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Snowpacks are natural water reservoirs providing a considerable amount of water for humans and ecosystems. However, current global snow products (e.g., ESA GlobSnow v3.0), lack high spatial resolution and regional calibrations necessary to capture the high heterogeneity of snow water equivalents (SWEs) in complex Asian mountainous terrains. Therefore, our understanding of snow drought characteristics in China remains limited. Herein, we used an improved SWE product calibrated specifically for China to explore the characteristics of snow droughts, delineated by a standardized SWE index (SWEI) between 1993 and 2019. Our analysis was focused over three main snow‐covered regions of China: Qinghai–Tibet Plateau (QTP), northern Xinjiang, Northeast China. Especially during the period from 1993 to 2010, we found that the SWEI increased significantly at rates of 0.022/yr (Northeast China), 0.017/yr (northern Xinjiang), and 0.011/yr (QTP) (p < 0.01, Mann‐Kendall trend test). Increased SWEI contributed to decreasing snow drought events across China, with an obvious short‐term characteristic, whilst area proportion of the identified 1‐month snow droughts was above 46.5% across three regions. Furthermore, we found that the occurrence of snow droughts was likely mediated by large‐scale atmospheric circulation, since increased water vapor transport caused a significant vapor flux convergence in cold seasons over three regions, especially in northern Xinjiang and Northeast China. Plain Language Summary: Snow droughts are caused by snow water equivalent (SWE) deficits and pose a significant climatic risk to humans and natural systems, particularly in snow‐dependent watersheds. Hence, understanding their main characteristics and driving forces is crucial for diagnosing and predicting potential climate risks. However, current research is not clear in terms of the occurrence and characteristics of snow drought in China. Therefore, we aim to investigate snow droughts based on specially calibrated SWE data in China. Alongside the increase of SWE in the three main snow‐covered areas across China, we found that the intensity of snow drought in China showed a clear downward trend, whilst both the extent and number of snow droughts decreased rapidly. Overall, these changes were likely regulated by atmospheric circulation, with the southward water vapor flux clearly increasing, providing a reliable source of water vapor and promoting the increase of snowfall. Our findings provide an important basis for the management and regulation of spring water resources to snow droughts in snow‐dependent watersheds. Key Points: A reliable snow water equivalent product calibrated specifically for China was used to assess snow droughtsBetween 1993 and 2019, the occurrence of snow droughts decreased rapidly, alongside their intensity and extentThe occurrence of snow droughts was regulated by large‐scale water vapor transport [ABSTRACT FROM AUTHOR]

Based on the cracked chevron notched Brazilian disc method, the I-type fracture toughness of Longmaxi Formation shale is measured and the influence of different factors on the fracture toughness of the shales are also discussed. The results show that the fracture toughness of the cores drilled parallel to the bedding ranges from 0.4744 to 0.8752 MPa m0.5 and that of the cores drilled perpendicular to the bedding ranges from 0.4259 to 0.6159 MPa m0.5, which means that the fracture toughness of shale is significantly anisotropy. The clay minerals in the shales have a positive effect on shale fracture toughness while the brittle minerals in shale play a negative role on shale fracture toughness. Being through high temperature processes, the microstructures of the shales are damaged, resulting in lower fracture toughness. Due to the hydration of shales, the interaction between the shale and the water leads to the decrease in the fracture toughness. The increase in the immersion pressure also cause the fracture toughness to decrease. [ABSTRACT FROM AUTHOR]