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AIM:To investigate the changes of retinal microcirculation after phacoemulsification and the influencing factors of visual acuity.METHODS: Retrospective analysis. A total of 264 cataract patients(264 eyes)who underwent phacoemulsification in our hospital from January 2022 to December 2022 were selected as the study objects. Patients were divided into < 0.3 group(66 eyes)and ≥0.3 group(198 eyes)according to the recovery of best corrected visual acuity(BCVA)at 3 mo after surgery. The changes of retinal microcirculation indexes were compared before and after treatment. Logistic regression and LASSO regression models were used to screen the influencing factors of postoperative BCVA. A nomogram prediction model of postoperative BCVA was constructed and verified. A restricted cubic spline Logistic regression model was established to analyze the dose-response relationship between end-diastolic velocity(EDV), peak systolic velocity(PSV)and the risk of BCVA recovery.RESULTS: At 3 mo postoperatively, EDV and PSV were significantly improved compared with those before treatment, and resistance index(RI)levels were significantly lower than those before treatment(all P0.05).CONCLUSION: After phacoemulsification, retinal microcirculation in cataract patients improved significantly. EDV, PSV, aqueous humor cell grade, fundus lesion grade, advanced age and Emery grade are all factors influencing poor BCVA recovery after cataract surgery.

The VSR-VSI dual three-phase pulse width modulation (PWM) converters based on the cascade connection of a front-end three-phase voltage source rectifier (VSR) and a back-end three-phase voltage source inverter (VSI) have been widely used in elevator energy feedback systems, but the front-end three-phase VSR using the traditional proportional integral (PI) double closed-loop control structure usually has the problem that the mid-end DC voltage cannot take into account the disturbance immunity and the follow-ability. Given this, an improved DC voltage regulation strategy of the three-phase PWM rectifier based on two-degree-of-freedom proportional integral differential (PID) is proposed. Firstly, the structure and working principle of the three-phase VSR-VSI dual three-phase PWM converters are expounded. Then, the PI double closed-loop control scheme of the front-end three-phase VSR and its parameter design process are given to analyze the reasons why this traditional scheme cannot have good disturbance immunity and follow-ability of the DC voltage regulation system. On this basis, an optimized DC voltage regulation improvement strategy for the front-end three-phase VSR based on two-degree-of-freedom PID and its corresponding parameter design method are given. Finally, the correctness and the superiority of the proposed three-phase PWM-VSR DC voltage regulation strategy are verified by using the simulation and experimental comparison results.

With the growing demand for transportation, there has been a significant increase in road-related projects, leading to potential risks in the safety of existing structures. This paper presents a study on the influence of new tunnel construction on the stability of an adjacent existing tunnel and provides valuable insights for the safety technology evaluation of similar tunnel crossing projects. In order to evaluate the influence of tunnel excavation on adjacent tunnels, the excavation process of a new tunnel near the original tunnel is simulated using the finite element software Midas GTS. This analysis includes the evaluation of static and dynamic responses. The results indicate that the horizontal and vertical displacements caused by the excavation of the railway tunnel are minimal. Furthermore, during the blasting excavation of the railway tunnel, the vibration velocity experienced by the highway tunnel remains below the safe allowable limit. These findings demonstrate that in this project, the influence of blasting excavation for the railway tunnel on the highway tunnel is both safe and manageable.

With the continuous increase of the spraying area, the problem of droplet drift risk in the spraying process of UAV is becoming increasingly prominent, especially the herbicide drift. In order to clarify the effect of the herbicide solution on the droplet size and the deposition and drift distribution characteristics sprayed by UAVs, the droplet sizes of 15 herbicide solutions sprayed by the centrifugal rotary atomizer nozzle installed in the plant protection UAV were measured in the laboratory, and the distribution of droplet deposition and drift in the spraying area and drift area were measured by adding a fluorescent tracer (60 g/hm2) to the tank in the field. The results showed that the herbicide solution had a significant effect on the droplet size distribution. The DV50 of all the other solutions was reduced after sprayed by the centrifugal atomizer except the Carfentrazone-ethyl water dispersible granule, and the maximum decrease ratio was 22.0%. The proportion of small droplets (V