Seawater pumped storage systems have bright prospect for energy storage in the coming years.The operational conditions of seawater pumped storage system are complex and harsh,where metal materials suff er from severe ...Seawater pumped storage systems have bright prospect for energy storage in the coming years.The operational conditions of seawater pumped storage system are complex and harsh,where metal materials suff er from severe general and local corrosion.The corrosion behavior of Q235B carbon steel in simulated seawater pumped storage system under operational conditions was studied by potentiodynamic polarization,cyclic potentiodynamic polarization,and scanning electron microscope(SEM).The results confi rm that the working pressure aff ected the corrosion resistance of Q235B carbon steel during the whole immersion period.The pressure promoted the electrochemical reaction of corrosion process and the corrosion rate increased with pressure at the initial immersion period.However,the stable rust layer formed after longtime immersion at diff erent pressures increased the corrosion resistance of carbon steel,and decreased the corrosion degree of carbon steel.Meanwhile,the working pressure aff ected the pitting corrosion behavior of Q235B carbon steel during the whole immersion period.The pitting corrosion potential was more negative and the tendency of pitting corrosion was higher at 4 MPa during the whole immersion period.However,pressure also accelerated the formation rate of protective rust layer on the steel surface.Q235B carbon steel has higher susceptibility to pitting corrosion at 4 MPa in the static seawater.展开更多
Cathodic protection is a very effective method to protect metals, which can form calcareous deposits on metal surface. Research on the interrelationship between fouling organism and calcareous deposits is very importa...Cathodic protection is a very effective method to protect metals, which can form calcareous deposits on metal surface. Research on the interrelationship between fouling organism and calcareous deposits is very important but very limited, especially sulfate-reducing bacteria(SRB). SRB is a kind of very important fouling organism that causes microbial corrosion of metals. A study of the influence of calcareous deposit on corrosion behavior of Q235 carbon steel in SRB-containing culture medium was carried out using electrochemical impedance spectroscopy(EIS), scanning electron microscopy(SEM) and surface spectroscopy(EDS). The calcareous deposit was formed with good crystallinity and smooth surface under the gradient current density of -30 μA cm^(-2) in natural seawater for 72 h. Our results can help elucidate the formation of calcareous deposits and reveal the interrelationship between SRB and calcareous deposits under cathodic protection. The results indicate that the corrosion tendency of carbon steel was obviously affected by Sulfate-reducing Bacteria(SRB) metabolic activity and the calcareous deposit formed on the surface of carbon steel under cathodic protection was favourable to reduce the corrosion rate. Calcareous deposits can promote bacterial adhesion before biofilm formation. The results revealed the interaction between biofouling and calcareous deposits, and the anti-corrosion ability was enhanced by a kind of inorganic and organic composite membranes formed by biofilm and calcareous deposits.展开更多
目的比较机器人辅助与腹腔镜下大子宫切除术患者术后并发症的发生率。方法回顾性分析武汉大学人民医院2020年1月至2021年4月病历资料,符合纳入、排除标准的病例共计170例,按手术方案分为机器人组(n=54)与腹腔镜组(n=116)。收集患者年龄...目的比较机器人辅助与腹腔镜下大子宫切除术患者术后并发症的发生率。方法回顾性分析武汉大学人民医院2020年1月至2021年4月病历资料,符合纳入、排除标准的病例共计170例,按手术方案分为机器人组(n=54)与腹腔镜组(n=116)。收集患者年龄、体质量指数(body mass index,BMI)、原发病、有无糖尿病、ASA麻醉评分、国际标准化比值(international standard ratio,INR)、肌酐、子宫大小、麻醉时长、手术时长、失血量、输血量、是否中转开腹、住院总天数、术后通气天数、术后1日疼痛评分、严重并发症发生率、中等并发症发生率及轻微并发症发生率等资料进行比较。结果两组患者年龄、BMI、原发病、有无糖尿病、ASA麻醉评分、INR、肌酐、子宫大小、是否中转开腹、住院总天数、术后通气天数、术后1日疼痛评分、严重并发症发生率、轻微并发症发生率结果比较,差异无统计学意义(P>0.05)。但两组患者手术时长、麻醉时长、失血量与中等并发症发生率具有统计学差异(P<0.05)。结论相比腹腔镜下子宫切除术,大子宫患者行机器人辅助子宫切除术可以缩短手术时长和麻醉时长、减少失血量、降低中等并发症的发生率。展开更多
基金Supported by the National Key R&D Program of China(Nos.2017YFB0903700,2017YFB0903702)。
文摘Seawater pumped storage systems have bright prospect for energy storage in the coming years.The operational conditions of seawater pumped storage system are complex and harsh,where metal materials suff er from severe general and local corrosion.The corrosion behavior of Q235B carbon steel in simulated seawater pumped storage system under operational conditions was studied by potentiodynamic polarization,cyclic potentiodynamic polarization,and scanning electron microscope(SEM).The results confi rm that the working pressure aff ected the corrosion resistance of Q235B carbon steel during the whole immersion period.The pressure promoted the electrochemical reaction of corrosion process and the corrosion rate increased with pressure at the initial immersion period.However,the stable rust layer formed after longtime immersion at diff erent pressures increased the corrosion resistance of carbon steel,and decreased the corrosion degree of carbon steel.Meanwhile,the working pressure aff ected the pitting corrosion behavior of Q235B carbon steel during the whole immersion period.The pitting corrosion potential was more negative and the tendency of pitting corrosion was higher at 4 MPa during the whole immersion period.However,pressure also accelerated the formation rate of protective rust layer on the steel surface.Q235B carbon steel has higher susceptibility to pitting corrosion at 4 MPa in the static seawater.
基金supported by the National Natural Science Foundation of China (Nos.41376003 and 41006054)the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDA13040405)
文摘Cathodic protection is a very effective method to protect metals, which can form calcareous deposits on metal surface. Research on the interrelationship between fouling organism and calcareous deposits is very important but very limited, especially sulfate-reducing bacteria(SRB). SRB is a kind of very important fouling organism that causes microbial corrosion of metals. A study of the influence of calcareous deposit on corrosion behavior of Q235 carbon steel in SRB-containing culture medium was carried out using electrochemical impedance spectroscopy(EIS), scanning electron microscopy(SEM) and surface spectroscopy(EDS). The calcareous deposit was formed with good crystallinity and smooth surface under the gradient current density of -30 μA cm^(-2) in natural seawater for 72 h. Our results can help elucidate the formation of calcareous deposits and reveal the interrelationship between SRB and calcareous deposits under cathodic protection. The results indicate that the corrosion tendency of carbon steel was obviously affected by Sulfate-reducing Bacteria(SRB) metabolic activity and the calcareous deposit formed on the surface of carbon steel under cathodic protection was favourable to reduce the corrosion rate. Calcareous deposits can promote bacterial adhesion before biofilm formation. The results revealed the interaction between biofouling and calcareous deposits, and the anti-corrosion ability was enhanced by a kind of inorganic and organic composite membranes formed by biofilm and calcareous deposits.
文摘目的比较机器人辅助与腹腔镜下大子宫切除术患者术后并发症的发生率。方法回顾性分析武汉大学人民医院2020年1月至2021年4月病历资料,符合纳入、排除标准的病例共计170例,按手术方案分为机器人组(n=54)与腹腔镜组(n=116)。收集患者年龄、体质量指数(body mass index,BMI)、原发病、有无糖尿病、ASA麻醉评分、国际标准化比值(international standard ratio,INR)、肌酐、子宫大小、麻醉时长、手术时长、失血量、输血量、是否中转开腹、住院总天数、术后通气天数、术后1日疼痛评分、严重并发症发生率、中等并发症发生率及轻微并发症发生率等资料进行比较。结果两组患者年龄、BMI、原发病、有无糖尿病、ASA麻醉评分、INR、肌酐、子宫大小、是否中转开腹、住院总天数、术后通气天数、术后1日疼痛评分、严重并发症发生率、轻微并发症发生率结果比较,差异无统计学意义(P>0.05)。但两组患者手术时长、麻醉时长、失血量与中等并发症发生率具有统计学差异(P<0.05)。结论相比腹腔镜下子宫切除术,大子宫患者行机器人辅助子宫切除术可以缩短手术时长和麻醉时长、减少失血量、降低中等并发症的发生率。
