Biogenic platinum-based bimetallic nanoparticles: Synthesis,characterization, antimicrobial activity and hydrogen evolution

In this study, platinum-based silver nanoparticles (Pt@Ag NPs) were synthesized by the green synthesis method, and their catalytic effects on hydrogen production were investigated. The characterization measurements of the synthesized NPs were performed by TEM, UV–Vis, XRD, and FTIR. According to TEM characterization results, Pt@Ag NPs had an average size of 5.431 nm. In experiments based on catalytic reactions for hydrogen production, test measurements were made at different parameters. It was observed that as the concentrations of the substrate and catalysts increased, the catalytic reaction accelerated, and the hydrogen release increased. Likewise, it was determined that hydrogen production increased with increasing temperature in different temperature experiments. The turnover frequency, entropy, activation energy, and enthalpy values are calculated as 702.38 h⁻¹, -160.5 J/mol.K, 32.48 kJ/mol, and 29.94 kJ/mol, respectively. According to the reusability test results, it was observed that the average reusability was found to be 85% after 5 cycles and it was confirmed that the NPs showed high-catalytic activity. In addition, the biological activities of Pt@Ag NPs, including antimicrobial, antioxidant and anticancer were tested. Pt@Ag NPs synthesized using Hibiscus sabdariffa (Hs) extract are thought to have the potential to be used in both biomedical and catalytic applications. The use of Pt@Ag NPs in the hydrogen production process shows great promise for green energy studies because it is environmentally friendly, non-toxic, and low cost.     

高精度钾热管铝凝固点炉研制及性能测试

热管作为等温炉衬可提高固定点炉温场均匀性。为提高铝凝固点复现水平,研制了1套高精度钾热管铝凝固点炉。介绍了钾热管和固定点炉的研制流程,并测试了钾热管固定点炉性能。测试结果表明:采用分段升温的方式,炉子升温曲线平缓,整个升温过程中没有明显过冲现象,可有效保护铝凝固点容器的使用寿命;钾热管铝凝固点炉垂直温场均匀性为6.6mK;利用该钾热管铝凝定点炉可以实现铝凝固点温坪的复现,温坪重复性为0.02mK。     

分散固相萃取-超低温液液微萃取-气相色谱质谱法测定烟熏及烧烤肉制品中16种欧盟优控多环芳烃

建立了分散固相萃取-超低温液液微萃取-气相色谱质谱法测定烟熏及烧烤肉制品中16种欧盟优控多环芳烃的分析方法.样品用乙腈提取、上清液经分散固相萃取净化后在-80℃条件下采用甲苯液液微萃取浓缩,选用DB-EUPAH色谱柱(20 m×0.18 mm×0.14μm)分离,最后经质谱检测定量.结果表明,16种欧盟多环芳烃在5～5...