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- Sun, Pengliang, et al.
(författare)
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Artificial chloroplast-like phosphotungstic acid — iron oxide microbox heterojunctions penetrated by carbon nanotubes for solar photocatalytic degradation of tetracycline antibiotics in wastewater
- 2022
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Ingår i: Advanced Composites and Hybrid Materials. - : Springer Science+Business Media B.V.. - 2522-0128 .- 2522-0136. ; 5:4, s. 3158-3175
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Tidskriftsartikel (refereegranskat)abstract
- Doping-inducted heterojunction is an effective strategy to boost the semiconductor photocatalysis. In this work, an artificial chloroplast-like HPWx@Fe2O3-CNTs photocatalyst was developed by a continuous hydrothermal process and microwave irradiation. This catalyst showed an excellent performance in degradation of biotoxic tetracycline (under mild conditions, tetracycline can be degraded by 100% in 100 min), the apparent rate constant of degradation was 5.5 times higher than that of pure Fe2O3. This is attributed to the synergistic photocatalysis of the Keggin unit of phosphotungstic acid to Fe2O3, which makes the photogenerated electrons trapped in the W5d vacancy state of the Keggin unit, thus delaying the recombination of electron–hole pairs. Moreover, the low-cost HPWx@Fe2O3-CNTs photocatalyst displayed a strong magnetism, leading to a facile separation of the photocatalyst. A relatively stable efficiency of degradation can be maintained. In the light radiation of “Baoxiang river” (Yunnan, China) water sample, the total organic carbon content decreased to 10.58%, which revealed a strong ability of organic carbon mineralization. In addition, E. coli as bacteria indicator was selected to quantitatively monitor the comprehensive toxicity changes in wastewater upon this photocatalytic technology. Both experimental and theoretical investigations demonstrated that the unique nano-scale biomimetic structures with high active sites, improvement of visible-light response, and separation and transfer of electrons and holes in heterojunction were responsible for the superior catalytic results.
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| 2. |
- Zhang, Yinlong, et al.
(författare)
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GCMVF-AGV : Globally Consistent Multiview Visual-Inertial Fusion for AGV Navigation in Digital Workshops
- 2023
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9456 .- 1557-9662. ; 72
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Tidskriftsartikel (refereegranskat)abstract
- An accurate and globally consistent navigation system is crucial for estimating the positions and attitudes of automated guided vehicles (AGVs) in digital workshops. A promising navigation technology for this purpose is tightly coupled visual-inertial fusion, which offers advantages such as quick response (QR), absolute scale, and accuracy. However, existing visual-inertial fusion systems have limitations, including long-term drift, tracking failures in textureless or poorly illuminated environments, and a lack of absolute references. To create a reliable and consistent AGV navigation framework and correct for long-term drift, we have designed a novel framework, globally consistent multiview visual-inertial fusion for AGV navigation (GCMVF-AGV). This framework uses a downward-looking QR vision sensor and a forward-looking visual-inertial sensor together to estimate AGV poses in real time. The downward camera provides absolute AGV positions and attitudes with reference to the global workshop frame. Furthermore, long-term visual-inertial drift, inertial biases, and velocities are periodically compensated between spatial intervals of QR codes by minimizing visual-inertial residuals with the rigid constraints of absolute poses estimated from the downward visual measurements. We have evaluated the proposed method on the developed AGV navigation platform, and experimental results demonstrate the position and attitude errors of less than 0.05 m and 2 degrees, respectively.
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