The oxidation of 3-picoline to nicotinic acid took place efficiently in an ethanol solution with 02 as the oxidant under the catalysis of T（o-Cl）PPMn at 40--150 ℃ and 0.5--3.0 MPa oxygen pressure. The influences of...The oxidation of 3-picoline to nicotinic acid took place efficiently in an ethanol solution with 02 as the oxidant under the catalysis of T（o-Cl）PPMn at 40--150 ℃ and 0.5--3.0 MPa oxygen pressure. The influences of temperature, oxygen pressure, reaction time, concentration of 3-picoline, concentration of sodium hydroxide, and concentration of T（o-Cl）PPMn catalyst, etc. on the production of nicotinic acid were investigated. The results show that T（o-Cl）PPMn presented excellent catalytic activity in the oxidation Of 3-pieoiine to nicotinic acid and the yield of nicotinic acid varied greatly with the reaction temperature, oxygen pressure, T（o-Cl）PPMn concentration, etc.展开更多
In an electrolytic cell with a proton exchange membrane, nicotinic acid was synthesized at the PbO2 anode. The relationship between the current density and the potential at different concentrations of 3-picoline and s...In an electrolytic cell with a proton exchange membrane, nicotinic acid was synthesized at the PbO2 anode. The relationship between the current density and the potential at different concentrations of 3-picoline and sulfuric acid as well as at different temperatures was studied with polarization curves. The effects of the concentrations of sulfuric acid and 3-picoline, the anode potential and the reaction temperature on the selectivity and the current efficiency were explored. The optimum conditions were determined by orthogonal experiments. Under optimum conditions the selectivity and the current efficiency for the synthesis of nicotinic acid might reach 89% and 65%, respectively. The, concentrations of 3-picoline and nicotinic acid were analyzed with high performance liquid chromatography and the product was characterized with elemental analysis, chromatography-mass spectrometry and IR spectrometry.展开更多
V-Mo-P oxide catalyst system was directly prepared from ll-molybdo-l-vanado phosphoric acid by thermal decomposition. Supported V-Mo-P oxide catalysts were prepared by wet impregnation method. Catalysts were character...V-Mo-P oxide catalyst system was directly prepared from ll-molybdo-l-vanado phosphoric acid by thermal decomposition. Supported V-Mo-P oxide catalysts were prepared by wet impregnation method. Catalysts were characterized by FTIR （Fourier transform infrared）, XRD （X-ray diffraction） and TPD （temperature programmed desorption）. The catalytic activity of V-Mo-P oxide catalysts were investigated for vapour phase ammoxidation of 3-picoline. The unsupported catalyst showed 92.1% yield where as V-Mo-P oxide/HZSM-5 showed the highest yield （80.4%） amongst the supported catalysts.展开更多
背景:3D打印技术可根据患者实际病情和治疗需求设计构建模型、手术导板和个性化植入体或固定物,在创伤性骨折修复中展示了巨大的应用前景。目的:综述3D打印技术在创伤性骨折中的应用。方法:检索Web of science、PubMed和中国知网数据库2...背景:3D打印技术可根据患者实际病情和治疗需求设计构建模型、手术导板和个性化植入体或固定物,在创伤性骨折修复中展示了巨大的应用前景。目的:综述3D打印技术在创伤性骨折中的应用。方法:检索Web of science、PubMed和中国知网数据库2020-2024年发表的创伤骨科领域3D打印技术应用的相关文献,英文检索词为“traumatic fracture,3D printing technology,digital model,surgical guide”,中文检索词为“创伤性骨折,3D打印技术,数字模型,手术导板”,经筛选和分析,最终纳入60篇文献进行分析。结果与结论:①创伤性骨折是各种致伤因素导致的骨骼连续性中断和完整性破坏的骨折现象,以可靠方案提高复位愈合效果,已成为骨外科相关研究领域亟需解决的热点问题;②3D打印技术是以数字模型数据为基础的,运用粉末状金属或聚合物等可黏合成型材料以立体光刻、沉积建模和光聚合物喷射等形式制造满足需求三维实体的技术,在数字骨科生物医学领域应用广泛;③3D打印技术在疾病诊断、术前规划、重建骨折三维模型、定制骨科植入体、定制固定支具及假肢、手术导板制作和骨缺损修复等方面发挥了显著的优势,可根据患者实际病情和治疗需求设计构建模型、手术导板和个性化植入体或固定物,为创伤性骨折的治疗提供了新的思路。展开更多
基金Supported by the National Natural Science Foundation of China(No.20576005)
文摘The oxidation of 3-picoline to nicotinic acid took place efficiently in an ethanol solution with 02 as the oxidant under the catalysis of T（o-Cl）PPMn at 40--150 ℃ and 0.5--3.0 MPa oxygen pressure. The influences of temperature, oxygen pressure, reaction time, concentration of 3-picoline, concentration of sodium hydroxide, and concentration of T（o-Cl）PPMn catalyst, etc. on the production of nicotinic acid were investigated. The results show that T（o-Cl）PPMn presented excellent catalytic activity in the oxidation Of 3-pieoiine to nicotinic acid and the yield of nicotinic acid varied greatly with the reaction temperature, oxygen pressure, T（o-Cl）PPMn concentration, etc.
文摘In an electrolytic cell with a proton exchange membrane, nicotinic acid was synthesized at the PbO2 anode. The relationship between the current density and the potential at different concentrations of 3-picoline and sulfuric acid as well as at different temperatures was studied with polarization curves. The effects of the concentrations of sulfuric acid and 3-picoline, the anode potential and the reaction temperature on the selectivity and the current efficiency were explored. The optimum conditions were determined by orthogonal experiments. Under optimum conditions the selectivity and the current efficiency for the synthesis of nicotinic acid might reach 89% and 65%, respectively. The, concentrations of 3-picoline and nicotinic acid were analyzed with high performance liquid chromatography and the product was characterized with elemental analysis, chromatography-mass spectrometry and IR spectrometry.
文摘V-Mo-P oxide catalyst system was directly prepared from ll-molybdo-l-vanado phosphoric acid by thermal decomposition. Supported V-Mo-P oxide catalysts were prepared by wet impregnation method. Catalysts were characterized by FTIR （Fourier transform infrared）, XRD （X-ray diffraction） and TPD （temperature programmed desorption）. The catalytic activity of V-Mo-P oxide catalysts were investigated for vapour phase ammoxidation of 3-picoline. The unsupported catalyst showed 92.1% yield where as V-Mo-P oxide/HZSM-5 showed the highest yield （80.4%） amongst the supported catalysts.
