Recent advances in nanofabrication technologies have spurred many breakthroughs in the field of photonic metamaterials that provide efficient ways of manipulating light-matter interaction at subwavelength scales. As one of the most important applications, photonic metamaterials can be used to implement novel optical absorbers. First the morphology engineering of various photonic metamaterial absorbers is discussed, which is highly associated with impendence matching conditions and resonance modes of the absorbers, thus directly determines their absorption efficiency, operational bandwidth, incident angle, and polarization dependence. Then, the recent achievements of various interdisciplinary applications based on photonic metamaterial absorbers, including structural color generation, ultrasensitive optical sensing, solar steam generation, and highly responsive photodetection, are reviewed. This report is expected to provide an overview and vision for the future development of photonic metamaterial absorbers and their applications in novel nanophotonic systems.
The International Atomic Energy Agency (IAEA) jointly with the Elettra Sincrotrone Trieste (EST) operates a multipurpose X‐ray spectrometry endstation at the X‐ray Fluorescence beamline (10.1L). The facility has been available to external users since the beginning of 2015 through the peer‐review process of EST. Using this collaboration framework, the IAEA supports and promotes synchrotron‐radiation‐based research and training activities for various research groups from the IAEA Member States, especially those who have limited previous experience and resources to access a synchrotron radiation facility. This paper aims to provide a broad overview about various analytical capabilities, intrinsic features and performance figures of the IAEA X‐ray spectrometry endstation through the measured results. The IAEA–EST endstation works with monochromatic X‐rays in the energy range 3.7–14 keV for the Elettra storage ring operating at 2.0 or 2.4 GeV electron energy. It offers a combination of different advanced analytical probes, e.g. X‐ray reflectivity, X‐ray absorption fine‐structure measurements, grazing‐incidence X‐ray fluorescence measurements, using different excitation and detection geometries, and thereby supports a comprehensive characterization for different kinds of nanostructured and bulk materials. A broad overview of the various analytical capabilities, intrinsic features and performance figures of the IAEA X‐ray spectrometry endstation operated at the X‐ray Fluorescence beamline of Elettra Sincrotrone Trieste is given, and different applications are demonstrated to familiarize the user community with the applicable intersdisciplinary research.
Synoptic classification is a methodology that represents diverse atmospheric variables and allows researchers to relate large-scale atmospheric circulation patterns to regional- and small-scale terrestrial processes. Synoptic classification has often been applied to questions concerning the surface environment. However, full applicability has been under-utilized to date, especially in disciplines such as hydroclimatology, which are intimately linked to atmospheric inputs. This paper aims to (1) outline the development of a daily synoptic calendar for the Mid-Atlantic (USA), (2) define seasonal synoptic patterns occurring in the region, and (3) provide hydroclimatological examples whereby the cascading response of precipitation characteristics, soil moisture, and streamflow are explained by synoptic classification. Together, achievement of these objectives serves as a guide for development and use of a synoptic calendar for hydroclimatological studies. In total 22 unique synoptic types were identified, derived from a combination of 12 types occurring in the winter (DJF), 13 in spring (MAM), 9 in summer (JJA), and 11 in autumn (SON). This includes six low pressure systems, four high pressure systems, one cold front, three north/northwest flow regimes, three south/southwest flow regimes, and five weakly defined regimes. Pairwise comparisons indicated that 84.3 % had significantly different rainfall magnitudes, 86.4 % had different rainfall durations, and 84.7 % had different rainfall intensities. The largest precipitation-producing classifications were not restricted to low pressure systems, but rather to patterns with access to moisture sources from the Atlantic Ocean and easterly (on-shore) winds, which transport moisture inland. These same classifications resulted in comparable rates of soil moisture recharge and streamflow discharge, illustrating the applicability of synoptic classification for a range of hydroclimatological research objectives.
Accurate forecasting of hourly suspended sediment concentration is a critical issue for reservoir management, especially during typhoon periods. This research proposes a two-stage forecasting approach integrating numerical and machine-learning-based models to provide accurate real-time forecasts of half-hourly suspended sediment concentration. In the first stage, the density current model, SRH2D, was verified and applied by the historical typhoon events due to the lack of measured suspended sediment concentration. Next, in the second stage, the calculated results from SRH2D based on the spatial-temporal relation were employed as the input of the MGSVM-based model. Finally, an application in the Shi-Men reservoir was conducted to demonstrate the forecasting performance of the proposed approach. The results indicated that the calculated data from the SRH2D model corresponded to the trend of measured data in spatial-temporal variation. Moreover, the proposed forecasting approach enables reasonably acceptable 0.5- to 3-h ahead forecasts of suspended sediment concentration by using the simulated data of half-hourly suspended sediment concentration. The accurate forecast conducted by the proposed approach is expected to be properly applied to reservoir management.