Baikang Zhu

The rotary vane vacuum pump plays a key role in the vapor recovery process at gasoline stations, where its geometric configuration directly influences system efficiency and stability. To address the limitations of conventional designs, this study develops a multi-objective optimization framework using particle swarm optimization (PSO). Under fixed chamber dimensions and specified constraints, the optimal design parameters are identified. The optimized pump achieves a 12.8% increase in average theoretical flow rate over the reference pump. Correlation analysis reveals that the exhaust port start angle has the strongest influence on performance, exhibiting a trade-off between compressed chamber pressure and exhaust pulsation. The rotor radius shows strong negative correlations with all objectives, while the intake port end angle is found to be a redundant parameter. Constraint sensitivity analysis indicates that the rotor radius and exhaust port start angle respond stably to variations in key constraints. Numerical simulations confirm a well-matched exhaust process, with the exhaust pulsation ratio minimized at an exhaust port start angle of 235°. This systematic approach provides an effective methodology for enhancing pump performance while respecting geometric constraints.

Extracting reliable corrosion kinetic parameters from polarization curves is particularly challenging for X70 steel under the synergistic effect of microbiologically influenced corrosion (MIC) and alternating current (AC) interference, as both factors significantly distort the electrochemical response. To address this, a novel fitting strategy was developed. In this approach, the overall polarization curve is reconstructed by combining separately modeled anodic and cathodic branches. To preserve the shape of the polarization curve, a slope-consistency constraint was enforced through dynamic penalty factors that balance fitting accuracy with shape preservation during optimization, which was performed using an intelligent algorithm. The results demonstrate the robustness of the proposed strategy, demonstrating low sensitivity to initial guesses and algorithmic parameters. Evaluation confirms that accuracy is maintained even when the data density is reduced by half. Among the parameters extracted, the Tafel slopes and corrosion current density show higher reliability than others. This work provides a robust and effective tool for the kinetic analysis of complex corrosion systems involving MIC and AC.

Dangerous Chemicals are prone to accidents such as leaks, fires and explosions, and serious accidents occurring during the storage of dangerous chemicals in China are particularly prominent. The serious harm of such accidents and its great threat to public safety, it is especially important to carry out efficient and accurate early warning of accidents and prevent them from happening in advance. This study combines Sparrow Search Algorithm (SSA), Genetic Algorithm (GA) and BP neural network to establish a SSA-GA-BP neural network warning model. Through the study of the safety status of dangerous chemicals storage, three early warning indicators and eight parameters were selected as the key factors of dangerous chemicals storage accidents. The Analytic Hierarchy Process (AHP) was employed to determine the weights of the warning indicators. The SSA-GA-BP model was utilized for data prediction, and a comparative analysis was conducted between the predicted results and the actual values. The results indicate that the dangerous chemicals storage accident early warning based on the SSA-GA-BP neural network model exhibits a high level of accuracy.

The use of oleophilic nutrients that contained nitrogen and phosphorus is a valid strategy to enhance bioremediation rate in the open marine environments contaminated with hydrocarbons where the presence of nutrients is limited. The bioremediation effectiveness of the natural oleophilic nutrients (uric acid and soya bean lecithin) and an artificial oleophilic fertilizer prepared in this study were tested with an efficient bacterial consortium. The artificial oleophilic fertilizer was prepared using urea solution, soya bean lecithin, alcohol and oleic acid to form a water-in-oil type microemulsion system. The bioremediation potential of the oil-degrading bacterial consortium and these oleophilic nutrients were implemented by flask-shaking tests and laboratory mesocosm experiments. The diesel oil degradation ratios of the natural oleophilic nutrients and oleophilic fertilizer were upto 73% and 60%, respectively, at the optimal application rate during the shake flask trials. In the mesocosm experiments, the oil concentration of the oleophilic fertilizer + bacterial consortium group was decrease from about 8000 mg/L to 823 mg/L after six days of incubation, and the number of bacteria in the seawater increased from 3×10⁴ to 1.8×10¹⁰ CFU/mL. The combination of these oleophilic nutrients and the consortium was an effective strategy to enhance bioremediation rate. This method could be exploited further for the development of an effective bioremediation technology for the marine oil pollution.

A new catalyst of S-BiOBr flower-like morphology was synthesized by simple pyrolysis and further used for photocatalytic degradation of TC. Phase structure analysis, elemental analysis and micromorphological analysis confirmed that S doping has a reinforcing effect on the polarization between the [Bi₂O₂S]²⁺ and [Br₂]^2- layers and is conducive to interlayer polarization and rapid charge transfer. In addition, its unique petal morphology is more favorable to the adsorption of contaminants on its surface and accelerates the reaction of catalyst surfactant with contaminants. It was also found that S-BiOBr degrades TC significantly better than single BiOBr@HCs, with up to 99.1% in 60 min illumination. In addition, the S-BiOBr catalyst has good reusability in antibiotic degradation. The results of photocatalytic mechanism analysis show that free radical O₂⁻ plays a major role in the photodegradation of organic model pollutants. Intermediates in TC degradation were identified, and their potential degradation pathways were prospected, and the toxicity development of TC in the degradation process was analyzed by toxicity assessment software. The S-BiOBr photocatalytic system developed in this paper provides a new idea for effective modification of bismuth-based semiconductors and has important guiding significance for future water purification.

Biofortification could improve the bioremediation efficiency of microbes in the reparation of marine environmental damage caused by oil spills. In this paper, Chlorella vulgaris LH-1 was used as a fortifier to enhance the degradation of a marine oil spill by endogenous microorganisms. The addition of C. vulgaris LH-1 increased the degradation efficiency of crude oil by 11.09–42.41% and considerably accelerated oil degradation efficiency. Adding C. vulgaris LH-1 to a crude oil environment can improve the activity of endogenous seawater microorganisms. The results of high-throughput sequencing showed that the main bacterial genera were Oceanicola, Roseibacillus, and Rhodovulum when exotrophic C. vulgaris LH-1 and seawater endogenous microorganisms degraded low-concentration crude oil together. However, the addition of high-concentration nutrient salts changed the main bacterial genera in seawater to unclassified Microbacterium, Erythrobacter, and Phaeodactylibacter. The addition of C. vulgaris LH-1 increased the abundance of marine bacteria, Rhodococcus, and Methylophaga and decreased the abundance of Pseudomonas, Cladosporium, and Aspergillus. The functional prediction results of phylogenetic investigation of communities by reconstruction of unobserved states indicated that C. vulgaris LH-1 could improve the metabolic ability of seawater endogenous microorganisms to degrade endogenous bacteria and fungi in crude oil.

Considering that simultaneous detection of xanthine (XA) and hypoxanthine (HXA) has been proved to be a reliable and feasible method for assessing fish freshness, a novel electrochemical sensing platform based on the ZnIn₂S₄/UiO-66-NH₂ modified glassy carbon electrode (GCE) was constructed in this study for XA and HXA determination. X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR) were performed to exhibit the morphology and structural characteristics of ZnIn₂S₄/UiO-66-NH₂. The Brunauer–Emmett–Teller (BET) displayed that the introduction of UiO-66-NH₂ can improve the specific surface area of the hybrid. Besides, the electrochemical sensing performance of ZnIn₂S₄/UiO-66-NH₂ was evaluated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). For simultaneously detecting XA and HXA, the fabricated electrochemical sensor shows wide linear ranges (0.025–40 µM and 0.3–40 µM) with low detection limits (0.0083 µM and 0.1 µM). This sensor also has 96–103% recovery in detecting XA and HXA content in large yellow croaker meat samples, demonstrating a promising application in the marine food industry.

With the assistance of surfactant, Fe nanoparticles are supported on g-C₃N₄ nanosheets by a simple one-step calcination strategy. Meanwhile, a layer of amorphous carbon is coated on the surface of Fe nanoparticles during calcination. Transmission electron microscopy (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma (ICP) were used to characterize the morphology, structure, and composition of the catalysts. By electrochemical evaluate methods, such as linear sweep voltammetry (LSV) and cyclic voltammetry (CV), it can be found that Fe₂₅-N-C-800 (calcinated in 800 °C, Fe loading content is 5.35 wt.%) exhibits excellent oxygen reduction reaction (ORR) activity and selectivity. In 0.1 M KOH (potassium hydroxide solution), compared with the 20 wt.% Pt/C, Fe₂₅-N-C-800 performs larger onset potential (0.925 V versus the reversible hydrogen electrode (RHE)) and half-wave potential (0.864 V vs. RHE) and limits current density (2.90 mA cm⁻², at 400 rpm). In 0.1 M HClO₄, it also exhibits comparable activity. Furthermore, the Fe₂₅-N-C-800 displays more excellent stability and methanol tolerance than Pt/C. Therefore, due to convenience synthesis strategy and excellent catalytic activity, the Fe₂₅-N-C-800 will adapt to a suitable candidate for non-noble metal ORR catalyst in fuel cells.