4 research outputs found

    Presentation1_Karst landslides detection and monitoring with multiple SAR data and multi-dimensional SBAS technique in Shuicheng, Guizhou, China.pdf

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    Shuicheng District is a karst mountain area, located in Guizhou Province, China. Its fragile stratum and frequent underground mining activities makes it prone to landslides. Owning to its wide coverage and frequent revisit, the InSAR technology has advantages in potential landslide identification and deformation monitor. However, affected by dense vegetation and atmospheric delay, it is much difficult to get sufficient effective targets to derive the deformation in this area. Besides, deformation derived from single orbit SAR data can result in the missing identification of some potential landslides and the misinterpreting of the real kinematics process of landslides. In this study, the multi-source SAR data, atmospheric error correction by quadratic tree image segmentation method, and phase-stacking method were selected to derive the surface deformation of this area. Besides, DS-InSAR and MSBAS method were combined to derive the deformation of Pingdi landslide. First, the potential landslides in this area were identified, surface deformation result, optical remote sensing images and geomorphological features were jointly considered. Then, the landslide distribution characteristics was analyzed in terms of slope, elevation and stratum. After that, the deformation along the LOS direction was acquired using the DS-InSAR method. The MSBAS method was used to retrieve the two-dimensional deformation of Pingdi landslide. Finally, the comprehensive analysis of triggering factors and failure process were conducted according to the spatial-temporal deformation characteristics and field investigation. The results indicated that landslides in Shuicheng district were mostly located in the junction of T1 and P3 stratum and mining related. Mining activity was the main cause of the Pingdi landslide deformation, the precipitation was the driving factor of the landslide instability. The research provides an insight into the explore the unstable slope distribution characteristic and the failure process of the landslides.</p

    Construction of Fully Substituted 2‑Pyridone Derivatives via Four-Component Branched Domino Reaction Utilizing Microwave Irradiation

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    Microwave irradiation, four-component branched domino reaction of methyl acetoacetate/2,4-pentanedione, diethyl malonate, triethyl orthoformate and amines offering an extremely efficient strategy for the construction of fully substituted 2-pyridone derivatives under sustainable conditions is established. This self-sorting branched domino transformation is proposed to proceed separate through N-nucleophilic addition and imine-enamine tautomerization/condensation reaction generated from enamino ester and diethyl ethoxymethylenemalonate, and then would be subjected to an aza-ene reaction and intramolecular cyclization mechanism to afford the 2-pyridones with only water and ethanol as byproducts. The simple experimental procedure, high bond-forming efficiency, step and atom economy, inexpensive readily available starting materials, moderate to excellent yields, and good functional group compatibility are other noteworthy advantages of this method

    High-Throughput Optical Sensing Immunoassays on Smartphone

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    We present an optical sensing platform on a smartphone for high-throughput screening immunoassays. For the first time, a designed microprism array is utilized to achieve a one-time screening of 64 samples. To demonstrate the capability and the reliability of this optical sensing platform on smartphone, human interleukin 6 (IL-6) protein and six types of plant viruses are immunoassayed. The ability of quantification is shown by a sigmoidal dose–response curve fitting to analyze IL-6 protein. The accuracy in measuring the concentrations of IL-6 protein achieves 99.1%. On the other hand, to validate on-field immunoassays by our device, a total of 1030 samples are assayed using three immunoassay methods to detect six types of plant viruses. The accuracy is up to 96.2–99.9%; in addition, there is a high degree of agreement with lab instruments. The total cost for this high-throughput optical screening platform is ∼$50 USD. The reading time is only 2 s for 64 samples. The size is just as big as a portable hard drive. Our optical sensing platform on the smartphone offers a route toward in situ high-throughput screening immunoassays for viruses, pathogens, biomarkers, and toxins by decentralizing laboratory tests. With this mobile point-of-care optical platform, the spread of disease can be timely stopped within a very short turnaround time
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