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Most visual simultaneous localization and mapping (SLAM) systems are based on the assumption of a static environment in autonomous vehicles. However, when dynamic objects, particularly vehicles, occupy a large portion of the image, the localization accuracy of the system decreases significantly. To mitigate this challenge, this paper unveils DOT-SLAM, a novel stereo visual SLAM system that integrates dynamic object tracking through graph optimization. By integrating dynamic object pose estimation into the SLAM system, the system can effectively utilize both foreground and background points for ego vehicle localization and obtain a static feature points map. To rectify the inaccuracies in depth estimation from stereo disparity directly on the foreground points of dynamic objects due to their self-similarity characteristics, a coarse-to-fine depth estimation method based on camera-road plane geometry is presented. This method uses rough depth to guide fine stereo matching, thereby obtaining the 3 dimensions (3D)spatial positions of feature points on dynamic objects. Subsequently, by establishing constraints on the dynamic object's pose using the road plane and non-holonomic constraints (NHCs) of the vehicle, reducing the initial pose uncertainty of dynamic objects leads to more accurate dynamic object initialization. Finally, by considering foreground points, background points, the local road plane, the ego vehicle pose, and dynamic object poses as optimization nodes, through the establishment and joint optimization of a nonlinear model based on graph optimization, accurate six degrees of freedom (DoFs) pose estimations are obtained for both the ego vehicle and dynamic objects. Experimental validation on the KITTI-360 dataset demonstrates that DOT-SLAM effectively utilizes features from the background and dynamic objects in the environment, resulting in more accurate vehicle trajectory estimation and a static environment map. Results obtained from a real-world dataset test reinforce the effectiveness.
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The development of bifunctional catalysts with subtle structures, high efficiencies, and good durabilities for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is crucial for overall water splitting. In this work, a multicomponent S-doped NiFe2O4/Ni-Fe micro nano flower electrocatalyst was synthesized rapidly on foam copper using a simple one-step constant current electrodeposition method. The introduction of S leads to the transformation of the microsphere structure of the Ni-Fe alloy into a cauliflower-like morphology and induces changes in the surface electronic structure, significantly enhancing the catalytic performance for the HER and OER. The S-NiFe2O4/Ni-Fe alloy/CF showed low overpotentials of 220 and 66 mV at 10 mA cm-2in 1.0 M KOH for the OER and HER, respectively. High durability OER and HER performances were demonstrated through 60 h of chronopotentiometry and 6000 CV cycles test. Excellent overall water splitting electrocatalytic activity was observed in the S-NiFe2O4/Ni-Fe alloy/CFâS-NiFe2O4/Ni-Fe alloy/CF two-electrode system. In particular, active-phase NiOOH, a highly active substance for OER, can be controllably formed in the reaction process owing to the nanoflower structure of multi-layer sulfur which slows down the dissolution of NiFe2O4/Ni-Fe alloy. These results suggest that this composite structure is a promising bifunctional electrocatalyst.
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The rational design of highly active and durable non-noble electrocatalysts for hydrogen evolution reaction (HER) is significantly important but technically challenging. Herein, a phosphor and cobalt dual doped copper-nickel alloy (P, Co-CuNi) electrocatalyst with high-efficient HER performance is prepared by one-step electrodeposition method and reported for the first time. As a result, P, Co-CuNi only requires an ultralow overpotential of 56 mV to drive the current density of 10 mA cm-2, with remarkable stability for over 360 h, surpassing most previously reported transition metal-based materials. It is discovered that the P doping can simultaneously increase the electrical conductivity and enhance the corrosion resistance, while the introduction of Co can precisely modulate the sub-nanosheets morphology to expose more accessible active sites. Moreover, XPS, UPS, and DFT calculations reveal that the synergistic effect of different dopants can achieve the most optimal electronic structure around Cu and Ni, causing a down-shifted d-band center, which reduces the hydrogen desorption free energy of the rate-determining step (H2O + e- + H* â H2 + OH-) and consequently enhances the intrinsic activity. This work provides a new cognition toward the development of excellent activity and stability HER electrocatalysts and spurs future study for other NiCu-based alloy materials.
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To develop hydrogen energy production and address the issues of global warming, inexpensive, effective, and long-lasting transition metal-based electrocatalysts for the synthesis of hydrogen are crucial. Herein, a porous electrocatalyst NiMo/Ni/NF was successfully constructed by a two-step electrodeposition process, and was used in the hydrogen evolution reaction (HER) of electrocatalytic water decomposition. NiMo nanoparticles were coated on porous Ni/NF grown on nickel foam (NF), leading to a resilient porous structure with enhanced conductivity for efficient charge transfer, as well as distinctive three-dimensional channels for quick electrolyte diffusion and gas release. Notably, the low overpotential (42 mV) and fast kinetics (Tafel slope of 44 mV dec-1) at a current density of 10 mA cm-2 in 1.0 M KOH solution demonstrate the excellent HER activity of the electrode, which was superior to that of recently reported non-noble metal-based catalysts. Additionally, NiMo/Ni/NF showed extraordinary catalytic durability in stability tests at a current density of 10 mA cm-2 for 70 h. The porous structure catalyst and the electrodeposition-electrocatalysis technique examined in this study offer new approaches for the advancement of the electrocatalysis field because of these benefits.
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Rapid advancements in immersive communications and artificial intelligence have created a pressing demand for high-performance tactile sensing gloves capable of delivering high sensitivity and a wide sensing range. Unfortunately, existing tactile sensing gloves fall short in terms of user comfort and are ill-suited for underwater applications. To address these limitations, we propose a flexible hand gesture recognition glove (GRG) that contains high-performance micropillar tactile sensors (MPTSs) inspired by the flexible tube foot of a starfish. The as-prepared flexible sensors offer a wide working range (5 Pa to 450 kPa), superfast response time (23 ms), reliable repeatability (â¼10000 cycles), and a low limit of detection. Furthermore, these MPTSs are waterproof, which makes them well-suited for underwater applications. By integrating the high-performance MPTSs with a machine learning algorithm, the proposed GRG system achieves intelligent recognition of 16 hand gestures under water, which significantly extends real-time and effective communication capabilities for divers. The GRG system holds tremendous potential for a wide range of applications in the field of underwater communications.
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Intelligent vehicles are constrained by road, resulting in a disparity between the assumed six degrees of freedom (DoF) motion within the Visual Simultaneous Localization and Mapping (SLAM) system and the approximate planar motion of vehicles in local areas, inevitably causing additional pose estimation errors. To address this problem, a stereo Visual SLAM system with road constraints based on graph optimization is proposed, called RC-SLAM. Addressing the challenge of representing roads parametrically, a novel method is proposed to approximate local roads as discrete planes and extract parameters of local road planes (LRPs) using homography. Unlike conventional methods, constraints between the vehicle and LRPs are established, effectively mitigating errors arising from assumed six DoF motion in the system. Furthermore, to avoid the impact of depth uncertainty in road features, epipolar constraints are employed to estimate rotation by minimizing the distance between road feature points and epipolar lines, robust rotation estimation is achieved despite depth uncertainties. Notably, a distinctive nonlinear optimization model based on graph optimization is presented, jointly optimizing the poses of vehicle trajectories, LPRs, and map points. The experiments on two datasets demonstrate that the proposed system achieved more accurate estimations of vehicle trajectories by introducing constraints between the vehicle and LRPs. The experiments on a real-world dataset further validate the effectiveness of the proposed system.
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As a non-noble metal electrocatalyst for the oxygen evolution reaction (OER), the binary NiFe layer double hydroxide (LDH) is expected to replace Ru-based and Ir-based anode materials for water decomposition. To attain threshold current density, nevertheless, a somewhat significant overpotential is still needed. In this work, layered double hydroxides of NiFe LDH are doped with V to form the terpolymer NiFeV LDH, which greatly increases the intrinsic activity of NiFe LDH and improves OER performance. This process is a straightforward and quick one-step electrodeposition process. Notably, NiFeV/NF has a low overpotential (218 mV at 10 mA cm-2) and faster kinetics (Tafel slope of 31 mV dec-1) as well as excellent durability and stability in 1 M KOH solution. In addition, the OER performance of the catalyst prepared in this work is better than that of a non-valuable metal catalyst that was recently reported. The V-doped NiFe LDH layered double hydroxides and the investigation of electrodeposition electrocatalytic methods in this work offer a fresh opportunity for the advancement of electrochemical technology.
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A new emerging disease called "translucent post-larvae disease" (TPD) in Penaeus vannamei, caused by a novel type of highly lethal Vibro parahaemolyticus (VpTPD), has become an urgent threat to the shrimp farming industry in China. In order to develop an effective disinfectant for the prevention and control of the VpTPD, the clinical protective effects of polyhexamethylene biguanide hydrochloride (PHMB) against VpTPD in Penaeus vannamei were investigated by carrying out an acute toxicity test of PHMB on post-larvae of P. vannamei and its effect of treatment test on VpTPD infection. The results showed that the median lethal concentration of disinfectant (LC50) values of PHMB to post-larvae of P. vannamei after treatment for 24 h, 48 h, 72 h, 96 h were 16.13 mg/L (14.18-18.57), 10.77 mg/L (9.93-11.72), 9.68 mg/L (8.53-11.64), 9.14 mg/L (7.70-10.99), respectively. In addition, a clinical trial showed that 1 mg/L PHMB showed a strong protective effect on the post-larvae of shrimp challenged with 101-104 CFU/ml of VpTPD. The relative percentage survival (RPS) of 1 mg/L PHMB on post-larvae of P. vannamei challenged with VpTPD at 101, 102, 103 and 104 CFU/ml were 63.65 %±6.81, 62.96 %±5.56, 60.00 %±3.75 and 66.67 %±3.75 at 96 hours post infection. The results highlight the clinical protective effects of the PHMB and therefor PHMB can be used as a preventive measure to control early TPD infection in shrimp culture. This study also provides valuable information for the prevention of other bacterial diseases in shrimp culture.
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Desinfectantes , Penaeidae , Vibrio parahaemolyticus , Animales , Penaeidae/microbiología , Larva , Desinfectantes/farmacologíaRESUMEN
Visual interaction is a promising strategy for the externalized expression and transmission of information, having wide application prospects in wearable luminous textiles. Achieving an autonomous luminous display and dynamic light response to environmental stimuli is attractive but attracts little attention. Herein, we propose a liquid responsive structure based on alternating-current electroluminescent fibers and demonstrate conductive-liquid-bridging electroluminescent fabrics with high integration and personalized patterns. Impressively, our electroluminescent fibers and textiles could afford a sensitive response and high robustness to water, glycerol, ethanol, and sodium chloride solution. The final electroluminescent textiles show an excellent luminescence performance of 149.08 cd m-2. On the proof of concept, a rain-sensing umbrella, luminous sportswear, and liquid response glove are fabricated to demonstrate water detection, visual interaction, and environmental warning. The textile-type visualizing-responding strategy proposed in this work may open up new avenues for the application of ACEL devices in the field of visual interaction.
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A ternary mixed metal oxide coating of Sn-Ru-CoO x was prepared by ultrasonic treatment. The effect of ultrasound on the electrochemical performance and corrosion resistance of the electrode was investigated in this paper. Results showed that the electrode prepared by ultrasonic pretreatment demonstrated more uniform oxide dispersion on the surface of the coating, smaller grain growth, and more compact surface morphology compared with the anode prepared without ultrasonic pretreatment. At the same time, the best electrocatalytic performance was obtained by the ultrasonically treated coating. The chlorine evolution potential was reduced by 15 mV. The anode prepared by ultrasonic pretreatment had a service life of 160 h, which was 46 h longer than the anode prepared without ultrasonic pretreatment.
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Touch panels are deemed as a critical platform for the future of human-computer interaction and metaverse. Recently, stretchable iontronic touch panels have attracted attention due to their superior adhesivity to the human body. However, such adhesion can not be named "real wearable", leading to discomfort for the wearer, such as rashes or itching with long-time wearing. Herein, a skin-friendly and wearable iontronic textile-based touch panel with highly touch-sensing resolution and deformation insensitivity is designed based on an in-suit growing strategy. This textile-based touch panel endows excellent interfacial hydrophilic and biocompatibility with human skin by overcoming the bottlenecks of the hydrogel-based uncomfortable sticky touch interface and low mechanical behavior. The developed touch panel enables handwriting interaction with good mechanical capacity (114 MPa), nearly 4145 times higher than pure hydrogel. More importantly, our touch panel possesses intrinsic insensitivity to wide external loading from the silver fiber (<0.003 g) to even heavy metal block (>10 kg). As proof of concept, the textile-based iontronic touch panel is applied to handwriting interaction, such as a flexible keyboard and wearable sketchpad. This iontronic touch panel with skin-friendly and wearable qualitities is helpful for next-generation wearable interaction electronics.
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Dispositivos Electrónicos Vestibles , Humanos , Piel , Electrónica , Plata , HidrogelesRESUMEN
In addition to complex preparation and low-yield syntheses, attaining high energy density while maintaining high power density remains a significant challenge for supercapacitor applications in the field of energy storage. Herein, two-dimensional (2D) nickel-based metal-organic framework (NiMOF) nanosheets are grown around carbon nanotubes (CNTs) to form NiMOF/CNTs composite, which is synthesized via a one-step solvothermal method at various temperatures. Thereinto, the NiMOF/CNTs composite synthesized at 180 °C (NiMOF/CNTs 180) exhibits enhanced electrical conductivity for ion and electron transport due to the addition of the CNTs, as well as the highest specific capacitance due to the unique 3D vine-like structure, which provides abundant active sites for electrochemical reactions. Specifically, the NiMOF/CNTs 180 composite demonstrates outstanding electrochemical performance with high specific capacitance (1855.0 F g-1 at 1 A g-1) and an excellent capacitance retention of 87.7% at 10 A g-1, indicating a favorable rate performance. The NiMOF/CNTs 180//AC asymmetric supercapacitors (ASCs) device assembled with NiMOF/CNTs 180 and activated carbon (AC) has a high specific capacitance of 320.0 F g-1 at 1 A g-1 and a maximum energy density of 113.8 W h kg-1 at 800.0 W kg-1. Therefore, the present work provides a handy and efficient synthesis strategy for supercapacitor devices with high energy density.
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The conventional Pb-Ag alloy possesses a high oxygen evolution reaction overpotential, poor stability, and short service life in acidic solutions, making it an unsuitable sort of anode material for the zinc electrowinning process. Therefore, a layered carbon-covered cobalt tetroxide (Co3O4@C)-reinforced PbO2-coated electrode is fabricated via a facile two-step pyrolysis-oxidation and subsequent electrodeposition process. As a result, the reinforced PbO2-coated electrode exhibits a low OER overpotential of 517 mV at 500 A m-2 and a Tafel slope of 0.152 V per decade in a zinc electrowinning simulation solution (0.3 M ZnSO4 and 1.53 M H2SO4). The reduced overpotential of 431 mV at 500 A m-2 compared to traditional Pb-0.76%Ag alloy leads to improved energy savings, which is attributable to the presence of Co3O4@C to refine the grain size and thus increase the effective contact area. Moreover, the reinforced PbO2-coated electrode has a prolonged service life of 93 h at 20 000 A m-2 in 1.53 M H2SO4. Therefore, an accessible and efficient strategy for preparing a coated electrode to improve OER performance for zinc electrowinning is presented in this research.
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The oxygen evolution reaction kinetics in industrial zinc electrowinning is sluggish, resulting in low electrocatalytic activity and substantial energy expenditure (about one-third of energy was wasted due to the strong polarization effect). Herein, the paper described a core-shell structured MnCo2O4.5@C modified PbO2 electrode through the pyrolysis and co-electrodeposition as a promising candidate for zinc electrowinning. As a result, the obtained Pb-0.2%Ag/α-PbO2/ß-PbO2-MnCo2O4.5@C composite electrode showed a sandwich-like structure, where Pb-0.2%Ag as a core, α-PbO2 as a mid-layer, and ß-PbO2-MnCo2O4.5@C served as an electrocatalytic layer. It also possessed improved OER catalytic activity, only required 680 mV to achieve a current density of 50 mA cm-2 and a Tafel slope of 216.04 mV dec-1 in an acidic solution containing 50 g L-1 Zn2+ and 150 g L-1 H2SO4. The current efficiency increased by 0.7% and the cell voltage reduced by 360 mV as compared to a conventional Pb-0.76%Ag alloy electrode, leading to a remarkable energy-consumption reduction of 283.5 kW h for producing per ton metallic zinc. Furthermore, Pb-0.2%Ag/α-PbO2/ß-PbO2-MnCo2O4.5@C exhibited a prolonged service life, which worked about 44 h under an ultra-high current density of 2 A cm-2. Hence, this paper provides the strategy to design and construct non-precious, high-performance catalyst for electrolysis and other applications.
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3D object detection methods based on camera and LiDAR fusion are susceptible to environmental noise. Due to the mismatch of physical characteristics of the two sensors, the feature vectors encoded by the feature layer are in different feature spaces. This leads to the problem of feature information deviation, which has an impact on detection performance. To address this problem, a point-guided feature abstract method is presented to fuse the camera and LiDAR at first. The extracted image features and point cloud features are aggregated to keypoints for enhancing information redundancy. Second, the proposed multimodal feature attention (MFA) mechanism is used to achieve adaptive fusion of point cloud features and image features with information from multiple feature spaces. Finally, a projection-based farthest point sampling (P-FPS) is proposed to downsample the raw point cloud, which can project more keypoints onto the close object and improve the sampling rate of the point-guided image features. The 3D bounding boxes of the object is obtained by the region of interest (ROI) pooling layer and the fully connected layer. The proposed 3D object detection algorithm is evaluated on three different datasets, and the proposed algorithm achieved better detection performance and robustness when the image and point cloud data contain rain noise. The test results on a physical test platform further validate the effectiveness of the algorithm.
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Algoritmos , LluviaRESUMEN
Flexible touch-sensing devices have attracted extensive attention in wearable electronics and human-machine interaction. The ionic touch-sensing hydrogels are ideal candidates for these scenarios, but the absorbed water evaporates easily from the hydrogel, reducing their working time and stability. Herein, we propose a touch-sensing fabric system composed of non-woven cellulose fabrics as a sheath shell layer encapsulated with a hydrogel filling layer. The resultant touch-sensing fabric has a super-thin structure (1 mm) and exhibits a low detecting threshold (50 Pa), high durability (100k times), strain/pressure insensitivity and extremely high touch positioning accuracy. In the proof of concept, a smart touch-sensing glove is equipped with our fabric, which can execute human-computer interaction as a flexible touch-sensing device.
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Tacto , Dispositivos Electrónicos Vestibles , Computadores , Humanos , Hidrogeles , TextilesRESUMEN
The high oxygen evolution overpotential of the Pb-Ag anode is one of the main reasons for the high energy consumption in Zn electrowinning. PbO2, owing to its high conductivity, good corrosion resistance and low cost, is widely used as an excellent coating material. In present research, a novel composite Ti/TiO2-NTs/PbO2 material was synthesized through a facile anodization, annealing, electrochemical reduction and galvanostatic deposition. The surface morphology, internal structure and the mechanisms of TiO2-NTs enhancing electrochemical performance were discussed. The results show that the self-organized high aspect ratio TiO2-NTs with diameter of â¼120 nm and length of â¼8 µm were obtained on Ti substrate. The Ti/TiO2-NTs/PbO2 composite material exhibits excellent oxygen evolution performance and good stability in Zn electrowinning simulation solution (50 g L-1 Zn2+, 150 g L-1 H2SO4) at 35 °C. Its oxygen evolution overpotential is only 630 mV under current density 50 mA cm-2, which is 332 m lower than that of Pb-0.76 wt% Ag (η = 962 mV) and only increases 22 mV after 5000 cycles of CV scanning. Its outstanding electrochemical performance is mainly ascribed to the introduction of TiO2-NTs in Pb(CH3COO)2 media since it refines the crystal grains, increases the electrochemical surface area, greatly reduces the charge transfer resistance (25.4 Ω cm2 to 2.337 Ω cm2) and enhances corrosion resistance. Therefore, the Ti/TiO2-NTs/PbO2 material prepared in Pb(CH3COO)2 medium may be an ideal anode for Zn electrowinning.
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The high energy consumption during zinc electrowinning is mainly caused by the high overpotential of the oxygen evolution for Pb-Ag alloys with strong polarization. The preparation of new active energy-saving materials has become a very active research field, depending on the synergistic effects of active particles and active oxides. In this research, a composite material, α(ß)-PbO2, doped with Co3O4 and CNTs on the porous Ti substrate was prepared via one-step electrochemical deposition and the corresponding electrochemical performance was investigated in simulated zinc electrowinning solution. The composite material showed a porous structure, finer grain size and larger electrochemical surface area (ECSA), which indicated excellent electrocatalytic activity. Compared with the Pb-0.76 wt% Ag alloy, the overpotential of oxygen evolution for the 3D-Ti/PbO2/Co3O4-CNTs composite material was decreased by about 452 mV under the current density of 500 A m-2 in the simulated zinc electrowinning solution. The decrease in the overpotential of oxygen evolution was mainly ascribed to the higher ECSA and lower charger transfer resistance. Moreover, it showed the lowest self-corrosion current density of 1.156 × 10-4 A cm-2 and may be an ideal material for use in zinc electrowinning.
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NiO, Ni-Co-Mn-O x and NiO/Ni-Co-Mn-O x on nickel foam substrates were prepared via a chemical bath deposition-calcination. The thermodynamic behavior was observed by TG/DTA. The chemical structure and composition, phase structure and microstructures were tested by XPS, XRD, FE-SEM and TEM. The electrochemical performance was measured by CV, GCD and EIS. The mechanism for formation and enhancing electrochemical performance is also discussed. Firstly, the precursors such as NiOOH, CoOOH and MnOOH grow on nickel foam substrates from a homogeneous mixed solution via chemical bath deposition. Thereafter, these precursors are calcined and decomposed into NiO, Co3O4 and MnO2 respectively under different temperatures in a muffle furnace. Notably, NiO/Ni-Co-Mn-O x on nickel foam substrates reveals a high specific capacity with 1023.50 C g-1 at 1 A g-1 and an excellent capacitance retention with 103.94% at 5 A g-1 after 3000 cycles in 2 M KOH, its outstanding electrochemical performance and cycling stability are mainly attributed to a porous sheet-sheet hierarchical nanostructure and synergistic effects of pseudo-capacitive materials and excellent redox reversibility. Therefore, this research offers a facile synthesis route to transition metal oxides for high performance supercapacitors.
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CeO2-Fe2O3 mixed oxides are very attractive as catalysts for catalytic oxidation. Herein, we report the structural dependence of the Ce1- xFe xO2-δ catalysts for CH4 combustion and CO oxidation via changing lattice distortion degrees, surface Fe2O3 states, and oxygen vacancy concentrations. The lattice distortion degree and oxygen vacancy concentration of Ce-Fe-O solid solution can be tuned by changing the contents of Fe and the precipitation temperatures in the preparation process. The precipitation at relatively high temperature (70 °C) promotes the lattice distortion, whereas a lower temperature (0 °C) helps the formation of surface oxygen vacancies. The in situ diffuse reflectance infrared/Raman experiments and the physicochemical characterization suggest that both the CO and CH4 oxidations mainly follow a Mars-van Krevelen mechanism. Both the lattice distortion and the surface iron species play a crucial role in determining the catalytic activity by affecting the redox property of the catalysts. The surface iron species, combined with the oxygen vacancies, improve the catalytic performance by enhancing the adsorption capacity of reactants and reducibility of catalysts. The lattice distortion of CeO2 contributes to the catalytic activity by tuning the oxygen mobility in the bulk, which promotes the re-oxidation rate of catalysts.