Spatiotemporal Patterns and Evolution of Storm Surge Threats along the Southeastern Coastline of China

The variability of storm surge poses a significant threat to coastal areas. A new metric named Accumulated Storm surge Potential Impact (ASPI) is proposed based on a new intensity parameter that removes other components from storm surge-induced water level rise. This new metric quantifies storm surge threat by combining frequency and intensity. The results show that storm surge threat has increased since the late 1990s due to greater general storm surges. The extreme storm surge threat did not follow the increasing trend until the mid-2000s. Different regional distribution patterns are found along this coast. The storm surge threat exhibited a -++ zonal tripole pattern, the negative phase was along the north coastline of Hangzhou Gulf and the positive phase was from the center to southern coast area of Zhejiang province and along the eastern coast area of Leizhou Peninsula. Long-term storm surge threats change spatial distribution pattern in three periods. More precarious threats from the center to southern coast areas of Zhejiang province illustrated a poleward shift of storm surge threats consistent with the trend of long-term tropical cyclone landfall. Meanwhile, the strong threat along the eastern coast line of Leizhou Peninsula was sustained from 1960 to 1995, then became weaker from 1996 to 2015. The evolution pattern of storm surge threat along the southeastern coastline of China could be applied for coastal adaptation research under climate change scenarios

RESEARCH OF RUBBER FATIGUE OPTIMIZATION UNDER MULTIAXIAL LOADING

This paper introduces an analysis method,which combines the crack fatigue prediction theory and rubber elastic structure optimization,to optimize the structure of a rubber bushing. Using stress in rubber as the optimization parameters,the method can predict fatigue life of the rubber bushing by applying crack energy density. In summary,using the fatigue result,this new analysis method can predict rubber fatigue life and provide optimized structure of rubber parts. This combination of the crack fatigue prediction theory and rubber elastic structure optimization ensures the convenience of engineering application and provides a guidance to reduce rubber structure developing time

Improving Beneficiation of Copper and Iron from Copper Slag by Modifying the Molten Copper Slag

In the paper, a new technology was developed to improve the beneficiation of copper and iron components from copper slag, by modifying the molten slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS) was employed to determine the mineralogy of the modified and unmodified slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the copper grade of rougher copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified copper slag. Moreover, matte and magnetite grains in the modified slag aggregated together and grew obviously to the mean size of over 50 μm, resulting in an improvement of beneficiation of copper and iron

Biogenic Polyphosphate Nanoparticles from <i>Synechococcus</i> sp. PCC 7002 Exhibit Intestinal Protective Potential in Human Intestinal Epithelial Cells In Vitro and Murine Small Intestine Ex Vivo

Polyphosphates are one of the active compounds from probiotics to maintain gut health. The current research extracted and purified intact biogenic polyphosphate nanoparticles (BPNPs) from <i>Synechococcus</i> sp. PCC 7002 cells. BPNPs were near-spherical anionic particles (56.9 ± 15.1 nm) mainly composed of calcium and magnesium salt of polyphosphate and were colloidally stable at near-neutral and alkaline pH. BPNPs survived gastrointestinal digestion in mice and could be absorbed and transported by polarized Caco-2 cell monolayers. They dose-dependently increased the tightness of intercellular tight junction and the expression of claudin-4, occludin, zonula occludens-1, and heat shock protein 27 in Caco-2 cell monolayers. BPNPs also effectively attenuated H₂O₂-induced cell death, plasma membrane impairment, and intracellular superoxide production in NCM460 cells. In addition, they conferred resistance to H₂O₂-induced barrier disruption in freshly excised mouse small intestine. Our results suggest that BPNPs are a promising postbiotic nanomaterial with potential applications in gut health maintenance

Room Temperature Magnetic Properties of Fe/Co-Doped Barium Niobate Crystals

Perovskite-type structure BaNbO₃ and Fe/Co-doped BaNbO₃ nanocubes with a pure cubic phase have been synthesized by a composite-hydroxide-mediated method. X-ray diffraction and X-ray photoelectron spectroscopy reveal that Fe³⁺/Co²⁺ are incorporated into the BaNbO₃ lattices. These doped samples exhibit smaller band gaps and semiconducting conduction quite different from the characteristics of BaNbO₃. The resistivity is reduced 3–4 orders of magnitude after doping the BaNbO₃ with Fe and Co ions. By comparing with the pure BaNbO₃, we found that ferromagnetic property is achieved on the Fe/Co-doped BaNbO₃ samples. The mechanism of magnetic property for Fe/Co-doped BaNbO₃ is discussed by density functional theory, which provides an evident 3d transition metal doped easily in substitution of the B site element to produce ferromagnetism in ABO₃-type ferroelectric semiconductor oxide. The report indicates that the 3d transition metal doped BaNbO₃ may be a good candidate for new multiferroics