Management and operation of extra-large Fangcang hospitals:experience and lessons from containing the highly contagious SARS-CoV-2 Omicron in Shanghai,China

Introduction Omicron is more contagious and stealthier than the previous strains.The basic reproduction number of Omicron is around 8–12,whereas that of the previous mainstream strain Delta is only 5–8[1].Omicron’s symptoms are relatively mild[2]compared with Delta’s symptoms;however,Omicron’s transmission ability is very strong,and its risk to children and the elderly remains high[3].In addition,the vaccine’s preventive effect on Omicron has weakened.Therefore,Omicron can easily cause a rapid outbreak in a city.The population density of megacities and the limited public health resources further exacerbate the difficulty of Omicron prevention and control.

Brominated Butyl Rubber Anticorrosive Coating and its Self-healing Behaviors

Self-healing anticorrosive coatings in extreme environment have attracted considerable interest from researchers.In this work,4-tert-butylpyridine(TBP)was incorporated into brominated butyl rubber(BIIR)polymer networks to form a reversible ionic bond with the highly reactive bromine anion.Based on the low glass transition temperature of the BIIR polymer and the electrostatic effects,a robust self-healing anticorrosive coating of TBP-BIIR was prepared.TBP-BIIR coating showed a maximum protection efficiency(PE)of more than 94%(TBP-BIIR-acid,94.37%;TBP-BIIR-alkali,94.95%;TBP-BIIR-salt,95.49%)when treated with a strong acid(HNO_(3),pH=2),strong base(NaOH,pH=12)and high salt solution(3.5 wt%NaCl).In addition,the PE of coating repaired exceed 89%,and the maximum PE value was approximately 95%in different solutions,which demonstrated its extinguished self-healing abilities.These results indicated that the TBP-BIIR anticorrosive coating could provide excellent safety and durability in special environment,which would be extremely beneficial to improve the working life of metal parts used in aviation and shipping,oil and gas and related industries.

A high-Nb-TiAl alloy with ultrafine-grained structure fabricated by cryomilling and spark plasma sintering

In this work,an ultrafine-grained high-Nb-TiAl alloy with a nominal composition of Ti-45Al-8Nb-0.2W-0.2B(at%)was prepared by cryomilling and subsequent spark plasma sintering(SPS)technique.The chemical composition,particle size,morphology and crystallite size of cryomilled powder were studied.It is found that cryomilling can effectively reduce the particle size and enhance grain refinement.The ingots sintered at 900 and 1000℃ show an equiaxed near-γmicrostructure with grain sizes<700 nm,while the sample sintered at 1100℃exhibits duplex microstructure.Especially,the one sintered at 1000℃ has excellent mechanical properties,whose compression yield strength,fracture strength,bending strength and plastic strain achieve 1310,2174,578 MPa and 16.8%,respectively.The reasons for the effect of cryomilling and the mechanical behavior of sintered ingots were discussed.It is suggested that cryomilling in combination with SPS is an effective way to synthesize high-NbTiAl alloy with ultrafine-grained structure.