Search

The degradation of organic pollutants by transition metal activated peroxymonosulfate (PMS) has important application value in the field of advanced oxidation. MnO2/SiC composite catalyst was prepared by hydrothermal method on the surface of silicon carbide (SiC), which was used to activate PMS to degrade and remove methylene blue (MB) from water. The results show that MnO2 is uniformly attached to the surface of SiC in the form of particles, and the removal rate of MB by MnO2/SiC-PMS system reaches 99% within 40 min. The MnO2/SiC-PMS system can achieve high degradation efficiency of MB over a wide pH range (5.0~9.0), while 5 mmol/L Cl- and NO3- had no significant effect on the MnO2/SiC-PMS system. Phosphate and bicarbonate have quenching effect on oxidative free radicals, leading to a decrease in the degradation efficiency of MB in the MnO2/SiC PMS system. The results of free radical quenching experiments indicate that plays a major role in the MnO2/SiC-PMS system. In addition, MnO2/SiC has good recyclability. [ABSTRACT FROM AUTHOR]

Current research predominantly relies on single travel data sources to simulate single-modal transportation networks, making it challenging to objectively and comprehensively reflect the real travel characteristics of residents. This paper presents a modeling method of multi-modal transportation network and a multifeature fusion algorithm for analyzing resident travel characteristics, taking Shenzhen as a case study. Firstly, taking into consideration the spatio temporal variations in transportation networks, a partitioning algorithm of multiscale transportation zones is designed to simplify the complex network. Next, a multi-model transportation network is constructed by connecting station path attributes with transportation zones. Finally, mobile trajectory mining and feature fusion techniques are adopted to design a fusion algorithm of multi-modal travel features, systematically depicting resident travel characteristics in a multi-model context. Experimental results demonstrate what compared to using a single data source alone, the proposed method effectively mitigates data bases, provides a more accurate representation of traffic density among different transportation regions, and offers a more comprehensive insight into residents' travel behaviors and preferences, and can better provide scientific decision-making for urban planning and transportation management. [ABSTRACT FROM AUTHOR]

Objective: To explore the effectiveness of proximal femoral nail antirotation (PFNA) combined with mini plate for reconstruction of lateral femoral wall in the treatment of type AO/Orthopaedic Trauma Association (AO/OTA) type 31-A3 intertrochanteric fracture., Methods: The clinical data of 70 elderly patients with AO/OTA type 31-A3 intertrochanteric fracture treated between January 2013 and January 2018 were retrospectively analyzed. They were divided into group A (PFNA alone, 35 cases) and group B (PFNA combined with mini plate reconstruction of lateral femoral wall, 35 cases). There was no significant difference in the general data of gender, age, side, cause of injury, time from injury to operation between the two groups ( P >0.05). The operation time, intraoperative blood loss, fracture healing time, postoperative complications, and the tip apex distance (TAD) at 2 months after operation were recorded and compared between the two groups. Harris hip score was used to evaluate the function at 12 months after operation., Results: Both groups were followed up 9-21 months, with an average of 16.6 months. The operation time and intraoperative blood loss in group A were significantly less than those in group B ( P <0.05); there was no significant difference in TAD between the two groups at 2 months after operation ( t =0.096, P =0.462). There were 5 complications (14.3%) occurred in group A, including 2 cases of blade perforating from the hip joint, 2 cases of screw back out, and 1 case of bone nonunion; only 1 case (2.9%) in group B had screw back out after operation; there was no significant difference in the incidence of complications between the two groups ( χ 2 =2.917, P =0.088). All the fracture healed in group B, and 1 patient in group A suffered bone nonunion and eventually main nail fracture. The healing time of fracture in group A [(15.6±2.7) weeks] was significantly longer than that in group B [(12.5±2.5) weeks], showing significant difference ( t =2.064, P =0.023). At 12 months after operation, according to Harris score, the results were excellent in 5 cases, good in 9 cases, fair in 13 cases, and poor in 8 cases in group A, the qualified rate (Harris score>70) was 77.14%; and the results were excellent in 7 cases, good in 11 cases, fair in 16 cases, and poor in 1 case in group B, the qualified rate was 97.14%; there was significant difference in the qualified rate between the two groups ( χ 2 =6.248, P =0.012)., Conclusion: Compared with PFNA alone, the treatment of AO/OTA type 31-A3 intertrochanteric fracture with PFNA combined with mini plate reconstruction of lateral femoral wall can significantly reduce postoperative complications, promote fracture healing, and improve functional recovery of patients after operation.