RS Dynamics (Czechia)

Water quality and hydrogeochemical mechanisms of river water in recharge areas are of great significance for environmental safety and ecological stability. Here, water quality and associated mechanisms in river water of the Qingshui River were assessed using hydrochemical and isotopic data (δ2HH2O and δ18OH2O), combined with the Entropy-weighted Water Quality Index (E-WQI) and positive matrix factorization (PMF) model. The results showed that water quality of the agricultural reach is dominated by an "excellent level," while ~ 43% of samples from the urban reach showed a "good level." Water quality is mainly driven by mineral dissolution (36.8% and 57.0% for the agricultural and urban reaches) and agricultural inputs (37.7% and 21.7% for the agricultural and urban reaches), while positive cation exchange contributes less to hydrochemical components. Furthermore, the construction of artificial channels enhances the effect of evaporation on hydrochemistry and alters the water-rock interaction processes. Those results provide new insights into evaluating hydrogeochemical mechanisms in the river system of piedmont regions.

Fused in sarcoma (FUS) forms phase-separated condensates implicated in amyotrophic lateral sclerosis (ALS). Although millimolar ATP concentrations paradoxically dissolve FUS condensates through hydrotropic activity, condensates nevertheless persist in cells, suggesting active regulatory mechanisms. Here, using a reconstituted system, we show that the AAA+ATPase valosin-containing protein (VCP) counteracts ATP-driven dissolution of FUS condensates. VCP preserved both wild-type and ALS-linked P525L condensates under high ATP conditions, and this protection required catalytic ATPase activity rather than stable partitioning into condensates. The effect was abolished by the D2-specific inhibitor ML240. Our findings establish direct biochemical evidence that VCP ATPase activity maintains FUS condensates under high ATP conditions, highlighting ATPase-driven enzymatic control of liquid-liquid phase separation as a potential general principle with implications for neurodegeneration.

The liquefaction of gravelly soils during earthquakes remains a challenging hazard to evaluate because larger soil particles can interfere with traditional in situ tests such as the standard penetration test (SPT) and cone penetration test (CPT). This study investigates six sites affected by the 2020 Mw 6.4 Petrinja, Croatia earthquake, where gravelly liquefaction ejecta was observed. Subsurface investigations included boreholes to define the soil profile, shear wave velocity (Vs) profiling using the multichannel analysis of surface waves (MASW) and horizontal to vertical spectral ratio (HVSR), and large-diameter (74-mm) dynamic cone penetration tests (DPT). At several sites, DPT blow counts increased through silty clay surface layers, whereas CPT tip resistance from companion testing remained constant. The increase in DPT resistance was thus attributed to side friction along the drill rods, and two subsequent DPT soundings were conducted to isolate this effect: (1) a cased DPT (cDPT), where the overlying material was removed and the hole was cased to the target gravelly layer; and (2) an instrumented DPT (iDPT), used to measure the hammer energy transferred to the cone. Corrected DPT blow counts (N120′) and normalized shear wave velocities (Vs1) from critical gravelly layers were evaluated using recent probabilistic DPT- and Vs-based liquefaction triggering models. These methods correctly predicted liquefaction manifestation at each of the sites. Results support the continued development of energy-corrected DPT and Vs-based approaches for liquefaction assessment in gravelly soils and provide valuable case history data to continue refining probabilistic triggering relationships.

Calcareous soils are characterized by high pH and rapid nitrification, which often lead to excessive nitrate accumulation, nitrogen (N) loss, and increased nitrous oxide (N₂O) emissions. Effective inhibition of nitrification or enhancement of inorganic N retention is therefore crucial for enhancing N use efficiency (NUE) and mitigating N₂O emissions in such systems. Biochar and 3,4-dimethylpyrazole phosphate (DMPP) are widely used N management strategies; however, their relative effectiveness in improving NUE and mitigating N₂O emissions, as well as the underlying mechanisms regulating soil N transformations, remain poorly understood, particularly in calcareous soils. In this study, two consecutive seasons of pot experiments were conducted with eight treatments: control, phosphate and potash fertilizer (PK), N, phosphate and potash fertilizer (NPK), NPK + DMPP, NPK + low biochar (10 t ha^‒1), NPK + high biochar (30 t ha^‒1), NPK + low biochar + DMPP, and NPK + high biochar + DMPP. The effects of biochar and DMPP, applied alone, or in combination with, on crop N uptake, NUE, yield, soil gross N transformation rates, and N₂O emissions, were systematically evaluated. Results showed that DMPP significantly enhanced crop N uptake and yield by 30.8%‒49.1% and 19.0%‒48.9%, increased NUE by 14.4%–17.9%, and reduced cumulative N₂O emissions by 77.0%–85.1% relative to NPK across both seasons. Mechanistically, compared to NPK, DMPP effectively suppressed ammonia-oxidizing bacteria activity by 27.4%‒42.4%, and nitrification rates by 50.0%‒55.5%, but increased the microbial ammonium immobilization-to-nitrification ratio by 11.9%‒20.8%, and prolonged the residence time of inorganic N, thereby enhancing N retention and utilization. In contrast, both low and high biochar additions promoted microbial N immobilization but accelerated nitrification, decreased NUE, and stimulated N₂O emissions; even co-application with DMPP did not counteract these effects. Overall, DMPP proved more effective than biochar in stabilizing inorganic N, improving NUE and crop yield, and mitigating N₂O emissions in calcareous soils, representing a key strategy for optimizing N management in such agroecosystems.

Karst vegetation ecosystems are highly sensitive to climate change. However, relative to the other vegetation ecosystems, the adaptability of the vulnerable vegetation in the karst ecosystem to drought events remains unclear, especially in quantifying the contribution of different factors, including forest age, canopy height, terrain slope, precipitation, and human population. Here, we developed an evaluation framework based on a vegetation response intensity (RI), which includes drought stress windows and delayed vegetation response windows to detect vegetation adaptability to drought stress. Results show that the vegetation adaptability in global karst areas shows an increasing trend (-0.06 yr-1, p < 0.01), but shows significant differences. Although vegetation in all karst regions shows weak adaptability to short-term sudden droughts, vegetation adaptability in Europe (RI = 0.05) and North America (RI = 0.10) is significantly stronger than that in southwest China (RI = 0.23) for long-term drought. Notably, although the ecological restoration process can rapidly increase greenery in sensitive and fragile karst areas, the artificially restored vegetation with a lower age lacks adaptability to drought events in the short term. The adaptability of vegetation in karst areas to drought is mainly influenced by forest age (improved: 16.67%), slope (degraded: 18.87%), precipitation (degraded: 32.27%), and population (degraded: 31.22%) disturbance. Ecosystems with more complete ecological succession and longer duration exhibit strong adaptability to drought.

A set of thick carbonate rocks is developed in Gaoyuzhuang-Wumishan Formations of Jixian System in Xiong ‘an New Area and its adjacent areas, with diverse dolomite rock types, complex reservoir space, and large differences in physical properties, which are the main layers of hydrocarbon and geothermal resources. However, it is difficult to identify the paleokarstification, and the paleoenvironmental characteristics are not clear. The major and trace elements, carbon, oxygen and strontium isotopes of Gaoyuzhuang-Wumishan Formations are analyzed based on field geological investigation, core observation, thin section identification and physical property analysis. The results show that dolomite and siliceous bands of Gaoyuzhuang-Wumishan Formations are formed in the warm subtropical climate of seawater environment, which are partially affected by meteoric water, characterized by interactive marine, and the depth of water as a whole is relatively shallow, mainly in an oxidizing environment, affected by different degree of terrestrial fluids. The fluid temperature at the time of formation of the dolomite fillings is significantly higher than that of the seawater in the same period, which is controlled by the high temperature fluid transformation after burial. The calcite fillings exhibit a meteoric water genesis, having precipitated under anoxic reducing conditions at temperatures equivalent to those of dolomite. Four periods of carbonate paleokarstification and depositional environments have been revealed, which are marine syndiagenetic depositional period or eogenetic karst, shallow burial period, medium-deep burial period or high-temperature paleoenvironment and the hypergene period of meteoric water karstification.

The efficient recovery of coalbed methane (CBM) depends on the desorption and diffusion process, which is critical for releasing methane from coal seams and facilitating its flow to production wells. In this study, a composite wetting-corrosion method, utilizing a new combination of surfactant and acid, was proposed to promote the desorption and diffusion of CBM. The microstructure and CH4 desorption-diffusion characteristics of the coal treated with the composite wetting-corrosion method were evaluated at different cocamidopropyl betaine (CAB) and hydrochloric acid (HCl) concentrations. The relationship between wettability, specific surface area, and CH4 adsorption–desorption was analyzed, and the pore connectivity effects on CH4 diffusion were investigated. The results show that the composite treatment effectively removed corrodible minerals and residues from the coal surface and the pores. The intensity ratios of the diffraction peaks of calcite and kaolinite to quartz (standard peak) decreased by 17.35–66% compared to the HCl-treated coal. The wetting effect of the surfactants was utilized to expand the corrosion area in this composite method. As a result, the pore volume increased to 11.91 × 10–3 cm3/g, the mass transfer Biot number declined by 31.57–44.86%, and the diffusion coefficient increased by 22.5–91.5%. Additionally, due to the inhibiting effect of surfactants on CH4 adsorption, the CH4 adsorption and residual adsorption amounts decreased to 0.1092 and 0.0148 mol/kg, respectively, while the desorption rate increased to 86.46%. Therefore, the composite method demonstrated superior performance in promoting CH4 desorption and diffusion compared with that treated by the HCl solution. This study has provided a new insight into the improvement of the wetting-corrosion methods for CBM recovery.

In the coal mining process, injecting nitrogen into thegoaf isan effective method to suppress coal spontaneous combustion, whichis widely adopted due to its significant inhibitory effect and lowcost. Optimizing the injection volume and position of nitrogen iscrucial for enhancing fire prevention and extinguishing efficiencyand reducing safety risks. This study utilized CFD numerical simulationtechnology to investigate the spontaneous combustion risk in the goafof the 81203 working face in Baode Coal Mine under the combined U+ L ventilation and downwind ventilation conditions. The influenceof different nitrogen injection positions and volumes on the distributionof the “three zones” related to coal spontaneous combustionin the goaf was analyzed. By simulating the changes in the oxygenand methane concentration fields in the goaf, this study proposedan optimized nitrogen injection strategy to improve fire preventionand extinguishing efficiency. The results show that setting a nitrogeninjection port 90 m from the working face on the intake side of the81203 auxiliary transport drift and injecting at a rate of 400m3/h meters per hour can achieve the best inhibitory effectand reduce costs.

This work designed an efficient recovery of fluorine resources from fluoride-containing solid waste (FCSW) using acid-free aluminum salt and mechanochemical activation coupling methods. First, FCSW was leached in the traditional acid-free aluminum salt system, and the effects of various factors on the leaching efficiency in the leaching process were investigated. The kinetics and mechanism of the leaching process were further studied. Then, FCSW was treated by using a coupled mechanical activation technique, and the leaching conditions were optimized. Under optimal conditions, the fluoride leaching efficiency reached 98.09%, significantly higher than that of traditional leaching (75.86%), with the improvement mainly attributed to the reduction in the particle size, increase in the specific surface area, and decrease in the activation energy. Notably, the resulting leachate can directly prepare cryolite with a purity of 95.88%. Additionally, the process proposed in this study yields significant economic benefits and is environmentally friendly. This work provides a new strategy for the efficient recovery of fluorine resources from FCSW and a strong guarantee for the development of the fluorine chemical industry.