Ecological efficiency mainly emphasizes the importance of balancing the relationships between natural resources, energy, the ecological environment and economic growth, which has aroused widespread ...concern worldwide. China’s rapid economic development has inevitably been accompanied by serious resource exhaustion, environmental pollution and ecological deterioration in the past several decades, which has brought huge challenges to China’s sustainable development. Therefore, establishing the evaluation framework of total-factor ecological efficiency (TFEE) and identifying its driving force have a great significance for improving China’s sustainable development capabilities. First, an ecological efficiency evaluation framework is established based on the theory of total-factor analysis. Second, the super efficient hybrid distance model considers undesirable output and measures TFEE nationwide in 30 provinces and four regions during the period 2003–2017. Finally, the spatial effect of TFEE and its influencing factors are examined by using a spatial Durbin model. The empirical results show that (1) nationwide and regional TFEEs have different degrees of decline during the study period. There were significant differences among the 30 provinces and four regions. Beijing, Tianjin and Shanghai are efficient, while the other provinces have not been as effective. The TFEEs of the four regions are not effective with an ordering of eastern > northeast > central > western. (2) Moran’s
I
index shows that the TFEE nationwide has a positive spatial autocorrelation with strong spatial agglomeration. However, the spatial distribution pattern of TFEE in China was unstable and labile. The Moran scatter plot indicates that China’s provincial TFEE has not only spatial dependence characteristics but also differences in spatial correlation. (3) Most factors are bound up with TFEE to various degrees: technological progress (TP), industrial agglomeration (IG) and human capital (HC) play a positive role, while industrial structure (IS), the level of urbanization (CITY) and energy intensity (EI) play a negative role. Additionally, environmental regulation (GZ) shows a U-type relationship with TFEE. The level of economic development (GDP) and foreign direct investment (FDI) cannot have a significant impact on TFEE at this stage. (4) The spatial Durbin model results show that TFEE has a significant spatial spillover effect, and the improvement of the TFEE of a province will increase the TFEE of neighbouring provinces. The confirmed spatial spillover effects of technological progress (TP), industrial structure (IS), the level of urbanization (CITY), industrial agglomeration (IG) and human capital (HC) can significantly impact the TFEE of neighbouring provinces. Among them, technological progress (TP), the level of urbanization (CITY) and human capital (HC) can significantly improve the TFEE of neighbouring provinces, and the level of economic development (GDP) and foreign direct investment (FDI) can significantly inhibit the improvement of TFEE in neighbouring provinces.
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CEKLJ, 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
In this Communication, we report a high-efficiency electrocatalyst for electrochemical water oxidation based on an Fe-doped Ni2P nanosheet array on a conductive carbon cloth. This catalyst shows a ...low onset overpotential of 190 mV, and it demands overpotentials of only 215 and 235 mV to drive 50 and 100 mA cm–2, respectively, with high electrochemical durability. This work offers us an attractive earth-abundant 3D catalyst electrode in water-splitting devices toward the mass production of hydrogen fuels for applications.
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IJS, KILJ, NUK, PNG, UL, UM
Offshore and inland river ship detection has been studied on both synthetic aperture radar (SAR) and optical remote sensing imagery. However, the classic ship detection methods based on SAR images ...can cause a high false alarm ratio and be influenced by the sea surface model, especially on inland rivers and in offshore areas. The classic detection methods based on optical images do not perform well on small and gathering ships. This paper adopts the idea of deep networks and presents a fast regional-based convolutional neural network (R-CNN) method to detect ships from high-resolution remote sensing imagery. First, we choose GaoFen-2 optical remote sensing images with a resolution of 1 m and preprocess the images with a support vector machine (SVM) to divide the large detection area into small regions of interest (ROI) that may contain ships. Then, we apply ship detection algorithms based on a region-based convolutional neural network (R-CNN) on ROI images. To improve the detection result of small and gathering ships, we adopt an effective target detection framework, Faster-RCNN, and improve the structure of its original convolutional neural network (CNN), VGG16, by using multiresolution convolutional features and performing ROI pooling on a larger feature map in a region proposal network (RPN). Finally, we compare the most effective classic ship detection method, the deformable part model (DPM), another two widely used target detection frameworks, the single shot multibox detector (SSD) and YOLOv2, the original VGG16-based Faster-RCNN, and our improved Faster-RCNN. Experimental results show that our improved Faster-RCNN method achieves a higher recall and accuracy for small ships and gathering ships. Therefore, it provides a very effective method for offshore and inland river ship detection based on high-resolution remote sensing imagery.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Large-scale and high-efficient water collection of microfibers with long-term durability still remains challenging. Here we present well-controlled, bioinspired spindle-knot microfibers with cavity ...knots (named cavity-microfiber), precisely fabricated via a simple gas-in-water microfluidic method, to address this challenge. The cavity-microfiber is endowed with unique surface roughness, mechanical strength, and long-term durability due to the design of cavity as well as polymer composition, thus enabling an outstanding performance of water collection. The maximum water volume collected on a single knot is almost 495 times than that of the knot on the cavity-microfiber. Moreover, the spider-web-like networks assembled controllably by cavity-microfibers demonstrate excellent large-scale and high-efficient water collection. To maximize the water-collecting capacity, nodes/intersections should be designed on the topology of the network as many as possible. Our light-weighted yet tough, low-cost microfibers with high efficiency in directional water transportation offers promising opportunities for large-scale water collection in water-deficient areas.
Flexible electronics have emerged as an exciting research area in recent years, serving as ideal interfaces bridging biological systems and conventional electronic devices. Flexible electronics can ...not only collect physiological signals for human health monitoring but also enrich our daily life with multifunctional smart materials and devices. Conductive hydrogels (CHs) have become promising candidates for the fabrication of flexible electronics owing to their biocompatibility, adjustable mechanical flexibility, good conductivity, and multiple stimuli‐responsive properties. To achieve on‐demand mechanical properties such as stretchability, compressibility, and elasticity, the rational design of polymer networks via modulating chemical and physical intermolecular interactions is required. Moreover, the type of conductive components (eg, electron‐conductive materials, ions) and the incorporation method also play an important role in the conductivity of CHs. Electron‐CHs usually possess excellent conductivity, while ion‐CHs are generally transparent and can generate ion gradients within the hydrogel matrices. This mini review focuses on the recent advances in the design of CHs, introducing various design strategies for electron‐CHs and ion‐CHs employed in flexible electronics and highlighting their versatile applications such as biosensors, batteries, supercapacitors, nanogenerators, actuators, touch panels, and displays.
Flexible electronics can not only collect physiological signals for human health monitoring but also enrich our daily life with multifunctional smart devices by serving as ideal interfaces bridging biological systems and conventional electronic devices. In this review, recent advances in the design of conductive hydrogels (CHs) for flexible electronics are highlighted. Extensive electron‐CHs and ionic‐CHs as well as their hybrids are reviewed based on both fabrication strategies and associated applications in flexible electronics such as biosensors, batteries, supercapacitors, nanogenerators, actuators, touch panels, and displays. Current challenges and future research perspectives of CHs are also proposed.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The CoS2 nanoneedle array on Ti mesh (CoS2 NA/Ti) was successfully synthesized via hydrothermal and sulfuration processes and utilized as a highly active and robust bifunctional catalyst for urea ...electrolysis in alkaline solutions.
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In this work, we report that uniformly CoS2 nanoneedle array grown on Ti mesh (CoS2 NA/Ti) behaves as a stable and efficient bifunctional electrocatalyst for urea-assisted electrolytic hydrogen production via overall urea splitting. As a non-noble metal electrocatalyst, CoS2 NA/Ti exhibited excellent urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) catalytic activity in 1.0M KOH with 0.3M urea solution. Only a cell voltage of 1.59V is required to achieve a current density of 10mAcm−2 for full urea splitting in 1.0M KOH with 0.3M urea.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Abstract
Overcoming the sluggish kinetics of alkaline hydrogen oxidation reaction (HOR) is challenging but is of critical importance for practical anion exchange membrane fuel cells. Herein, abundant ...and efficient interfacial active sites are created on ruthenium (Ru) nanoparticles by anchoring atomically isolated chromium coordinated with hydroxyl clusters (Cr
1
(OH)
x
) for accelerated alkaline HOR. This catalyst system delivers 50-fold enhanced HOR activity with excellent durability and CO anti-poisoning ability via switching the active sites from Ru surface to Cr
1
(OH)
x
-Ru interface. Fundamentally different from the conventional mechanism merely focusing on surface metal sites, the isolated Cr
1
(OH)
x
could provide unique oxygen species for accelerating hydrogen or CO spillover from Ru to Cr
1
(OH)
x
. Furthermore, the original oxygen species from Cr
1
(OH)
x
are confirmed to participate in hydrogen oxidation and H
2
O formation. The incorporation of such atomically isolated metal hydroxide clusters in heterostructured catalysts opens up new opportunities for rationally designing advanced electrocatalysts for HOR and other complex electrochemical reactions. This work also highlights the importance of size effect of co-catalysts, which should also be paid substantial attention to in the catalysis field.
Antibiotics are widely used in the treatment of bacterial infections and as food additives in the livestock industry. The wide usage of antibiotics causes residues in animal products, like milk, eggs ...and meat. A number of studies have reported that antibiotic residues exist at high concentrations in watercourses around the world. Doxycycline (DH), oxytetracycline (OTCC) and florfenicol (FF) are the three most commonly used veterinary antibiotics in China. However, studies of the toxic effects of DH, OTCC and FF are limited. In this study, six-moth-old healthy male adult zebrafish were exposed to 0, 10, 30, 100 μg/L DH, OTCC or FF for 21 days. After exposure, some biochemical parameters changed significantly, including total cholesterol (TC), triglyceride (TG), pyruvate and acid phosphatase (ACP). In addition, mucus secretion in the gut decreased and the transcription of related genes also decreased significantly. Moreover, the composition of microbiota in the gut changed significantly. DH, OTCC and FF exposure caused the decrease of diversity of gut microbiota. The relative abundance of Proteobacteria increased significantly after OTCC and FF exposure and Fusobacteria decreased in all antibiotic-treated groups. Further functional prediction analysis also suggested changes in gut microbiota in the OTCC and FF-treated groups, especially those linked to metabolism. To support this idea, we confirmed that some glycolipid related genes also increased significantly in the liver of adult zebrafish after antibiotic exposure. According to these results, DH, OTCC or FF exposure could cause the gut microbiota dysbiosis and dysfunction, and hepatic metabolic disorder in adult male zebrafish.
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•Doxycycline, oxytetracycline and florfenicol decreased gut mucus secretion.•Antibiotic exposure induced gut microbiota dysbiosis and dysfunction.•The hepatic glycolipid metabolism was also affected.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the field of remote sensing, cloud and cloud shadow will result in optical remote sensing image contamination, particularly high cloud cover, which will result in the complete loss of certain ...ground object information. The presence of thick cloud severely limits the use of optical images in production and scientific research, so it is critical to conduct further research into removing the thick cloud occlusion in optical images to improve the utilization rate of optical images. The state-of-the-art cloud removal methods proposed are largely based on convolutional neural network (CNN). However, due to CNN’s inability to gather global content information, those cloud removal approaches cannot be improved further. Inspired by the transformer and multisource image fusion cloud removal method, we propose a transformer-based cloud removal method (Former-CR), which directly reconstructs cloudless images from SAR images and cloudy optical images. The transformer-based model can efficiently extract and fuse global and local context information in SAR and optical images, generating high-quality cloudless images with higher global consistency. In order to enhance the global structure, local details, and visual effect of the reconstructed image, we design a new loss function to guide the image reconstruction. A comparison with several SAR-based cloud removal methods through qualitative and quantitative experimental evaluation on the SEN12MS-CR dataset demonstrates that our proposed method is effective and superior.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
When the SLAM algorithm is used to provide positioning services for a robot in an indoor scene, dynamic obstacles can interfere with the robot’s observation. Observing the ceiling using an ...upward-looking camera that has a stable field of view can help the robot avoid the disturbance created by dynamic obstacles. Aiming at the indoor environment, we propose a new ceiling-view visual odometry method that introduces plane constraints as additional conditions. By exploiting the coplanar structural constraints of the features, our method achieves better accuracy and stability in a ceiling scene with repeated texture. Given a series of ceiling images, we first use the semi-direct method with the coplanar constraint to preliminarily calculate the relative pose between camera frames and then exploit the ceiling plane as an additional constraint. In this step, the photometric error and the geometric constraint are both optimized in a sliding window to further improve the trajectory accuracy. Due to the lack of datasets for ceiling scenes, we also present a dataset for the ceiling-view visual odometry for which the LiDAR-Inertial SLAM method provides the ground truth. Finally, through an actual scene test, we verify that, in the ceiling environment, our method performs better than the existing visual odometry approach.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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