Responding mechanism of macro-micro characteristics and water abundance on Jurassic sandstone in Northern Shaanxi Province

The water abundance of sandstone aquifer is the basis of mine water prevention and control. With the gradual development of the Jurassic coal resources in northern Shaanxi areas, the study of water abundance of Jurassic sandstone aquifer is of great significance to ensure safe and efficient mining. However, how its heterogeneity affects water abundance, that is the influence mechanism is still unclear. Taking Dahaize Coal Mine as the research area, through the division of sedimentary facies and 38 typical sandstone samples casting thin section image analysis, mercury injection, nuclear magnetic resonance and so on laboratory tests, combined with the results of borehole pumping test, the sedimentary facies, micro pore structure and its relationship with water abundance of Jurassic Zhiluo Formation and Yan’an Formation were studied. The response mechanism of sandstone microscopic pore structure on water abundance is revealed. The results show that the lower Zhiluo Formation in Dahaize Coal Mine mainly develops river sand dam and flood plain sedimentary microfacies of river sedimentary system; The third section of Yan’an Formation mainly develops distributary channel and interdistributary bay sedimentary microfacies of delta sedimentary system. The river sedimentary system is generally more water abundance than the aquifer of delta sedimentary system. The water abundance of channel sand dam dominated by coarse sandstone and medium sandstone is stronger than that of flood plain dominated by medium sandstone and fine sandstone. The water abundance of distributary channel with large sandstone thickness and sand ratio is larger than that of interdistributary bay with small sandstone thickness and sand ratio. The microscopic pore structure could be divided into four types by physical properties, lithology, pore distribution, connectivity, which are type Ⅰ for large pore and coarse throat, type Ⅱ for mesopore and middle-fine throat, type Ⅲ for keyhole and fine throat, type Ⅳ for small- microporous and micro-fine throat, and the pore structure becomes worse and the water abundance becomes weaker from I to IV. The macroscopic sedimentary facies and microscopic pore structure of the sandstone jointly characterize the water abundance of aquifer. It provides a new idea for the characteristics and scientific prediction of water abundance of sandstone aquifer, and provides theoretical basis for mine water control

AGN STORM 2. I. First results: A Change in the Weather of Mrk 817

We present the first results from the ongoing, intensive, multiwavelength monitoring program of the luminous Seyfert 1 galaxy Mrk 817. While this active galactic nucleus was, in part, selected for its historically unobscured nature, we discovered that the X-ray spectrum is highly absorbed, and there are new blueshifted, broad, and narrow UV absorption lines, which suggest that a dust-free, ionized obscurer located at the inner broad-line region partially covers the central source. Despite the obscuration, we measure UV and optical continuum reverberation lags consistent with a centrally illuminated Shakura–Sunyaev thin accretion disk, and measure reverberation lags associated with the optical broad-line region, as expected. However, in the first 55 days of the campaign, when the obscuration was becoming most extreme, we observe a de-coupling of the UV continuum and the UV broad emission-line variability. The correlation recovered in the next 42 days of the campaign, as Mrk 817 entered a less obscured state. The short C IV and Lyα lags suggest that the accretion disk extends beyond the UV broad-line region. Unified

Occurrence and risk assessment of triclosan in freshwater lakes in the middle Yangtze River basin (Wuhan, Central China)

Triclosan (TCS) is an endocrine disrupting chemical which is commonly used as a disinfectant in pharmaceuticals and personal care products (PPCP's). Since early 2020, the worldwide outbreak of COVID-19 has increased the use of PPCP's, so the occurrence and impact of TCS on freshwater lakes should be considered. However, little attention has been given to the effect of TCS on freshwater lakes in China. This study is the first attempt at a risk assessment focusing on the temporal and spatial occurrence of TCS in freshwater lakes in the middle Yangtze River basin. The surface water and sediments of Donghu Lake and Liangzi Lake (Wuhan, Central China) were collected from October 2020 to August 2021. The maximum concentrations of TCS were 466 ​ng/L and 239 ​ng/L in surface water, 71 ​ng/g and 25 ​ng/g (dry weight) in sediments of Donghu Lake and Liangzi Lake, respectively. Significant temporal and spatial differences of TCS were observed within and between the lakes, with the highest concentrations measured in winter. Furthermore, higher concentrations of TCS were observed in areas that are more impacted by human activities. There was a significant positive correlation between TCS and nitrogen in the surface water. A risk assessment using the risk quotient (RQ) method showed that a potentially high risk (RQ ​> ​1) was found only in surface waters from Donghu Lake, and that the sediments posed a lower risk than the surface waters. These results provide timely data on the temporal and spatial occurrence of TCS in freshwater lakes in China following the outbreak of COVID-19 and demonstrate a possible high risk of exposure to TCS for aquatic biota

Superassembled biocatalytic porous framework micromotors with reversible and sensitive pH-speed regulation at ultralow physiological H2O2 concentration

Synthetic nano/micromotors are a burgeoning class of materials with vast promise for applications ranging from environmental remediation to nanomedicine. The motility of these motors is generally controlled by the concentration of accessible fuel, and therefore, engineering speed-regulation mechanisms, particularly using biological triggers, remains a continuing challenge. Here, control over the movement of superassembled porous framework micromotors via a reversible, biological-relevant pH-responsive regulatory mechanism is demonstrated. Succinylated β-lactoglobulin and catalase are superassembled in porous framework particles, where the β-lactoglobulin is permeable at neutral pH. This permeability allows the fuel (H O ) to access catalase, leading to autonomous movement of the micromotors. However, at mild acidic pH, succinylated β-lactoglobulin undergoes a reversible gelation process, preventing the access of fuel into the micromotors where the catalase resides. To one's knowledge, this study represents the first example of chemically driven motors with rapid, reversible pH-responsive motility. Furthermore, the porous framework significantly enhances the biocatalytic activity of catalase, allowing ultralow H O concentrations to be exploited at physiological conditions. It is envisioned that the simultaneous exploitation of pH and chemical potential of such nanosystems could have potential applications as stimulus-responsive drug delivery vehicles that benefit from the complex biological environment