The new plasmonic photocatalyst Ag@Ag(Br,I) was synthesized by the ion-exchange process between the silver bromide and potassium iodide, then by reducing some Ag(+) ions in the surface region of Ag(Br,I) particles to Ag(0) species. Ag nanoparticles are formed from Ag(Br,I) by the light-induced chemical reduction reaction. The Ag@Ag(Br,I) particles have irregular shapes with their sizes varying from 83 nm to 1 mum. The as-grown plasmonic photocatalyst shows strong absorption in the visible light region because of the plasmon resonance of Ag nanoparticles. The ability of this compound to reduce Cr(VI) under visible light was compared with those of other reference photocatalyst. The plasmonic photocatalyst is shown to be highly efficient under visible light. The stability of the photocatalyst was examined by X-ray diffraction and X-ray photoelectron spectroscopy. The XRD pattern and XPS spectra prove the stability of the plasmonic photocatalyst Ag@Ag(Br,I).

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Electrify your chemistry! Pyroelectric heterolayered BiOIO3 nanoplates efficiently separate photogenerated electron‐hole pairs due to the combined effect of their heterolayered structure and internal polar field (see scheme). Pyroelectric BiOIO3 nanoplates, synthesized by a simple hydrothermal method, were found to possess a superior photocatalytic activity under UV irradiation.

Aim The long-term cyclical patterns of China's geopolitical shifts are of great interest to scholars and the public, but to date there has been no satisfactory explanation for the alternating occupancy patterns of the country's pastoral and agrarian polities. We fill this gap by differentiating the agroecological settings of these polities over time and quantitatively analysing the relationships between climate change and historical geopolitical variations.Location China.Methods Our dataset comprised 38 palaeohydroclimate reconstructions, the historical boundaries of China's empire and the changes in its size, and 1028 wars and 2737 battle locations over the past 2300 years. China-wide precipitation during the period was reconstructed using the 'weighted composite plus scale' method. Timeseries analyses were performed to identify the strength of the associations between climate change and the geopolitical variables. Granger causality analysis and wavelet analysis were performed to verify the hypothesized causal links. Wavelet analysis was also used to identify the possible interactions (i.e. frequencies, significance, consistency and synchrony) between the signal components of the climatic and geopolitical variables at different temporal scales. ResultsChina's mean precipitation fell into three multicentennial cycles. The geopolitical variables corresponded to those cycles in the imperial era. The spatialtemporal frequencies of the boundaries and size of the agriculturalist empires and its frontiers with pastoralist empires were regulated by the long-term (lowfrequency) precipitation fluctuations at the multicentennial scale. Wars of aggression were an important explanatory factor driving the land-occupancy patterns of the two ecoempires under climate change, and caused most of the territorial shifts. Short-term (high-frequency) geopolitical changes were not associated with climate change.Main conclusions Precipitation-induced ecological change was an important factor governing the macrogeopolitical cycles in imperial China. Long-term territorial expansion favoured the polity (agriculturalist or pastoralist) that was better adapted to the changing ecological conditions in the country's heartland.

Medium and large construction projects typically involve multiple structural consultants who use a wide range of structural analysis applications. These applications and technologies have inadequate interoperability and there is still a dearth of investigations addressing interoperability issues in the structural engineering domain. This paper proposes a novel approach which combines an Industry Foundation Classes (IFC)-based Unified Information Model with a number of algorithms to enhance the interoperability:(a) between architectural and structural models, and (b) among multiple structural analysis models (bidirectional conversion or round tripping). The proposed approach aims to achieve the conversion by overcoming the inconsistencies in data structures, representation logics and syntax used in different software applications.The approach was implemented in both Client Server (C/S) and Browser Server (B/S) environments to enable central and remote collaboration among geographically dispersed users. The platforms were tested in four large real-life projects. The testing involved four key scenarios:(a) the bidirectional conversion among four structural analysis tools; (b) the comparison of the conversion via the proposed approach with the conversion via direct links among the involved tools; (c) the direct export from an IFC-based architectural tool through the Application Program Interface (API), and (d) the conversion and visualization of structural analysis results. All these scenarios were successfully performed and tested in four significant case studies. In particular, the conversion among the four structural analysis applications (ETABS, SAP2000, ANSYS and MIDAS) was successfully tested for all possible conversion routes among the four applications in two of the case studies (i.e., Project A and Project B). The first four steps of natural mode shapes and their natural vibration periods were calculated and compared with the converted models. They were all achieved within a standard deviation of 0.1s and 0.2s in Project A and Project B, respectively, indicating an accurate conversion.