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The occurrence of rockburst is related to the surrounding rock stress and geological rock mass strength. Rockburst occurs frequently during the construction at a deep tunnel in southwest China (a tunnel with a depth of approximately 2080 m, and a length of 13 km), leading to casualties, damage to construction equipment, and schedule delays. The application of the rockburst criteria based on the stress-strength/strength-stress ratio shows that they are not suitable for the construction stage. This paper suggests a simple and feasible rockburst intensity criterion based on the Geological Strength Index (GSI) for the construction stage. In this criterion, the strength of the rock mass exposed during excavation is estimated by the Hoek-Brown criterion and is used to reflect the geological conditions of the surrounding rock, considering the influences of the joint conditions and engineering disturbance. The maximum principal stress along the tunnel is obtained by the in situ stress inversion. The ratio of the rock mass strength to the maximum principal stress (σcm/σ1) is taken as the evaluation index. The criterion is as follows: σcm/σ1 > 1.2, none rockburst; 0.75 < σcm/σ1 ≤ 1.2, slight rockburst; 0.4 < σcm/σ1 ≤ 0.75, moderate rockburst; and σcm/σ1 ≤ 0.4, intense rockburst. The engineering applications show the reliability of this rockburst intensity criterion. The results of this paper provide a reference for rockburst intensity evaluation during the construction stage of deep tunnels. [ABSTRACT FROM AUTHOR]

The Jinlong village landslide is located in Zitong County, Sichuan and approximately 150 km east of Wenchuan. The landslide has exhibited creep deformation for nearly 30 years. Field investigations indicated that the slope deformation was caused by the combined effects of unfavorable topographic and geological conditions and earthquakes. The sliding surface is along a contact between silty clay and mudstone. The Wenchuan earthquake accelerated the creep, causing bulging of the ground surface. Shear test results of the silty clay near the sliding surface indicated that the residual strength is consistent with the stability state of the landslide. The factors of safety were calculated using the limit equilibrium method (LEM) and the method of fast Lagrangian analysis of continua in two dimensions. The results using the LEM indicate that the stability is clearly affected by seismic shaking, and when the peak ground acceleration is 0.08 g, the slope reaches the limit state. The shear failure surface given by numerical simulation develops on the contact between the clay and silty mudstone, which confirmed the assumed sliding surfaces' location using the LEM. [ABSTRACT FROM AUTHOR]

Fengyun-4A (FY-4A) is a new generation geostationary satellite that provides high temporal resolution atmospheric observations of China and the adjacent regions. This study proposed to assimilate FY-4A observations via a combined utilization of a 3D variational method and a random forest approach. The ground-level PM 2.5 concentrations were estimated as an intermediate variable and subsequently assimilated based on the Gridpoint Statistical Interpolation (GSI) system. Four parallel experiments were conducted to verify the proposed method, including a control experiment and three data assimilation experiments that assimilated satellite observations and ground observations alone and simultaneously. Results showed that the proposed approach improved PM 2.5 predictions for most sites, especially in the highly polluted Beijing-Tianjin-Hebei and Yangtze River Delta regions. Assimilating PM 2.5 estimations from satellite showed an advantage over the assimilation of ground PM 2.5 observations in places where local or upstream regional PM 2.5 monitoring sites are sparse. Simultaneous assimilation of the PM 2.5 from satellite and ground observations further improved the PM 2.5 predictions accuracy in most places. • The FY-4A observations were assimilated using the GSI 3DVAR assimilation system. • Assimilating satellite-based PM 2.5 estimation improved PM 2.5 predictions. • Satellite observations show a spatially wider influence on PM 2.5 predictions than in situ observations. [ABSTRACT FROM AUTHOR]

• We provide basic reproductive information of two lineages of four-eyed sleepers in sympatric regions for the first time. • Two sympatrically lineages showed asynchrony in the reproductive cycles which might be a strategy to reducing hybridization. • With morphological differences, sexual preference might exist between two lineages to decreasing hybridization. The two phylogeographic lineages [South China Sea (SCS) lineage and East China Sea (ESC) lineage] of the four-eyed sleeper (Bostrychus sinensis) occur sympatrically along the southeastern coast of China, where there is a small percentage of hybrids in a natural habitat. To assess the mechanism responsible for the incomplete reproductive isolation between the SCS and ECS lineages of four-eyed sleeper, there was sampling of individuals from the Yueqing Bay from November 2018 to November 2019 to determine whether there are differences in characteristics of the reproductive cycles and reproductive biology. The two lineages varied in reproductive seasonality, body size and shape, and egg number. The SCS lineage spawned annually between May and August, with the absolute fecundity (AF) of the SCS lineage being 9960 to 39,517 eggs per female, and there was positive allometric growth of this species. The ECS lineage spawned annually between June and July, with females producing 4064 to 10,370 eggs per fish and individuals having an isometric growth pattern. Preliminary results indicated that there was partial overlap in the spawning season between the two lineages in the sympatric region, which may not be a primary factor in the incomplete reproductive isolation. Furthermore, the lineage differences in fecundity and body shape and size may lead to variation in mate choice and reproductive strategy. The results from this study provide insight into the biology, reproductive strategies, and speciation of the four-eyed sleepers. [ABSTRACT FROM AUTHOR]