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Spatiotemporal tendency of total phosphorus (TP) concentrations in Hongze Lake were estimated using multiple Moderate - Resolution Imaging Spectroradiometer/Aqua images (MODIS) from 2003 to 2017. Considering the non-significant spectral features of phosphorus, this study was designed to primarily link TP with sensitive water quality parameters. Suspended particulate matter (SPM) was identified because SPM contents are sensitive to TP in Hongze Lake and also have notable response wavelengths including red, blue, and green bands. Therefore, a TP estimation model was developed based on the band integration methods suitable for lake SPM. The results showed that: 1) the exponential model of 645 nm and 555 nm is the most suitable model for TP estimation in Hongze Lake, in which the R2 value for calculation and validation can both reach 0.7; 2) the best TP assessment accuracy always occurred when the SPM values were of a moderate level. The threshold values can be approximately designated as 40 ~ 70 mg/L; 3) the TP concentrations of the entire lake have apparently increased since 2012, and achieved a peak in 2014 because of substantial dredging activities; and 4) the center of the lake showed the highest TP concentrations, while the two bays in the northern and western lake showed the lowest TP concentra-tions. These spatial variations can be attributed to the integration of several factors including meteorological phenomena, land use change, and human disturbance such as dredging activities. This study further indicates that the Rayleigh-corrected reflectance of red band and green band derived from MODIS can be proposed as the suitable indicators for TP monitoring, especially in SPM-dominated lakes. In addition, more ideal modeling effect can be expected when lake SPM contents kept in a medium level (e.g. 40 ~ 70 mg/L within Hongze Lake). [ABSTRACT FROM AUTHOR]

Organic matter transport from watershed soil into an aquatic ecosystem plays a key role in the fate of contaminants and lake eutrophication. Special emphasis is needed to understand whether sensitive river indicators can reflect watershed non-point source organic carbon (OC) pollution, in which the accurate assessment of non-point source (NPS) pollution is crucial. This study selected a sub-basin within the Taihu basin, China, as the study site, a typical rural-urban fringe region undergoing rapid urbanization where soil organic carbon (SOC) loss would likely take place due to the integration of agriculture NPS and impervious surface NPS. The seasonal tendency of NPS soil organic carbon (SOC) loads were evaluated by using the integration of SEDD and PLOAD models, which consider the sediment adsorption fraction loads (Sed-OC) and runoff dissolved fraction loads (Dis-OC) together. And then the sensitive water indicators for OC loads were determined by measurements of inflowing river properties and stepwise regression analysis. The results showed that active dissolved carbon fraction loads were the dominant contributors to the total organic carbon loads (Tot-OC) and that Sed-OC loads have more spatial variation. With respect to sensitive river properties, the lignin owned the greatest correlation degree with different OC fraction loads, in which the correlation coefficient between particulate lignin and Sed-OC loads reached 0.782, which is the greatest among the different indicators. In addition, the colored dissolved organic matter (CDOM) was also correlated with Dis-OC loads. However, the particulate organic carbon (POC) was not well related to OC loads. The findings of this study are useful for better understanding the nutrient migration from watershed soil into aquatic ecosystem controlled by watershed NPS pollution. [ABSTRACT FROM AUTHOR]

Orthorhombic CeNiSi2-type polycrystalline RNiSi2 (R=Gd, Dy, Ho, Er, Tm) compounds were synthesized and the magnetic and magnetocaloric properties were investigated in detail. The transition temperatures of RNiSi2 compounds are all in a very low temperature range (<30 K). As temperature increases, all of the compounds undergo an AFM to PM transition (GdNiSi2 at 18 K, DyNiSi2 at 25 K, HoNiSi2 at 10.5 K, ErNiSi2 at 3 K and TmNiSi2 at 3.5 K, respectively). ErNiSi2 compound shows the largest ( Δ S M ) m a x (maximal magnetic entropy change) among these compounds. The value of ( Δ S M ) m a x is 27.9 J/kgK under a field change of 0-5 T, which indicates that ErNiSi2 compound is very competitive for practical applications in low-temperature magnetic refrigeration in the future. DyNiSi2 compound shows large inverse MCE (almost equals to the normal MCE) below the TN which results from metamagenitic transition under magnetic field. Considering of the normal and inverse MCE, DyNiSi2 compound also has potential applications in low-temperature multistage refrigeration. [ABSTRACT FROM AUTHOR]

The hard magnetic (La,Ce)Co5 nanoflakes with high coercivity and narrow thickness distribution have been successfully obtained by surfactant-assisted ball milling (SABM). The magnetic properties, morphology and interaction of (La,Ce)Co5 nanoflakes are studied in this work. The coercivity and remanence ratio of (La,Ce)Co5 nanoflakes are 5.48 kOe and 0.71, respectively. The X-ray powder diffraction (XRD) patterns indicate that the (La,Ce)Co5 nanoflakes are CaCu5-type hexagonal crystal structure. The average thickness and aspect ratio are 47 nm and 40, respectively. The intergrain interaction of the (La,Ce)Co5 nanoflakes is studied using the δm(H)-curves technique which shows the magnetostatic-dominated particle interaction. The high coercivity and narrow thickness distribution of (La,Ce)Co5 nanoflakes could be promising for the future development of the high performance soft/hard exchange spring magnets. [ABSTRACT FROM AUTHOR]

The hard magnetic MMCo5 nanoflakes with high coercivity and narrow size distribution have been successfully obtained by three steps surfactant-assisted ball milling (SABM). The magnetic properties, phase structure and morphology of these MMCo5 nanoflakes were studied in this work. The coercivity and the remanence ratio of MMCo5 nanoflakes reached to 5.89 kOe and 0.75, respectively. The X-ray powder diffraction (XRD) patterns indicated that the MMCo5 nanoflakes were CaCu5-type hexagonal crystal structure. The average thickness, in-plane size and aspect ratio reached to 20 nm, 0.9 μm and 60, respectively. The low cost and great properties of MMCo5 nanoflakes with a centralized thickness distribution could be the building blocks for the future high-performance nanocomposite permanent magnets with an enhanced energy product. [ABSTRACT FROM AUTHOR]

This study was conducted between November to December 2020, consisting of six representative cities, Beijing, Shanghai, Shenzhen (with comprehensive smoke-free legislation), and Changsha, Chongqing, Shenyang (without comprehensive smoke-free legislation), 678 subjects were enrolled eventually, the mean age of the 678 subjects was (35.61±12.91)years old. Subjects from cities with comprehensive smoke-free legislation accounted for 49.71% of the total; male subjects accounted for 19.47%; meanwhile subjects from large, medium, and small restaurants accounted for 13.57% (92), 37.32% (253) and 49.11% (333) respectively. The analysis results indicate that the positive rate of restaurants staff of cotinine and 3'-hydroxynicotinine was lower in cities with comprehensive smoke-free legislation(34.12% vs 68.04%, χ²=78.01, P <0.001; 16.32% vs 41.94%, χ²=53.79, P <0.001), with staff from cities with comprehensive smoke-free legislation have lower concentrations of cotinine and 3'-hydroxynicotinine than their counterparts from cities without comprehensive smoke-free legislation(0.250 ng/ml vs 0.742 ng/ml, P <0.001; 0.250 ng/ml vs 0.250 ng/ml, P <0.001). No statistically significant difference in the concentration of cotinine and 3'-hydroxynicotinine in saliva between staff from restaurants of different sizes was detected ( P >0.05).