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Semantic segmentation of remote sensing (RS) images, which is a fundamental research topic, classifies each pixel in an image. It plays an essential role in many downstream RS areas, such as land-cover mapping, road extraction, traffic monitoring, and so on. Recently, although deep-learning-based methods have shown their dominance in automatic semantic segmentation of RS imagery, the performance of these existing methods has relied heavily on large amounts of high-quality training data, which are usually hard to obtain in practice. Moreover, human-in-the-loop semantic segmentation of RS imagery cannot be completely replaced by automatic segmentation models, since automatic models are prone to error in some complex scenarios. To address these issues, in this paper, we propose an improved, smart, and interactive segmentation model, DRE-Net, for RS images. The proposed model facilitates humans' performance of segmentation by simply clicking a mouse. Firstly, a dynamic radius-encoding (DRE) algorithm is designed to distinguish the purpose of each click, such as a click for the selection of a segmentation outline or for fine-tuning. Secondly, we propose an incremental training strategy to cause the proposed model not only to converge quickly, but also to obtain refined segmentation results. Finally, we conducted comprehensive experiments on the Potsdam and Vaihingen datasets and achieved 9.75% and 7.03% improvements in N o C 95 compared to the state-of-the-art results, respectively. In addition, our DRE-Net can improve the convergence and generalization of a network with a fast inference speed. [ABSTRACT FROM AUTHOR]

Selenium (Se) is an essential nutrient element for humans, and Se-enriched products are gaining popularity due to their health benefits. However, Enshi, a region in China naturally rich in Se, a high background value of cadmium (Cd) is discovered, which severely impacts local Se-enriched agriculture. Therefore, it is crucial to explore the geochemical relationship between Se and Cd. In this study, we analyzed soil profiles and parent rocks of different geological ages from Enshi to investigate the accumulation and distribution of Se and Cd. The ratio of redox sensitive elements and the multivariate statistical analysis, along with XRD and XPS analysis, were utilized to investigate the correlated relationship between Se and Cd and the underlying geochemical mechanisms. The results showed that average Se and Cd contents in rocks were 1.67 and 0.32 mg/kg. Se and Cd levels reached highest at Permian in rocks of different geological ages, which may be related to the Permian Dongwu movement near the study area. The highest migration rate of Cd and Se from rock to soil was 12 and 1.5 times. The soil Se and Cd fractions were mostly in bound states, with the largest fraction of Se being organic-bound at an average of 45.9%. The reducible and the residue state accounted for the largest proportion in the Cd fractions, with an average of 40.6% and 25.6%. Redox-sensitive element ratios indicate a reducing forming environment of deep sediments in the Permian strata. Furthermore, the correlation and PCA analysis revealed highly significant positive correlations between Se, Cd, V and Cr, suggesting that the sources of Se and Cd were closely related to volcanic and biological activities. In conclusion, a strong geochemical relationship was observed between Se and Cd. And as a result, metal pollution must be closely monitored during the production of Se-enriched agriculture in Se-enriched regions. [Display omitted] • The Se and Cd and the instructive geochemical elements were analyzed in the soil profiles of typical geological ages. • The geochemical accompanying relationship between Se and Cd was firstly reported in the natural Se-rich areas. • The content and fractions of Se and Cd were varied with the geological ages. • The migration rate of Cd from rock to soil was much higher than that of Se. • Closely geochemical correlationship between Se and Cd in soil profiles were found. [ABSTRACT FROM AUTHOR]

The largely stagnant marine ecosystem following the Permian–Triassic mass extinction (PTME) was superseded by the appearance of marine reptiles. One of the most abundant Early Triassic (Spathian) marine reptile faunas occurs in the Nanzhang‐Yuan'an area of Hubei Province, South China, and provides remarkable information for understanding biotic recovery after the PTME. Situated on the north edge of the Middle Yangtze Platform in South China, the well‐exposed Zhangjiawan stratigraphic succession in Yuan'an County represents one of the most productive sections, yielding abundant marine reptiles. Intensive sampling of this section reveals a unique conodont community both before and during the emergence of the Nanzhang‐Yuan'an Fauna (NYF). Occurrences of Neostrachanognathus tahoensis below the NYF and deposition of ʻGreen Bean Rock (GBR)ʼ above the NYF restricted this fauna to the latest Early Triassic. Except for the coniform Neostrachanognathus, this conodont community consists of abundant Ellisoniidae characterized by ramiform P1 elements. Foraminifers and fish found together with the conodont elements form other low‐level parts of the local food web. Other temporally coincident sections nearby, for example, the Yanduhe section of western Hubei Province, yield only rare conodonts. Hence, the unique conodont community from the Zhangjiawan section suggests that the Nanzhang‐Yuan'an area might be a "refuge area" for the Early Triassic marine ecosystem, or at least for the marine reptiles and the conodont communities. Although the direct connection between conodonts and marine reptiles is still uncertain, low‐level consumers—conodont animals‐played important roles in the food webs of NYF. The collision of the South China and North China blocks removed this "refuge area" and witnessed the disappearance of endemic Hupeisuchians. [ABSTRACT FROM AUTHOR]

The abrupt weakening of the East Asian summer monsoon (EASM) during Younger Dryas (YD) has been attributed to freshwater discharge into the North Atlantic ocean and resultant Northern Hemisphere cooling. Recent studies have found that sea ice variability in the Nordic Sea during the YD exerted a great influence upon the northern high-latitude climate. However, the influence of sea ice upon EASM evolution during YD event remains unclear. In this paper, we report two precisely-dated speleothem oxygen isotope records from the EASM-dominated region of central China. Our records archive abrupt changes in EASM variability during the YD event. Initially, there was a significant strengthening of the EASM during the mid-YD following the gradually increased Atlantic meridional overturning circulation (AMOC). Later this trend reversed at ∼12.15 ka due to northern high-latitude sea ice fluctuations and a consequent reduction of AMOC. At the YD termination, abrupt intensification of the EASM was synchronous with the rapid decline of sea-ice and recovery of the AMOC indicating that sea ice variability was a significant influence on high latitude climate and EASM variation during the YD. • A new speleothem δ18O record show significant EASM strengthening during mid-YD. • Mid-YD oscillation in EASM linked with NH sea ice variability. • Abrupt EASM intensification at YD termination synchronous with the rapid decline of sea ice. • Drier interval following the YD termination in central China. [ABSTRACT FROM AUTHOR]

Developing a portable device for visual and on-site detection of fluoride in groundwater is highly anticipated. In this paper, 2-(tert -butyl-diphenylsilanyloxy)−5-nitro-1 H -benzoimidazole (1) has been rationally designed via a silanization reaction for self-calibration detection of fluoride, and the detection limit was calculated as 0.11 μM. The contact of 1 with fluoride would induce the cleavage of Si-O bond and trigger the emergence of excited state intramolecular proton transfer (ESIPT) process, and then the enol-like emission at 437 nm decreased accompanying with the increase of keto-like tautomerism emission at 550 nm. More importantly, considering the demand of field detection for fluoride in groundwater and combining the function of smartphone to obtain the chroma of photos. The chroma value of the fluorescence color changes from blue to yellow could be conveniently determined through a color recognizer application installed in smartphone. The device can accurately reflect the concentration of fluoride by analyzing the chroma value. The test in actual water samples confirmed that the simple device based on smartphone could be used efficiently for visual, on-site and accurate detection of fluoride in groundwater. [Display omitted] • 1 was prepared as a self-calibration fluoride probe. • The detection limit of 1 toward fluoride is as low as 2.09 ppb. • Fluoride detection is based on the triggered Si-O cleavage driven ESIPT process. • Smartphone as a device was prepared for visual and on-site detection of fluoride. [ABSTRACT FROM AUTHOR]

• Mg/Al HT was firstly used as ozonation catalyst and has satisfied catalytic activity. • COD removal efficiency of Mg 3 /Al HT was even higher than α-FeOOH (68 % vs. 50 %). • Not only OH but also O 2 − and 1O 2 were the reactive species for 2,4-D degradation. • Surface acid and base site are the active centers of Mg/Al HT in catalytic ozonation. • Mg/Al HT provides a promising catalyst alternative for catalytic ozonation. The Mg/Al hydrotalcite (Mg/Al HT) was firstly used as a heterogeneous ozonation catalyst and 2,4-dichlorophenoxyacetic acid (2,4-D) was efficiently degraded by Mg 3 /Al HT with a COD removal of 68 %. It was higher than that of α-FeOOH with a COD removal of 50 %. The effects of Mg/Al atomic ratio, phosphate and pyrrole on the ozonation performance of Mg/Al HTs were also investigated. The X-ray photoelectron spectroscopy (XPS), nitrogen adsorption-desorption experiment and temperature programmed desorption of adsorbed CO 2 or NH 3 were used to characterize the surface properties of Mg/Al HT. The surface acidity and basity was proven to be responsible to the excellent ozonation activity of Mg/Al HT. The results of electron spin resonance (ESR) analysis and probe experiments confirmed that OH, O 2 − and 1O 2 were involved in the 2,4-D degradation process and their contributions are as followed: OH > O 2 - >1O 2. The synergistic effect of surface acid (ozone adsorption center) and base sites (catalytic center) determines Mg/Al HT in the enhanced catalytic ozone decomposition into reactive species. More important, the transition metal free based Mg/Al HTs is steady, non-toxic, naturally abundant and environment friendly, which provided a promising alternative in practical water treatment by catalytic ozonation. [ABSTRACT FROM AUTHOR]