The objective of this study was to evaluate and classify soil nutrient status using advanced 3S (global
positioning system, GPS; remote sensing, RS; and geographic information system, GIS) technology. Firstly, multi-temporal Landsat TM 5 images with 30 m spatial resolution were utilized to identify the field-scale farmlands. The overall classification accuracy reached 86.96%, with a kappa coefficient of 0.743. selleck chemical Additionally, the correlation coefficient (r) reached 0.942 by comparing the remote sensing-based farmland area with the statistical data. Subsequently, organic matter, total nitrogen, available phosphorus and available potassium from 7,435 field sample points positioned by GPS receiver, were used to generate a comprehensive soil nutrient PRIMA-1MET price index in GIS software, according to the classification criteria of Beijing Soil and Fertilizer Workshop. Finally, a classification map of field-scale soil nutrient levels (very high, high, moderate, low & very low) was created using the farmlands as mask layers. The analysis results showed that the soils at moderate and low levels dominated the Beijing’s farmlands, which accounted for 46.1% and 39.1%, respectively; high and very low level soils were the second place whose ratios were 10.4% and 4.3%, respectively; and very high level soils could be rarely found. Yanqing County, Tongzhou District and Changping Selleck EPZ6438 District have better soil
nutrient status as a whole. (C) 2012 Friends Science Publishers”
“Clinical applications of current photodynamic therapy (PDT) agents are often limited by their low singlet oxygen (O-1(2)) quantum
yields, as well as by photobleaching and poor biocompatibility. Here we present a new PDT agent based on graphene quantum dots (GQDs) that can produce O-1(2) via a multistate sensitization process, resulting in a quantum yield of similar to 1.3, the highest reported for PDT agents. The GQDs also exhibit a broad absorption band spanning the UV region and the entire visible region and a strong deep-red emission. Through in vitro and in vivo studies, we demonstrate that GQDs can be used as PDT agents, simultaneously allowing imaging and providing a highly efficient cancer therapy. The present work may lead to a new generation of carbon-based nanomaterial PDT agents with overall performance superior to conventional agents in terms of O-1(2) quantum yield, water dispersibility, photo-and pH-stability, and biocompatibility.”
“We study polarization independent improved light trapping in commercial thin film hydrogenated amorphous silicon (a-Si:H) solar photovoltaic cells using a three-dimensional silver array of multiresonant nano-disk structures embedded in a silicon nitride anti-reflection coating to enhance optical absorption in the intrinsic layer (i-a-Si:H) for the visible spectrum for any polarization angle.
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