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Simultaneous Location and Mapping (SLAM) is a common algorithm for position estimation in GNSS-denied environments. However, the high structural consistency and low lighting conditions in tunnel environments pose challenges for traditional visual SLAM and LiDAR SLAM. To this end, this paper presents LiDAR and optical flow fusion odometry (LOFF), which uses a direction-separated data fusion method to fuse optical flow odometry into the degenerate direction of the LiDAR SLAM without sacrificing the accuracy. Moreover, LOFF incorporates detectors and a compensator, allowing for a smooth transition between general environments and degeneracy environments. This capability facilitates the stable flight of unmanned aerial vehicles (UAVs) in GNSS-denied tunnel environments, including corners and long-distance consistency. Through real-world experiments conducted in a GNSS-denied pedestrian tunnel, we demonstrate the superior position accuracy and trajectory smoothness of LOFF compared to state-of-the-art visual SLAM and LiDAR SLAM.

The solid-state batteries have received widespread attention due to their excellent stability and safety, however, the low ionic conductivity and weak interface contact always restricted its performance. In this work, we propose an in situ thermally crosslinked and solidified polymer electrolyte with polyethylene glycol diacrylate (PEGDA) as scaffold in which succinonitrile (SN) and lithium bis-trifluoromethanesulfonimide (LiTFSI) were further introduced to improve the ionic conductivity. Herein, the composite gel was served as not only solid-solid interface material but also solid-state electrolyte. Different with conventional polymer gels, the solvent evaporation could not happen for this composite material during the solidification process, and therefore resulting in good interface contact without inside bubbles. We further present the investigation on transport principle of Li+ in the solid-state electrolyte and the effect of molecular chain on ionic conductivity. The conductivity of the solid-state electrolyte can reach 1.76 × 10−4 S cm−1 at room temperature without any assistance of liquid electrolytes, which is attributed to the short molecular chain of PEGDA. Electrochemical window of the solid-state electrolyte can reach 5.2 V after cross-linking treatment. And the lithiumoxygen battery using this solid-state electrolyte can stably cycle for more than 1100 cycles with a current density of 200 mA g−1 and a limit capacity of 200 mAh g−1 at room temperature. [ABSTRACT FROM AUTHOR]

Due to the development needs of electric transportation as well as sustainability and physical health, lithium-oxygen batteries (LOBs) have attracted much attention with its superior theoretical specific energy density. In this study, we report our findings on a biomass material, oak-derived carbon (ODC), which is served as an efficient cathodic catalyst in LOBs system for the first time. In contrast to traditional commercial carbon catalysts, biomaterials are abundant in heteroatoms, such as N, P and S, leading to a substantial increase in electrochemical activity of cathodes. Compared with functional doped carbon, natural biomass carbon with abundant and uniform heteroatoms is easy to obtain and low in price. In this work, LOBs with the optimized ODC cathodes present the highest discharge capacity of 37000 mAh g-1, the number of which is among the best, and the batteries keep stable over 400 cycles, suggesting a great prospect. [ABSTRACT FROM AUTHOR]

Herein, we report a binder-free, low-cost and high performance cathode for lithium-oxygen batteries based on carbon black BP2000 decorated Ni(OH)2 nanoflakes array on Ni foam. The Ni(OH)2 nanoflakes array is fabricated by hydrothermal treatment of Ni foam in acidic medium without nickel salt. The highly organized structure of Ni(OH)2 nanoflakes array provides a more uniform distribution of catalysts and discharge products, resulting in high capacity with a relatively stable cycling voltage profile. The cathode outputs a discharge capacity as high as 12400 mAh gcarbon−1 at 160 mA gcarbon−1, which is 244% higher than that of BP2000 decorated Ni foam electrode without Ni(OH)2 nanoflakes array. The cathode can sustain 100 cycles under a capacity limitation of 320 mAh gcarbon−1 with high energy efficiency (~67%). Our work points out the key issues and suggests an effective method for the surface modification technology. [ABSTRACT FROM AUTHOR]

In this study, a three-dimensional CNTs-grafted graphene foam has been fabricated by a chemical vapor deposition method. The nanoarchitectured composite is employed as a cathode for lithium-oxygen (Li-O2) batteries and exhibits a substantially enhanced capacity of 20300 mAh g-1 at 0.05 mA cm-2, the number of which is among the highest prototype Li-O2 batteries reported to date. And the cathode can still exhibit a capacity of 3000 mAh g-1 when the current density is increased to 0.15 mA cm-2. The improved performance, e.g., discharge capacity and rate capability, is mainly attributed to the synergistic effects of CNTs and graphene, which not only provide an effective channel for the transportation of oxygen and Li ion but also offer more and fast pathways for electron transport. In addition, the forest distribution of CNTs hinders the restack of graphene, contributing to the stability of Li-O2 batteries. This study demonstrated that the CNTs-grafted graphene foams would be likely to be a good alternative cathode material for Li-O2 batteries in the future. [ABSTRACT FROM AUTHOR]

Cellular metals with the large surface/volume ratios and excellent electrical conductivity are widely applicable and have thus been studied extensively. It is highly desirable to develop a facile and cost‐effective process for fabrication of porous metallic structures, and yet more so for micro/nanoporous structures. A direct‐flame strategy is developed for in situ fabrication of micron‐scale cellular architecture on a Ni metal precursor. The flame provides the required heat and also serves as a fuel reformer, which provides a gas mixture of H2, CO, and O2 for redox treatment of metallic Ni. The redox processes at elevated temperatures allow fast reconstruction of the metal, leading to a cellular structure on Ni wire. This process is simple and clean and avoids the use of sacrificial materials or templates. Furthermore, nanocrystalline MnO2 is coated on the microporous Ni wire (MPNW) to form a supercapacitor electrode. The MnO2/MPNW electrode and the corresponding fiber‐shaped supercapacitor exhibit high specific capacitance and excellent cycling stability. Moreover, this work provides a novel strategy for the fabrication of cellular metals and alloys for a variety of applications, including catalysis, energy storage and conversion, and chemical sensing. [ABSTRACT FROM AUTHOR]

This work focuses on the effects of the reducing and sintering behavior for NiO→Ni on the microstructures and performances of conventional Ni/YSZ (YSZ: yttria-stabilized zirconia) anodes for anode-supported solid oxide fuel cells (SOFCs). A strong dependence of reducing and sintering behavior on the initial reduction temperature for NiO→Ni was demonstrated. Some identical NiO/YSZ anodes were heated from room temperature (RT) to 850°C with a heating rate of 10°C/min. and the reducing gas H2 was provided at different temperatures, such as, RT, 600, 650 or 700°C. As a result of initial reduction temperature, the reducing process was found to obviously affect the specific surface areas (BET test), microstructures (SEM test), conductivities (conductivity test) and electrochemical performances (power output and polarization resistance) of reduced Ni/YSZ anode. A model was finally proposed to simulate the reducing and sintering mechanism and combined effects for NiO/YSZ→Ni/YSZ anodes at different initial reduction temperatures. [ABSTRACT FROM AUTHOR]

The aim of this work is to develop and evaluate a novel composite cathode with prominent stability for the operation of solid oxide fuel cell (SOFC). A La0.85Sr0.15MnO3 (LSM) nano-film has been successfully prepared onto a porous La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode via a water-based impregnation process, with the help of control system for LSM-film deposition. The quality of LSM-film is found to be influenced much by drying process, especially relative humidity (RH). The LSM-film is used to improve the operational stability of the LSCF cathode through surface treatment. The interfacial polarization resistance of LSCF cathode is reduced by 20% at 750°C after the introduction of LSM thin-film coating. It is found that the polarization behavior of blank LSCF cathode and LSM-film modified LSCF cathode is strikingly different especially under cathodic bias. A stable (even increasing) power output is observed for modified LSCF cathode, by contrast, 8% degradation is observed for blank LSCF cathode for ~100 h operation of SOFC at 750°C. [ABSTRACT FROM AUTHOR]

The article examines the use of a telescopic system for middle cerebral artery occlusion. This system uses screen-imaging guidance and a modified portable video macroscope. It was found that magnification of the modified portable video macroscope was appropriate in the operation. It concludes that the screen-imaging telescopic system is effective in the screen surgical operation and can be used for establishing a middle cerebral artery occlusion model and micro-neurons surgery.

The article focuses on the study which verifies the practicability of performing screen-based surgical operations using a portable medium-soft electronic endoscope (pmsEE). A pmsEE real-time viewing and recording system (RTVRS) was used in the occlusion of the middle cerebral artery in rat. Moreover, results show that self-designed pmsEE RTVRS could be used for portable endoscopic screen-based surgical operations.

In the present study, the performances of a single solid oxide fuel cell (SOFC) and a micro-SOFC stack fueled with flame of combusting liquefied petroleum gas (LPG) were studied. La0.75Sr0.25Cr0.5Mn0.5O3-δ and Ni coimpregnated yttria-stabilized zirconia were used as the anode material of the direct-flame SOFC. The operation temperature of the cell can be sustained at 500-700°C for the combustion of LPG. With the anode facing the LPG flame and the La0.8Sr0.2MnO3-δ cathode freely exposing to ambient air, the single cell exhibited an open-circuit voltage (OCV) of more than 0.85 V and the maximum power density (Pmax) of 238 mW/cm². The micro-SOFC stack with three single cells connected in series demonstrated an OCV of 2.5 V and the maximum power output of 64 mW (corresponding to a Pmax of 139 mW/cm²). The cell performance was found to be strongly influenced by the cell temperature. And the temperature is determined by cell position and gas composition. Additionally, the cell stability and carbon deposition after operation on the diffusion flame of the LPG were also tested. [ABSTRACT FROM AUTHOR]

In this paper. perovskite oxide La0.75Sr0.25Cr0.5Mn0.5O3-δ (LSCM) mixed with a small fraction Ni has been used as the anode of single-chamber solid oxide fuel cell(s) operating in a methane-oxygen mixture. The anode is prepared by an ion impregnation method, whereby a proper mixed solution with metal nitrates and urea is incorporated into the porous presintered yttria-stabilized zirconia (YSZ) anode matrix. After sintering at 1100°C, the impregnated materials change to unique microparticles adhered to the YSZ matrix. These microparticles themselves become porous after reducing in single-chamber conditions, and this porous character is expected to facilitate the anode reaction because it would improve the gas transport. The influence of the environmental temperature and gas composition on the cell performance is also investigated. A maximum power density of 285 mW/cm2 is achieved at a gas composition of CH4:O2 2:1 and a furnace temperature of 800°C. The redox cycling test demonstrates that the stability of the LSCM-based anode is better compared to the conventional Ni-YSZ anode. [ABSTRACT FROM AUTHOR]