RESUMEN
Ecological environmental issues are global focus problems. Achieving carbon neutrality is a fundamental measure to protect the ecological environment. Government environmental governance plays a key role in the process of moving towards a carbon neutral vision since the externality of the environment. Therefore, it is of great signiï¬cance for achieving the goal of carbon neutrality to evaluate the governmental ecological environment performance and propose improved suggestions based on the evaluation results. However, most existing evaluation methods have the disadvantages that it is difficult to avoid information distortion and loss during the evaluation process. To overcome these problems, an evaluation model based on a DPSIR-improved matter-element extension cloud model is proposed in this study, which combines the Drivers-Pressures-State-Impact-Response (DPSIR) model, the entropy weight method, the cloud model, matter element extension theory, and the cloud entropy optimization algorithm. The ecological environmental performance of China in 2019 was evaluated based on the proposed model, exampling as Jiangsu province. The results showed that the cloud digital eigenvalues of ecological environmental performance was (2.1852, 0.2956, 0.1), indicating that the ecological environmental performance was good level. However, the ambient air quality needed to be improved. To achieve carbon neutrality, suggestions including strengthening propagating, increasing investment, optimizing the industrial structure, and building a modern environmental governance system are proposed.
Asunto(s)
Carbono , Conservación de los Recursos Naturales , China , Política Ambiental , IndustriasRESUMEN
An efficient and easy sample pretreatment methodology was proposed for the detection of photoinitiator 4-methylbenzophenone from milk before high-performance liquid chromatography. Appropriate conditions for demulsification were studied. The parameters affecting cloud point extraction, such as concentration of Tween-20, electrolyte salt, equilibration temperature, and time, have been investigated. When the spiked level was 200-1000 µg/kg, the average addition standard recovery was 99.14-105.98% with the optimum cloud point extraction conditions (concentration of Tween-20, 138 g/L; mass of anhydrous sodium sulfate, 0.75 g; equilibration temperature, 65°C; equilibration time, 30 min). To decrease the detection limits, further work about the organic solvent, shaking time, and ultrasonic parameters was carried. When the spiked level was 10-100 µg/kg, the average addition standard recovery was 70.40-106.91% with the optimum cloud point extraction and enrichment conditions (optimum cloud point extraction conditions; volume of cyclohexane, 30 mL; shaking time, 20 min; time of ultrasonic, 20 min; temperature of ultrasonic bath, 45°C).
Asunto(s)
Benzofenonas/análisis , Leche/química , Animales , Fraccionamiento Químico , Cromatografía Líquida de Alta Presión , UltrasonidoRESUMEN
This study described a simple, specific, and sensitive method using immunoaffinity magnetic purification coupled with high-performance liquid chromatography-fluorescence (HPLC-FL) detection for determination of bovine lactoferrin (bLf) in dairy products. BLf was selectively extracted from dairy products using immunoaffinity beads and then detected by HPLC-FL with its intrinsic fluorescence. During the analysis, standard solutions of bLf were pretreated with Tween 20, an anti-adsorptive agent, for blocking the nonspecific binding of bLf to polypropylene tubes. The calibration curve was linear over the range of 0.8-30 µg mL-1. The validated method was successfully applied to measure bLf at the intact level in dairy products.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Productos Lácteos/análisis , Inmunoensayo/métodos , Lactoferrina/análisis , Lactoferrina/aislamiento & purificación , Magnetismo/métodos , Animales , Bovinos , Cromatografía Líquida de Alta Presión/instrumentación , FluorescenciaRESUMEN
Microcystins (MCs) is a kind of hepatotoxin, which is the secondary metabolite of cyanobacteria. Bi2O2CO3 (BOC) is a kind of cheap and nontoxic semiconductor material. BOC was synthetized by solvothermal method and then microcystin-LR (MC-LR) and microcystin-RR (MC-RR) were removed by BOC, through adsorption and photocatalytic degradation. When the dosage of BOC is 6 g/L, the MC-LR and MC-RR in the natural water sample can be completely adsorbed in 30 min and then after 12 h irradiation, MC-LR and MC-RR were photocatalytically degraded by BOC.