Excessive P content (≥ 10 wt%) easily leads to cracks on the surface of electrodeposited NiP coatings, causing rapid deterioration of corrosion performance. This study uses picosecond laser remelting ...(LR) technology to close cracks and improve corrosion performance. The influence of the laser parameters on the quality of laser-remelted (LRed) coatings in ambient air is discussed in detail, and the corrosion performance is evaluated through electrochemical corrosion tests. The results indicated that the scanning rate, laser power, and repetition frequency significantly affect the degree of crack closure and LRed defects. For cracks of similar sizes, both multiple-LR with a lower power (10.4 W, five times) and single-LR with a higher power (19.2 W, once) achieved an excellent crack closure. After single-LR, the surface roughness increased from 3.9 ± 0.3 nm to 33.4 ± 3.2 nm. In addition, the LRed layer crystallized from the initial amorphous state. Although the energy-dispersive spectroscopy results indicated that the oxidation behavior during the LR process was insignificant, X-ray photoelectron spectroscopy showed that the surface composition evolved from Ni/Ni–P compounds to Ni–POx after LR. Electrochemical corrosion tests indicated that the corrosion current density decreased approximately three times from 9.19 × 10−6 to 2.91 × 10−6 A/cm2 after LR. Moreover, the corrosion mechanism shifted from the original stress corrosion to pitting corrosion. Thus, the LR technology can effectively improve the corrosion performance and reduce the issues caused by cracks.
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•Picosecond laser remelting removes surface cracks in NiP coating.•Laser remelted quality mainly affected by laser power and spot overlap rate.•The corrosion rate after laser remelting reduces by approximately three times.•The corrosion mechanism evolved from stress to pitting corrosion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To meet the requirements of structural and functional integration, machinability and workability of engineering materials, continuous mesophase pitch-based carbon fiber (MPCF) reinforced 2024 ...aluminum (Al) matrix composites with 20–50 vol % MPCF were fabricated by vacuum hot pressing method. The effects of MPCF volume fraction and T6 heat treatment on microstructure, thermal and mechanical properties of MPCF/2024Al composites were investigated. The results show that the interface of the as-sintered composite was well bonded. After T6 heat treatment, the amorphous layer at the interface changed from continuous to discontinuous and the interfacial bonding was further improved, but there was no interfacial reaction. The increase of MPCF volume fraction was beneficial to improve the thermal conductivity (TC) and elastic modulus (E) of the as-sintered composites, up to 258.3 W/(m⋅K) and 343.5 GPa respectively, while the composites with 30 vol % and 40 vol % MPCF respectively had the highest ultimate tensile strength (UTS) and a coefficient of thermal expansion (CTE) close to zero. After heat treatment, the TC and E were slightly changed, while the CTE was further reduced and UTS was significantly improved. In this work, the heat-treated composite with 30 vol % MPCF had the highest UTS of 499.3 MPa and good thermal properties, and the TC of this composite may be further improved by using MPCFs with higher TC. Therefore, this composite is expected to become a promising engineering material integrating structure and function.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Antibiotics are widely used in China's aquaculture, agricultural, and clinical settings and can lead to antibiotic resistance in various pathogens. Although the pooled prevalence estimate (PPE) and ...antibiotic resistance of Escherichia coli (E. coli) in food and clinical settings has been extensively studied, a comprehensive analysis of the published literature is lacking. We conducted a comprehensive search for research indicators for 2001–2020 in eight major Chinese and English literature databases. Antibiotic PPE and resistance trends of 5933 and 29,451 E. coli isolates were screened and analysed in 35 food studies (total 1821) and 62 clinical studies (total 5159). E. coli strains derived from food had the highest antibiotic resistance rate to tetracycline (TET, 71.3 %), followed by trimethoprim-sulfamethoxazole (SXT, 62.5 %) and cefazolin (CFZ, 36.2 %). E. coli strains isolated from clinical environments were highly resistant to piperacillin (PIP, 71.7 %), TET (68.3 %) and CFZ (60.9 %), consistent with foodborne E. coli drug resistance patterns. E. coli strains isolated from food and clinical samples collected in laboratories carry multiple antibiotic resistance genes (ARGs), such as blaTEM, gryA, gryB, sul1, and tetA, making E. coli a reservoir of ARGs. This study highlights the presence of drug-resistant E. coli pathogens and ARGs in food and clinical environments.
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•First meta-analysis quantification of food and clinically drug-resistant E. coli isolates in China•High levels of drug-resistant E. coli isolated from food and clinical environments•Isolated E. coli was highly resistant to tetracycline and trimethoprim sulfamethoxazole.•blaTEM and gryA were the highly homologous ARGs in experimental isolation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•HR-IR spectroscopy was applied to study gaseous water and water-alcohol mixtures.•The spectral features of water clusters of different size were observed.•A method based on PCA ...rotation was used to separate the overlapping spectra.•The structure of water cage around alcohol was revealed.
Interactions of water and chemical or bio-compound have a universal concern and have been extensively studied. For spectroscopic analysis, the complexity and the low resolution of the spectra make it difficult to obtain the spectral features showing the interactions. In this work, the structures and interactions in gaseous water and water-alcohol mixtures were studied using high-resolution infrared (HR-IR) spectroscopy. The spectral features of water clusters of different sizes, including dimer, trimer, tetramer and pentamer, were observed from the measured spectra of the samples in different volume concentrations, and the interactions of water and methanol/ethanol in the mixtures were obtained. In the analysis, a method based on principal component analysis was used to separate the overlapping spectra. In water-alcohol mixtures, when water is less, water molecules tend to interact with the OH groups on the exterior of the alcohol aggregate, and with the increase of water, a water cage forms around the aggregates. Furthermore, the ratio of the molecule number of methanol in the aggregate to that of water in the cage is around 1:2.3, and the ratio for ethanol is about 1:3.2.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Proton-conducting reversible solid oxide cells (PC-RSOCs) have attracted much attention for their advantages of working as energy storage devices. In this study, orthorhombic-perovskite structure ...BaCe0.8−xZr0.2InxO3−δ (x = 0, 0.1, 0.2, 0.3, 0.4) materials have been synthesized. The effect of different indium doping contents on the stability and electrical properties has been investigated. Experimental results reveal that the BaCe0.5Zr0.2In0.3O3−δ possesses the highest proton conductivity with desirable density. Besides, the stability of BaCe0.5Zr0.2In0.3O3−δ is obviously improved in moist air (20 vol% H2O) atmosphere. Anode-supported PC-RSOC with BaCe0.5Zr0.2In0.3O3−δ membrane as an electrolyte displays a maximum power density of 151 mW·cm−2 at 700 °C in solid oxide fuel cell (SOFC) mode. Meanwhile, the PC-RSOC with BaCe0.5Zr0.2In0.3O3−δ electrolyte membrane in solid oxide electrolysis cell (SOEC) mode can also manifest high current density of −729 mA cm−2 at 700 °C with an applied voltage of 1.5 V, and maintains a stable current density of around −124 mA·cm−2 at 700 °C with an applied voltage of 1.1 V for more than 60 h. These encouraging results suggest the potential application of BaCe0.5Zr0.2In0.3O3−δ as electrolyte material for intermediate-temperature PC-RSOCs.
•The properties of In-doped BaCe0.8−xZr0.2InxO3−δ were systematically studied.•The BaCe0.5Zr0.2In0.3O3−δ (BCZI3) ceramic displayed high conductivity and density.•The BCZI3 presented excellent stability in moist air (20 vol%) atmosphere.•The RSOC with BCZI3 electrolyte showed good performance and stability.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
We aimed to conduct a meta-analysis investigating the association between consumption of vegetables and fruits and breast cancer survival. A comprehensive search of the PubMed and EMBASE was ...performed from the inception to September 30, 2016. The summary hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using a random effects model. Ten studies, with a total of 31,210 breast cancer cases, were included in the meta-analysis. The summary HRs (95% CIs) of overall survival (highest vs. lowest) were 1.08 (0.88-1.33; I
= 41.1%) for pre-diagnostic intake of vegetables and fruits combined, 0.96 (0.71-1.30; I
= 48.4%) for vegetables alone, and 0.83 (0.67-1.02; I
= 0) for fruit alone. No significant risk associations of overall survival were found for post-diagnostic intake of vegetables and fruits. Line dose-response analyses indicated the likely results for both pre- and post- diagnostic dietary intake. No significant association was found between intake of vegetables and fruits and breast cancer-specific mortality. In addition, intake of cruciferous vegetables was not associated with death from breast cancer. Our findings indicated a borderline inverse association between pre-diagnostic intake of fruit and overall survival of breast cancer, whereas intake of vegetables was not associated with survival.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Purpose
At present, smartphones are embedded with accelerometers, gyroscopes, magnetometers and WiFi sensors. Most researchers have delved into the use of these sensors for localization. However, ...there are still many problems in reducing fingerprint mismatching and fusing these positioning data. The purpose of this paper is to improve positioning accuracy by reducing fingerprint mismatching and designing a weighted fusion algorithm.
Design/methodology/approach
For the problem of magnetic mismatching caused by singularity fingerprint, derivative Euclidean distance uses adjacent fingerprints to eliminate the influence of singularity fingerprint. To improve the positioning accuracy and robustness of the indoor navigation system, a weighted extended Kalman filter uses a weighted factor to fuse multisensor data.
Findings
The scenes of the teaching building, study room and office building are selected to collect data to test the algorithm’s performance. Experiments show that the average positioning accuracies of the teaching building, study room and office building are 1.41 m, 1.17 m, and 1.77 m, respectively.
Originality/value
The algorithm proposed in this paper effectively reduces fingerprint mismatching and improve positioning accuracy by adding a weighted factor. It provides a feasible solution for indoor positioning.
Feature matching is determining true correspondences between image pairs, important for many computer vision applications. It is challenging to determine true correspondences quickly under scene ...changes in viewpoint, rotation, scaling and illumination. Higher accuracy and efficiency are required for feature matching. While other methods determine true correspondences by treating the images independently, we instead condition on image pairs to take account of the affine information between them.To achieve this, we propose AAM-ORB, an efficient and robust algorithm for feature matching in the scene-shift. The key to our approach is an affine attention module (AAM), which can condition the affine features on both images to boost robustness. AAM is integrated into the well-known ORB feature matching pipeline, resulting in a significant improvement. Although remarkably matching accuracy, AAM can reduce computation efficient. To overcome this, we select a grid-based motion statistics for separating true correspondences from false ones at high speed. Extensive experiments show that AAM-ORB surpasses state-of-the-art approaches for feature matching on benchmark datasets. Moreover, the proposed AAM-ORB has less time consumption. Finally, AAM-ORB achieves better performance and efficiency of feature matching under scene changes.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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