Qingdao Center of Resource Chemistry and New Materials

The increasing environmental pollution caused by metal nanoparticles (NPs) has become a major concern, among which the ecological toxicity of zinc oxide (ZnO) NPs attracts particular attention. In this study, the Yellow River Estuary sediment was used as a research focus. A noncontact conductivity method was used to enable real-time, nondestructive monitoring of the growth kinetics of Bacillus licheniformis and Vibrio parahaemolyticus . Combining a noncontact conductivity method with high-throughput sequencing systematically revealed the multilevel toxic effects of ZnO NPs, from individual strains to the microbial community. The results showed that ZnO NPs prolonged the growth lag phase and reduced the maximum metabolic activity of both strains. These inhibitory effects were more pronounced at higher concentrations. At 160 mg/L ZnO NPs, the cell wall integrity of B. licheniformis and V. parahaemolyticus decreased by 21.99% and 12.38%, respectively. In addition, the lactate dehydrogenase release significantly increased ( p < 0.01), and the intracellular reactive oxygen species levels were 15.34 times and 4.27 times those of the control group. Microbial analysis revealed that ZnO NPs significantly reduced the α-diversity index (with Chao and Shannon indices decreasing by 55.35% and 18.11%, respectively) and altered the composition of functional bacteria. This study integrated multiple methods to elucidate multilevel mechanisms, providing critical data and theoretical support for nanomaterial ecological risk assessment in estuarine environments.

The CL-20/1,4-DNI cocrystal is a novel high explosive with exceptional energy density and detonation parameters. However, in comparison with insensitive explosives including TNT and TATB, it still retains a relatively high level of sensitivity. To mitigate the sensitivity of the CL-20/1,4-DNI cocrystal explosive, this study constructed a molecular model of the CL-20/1,4-DNI cocrystal, and then separately incorporated five distinct classes of polymers-butadiene rubber (BR), ethylene-vinyl acetate copolymer (EVA), polyethylene glycol (PEG), fluoropolymer (F2603), and polyvinylidene fluoride (PVDF)-onto its four most probable crystal planes, namely (1 0 1), (0 0 2), (0 1 1), and (1 1 0), a series of polymer-bonded explosives (PBXs) were thereby fabricated, and the influence of varying polymer matrices on the resulting materials-including their stability, trigger bond length, mechanical properties, and detonation performance-was systematically predicted and evaluated. Among the five developed PBX models, the CL-20/1,4-DNI/PEG composite attained the highest binding energy and the shortest trigger bond length. These outcomes demonstrate that the CL-20/1,4-DNI/PEG system possesses optimal stability, compatibility, and minimal sensitivity. Additionally, while the CL-20/1,4-DNI/F2603 composite exhibited superior detonation initiation capability, of note is that the compatibility of this particular formulation was relatively low. Consequently, the CL-20/1,4-DNI/PEG composite, which demonstrates an optimal stability-performance balance, emerges as the definitive choice, highlighting PEG as the preferred binder for CL-20/1,4-DNI-derived PBXs. Utilizing the molecular dynamics (MD) framework implemented in Materials Studio, the relevant functions embedded in the Forcite module were employed for the calculations; the performance of CL-20/1,4-DNI-based PBXs was evaluated. The simulation parameters were configured to a time step of 1fs and a cumulative run time of 2ns. The isothermal-isobaric (NPT) ensemble was employed for the 2-ns MD simulations. The COMPASS force field was adopted, and the simulation temperature was fixed at 295 Kelvin (K).

Serpentinites formed in abyssal settings show large variations in boron concentration and δ¹¹B, even within similar tectonic environments. To explore the processes controlling boron incorporation and isotopic fractionation during oceanic serpentinization, we developed a stepwise reaction-path model simulating progressive water–rock interaction, using experimentally derived data for B partioning and isotopic fractionation between fluid and rock. The model tracks the coupled evolution of B concentration and δ¹¹B in the solid through multiple reaction loops, characterized by evolving temperature and decreasing water–rock ratios.Model results indicate that B concentration and δ¹¹B evolve asynchronously during serpentinization. However, at given B contents, serpentinites show a variety of δ¹¹B values, reflecting its strong sensitivity to reaction history rather than equilibrium with a single fluid reservoir. Progressive reaction loops produce divergent isotopic trajectories, in response to the degree of fluid renewal and cumulative fractionation during serpentinization.Comparison with natural samples shows that B systematics of serpentinites from the Atlantis Massif are best explained by multi-stage serpentinization under relatively restricted fluid conditions, during which progressive fractionation drives δ¹¹B toward lower values despite significant B enrichment. In contrast, serpentinites from the 15°20′N transform fault, Mid-Atlantic Ridge, consistently exhibit seawater-like δ¹¹B, more resembling open-system behaviors involving repeated interactions between fresh fluids and new rock volumes.These results demonstrate that reaction-path modeling provides a robust framework for interpreting boron isotope systematics in abyssal serpentinites and highlight the critical role of fluid–rock interaction history, along with temperature and bulk composition, in controlling δ¹¹B signatures.