Pt3Co alloy nanoparticles were prepared by the reduction of H2PtCl6 and Co(OOCCH3)2 using NaBH4 as a reducing agent. The Pt3Co core-Pt shell nanoparticles (Pt3Co@Pt) were synthesized using hydrogen absorption reductio...Pt3Co alloy nanoparticles were prepared by the reduction of H2PtCl6 and Co(OOCCH3)2 using NaBH4 as a reducing agent. The Pt3Co core-Pt shell nanoparticles (Pt3Co@Pt) were synthesized using hydrogen absorption reduction and characterized by plasma-atomic emission spectrometry (ICP), transmission electron microscopy (TEM), X-ray diffraction (XRD) and SQUID magnetometer. The results show that average size of Pt3Co@Pt nanoparticles is 3.6 nm with a standard deviation of 0.9 nm. Heating Pt3Co nanoparticles in air at 700 ℃ for 1 h, Co in Pt3Co nanoparticles was oxidized to Co3O4 and CoO; while no oxidation tendency was detected for Pt3Co@Pt nanoparticles. The crystallize structure of Pt3Co@Pt changed from the face centered cube (fcc) to the face centered tetragonal (fct) after the heating treatment. The coercivity of the heated Pt3Co@Pt reached to 276 Oe at room temperature.展开更多
文摘以人参愈伤组织为试材,采用单因子试验和L16(45)正交试验,对2,3,5-氯化三苯基四氮唑(2,3,5-Triphenyltetrazolium Chloride,TTC)-脱氢酶还原法测定人参细胞活力的条件进行优化。选取TTC浓度、p H值、反应温度、反应时间作为试验中的4个因子,以吸光光度值和酶活力值为考察指标,探讨TTC-脱氢酶还原法测定人参细胞活力的最佳条件。结果表明,反应温度对人参细胞活力影响达到极显著水平(P<0.01),反应时间对人参细胞活力影响达到显著水平(P<0.1),得出人参细胞活力测定的最佳条件为TTC溶液浓度0.4%、p H 7.5、反应温度25℃、反应时间18h。
文摘Pt3Co alloy nanoparticles were prepared by the reduction of H2PtCl6 and Co(OOCCH3)2 using NaBH4 as a reducing agent. The Pt3Co core-Pt shell nanoparticles (Pt3Co@Pt) were synthesized using hydrogen absorption reduction and characterized by plasma-atomic emission spectrometry (ICP), transmission electron microscopy (TEM), X-ray diffraction (XRD) and SQUID magnetometer. The results show that average size of Pt3Co@Pt nanoparticles is 3.6 nm with a standard deviation of 0.9 nm. Heating Pt3Co nanoparticles in air at 700 ℃ for 1 h, Co in Pt3Co nanoparticles was oxidized to Co3O4 and CoO; while no oxidation tendency was detected for Pt3Co@Pt nanoparticles. The crystallize structure of Pt3Co@Pt changed from the face centered cube (fcc) to the face centered tetragonal (fct) after the heating treatment. The coercivity of the heated Pt3Co@Pt reached to 276 Oe at room temperature.
