero-order hold. However, it is difficult to use triangle sample and hold in practice. In this paper, an approximated method of using triangle sample and hold is proposed. More importantly, on the basis of that method, we explicitly derive the corresponding accurate sampled-data model of controlled models. In addition, we also provide the expression for sampling zeros and the theorem for the stability of a linear control system in the fast sampling process. The results of this paper show that the proposed method has the same advantages as the accurate one. Finally, theoretical findings are validated through numerical simulations with different considerations. [ABSTRACT FROM AUTHOR]

With combining multi-particle collision dynamics (MPCD) for the solvent and molecular dynamics (MD) for the polymer chains, we have studied the conformation and untying behaviors of a trefoil knot polymer chain translocated through a confined funnel-like channel. For the trefoil knot chain, we found that the untying knot behavior mostly happens during the translocation process, and the translocation behavior of linear chains is also simulated as a comparison. Some characteristics of the trefoil knot chain during translocation process, such as average gyration radius and the average end-to-end distances are discussed, and we statistic the scale relations of the translocation time versus the chain length, and that of the chain rigidity. This study may help to understand translocation behaviors of the knotted linear polymer chain in the capillary flow field. [ABSTRACT FROM AUTHOR]