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Atmospheric deposition is an important source of marine metallic elements, which have a non-negligible impact on marine ecology. Trace metals from different sources undergo their respective transport processes in the atmosphere, ultimately depositing into the ocean. This study aims to provide gridded data on sea-wide concentrations, deposition fluxes, and soluble deposition fluxes with detailed source categories of metals using the modified Community Multiscale Air Quality (CMAQ) model. A monthly emission inventory of six metals – Fe, Al, V, Ni, Zn, and Cu – from terrestrial anthropogenic, ship, and dust sources in East Asia (0–55° N, 85–150° E) in 2017 was developed. Most metals came primarily from land-based sources, contributing over 80 %. The annual marine atmospheric deposition fluxes of Fe, Al, V, Ni, Zn, and Cu were 8827.0, 13 384.3, 99.3, 82.4, 162.7, and 86.5 µgm-2 , respectively, and the corresponding soluble deposition fluxes were 634.3, 1701.6, 74.3, 46.1, 113.0, and 42.0 µgm-2. The contributions of each source of trace metals varied in emissions, atmospheric concentrations, and depositions. Dust sources, as a main contributor of Fe and Al, accounted for a higher proportion of emissions (∼90 %) than marine deposition fluxes (∼20 %). However, anthropogenic sources have larger shares of the marine deposition flux compared with emissions. The deposition of Zn, Cu, and soluble Fe in East Asian seas was dominated by terrestrial anthropogenic sources, while V and Ni were dominated by shipping. The identification of the dominant source of metal deposition offers a foundation for dynamic assessments of the marine ecological effects of atmospheric trace metals. The source-resolved seasonal gridded data make it possible to calculate the soluble metal deposition flux on a source-by-source basis. [ABSTRACT FROM AUTHOR]

Identifying precursor information to rock failure is key to rock dynamic disaster warning. To solve the problem that a single in-situ monitoring method cannot accurately identify the precursors to rock failure, this paper combined a digital image correlation method, thermal infrared radiation and acoustic emission technology to conduct a multi-physical field joint monitoring experiment of granite under three-point bending. The information about strain, thermal infrared and acoustic emission of the rock brittle failure process could be obtained, and the variations in multi-physical field indices of the rock brittle failure process were analysed. Based on the theory of critical slowing-down, the study of the multi-physical field effects of critical slowing-down characteristics in the rock failure process, and further exploration of the precursor characteristics of the brittle failure of rock were undertaken. The results indicate that the strain, infrared, and acoustic emission parameters show sudden changes during brittle failure of granite. The lag step size has little effect on the variance of changes in multi-physical field parameters and exerts a similar influence on the changes in the autocorrelation coefficient curve. The degree of influence of the window length on the variance and autocorrelation coefficient curves of multi-physical field parameters is as follows: infrared field > strain field > acoustic emission field. Compared with the autocorrelation coefficient, the variance parameter is more universal and is better when the critical slowing-down theory is used to investigate the characteristics of multi-physical fields. The four parameters of the strain field variance, infrared field variance, the variance and autocorrelation coefficient for acoustic emission field increase sharply before fracture, representing precursor information to the brittle failure of granite. The four parameters can be used as disaster warning indicators in rock. Multi-mode joint monitoring and a comprehensive analysis of multi-physical information are beneficial to accurately determine the precursor points of rock failure disaster. [ABSTRACT FROM AUTHOR]

Atmospheric deposition is an important source of marine metallic elements, which have a non-negligible impact on marine ecology. Atmospheric trace metals come from different sources, undergo their respective transport processes, and are deposited into seas finally. This study aims to provide gridded data on sea-wide concentrations, deposition fluxes, and soluble deposition fluxes with detailed source categories of metals by the modified Community Multiscale Air Quality (CMAQ) model. A monthly emission inventory of six metals – Fe, Al, V, Ni, Zn, and Cu – from land anthropogenic, ship, and dust sources in East Asia (0–55° N, 85–150° E) in 2017 was developed. Most metals came mainly from land-based sources, contributing over 80 %. The annual marine atmospheric deposition fluxes of Fe, Al, V, Ni, Zn, and Cu were 9614, 15000, 102, 84, 171, 88 μg·m-2, and soluble deposition fluxes were 646.8, 1799.6, 43.3, 36.3, 118.4, 42.9 μg·m-2, respectively. Contributions of each source for trace metals varied in emissions, atmospheric concentrations, and depositions. Dust source, as a main contributor of Fe and Al, accounted for a higher proportion of emissions (~90 %) than marine deposition fluxes (~20 %). However, anthropogenic sources have larger shares of marine deposition flux compared with emissions. The deposition of Zn, Cu, and soluble Fe in East Asian seas was dominated by land anthropogenic sources, while V and Ni were dominated by shipping. The seasonal gridded data and the identification of the dominant source of metal deposition offer a foundation for dynamic assessments of the marine ecological effects of atmospheric trace metals. This study also implies the importance of potential co-synthesis and complementation effects of multiple trace elements deposited into marine ecosystems. [ABSTRACT FROM AUTHOR]

Unequal flaws are widespread in rock engineering, in which the extensions induced by excavation and unloading are the main factors leading to engineering instability. Rock deformation and failure are essentially the results of energy transmission. In order to study the influence of flaw type and angle on the mechanical properties and energy characteristics of the flawed rock mass, uniaxial compression tests were conducted using particle flow numerical analysis software. The results show that the crack initiation strength and peak strength of the sample increase with the increase in the flaw angle. For smaller flaw angles, the sample shows obvious plastic deformation during uniaxial compression. For larger flaw angles, the sample shows elastic–brittle properties, whose storage energy is larger. The peak strength of samples with flaws of unequal length presents an obvious decrease compared with that of flawed samples with flaws of equal length, and the extent of the reduction is 6.15% on average. Unequal flaws decrease the ability of the flawed sample to absorb strain energy. Compared with flawed samples with equal flaws, flawed samples with unequal flaws decrease the boundary energy and elastic strain energy by 9.29% and 9.95% on average, respectively. Flaws of unequal length in this sample can weaken the performance of the flawed sample. [ABSTRACT FROM AUTHOR]