Thermal runaway evolution of a 280 Ah lithium-ion battery with LiFePO_(4) as the cathode for different heat transfer modes constructed by mechanical abuse

Lithium iron phosphate batteries have been increasingly utilized in recent years because their higher safety performance can improve the increasing trend of recurring thermal runaway accidents.However,the safety performance and mechanism of high-capacity lithium iron phosphate batteries under internal short-circuit challenges remain to be explored.This work analyzes the thermal runaway evolution of high-capacity LiFePO_(4) batteries under different internal heat transfer modes,which are controlled by different penetration modes.Two penetration cases involving complete penetration and incomplete penetration were detected during the test,and two modes were performed incorporating nails that either remained or were removed after penetration to comprehensively reveal the thermal runaway mechanism.A theoretical model of microcircuits and internal heat conduction is also established.The results indicated three thermal runaway evolution processes for high-capacity batteries,which corresponded to the experimental results of thermal equilibrium,single thermal runaway,and two thermal runaway events.The difference in heat distribution in the three phenomena is determined based on the microstructure and material structure near the pinhole.By controlling the heat dissipation conditions,the time interval between two thermal runaway events can be delayed from 558 to 1417 s,accompanied by a decrease in the concentration of in-situ gas production during the second thermal runaway event.

Liver Function Derangement in Patients with Severe Fever and Thrombocytopenia Syndrome

Background and Aims:Patients with severe fever with thrombocytopenia syndrome(SFTS)commonly show liver function impairment.This study aimed to characterize the liver function indices in SFTS patients and investigate their association with mortality.Methods:Clinical information and laboratory results of 459 laboratory-confirmed SFTS patients,including 78 deceased and 381 surviving patients,were retrospectively analyzed.To explore the infectivity of SFTS caused by novel Bunyavirus(SFTSV)in hepatocytes,Huh7 human hepatoma cells were infected with various concentrations of SFTSV in vitro.Results:The proportion of SFTS patients developing liver injury during hospitalization was 73.2%(336/459);the hepatocellular injury was the predominant type.The median time to occurrence of liver injury from disease onset was 8 d.Liver injury in the deceased group occurred earlier than that in the surviving group.Alanine aminotransferase(ALT)level between 2–5 times upper limit of normal(ULN)at 4–6 d and between 5–15 ULN at 7–12 d of disease course were independent predictors of mortality.Alkaline phosphatase(ALP)>2 ULN at 7–9 d and elevated ALP at 10–12 days after disease onset were risk factors for death.ALT and aspartate transaminase(AST)levels were correlated with lymphocyte count and platelet-to-lymphocyte ratio(PLR).Total bilirubin(TB),ALT,AST levels showed positive correlation with viral load.In the in vitro experiment,SFTSV infected and replicated inside Huh7 cells.Conclusions:Liver injury is common in SFTS patients.ALT and ALP were independent predictors of SFTS-related mortality.Frequent monitoring and evaluation of liver function indices are needed for SFTS patients.

Localization technique research of a pipeline robot based on the magnetic-dipole model

The magnetic field distribution of an emission antenna is studied in this paper.When the slenderness ratio of the emission antenna is high,the emission antenna can be simplified as a magnetic dipole for practical application.The numerical results of the magnetic dipole magnetic field show that the magnetic magnitude distribution has a hump-shape,whose direction is perpendicular with the antenna axis direction.A localization method based on the hump-shape signal detection is presented.The experimental result shows that the precision can reach a value of±5 cm.The method can be used to localize a pipeline robot working in a metal pipe.

Formation of sulfur oxide groups by SO_(2) and their roles in mercury adsorption on carbon-based materials

The presence of SO_(2) display significant effect on the mercury(Hg) adsorption ability of carbon-based sorbent. Yet the adsorption and oxidation of SO_(2) on carbon with oxygen group, as well as the roles of different sulfur oxide groups in Hg adsorption have heretofore been unclear. The formation of sulfur oxide groups by SO_(2) and their effects on Hg adsorption on carbon was detailed examined by the density functional theory. The results show that SO_(2) can be oxidized into SO_(2) by oxygen group on carbon surface. Both C-SO_(2) and C-SO_(2)can improve Hg adsorption on carbon site, while the promotive effect of C-SO_(2) is stronger than C-SO_(2). Electron density difference analyses reveal that sulfur oxide groups enhance the charge transfer ability of surface unsaturated carbon atom, thereby improving Hg adsorption. The experimental results confirm that surface active groups formed by SO_(2) adsorption is more active for Hg adsorption than the groups generated by SO_(2).