Qingdao University of Science & Technology

Ammonia (NH₃) is emerging as a promising alternative fuel due to its high energy d. and non-carbon mature.However, its large-scale industrial application is limited by its low reactivity and high nitrogen oxide (NO_x) emissions during combustion.This paper investigated the effect of ultrasonic excitation on the combustion and emission characteristics of ammonia-methane-air partially premixed flame in a laboratory-scale burner.The flame temperature distribution was reconstructed using deflection tomog., and the flue gas composition was measured using a multicomponent gas analyzer.Numerical simulations were also conducted under the same exptl. conditions.The exptl. results showed that applying various ultrasonic frequencies resulted in a stable flame.The ultrasonic excitation resulted in changes in flame brightness and color, as well as a reduction in nitric oxide (NO) emission.Compared to the case without ultrasonic excitation, the maximum flame temperature increased by 17.85%, and NO emission decreased by 19.04% when excited with 20.2 kHz ultrasonic.The simulation results indicated that ultrasonic excitation enhanced the formation of free radicals.Single-point and rate of production (ROP) anal. further revealed that ultrasonic excitation enhanced the dehydrogenation of NH_i and the polymerization between NH₂ and NH.Addnl., ultrasonic excitation accelerated the direct reactions between NH and N with NO, leading to the formation of N₂.

Nitroreductase (NTR) is an endogenous reductase overexpressed in hypoxic tumors, with its levels closely correlated to the degree of hypoxia. This correlation has significant clinical implications for the analysis of tumor hypoxia, as it allows for the indirect detection of nitroreductases. Due to their simplicity, noninvasive nature, and excellent spatiotemporal resolution, various fluorescence methods have been developed for the analysis of nitroreductase and tumor hypoxia. In this study, we present the design, synthesis, in vitro evaluation, and biological application of an NTR-activated fluorescent probe, F-NTR. Utilizing an oxanthrene fluorophore as the core component, F-NTR incorporates a 4-nitrobenzene recognition group. This innovative probe, which introduces a nitro group, demonstrates high selectivity and reactivity towards nitroreductase (NTR) due to its reducing properties. Furthermore, probe F-NTR is capable of accurately identifying hypoxic environments, which provides a basis for precise detection and localization of tumors. This work lays the groundwork for future investigations into cell metabolism, tumor metabolism, and the surgical management of solid tumors under hypoxic conditions.

The development of efficient wastewater treatment technologies is crucial for the sustainable advancement of the chem., pharmaceutical, and food industries.In this study, the azeotrope of Et propionate/n-propanol/water in liquor wastewater was successfully separated via extractive distillation and extractive pressure swing distillation technologies.Ethylene glycol was determined as the optimal entrainer based on relative volatility, and the interaction between azeotrope and entrainer was further explored through electrostatic potential and σ-profile anal.We employed the multi-objective optimization method to optimize different process flows, focusing on total annual cost and gas emissions as objective functions.The optimal solutions weighing economic and environmental factors were obtained.Addnl., heat-integrated technol. was used to explore energy-saving distillation processes to tackle the issue of excessive energy consumption.Finally, eight separation processes were discussed and analyzed from the perspective of economic, environmental, energy, and exergy.The findings indicated that the heat-integrated new four-column pressure swing-assisted extractive distillation process exhibited the most favorable environmental and economic performance.Compared with the extractive distillation process, the heat-integrated new four-column pressure swing-assisted extractive distillation scheme achieved a reduction of 28.14% in total annual cost and 47.47% in gas emissions.This study provides valuable insights for recycling Et propionate and n-propanol from industrial wastewater and has certain reference significance for future research.