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The construction scale of a wastewater centralized treatment facility in a printing and dyeing cluster improvement park in Zhejiang Province was 30 000 m3/d. According to the characteristics of wastewater in the park, the main process of “regulation tank+cooling system+reaction initial sedimentation tank+anaerobic hydrolysis tank+A/O biochemical tank+secondary sedimentation tank+high-efficiency sedimentation tank” was adopted. The results showed that the process was stable and efficient. When the average COD, BOD5, and total antimony in the influent were 1 370, 360 and 1.17 mg/L, the COD, BOD5, and total antimony in effluent were respectively reduced to 88, 7.4, and 0.049 mg/L, with the corresponding removal rates of 94%, 98% and 96%. The effluent met the indirect discharge requirements in Table 2 of “Discharge Standards of Water Pollutants for Dyeing and Finishing of Textile Industry”(GB 4287-2012). The project adopted a coagulation agent enhanced initial sedimentation process to achieve effective carbon capture of wastewater and indirectly export energy, which was conducive to the reduction of carbon emissions. The main treatment unit adopted intensive combination and deep pool design to save land, which could be used as a reference for land limited wastewater plants.

ObjectiveTo study the epidemiological features of hand， foot， and mouth disease （HFMD） in Minhang District of Shanghai and to explore the possible effects of meteorological factors on the onset of HFMD， aiming to provide a reference for the prevention and control of HFMD.MethodsThe incidence data of HFMD in Minhang District from 2014 to 2018 were collected for descriptive analysis. The data of meteorological factors that might affect HFMD were analyzed by Pearson analysis and multiple linear stepwise regression.ResultsThe average incidence rate of HFMD in Minhang District from 2014 to 2018 was 271.51 per 100 000. The incidence of Huacao， Pujiang and Maqiao community were the highest. The incidence of HFMD in males was higher than in females and the 0‒5 age group had the largest number of cases， mainly in scattered children and children in kindergartens. The results of multiple linear stepwise regression analysis showed that the incidence of HFMD was negatively correlated with the weekly average air pressure （b=-4.32， P=0.004）， and was positively correlated with the weekly minimum temperature （b=2.62， P=0.040） and the weekly average relative humidity （b=1.71， P=0.010）. The correlation with weekly average temperature， weekly maximum temperature， weekly precipitation， weekly average air pressure and weekly average water vapor pressure was not significant.ConclusionMeteorological factors in Minhang District of Shanghai are closely related to the occurrence of HFMD. Comprehensive measures should be taken to prevent and control HFMD.

Advanced airborne power generation technology represents one of the most effective solutions for meeting the electricity requirements of hypersonic vehicles during long-endurance flights. This paper proposes a power generation system that integrates a high-temperature fuel cell to tackle the challenges associated with power generation in the hypersonic field, utilizing techniques such as inlet pressurization, autothermal reforming, and anode recirculation. Firstly, the power generation system is modeled modularly. Secondly, the influence of key parameters on the system's performance is analyzed. Thirdly, the performance of the power generation system under the design conditions is simulated and evaluated. Finally, the weight distribution and exergy loss of the system's components under the design conditions are calculated. The results indicate that the system's electrical efficiency increases with fuel utilization, decreases with rising current density and steam-to-carbon ratio (SCR), and initially increases before declining with increasing fuel cell operating temperature. Under the design conditions, the system's power output is 48.08 kW, with an electrical efficiency of 51.77%. The total weight of the power generation system is 77.09 kg, with the fuel cell comprising 69.60% of this weight, resulting in a power density of 0.62 kW/kg. The exergy efficiency of the system is 55.86%, with the solid oxide fuel cell (SOFC) exhibiting the highest exergy loss, while the mixer demonstrates the greatest exergy efficiency. This study supports the application of high-temperature fuel cells in the hypersonic field. [ABSTRACT FROM AUTHOR]

Fast and efficient mixing of high-speed shear flow formed by fuel and oxidizer is of great importance for the improvement of rocket-based combined cycle engine performance. Nevertheless, the existence of compressibility effects of high-speed flow significantly inhibits the growth process of a mixing layer. Moreover, a finite-length combustor of the engine calls for more effective enhanced-mixing strategies to complete mixing in a shorter streamwise distance. To this end, in present paper, the strategy called dual plate cavity (DPC) is proposed to promote mixing. Three cases including the benchmark, front-DPC and back-DPC cases are selected to perform the comparative study. By means of high-order direct numerical simulations, the structure evolution characteristics and turbulence intensity distributions are researched. The index of velocity thickness is utilized to assess the mixing layer growth. The results indicate that with the introduction of DPC, the mixing process is dramatically promoted. The penetration behavior of newly found T-shaped structures into the upper main stream can engulf more fluid into the mixing region. Specifically, in the back-DPC case, the coexistence of both large-scale and small-scale structures in the far flow field can improve the turbulence intensity. The spatial correlation analysis results show that with the influence of DPC, the structure sizes are much larger than that of the benchmark case in the same streamwise position. Meanwhile, the contour line equal to 0.5 possesses property of distortion for the back-DPC case. The drastic pulsation of a mixing layer edge can obviously promote the mixing process. Through exploration of the enhanced-mixing mechanisms, this work indicates that the proposed DPC strategy is a good candidate for efficient mixing, and in the future, more detailed work including three-dimensional simulations concerning the strategy optimization is suggested to be performed. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore the effects of cold atmospheric plasma (CAP) treatment on the biological behavior of human gingival fibroblasts (HGFs) cultured on the surface of high-transparency zirconia. Two types of zirconia, 3Y-ZTP and 4Y-PSZ, were subjected to a CAP treatment for various treatment durations. Analyses of the physical and chemical properties of 3Y-ZTP and 4Y-PSZ were conducted using scanning electron microscopy, contact angle measurements, and X-ray photoelectron spectroscopy, both before and after CAP treatment. The biological responses of HGFs on both surfaces were assessed using CCK-8 assay, confocal laser scanning microscopy, and real-time PCR. Initially, the oxygen and hydroxyl contents on the surface of 4Y-PSZ exceeded those on 3Y-ZTP. CAP treatment enhanced the surface hydrophilicity and the reactive oxygen species (ROS) content of 4Y-PSZ, while not altering the surface morphology. After CAP treatment, HGFs' adhesion on 4Y-PSZ was superior, with more pronounced effects compared to 3Y-ZTP. Notably, HGFs counts and the expression of adhesion-related genes on 4Y-PSZ peaked following the CAP exposures for 30 s and 60 s. Consequently, this study demonstrates that, following identical CAP treatments, 4Y-PSZ is more effective in promoting HGFs adhesion compared to traditional 3Y-ZTP zirconia. [ABSTRACT FROM AUTHOR]