The vacuum volatilization kinetics of Pb in In-Pb solder was investigated.The results indicate a significant increase in the vacuum volatilization rates of Pb,25In-75Pb,40In-60Pb,and In with increasing temperatures fr...The vacuum volatilization kinetics of Pb in In-Pb solder was investigated.The results indicate a significant increase in the vacuum volatilization rates of Pb,25In-75Pb,40In-60Pb,and In with increasing temperatures from 923 to 1123 K,system pressure of 3 Pa and holding time of 30 min.The mass transfer coefficients and apparent activation energies of Pb and its alloys were determined at various temperatures.Additionally,a kinetics model was developed to describe Pb vacuum volatilization in high-temperature melts.It is obtained that the vapor mass transfer is the factor limiting the vacuum volatilization rates of Pb and In-Pb alloys under the above specified conditions.展开更多
The substitution of traditional blast furnaces with steel-belt furnaces for antimony smelting was proposed.The influence of various parameters on the oxidative volatilization of stibnite was studied according to the p...The substitution of traditional blast furnaces with steel-belt furnaces for antimony smelting was proposed.The influence of various parameters on the oxidative volatilization of stibnite was studied according to the production practice of steel-belt furnaces.Furthermore,the kinetics of oxidative volatilization was elucidated using differential thermal gravimetric analyses and non-isothermal analysis methods.The results indicated that the oxygen concentration and the temperature were pivotal variables in the oxidative volatilization process.Notably,the volatilization efficiency of antimony was 97.25%under optimal conditions.Moreover,the kinetic control stages were divided into chemical reaction control(440-490°C),internal diffusion control(500-550°C),and chemical reaction control(560-580°C).These stages corresponded to activation energies of 16.40-18.79,120.86-195.96,and 24.00-28.31 kJ/mol,respectively.展开更多
为探究套袋对‘红花鹰嘴桃’果实品质的影响,采用气相色谱-串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)技术分析套袋组与未套袋组桃果实的代谢物。结果表明,在‘红花鹰嘴桃’果实中共鉴定出634种代谢物,包括糖类1...为探究套袋对‘红花鹰嘴桃’果实品质的影响,采用气相色谱-串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)技术分析套袋组与未套袋组桃果实的代谢物。结果表明,在‘红花鹰嘴桃’果实中共鉴定出634种代谢物,包括糖类11种、游离脂肪酸33种、挥发性物质590种。其中显著差异代谢物107个,包括上调物质59个,下调物质48个。与未套袋组相比,套袋组果实外观品质提升,山梨醇和油酸含量显著降低(P<0.05),挥发性物质种类更丰富,果实青香味减弱而花果甜香味增强。但套袋组果实的甜度值以及糖类物质、游离脂肪酸和挥发性物质总含量与未套袋组相比均无显著差异(P>0.05)。本研究可为桃果实套袋品质提升提供重要的理论依据。展开更多
为鉴定线香中主要挥发性成分,进一步揭示这些成分在不同样品间的差异及其对香气特征的贡献,采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid-phase microextraction gas chromatography-mass spectrometry,HS-SPME-GC-MS)结...为鉴定线香中主要挥发性成分,进一步揭示这些成分在不同样品间的差异及其对香气特征的贡献,采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid-phase microextraction gas chromatography-mass spectrometry,HS-SPME-GC-MS)结合多元统计分析方法对粘粉燃烧产物、金银花粉、金银花粉燃烧产物、线香燃烧产物中挥发性成分进行提取鉴定,并确定关键挥发性成分。结果表明,从4种样品中共鉴定出102种挥发性成分,以芳香族、杂环类、酮类化合物等成分为主。主成分分析、正交偏最小二乘法判别分析及聚类热图分析表明,金银花粉燃烧产物和线香燃烧产物挥发性成分组成相似,与粘粉燃烧产物及金银花粉挥发性成分存在较大差异,并筛选出25种投影变量的重要性(variable important for the projection,VIP)>1的关键挥发性成分。研究结果为金银花线香的进一步开发提供理论依据,也为中药材的应用拓展了新方向。展开更多
基金financially supported by the Fundamental Research Project of Yunnan Province,China(Nos.202301AW070020,202201AT070229,202105AC160091,202202AB080018).
文摘The vacuum volatilization kinetics of Pb in In-Pb solder was investigated.The results indicate a significant increase in the vacuum volatilization rates of Pb,25In-75Pb,40In-60Pb,and In with increasing temperatures from 923 to 1123 K,system pressure of 3 Pa and holding time of 30 min.The mass transfer coefficients and apparent activation energies of Pb and its alloys were determined at various temperatures.Additionally,a kinetics model was developed to describe Pb vacuum volatilization in high-temperature melts.It is obtained that the vapor mass transfer is the factor limiting the vacuum volatilization rates of Pb and In-Pb alloys under the above specified conditions.
基金supported financially by the National Natural Science Foundation of China(No.52074362)。
文摘The substitution of traditional blast furnaces with steel-belt furnaces for antimony smelting was proposed.The influence of various parameters on the oxidative volatilization of stibnite was studied according to the production practice of steel-belt furnaces.Furthermore,the kinetics of oxidative volatilization was elucidated using differential thermal gravimetric analyses and non-isothermal analysis methods.The results indicated that the oxygen concentration and the temperature were pivotal variables in the oxidative volatilization process.Notably,the volatilization efficiency of antimony was 97.25%under optimal conditions.Moreover,the kinetic control stages were divided into chemical reaction control(440-490°C),internal diffusion control(500-550°C),and chemical reaction control(560-580°C).These stages corresponded to activation energies of 16.40-18.79,120.86-195.96,and 24.00-28.31 kJ/mol,respectively.
文摘为探究套袋对‘红花鹰嘴桃’果实品质的影响,采用气相色谱-串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)技术分析套袋组与未套袋组桃果实的代谢物。结果表明,在‘红花鹰嘴桃’果实中共鉴定出634种代谢物,包括糖类11种、游离脂肪酸33种、挥发性物质590种。其中显著差异代谢物107个,包括上调物质59个,下调物质48个。与未套袋组相比,套袋组果实外观品质提升,山梨醇和油酸含量显著降低(P<0.05),挥发性物质种类更丰富,果实青香味减弱而花果甜香味增强。但套袋组果实的甜度值以及糖类物质、游离脂肪酸和挥发性物质总含量与未套袋组相比均无显著差异(P>0.05)。本研究可为桃果实套袋品质提升提供重要的理论依据。
文摘为鉴定线香中主要挥发性成分,进一步揭示这些成分在不同样品间的差异及其对香气特征的贡献,采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid-phase microextraction gas chromatography-mass spectrometry,HS-SPME-GC-MS)结合多元统计分析方法对粘粉燃烧产物、金银花粉、金银花粉燃烧产物、线香燃烧产物中挥发性成分进行提取鉴定,并确定关键挥发性成分。结果表明,从4种样品中共鉴定出102种挥发性成分,以芳香族、杂环类、酮类化合物等成分为主。主成分分析、正交偏最小二乘法判别分析及聚类热图分析表明,金银花粉燃烧产物和线香燃烧产物挥发性成分组成相似,与粘粉燃烧产物及金银花粉挥发性成分存在较大差异,并筛选出25种投影变量的重要性(variable important for the projection,VIP)>1的关键挥发性成分。研究结果为金银花线香的进一步开发提供理论依据,也为中药材的应用拓展了新方向。
