Search

Grassland aboveground biomass (AGB) is an important indicator for studying the change in grassland ecological quality and carbon cycle. The rapid development of high-resolution remote sensing and unmanned aerial vehicles (UAV) provides a new opportunity for accurate estimation of grassland AGB on the plot scale. In this study, the mountain grassland was taken as the research object. Using UAV Light Detection and Ranging (LiDAR) data and multispectral satellite images, the influence of topographic correction methods on AGB estimation was compared and a series of LiDAR metrics and vegetation indices were extracted. On this basis, a comprehensive indicator, the vegetation index-height-intensity model (VHI), was proposed to estimate AGB quickly. The results show that: (1) Among the four topographic correction methods, the Teillet regression has the best effect, and can effectively improve the accuracy of AGB estimation in mountain grassland. The correlation between corrected ratio vegetation index and AGB was the highest (correlation coefficient: 0.682). (2) Among the height and intensity metrics, median height and max intensity yielded the higher accuracy in estimating AGB, with Root Mean Square Error (RMSE) of 322 g/m2 and 333 g/m2, respectively. (3) The VHI integrated spectrum and LiDAR information, and its accuracy for AGB estimation for mountain grassland, was obviously better than other indicators, with an RMSE of 272 g/m2. We also found that the accuracy of VHI in univariate models was comparable to that of complex multivariate models such as stepwise regression, support vector machine, and random forest. This study provides a new approach for estimating grassland AGB with multi-source data. As a simple and effective indicator, VHI has shown strong application potential for grassland AGB estimating in mountainous areas, and can be further applied to grassland carbon cycle research and fine management. [ABSTRACT FROM AUTHOR]

The main objective of this study was to investigate the effects of combining subsoil and incorporation of corn stover on soil profile, soil physicochemical properties, and corn yield. A five-year field trial was conducted that consisted of two treatments arranged in a completely random design and replicated three times. Two soil management operations were tested: subsoil + corn stover incorporation (plow construction [PC] treatment) and conventional rotary tillage (control check [CK] treatment). Compared with rotary tillage, it was found that combining subsoil and corn stover incorporation significantly affected corn grain yield in all seasons. Further, combining subsoil and corn stover incorporation significantly increased the thickness of the plow layer, quantity of plow layer soil, thickness of the plow pan and soil bulk density, as well as soil organic matter, available nitrogen, available phosphorus, and available potassium. Evidence indicates that reconstructing the soil plow layer through combination of subsoil and corn stover incorporation improved soil structure, nutrient content, and corn yield. It is of interest that farmers are now applying subsoil and returning crop straw instead of solely relying on rotary tillage. [ABSTRACT FROM PUBLISHER]

• A facile method of directly converting electroplating sludge into nickel-based energy storage composites. • The unique embedded multilevel nanostructure improves the effective reaction of active substances with electrolyte. • Fe-Al co-doped α-Ni(OH) 2 and Ni(HCO 3) 2 composites show high specific capacitance and good cycling stability. The recovery of heavy metals from electroplating sludge is an important technology, which can not only reduce environmental pollution, but also serve as a secondary source of metals. However, the current techniques are either non-selective or difficult to operate, which limits its applications in recovery technologies. Herein, based on the existence of multiple metal ions in electroplating sludge, Fe and Al co-doped ultrathin α-Ni(OH) 2 nanosheets embedded in Ni(HCO 3) 2 nanowire assembly spheres were prepared by adjusting the ratio of urea under hydrothermal condition. Under the optimum conditions, the recovery of Ni, Fe, and Al are 92.58%, 81.52%, and 61.19% respectively. In addition, at the current density of 1 A g−1, the specific capacitance of the spherical composite electrode is as high as 495.6 C g−1, and the retention rate of the initial capacity is 55.58% after 3500 cycles in 6 M KOH electrolyte, showing good cycling stability. Furthermore, the ASC device (NN-4//AC) achieved a high energy density of 30.27 Wh kg−1 at a power density of 0.37 kW kg−1. A new method for converting electroplating sludge into nickel-based energy storage materials was developed, which provided a new strategy and idea for the harmless and resourceful treatment of electroplating sludge. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen production from water is a promising method to obtain clean energy in the future. In this work, the sulfated TiO2 photocatalyst is successfully constructed in situ via a soft-templated method for photocatalytic water splitting to produce hydrogen. The content of sulfate species in TiO2 can be tuned by changing the amount of the surfactant. The photocatalyst with the appropriate content of sulfate ions exhibits an apparent quantum efficiency (AQE) of 3.9% at 365 nm and a high hydrogen production rate of 24.32 mmol h-1 g-1, which is 1.65 times that of commercial TiO2 (P25). The optimized photocatalyst has excellent photocatalytic activity for hydrogen evolution benefitting from the presence of sulfate ions on the surface of TiO2, large surface area and oxygen vacancies, which facilitates the rapid migration of photo-generated electrons to its surface and the improvement of the separation efficiency of photo-generated carriers. This work may inspire the rational design and the development of high-efficiency photocatalysts.

Background: X-linked hypophosphatemia (XLH) is the most common form of heritable rickets characterized by X-linked dominant inheritance, renal phosphate wasting, hypophosphatemia, and defective bone mineralization. Inactivating mutations of the PHEX gene located at Xp22.1 have been linked with this disease. Ethnic distribution of such mutations seems widespread but only a few mutations in the Chinese population have been reported to date., Materials and Methods: We report on a large Han Chinese family affected with XLH rickets, which included 13 patients from four generations. Polymerase chain reaction and direct sequencing were performed for all exons and intron-exon boundaries of the PHEX gene. The effect of nucleotide changes was analyzed using bioinformatic software. Prenatal diagnosis was performed on umbilical cord blood at the 20th gestational week., Results: A novel G-->A splice mutation in intron 7 (c.849+1G>A) was identified in all patients from the family. As confirmed by reverse-transcription (RT)-polymerase chain reaction (PCR), the mutation has rendered loss of a normal splice donor site (c.849+1G) while activating a cryptic one at c.849+519G, which resulted in addition of 518 nucleotides to the mature RNA. Prenatal diagnosis had excluded the fetus for carrying the same mutation. A healthy boy was born later., Conclusions: A novel splice mutation c.849+1G>A in the PHEX gene is responsible for XLH in the studied family. Further studies may enhance our understanding of the role of this mutation in the pathogenesis of XLH.