Enhanced stability of FA-based perovskite:Rare-earth metal compound EuBr_(2) doping

It is highly desirable to enhance the long-term stability of perovskite solar cells(PSCs)so that this class of photovoltaic cells can be effectively used for the commercialization purposes.In this contribution,attempts have been made to use the two-step sequential method to dope EuBr_(2)into FAMAPbI_(3)perovskite to promote the stability.It is shown that the device durability at 85℃in air with RH of 20%-40%is improved substantially,and simultaneously the champion device efficiency of 23.04%is achieved.The enhancement in stability is attributed to two points:(ⅰ)EuBr_(2)doping effectively inhibits the decomposition andα-δphase transition of perovskite under ambient environment,and(ⅱ)EuBr_(2)aggregates in the oxidized format of Eu(BrO_(3))_(3)at perovskite grain boundaries and surface,hampering humidity erosion and mitigates degradation through coordination with H_(2)O.

Four FDA-approved drugs exhibited inhibition effect on severe fever with thrombocytopenia syndrome virus in vitro

Objective:To screen the anti-SFTSV drugs from 1430 FDA-approved drugs via mini-genome system,and to investigate which stage of the infection process could be suppressed by the identified drugs.Methods:The SFTSV mini-genome system was used to screen drugs with inhibitory effect on SFTSV replication and transcription,and the 50%inhibitory concentration(IC_(50))of each drug was calculated by drug concentration gradient inhibition experiment.Drugs were used to pre-incubate with virus and then incubate with cells,to incubate with virus and cells simultaneously,to incubate with cells after virus invading into cells,or to incubate during the whole infection process,and then qRT-PCR was used to measure the viral RNA copies in the culture supernatant.These experiments were performed to quantitatively determine the inhibition effects of drugs on SFTSV indifferent stages of the whole process including virion stability,entry and post-entry stages,so as to clarify the inhibition mechanism of these drugs.Results:Four drugs including Mycophenolate mofetil,Mycophenolic acid,Nitazoxanide,and Vidofludimus were identified having efficient inhibitory effects on SFTSV RNA replication via minigenome system,with the IC_(50) of 0.014μmol/L,0.627μmol/L,1.283μmol/L,and 0.059μmol/L,respectively.All four drugs showed effective inhibition when adding during the whole SFTSV infection process as well as the post-entry stage.Conclusion:Mycophenolate mofetil,Mycophenolic acid,Nitazoxanide and Vidofludimus show efficient anti-viral effects on SFTSV infection.

Improvement of the microstructure and magnetic properties of(La,Ce)-Fe-B nanocrystalline ribbons

The obstacles of inferior microstructure and poor magnetic properties of(La,Ce)-Fe-B type magnets stand in the way of expanding their applications.In this work,(La,Ce)-Fe-B melt-spun ribbons were prepared with different La/Ce ratios and rare earth contents.The microstructure and magnetic properties of these ribbons were investigated.With the La/Ce ratio increased,the fraction of the CeFe_(2)phase decreased and the β-La phase segregated among matrix grains,which deteriorated the coercivity of the ribbons.Reducing the rare earth content effectively suppressed the β-La phase and improved the proportion of the matrix phase in the ribbons.Here,the optimal alloy composite(La_(15)Ce_(85))_(14)Fe_(80)B_(6) has been obtained with modified microstructure and inhibited secondary phases.Good ribbon performance was tested,with H_(cj)=4.51 kOe,B_(r)=6.29 kG and(BH)_(max)=6.81 MGOe.