The entropy engineering strategy has been used for the first time to improve the grain boundary (GB) barrier of CaCu 3 Ti 4 O 12 (CCTO) ceramics, in order to solve its nonlinear problem at around 300 ℃ and expand its application in the field of high-temperature thermistors . To achieve this goal, we prepared (CaBaEuZnSr) 0.2 Cu 3 Ti 4 O 12 (CBEZSCT) high-entropy ceramics, and the GB spontaneous segregation properties were exploited to improve the GB resistance of CBEZSCT ceramics. The results show that the GB activation energy of CBEZSCT high-entropy ceramics (0.87 eV) is higher than that of CCTO ceramics (0.7 eV), which linearizes the resistance temperature curve and extends the application temperature limit from 300° to 750 °C. The proposed method of using a high entropy strategy to tune the GB resistance of CCTO to optimize its performance is highly effective, thus providing a new way of thinking about studying high-performance CCTO materials.
The Langmuir isotherm model is widely used for modeling adsorption equilibrium data. The linearization method is mostly applied for estimations of the Langmuir parameters. However, it is not unified and requires further study. In this paper, the applicability and accuracy of four linearization methods of the Langmuir isotherm (equilibrium adsorbate concentration ( C e )/equilibrium adsorption capacity ( q e )- C e , 1/ q e -1/ C e , q e - q e / C e and q e / C e - q e ) in parameter estimations by linear least squares regression (LSR) were compared. The influence of linearization on the assumption about errors in the LSR variables was analyzed. The results showed that Langmuir-1 ( C e / q e - C e ) and Langmuir-4 ( q e / C e - q e ) followed the assumption for all evaluated conditions whereas Langmuir-3 ( q e - q e / C e ) violated the assumption for all conditions. Langmuir-2 (1/ q e -1/ C e ) obeyed the assumption of LSR only when C e approached the initial adsorbate concentration ( C 0 ). Langmuir-1 ( C e / q e - C e ) provided the most accurate estimations of the Langmuir parameters, particularly at low levels of random errors in C e and when the errors (%) in estimated maximum adsorption capacity ( q m ) and constant ( K a ) ranged from −5% to 5% and from −15% to 15% at low levels of errors (−0.5–0.5 mg/L), respectively. The Langmuir-1 isotherm model adequately represented the experimental equilibrium data of sulfamethoxazole (SMX) onto activated carbon with an R 2 value of 0.96.
The flame retardant tri (1, 3-dichloro-2-propyl) phosphate (TDCIPP) is widely present in environmental media and organisms. People have paid much attention to the growth and developmental toxicity of TDCIPP, but there is little information about its cardiotoxicity and potential mechanisms. In this study, marine medaka ( Oryzias melastigma ) embryos were exposed to TDCIPP solutions (0, 0.05, 0.5, 5, and 50 μg/L) for 21 days to investigate the adverse effects of TDCIPP on cardiac development. The results showed that TDCIPP exposure altered the heart rate at different stages of embryonic development. In addition, 50 μg/L TDCIPP resulted in increased sinus venosus (SV)–bulbus arteriosus (BA) distance, pericardial cysts, and cardiac linearization in newly hatched fish. During embryonic development, the expression level of key genes regulating cardiac development is disturbed. The early stage of cardiac development is the sensitive window period for the toxic effects of TDCIPP. Oxidative stress was observed in newly hatched juveniles, but no significant lipid peroxidation damage was observed. In addition, vitellogenin (VTG) levels in juvenile fish were significantly reduced. Our results show that TDCIPP exposure induces cardiotoxicity in marine medaka embryos, which is induced in the early stages and promotes heart defects by amplifying inflammatory responses at a later stage.
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