The deep sea is the frontier of materials research in the 21st century. Owing to the particularity of pressure (15–120 MPa), hydrothermal temperature (90–400°C), and explosive fluid (strong H₂S) in the deep‐sea hydrothermal field environment, the research on the corrosion mechanism of service materials in this environment under the coupling action of many harsh factors is almost blank. It has become the bottleneck of equipment and material research and development for China to explore the deep sea. This paper reviews the research progress of corrosion mechanisms of deep‐sea environmental materials at home and abroad, and forecasts the research trend and difficulties in this field, especially in the deep‐sea hydrothermal field. At the same time, it points out the urgency of the construction of harsh environment materials platform and its relevance to the discipline construction of marine college.

Nitrous oxide (N₂O), as one of the six greenhouse gases, is mainly produced in the biological nitrogen removal process of wastewater treatment plants (WWTPs). Establishing the N₂O kinetic model can provide insight into the N₂O generation mechanism and regulate its production. This work uses Activated Sludge Model NO.3 (ASM3) as the basic framework, combines organic storage with endogenous respiration theory, and couples ammonia oxidizing bacteria (AOB) denitrification pathway and the NH₂OH / NOH model to establish a kinetic model. Meanwhile, the Sequencing Batch Reactor (SBR) process with artificial simulated urban domestic sewage was used as the carrier; MATLAB and EXCEL software were used as tools to establish a model calculation program. The simulated values obtained by substituting the operating conditions of the SBR process into the model and the measured values of the SBR process were analyzed. The correlation coefficient (R²) between the experimental values and simulated values obtained for the 5 components of COD, ammonia, nitrite, nitrate and total N₂O is 0.952, 0.996, 0.902, 0.991, 0.956, respectively, which indicates that the N₂O kinetic model has great consistency, this further shows that the established model modeling mechanism is clear and accurate, and provides a new method for the N₂O dynamic model.

Excessive phosphorus in aquatic environments can lead to eutrophication, posing a significant deterioration of water quality. In this study, modified steel slag was used as a novel filter media in the biological aeration filter (BAF) to achieve a bioinduced phosphorus crystallization process for simultaneous removal and recovery of phosphorus from municipal wastewater. Phosphorus removal efficiency could reach 80% during 4 days of operation due to high adsorption capacity of the modified steel slag in the single BAF reactor, but the phosphorus removal efficiency decreased to 30% after 30 days of operation. The phosphorus removal efficiency of the BAF system increased to 70% under alternating anaerobic-aerobic (A/O) operation condition. Concentration of ${\mathrm{PO}}_4^{3-}\text{-}\mathrm{P}$ in anaerobic effluent reached $19.9\mathrm{mg}/\mathrm{L}$ at 68 days of operation and exceeded that in influent ($10.6\mathrm{mg}/\mathrm{L}$ ), indicating that phosphorus accumulating organisms (PAOs) were successfully enriched in the alternating A/O BAF system. Hydroxyapatite (HAP) crystals formation was confirmed based on analysis of scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX) and X-ray diffraction (XRD). The proposed phosphorus removal mechanism suggests that the release of phosphorus from PAOs and the release of ${\mathrm{Ca}}^{2+}$ and ${\mathrm{OH}}^{-}$ from the modified steel slag is beneficial to HAP crystals formation. These results indicated that the bioinduced phosphorus crystallization process achieved to improve phosphorus removal efficiency of the alternating A/O BAF system. This finding is a significant improvement to both biological and crystallization phosphorus removal processes, and has significant potential application for removal and recovery of phosphorus in wastewater treatment.

Objectives: This retrospective cohort study aimed to assess the efficacy of emergency cervical cerclage (ECC) performed with the combined McDonald‐Shirodkar technique in twin pregnancies between 18 and 26 weeks of pregnancy with painless cervical dilation 1 to 6 cm.Methods: A retrospective cohort study matched with the degree of cervical dilation was conducted. The study group (case group) included women with twin pregnancies undergoing combined McDonald‐Shirodkar approach with cervical dilation ≥1 cm between 18 to 26 weeks of gestation at four institutions, from December 2015 to December 2022. To minimize confounding factors, we elucidated the causality structure using a directed acyclic graph and performed 1:1 case–control matching. A control group underwent the McDonald approach. The primary outcome was gestational age (GA) at delivery. The secondary outcomes were pregnancy latency; the rates of spontaneous preterm birth at <28, <30, <32, and <34 weeks; and neonatal outcomes. Additional subanalysis was performed by dividing the patients into two subgroups of women with cervical dilation ≥3 cm and 0.05). After adjusting for confounders that were represented by a directed acyclic graph, median GA at delivery was significantly higher (30.5 vs 27 weeks; Bate: 3.40 [95% confidence interval (CI), 2.13–4.67], P < 0.001) and median pregnancy latency was significantly longer (56 vs 28 days; Bate: 24.04 [95% CI, 13.31–34.78], P < 0.001) in the case group compared with the control group. Rates of spontaneous preterm birth at <28, <30, <32, and <34 weeks were significantly lower in the case group than in the control group. For neonatal outcomes, there was higher birth weight (1543.75 vs 980 g; Bate: 420.08 [95% CI, 192.18–647.98], P < 0.001) and significantly lower overall perinatal mortality (7.1% vs 31%; adjusted odds ratio, 0.16 [95% CI, 0.04–0.70], P = 0.014) in the case group compared with the control group. When cervical dilation was ≥3 cm, the combined McDonald‐Shirodkar procedure can significantly reduce perinatal mortality (8.3% vs 46.7%; adjusted odds ratio, 0.09 [95% CI, 0.01–0.77], P = 0.028), significantly decrease the risk of delivery at <28 and <30 weeks, and prolong GA at delivery and pregnancy latency compared with the McDonald procedure.Conclusions: ECC performed with the combined McDonald‐Shirodkar procedure in women with twin pregnancies who have cervical dilation 1 to 6 cm in midtrimester pregnancy may reduce the rate of spontaneous preterm birth and improve perinatal and neonatal outcomes compared with the McDonald procedure, especially for twin pregnancies in women with cervical dilation of 3 to 6 cm and prolapsed membranes.

Due to the advantages of ceramic membrane such as high separation efficiency, easy operation, good chemical stability and low energy consumption, it has an expansive application prospect in the field of industrial wastewater treatment. However, the ceramic membrane has a low removal effect to the contaminants whose molecular diameters are smaller than the membrane pores, the poor water quality also aggravates the pollution and shortens the age of ceramic membrane. Therefore, it is significant to research the combination process of ceramic membrane. This article summarizes the current ceramic membrane combination process in industrial wastewater treatment, and describes their respective characteristics, mechanism of reaction and removal effects. Ultimately, we would put forward the direction of the ceramic membrane combination process in the future.