RESUMEN
Polyaniline (PANI), with merits of high electronic conductivity and capacity, is a promising material for zinc (Zn)-ion batteries. However, its redox window in Zn batteries is often limited, mainly due to the oxidative degradation at high potentials-in which imine groups can be attacked by water molecules. Here, we introduce phytic acid, a kind of supermolecule acid radical ion, as a dopant and electrolyte additive. Various in/ex situ analyses and theoretical calculations prove that the steric hindrance effect can prevent electroactive sites from the attack by water molecules. Meanwhile, the redox reaction can be stabilized by an even distribution of electron cloud due to the conjugated structure of phenazine groups. Accordingly, the assembled Zn-PANI battery can allow stable and long-term charge-discharge reactions to occur at a potential as high as 2.0 V with a discharged plateau of 1.5 V, and it also shows high rate performance and stable long cycle life (75% capacity retention after 1000 cycles at 10 A g-1).
RESUMEN
A new variance formula is developed using the generalized inverse of an increasing function. Based on the variance formula, a new entropy formula for any uncertain variable is provided. Most of the entropy formulas in the literature are special cases of the new entropy formula. Using the new entropy formula, the maximum entropy distribution for unimodel entropy of uncertain variables is provided without using the Euler-Lagrange equation.
RESUMEN
BACKGROUND: Occupational health impairment of medical personnel manifested as a prominent problem in COVID-19. The aim of this study is to investigate the occupational physical injuries of front-line medical staffs in Hubei province during the fight against COVID-19. MATERIAL AND METHODS: questionnaire survey was conducted among 476 medical staffs from 3 regions of Hubei Province, including general characteristics and the physical discomfort/damage suffered in the isolation wards during working hours. RESULTS: A total of 457 valid questionnaires were collected. The common physical discomfort/damage included skin injuries (22.76%), conjunctivitis (15.10%), falls (9.19%), intolerant unwell symptoms (8.53%) and sharp injuries (6.13%). Logistic regression analysis showed that: lack of protective work experience (OR = 2.049, 95% CI: 1.071-3.921), continuous working for 4 h (OR = 3.771, 95% CI: 1.858-7.654), and working >4 h (OR = 7.076, 95% CI: 3.197-15.663) were high-risk factors for skin injuries. Working continuously for 4 h (OR = 3.248, 95% CI: 1.484-7.110) and working >4 h (OR = 3.096, 95% CI: 1.232-7.772) were high-risk factors for conjunctivitis. Lack of protective work experience was a high risk factor for falls (OR = 5.508, 95% CI: 1.299-23.354). The high risk factors for intolerant unwell symptoms were continuous working for 4 h (OR = 5.372, 95% CI: 1.239-23.301) and working >4 h (OR = 8.608, 95% CI: 1.843-40.217). Working in a COVID-19 critical care unit (OR = 3.249, 95% CI: 1.344-7.854) and implementation of nursing (OR = 9.766, 95% CI: 1.307-72.984) were high risk factors for sharp injuries. CONCLUSIONS: Occupational physical injuries are universal in the COVID-19 ward. Those who take up nursing, work in a critical care ward, with no experience in an isolation ward for infectious diseases, and work continuously for ≥4 h on the same day should get more attention. Med Pr. 2022;73(3):209-18.