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One of the primary tasks for effective disaster relief after a catastrophic earthquake is robust communication. In this paper, we propose a simple logistic method based on two-parameter sets of geology and building structure for the failure prediction of the base stations in post-earthquake. Using the post-earthquake base station data in Sichuan, China, the prediction results are 96.7% and 90% for the two-parameter sets and all parameter sets, respectively, and 93.3% for the neural network method sets. The results show that the two-parameter method outweighs the whole parameter set logistic method and the neural network prediction and can effectively improve the accuracy of the prediction. The weight parameters of two-parameter set by the actual field data significantly show that the failure of base stations after earthquake is mainly due to the geological differences where the base stations are located. It can be envisioned that if the geological distribution between the earthquake source and the base station is parameterized, the multi-parameter sets logistic method can not only effectively solve the failure prediction after earthquakes and the evaluation of communication base stations under complex conditions, but also provide site selection evaluation for the construction of civil buildings and power grid towers in earthquake-prone areas. [ABSTRACT FROM AUTHOR]

Due to the future development of the construction industry towards the sustainable development direction of green, ecology, and safety in the future, the ultimate goal requirement of engineering projects will be higher, and the investment traditional objectives, time limit, and quality cannot meet the requirements of comprehensive management objectives. Therefore, safety and environmental management were added in this paper based on traditional management objectives from the perspective of the project owners, the relationship between objectives was analyzed, and an equilibrium optimization model of objectives was constructed. A series of Pareto optimal solutions were obtained by using multiobjective particle swarm optimization (MOPSO). Then, the best scheme was selected from the series solutions by using the efficiency coefficient method according to the specific requirements of project management. Finally, taking the objective comprehensive optimization management of a wind power project in Sichuan province as an example, 1000 paths are run by using a multitarget particle swarm algorithm, and the mean and standard deviation of the 1000 paths are calculated. The rationality of the model and the practicability of the multiobjective particle swarm optimization algorithm in the study of engineering project comprehensive optimization management were verified. It has realized the multiobjective optimization management of engineering projects and contributed to improving the quality of engineering management. [ABSTRACT FROM AUTHOR]

The shale reservoir develops cracks with different scales after hydraulic fracturing. The flowback fluid stays in the reservoir and the fracture, changing the water saturation of the shale reservoir, thus affecting the flow of shale gas. In order to study the effect of water on the seepage capacity of shale reservoirs under micro-crack conditions, the black shale of the Longmaxi Formation reservoir in Sichuan Province was selected and the core experiment was carried out after the crack-making treatment via Brazilian cracking. The influencing factors of shale reservoir seepage capacity under water condition were analyzed by the experimental methods of scanning electron microscopy and the theory of seepage mechanics. The results show that clay mineral content and fracture network development determine seepage capacity of shale reservoirs. The more clay minerals, the greater the decline of reservoir seepage capacity. The opening of the main crack and the distribution pattern of the micro crack control the scope of water in the crack system. The equations of the decreasing extent and area density of seepage capacity were established by fitting experimental data, and the influence of water on shale seepage capacity under micro-crack conditions was analyzed. [ABSTRACT FROM AUTHOR]

Clarifying the sources and historical variation of metal(loid)s in agricultural river sediments is vital for watershed contamination control and environmental improvements. In this study, a systematical geochemical investigation of Pb isotopic characteristics and the spatial-temporal distribution of metal(loid)s abundances was conducted to delineate the origins of metal(loid)s (Cd, Zn, Cu, Pb, Cr, and As) in sediments from an agricultural river, Sichuan Province, Southwest China. The results showed significant enrichment of Cd and Zn in the whole watershed, with substantial anthropogenic contributions of 86.1% and 63.1% for the surface sediments, and 79.1% and 67.9% for the core sediments, respectively. As was mainly derived from natural sources. Cu, Cr, and Pb were originated from the mixing sources of natural and anthropogenic processes. The anthropogenic origin of Cd, Zn, and Cu in the watershed was closely correlated with agricultural activities. The profile of EF-Cd and EF-Zn displayed an increasing trend from the 1960s–1990s, and then kept a high value, which was consistent with the development of national agricultural activities. Pb isotopic signatures suggested multiple sources of the anthropogenic Pb contamination, including industrial/sewage discharge, coal combustion, and vehicle exhaust. The average anthropogenic 206Pb/207Pb ratio (1.1585) approximated that of local aerosols (1.1660), suggesting aerosol deposition was a crucial pathway of anthropogenic Pb input to sediment. Furthermore, the anthropogenic Pb percentages (mean of 52.3 ± 10.3%) from the EF approach were in line with that from the Pb isotopic method (mean of 45.5 ± 13.3%) for sediments under intense anthropogenic impacts. [Display omitted] • Aerosol was the major contributor to Pb contamination. • Pollution history of Cd and Zn was in accord with national agricultural development. • Agricultural activities have long-term and continued impacts on Cd and Zn enriched. • Anthropogenic Pb percentages estimated by EF are close to that by Pb isotopes. [ABSTRACT FROM AUTHOR]