Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigate...Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigated to improve the selective conversion of siderite to magnetite and CO,enriching the theoretical system of green SMR using siderite as a reductant.According to the gas products analyses,the peak value of the reaction rate increased with increasing temperature,and its curves presented the feature of an early peak and long tail.The mechanism function of the siderite pyrolysis was the contraction sphere model(R_(3)):f(α)=3(1−α)2/3;E_(α)was 46.4653 kJ/mol;A was 0.5938 s^(−1);the kinetics equation was k=0.5938exp[−46.4653/(RT)].The in-situ HT-XRD results indicated that siderite was converted into magnetite and wüstite that exhibited a good crystallinity in SMR under a N_(2) atmosphere.At 620℃,the saturation magnetization(M_(s)),remanence magnetization(Mr),and coercivity(Hc)of the product peaked at 53.63×10^(-3)A·m^(2)/g,10.23×10^(-3)A·m^(2)/g,and 12.40×10^(3)A/m,respectively.Meanwhile,the initial particles with a smooth surface were transformed into particles with a porous and loose structure in the roasting process,which would contribute to reducing the grinding cost.展开更多
Using novolac phenolic resin, aniline and formaldehyde as raw materials, benzoxazine-phenolic copolymers with different percentages of benzoxazine rings were prepared. FT-IR was adopted to characterize the molecular s...Using novolac phenolic resin, aniline and formaldehyde as raw materials, benzoxazine-phenolic copolymers with different percentages of benzoxazine rings were prepared. FT-IR was adopted to characterize the molecular structure of the novolac-type phenolic resin and the benzoxazine-phenolic copolymer BP31. In order to understand the curing process of the copolymers, the curing behavior and curing kinetic characteristics were studied by differential scanning calorimetry （DSC）, and the catalytical effect of phenolic hydroxyl on the curing behavior of copolymers was investigated. To investigate the thermal properties of this resin, the thermal degradation behaviors of the cured samples were studied by thermal gravimetric （TG） method, and glass-transition temperatures （Tg） of the cured copolymers were also evaluated by DSC. The dynamic Ozawa method was adopted to determine the kinetic parameters of the curing process as well. The activation energy is 78.8 kJ/mol and the reaction rate constant is in the range from 40.0 to 5.2 （K/min）＂ according to reaction temperatures. The Ozawa exponent decreases from 2.4 to 0.7 with the increase of reaction temperature, and curing mechanism is expounded briefly according to the results. TG result shows that the highest char yield of copolymers is 50.3%. The highest Tg of copolymers is 489 K, which is much higher than that of pure benzoxazine resin.展开更多
Currently, multiple lines of cytotoxic chemotherapy for treatment of metastatic breast cancer are available, and Taxanes, used as monotherapy or in combination with anti-angiogenic drugs, such as Bevacizumab, are one ...Currently, multiple lines of cytotoxic chemotherapy for treatment of metastatic breast cancer are available, and Taxanes, used as monotherapy or in combination with anti-angiogenic drugs, such as Bevacizumab, are one of the most used schemes in clinical practice. These drugs have different side effects and the liver is one of the most affected organs. The objective of this paper is to report three cases of metastatic breast cancer with positive expression of hormone receptors and without amplification of HER-2 protein that were treated with Taxane and Bevacizumab, developed pseudocirrosis probably caused by these drugs and died due to liver failure. It can be drawn from the study that liver failure, as a pseudocirrhosis evolution, is an unusual but lethal event that may occur during the treatment of metastatic breast cancer with Taxanes and Bevacizumab. This warns the importance of diagnostic suspicion of this pathology.展开更多
基金Projects(51874071,52022019,51734005)supported by the National Natural Science Foundation of ChinaProject(161045)supported by the Fok Ying Tung Education Foundation for Yong Teachers in the Higher Education Institutions of China。
文摘Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigated to improve the selective conversion of siderite to magnetite and CO,enriching the theoretical system of green SMR using siderite as a reductant.According to the gas products analyses,the peak value of the reaction rate increased with increasing temperature,and its curves presented the feature of an early peak and long tail.The mechanism function of the siderite pyrolysis was the contraction sphere model(R_(3)):f(α)=3(1−α)2/3;E_(α)was 46.4653 kJ/mol;A was 0.5938 s^(−1);the kinetics equation was k=0.5938exp[−46.4653/(RT)].The in-situ HT-XRD results indicated that siderite was converted into magnetite and wüstite that exhibited a good crystallinity in SMR under a N_(2) atmosphere.At 620℃,the saturation magnetization(M_(s)),remanence magnetization(Mr),and coercivity(Hc)of the product peaked at 53.63×10^(-3)A·m^(2)/g,10.23×10^(-3)A·m^(2)/g,and 12.40×10^(3)A/m,respectively.Meanwhile,the initial particles with a smooth surface were transformed into particles with a porous and loose structure in the roasting process,which would contribute to reducing the grinding cost.
基金Project (20050106) supported by the Key Science and Technology Item of Guangdong Province,China
文摘Using novolac phenolic resin, aniline and formaldehyde as raw materials, benzoxazine-phenolic copolymers with different percentages of benzoxazine rings were prepared. FT-IR was adopted to characterize the molecular structure of the novolac-type phenolic resin and the benzoxazine-phenolic copolymer BP31. In order to understand the curing process of the copolymers, the curing behavior and curing kinetic characteristics were studied by differential scanning calorimetry （DSC）, and the catalytical effect of phenolic hydroxyl on the curing behavior of copolymers was investigated. To investigate the thermal properties of this resin, the thermal degradation behaviors of the cured samples were studied by thermal gravimetric （TG） method, and glass-transition temperatures （Tg） of the cured copolymers were also evaluated by DSC. The dynamic Ozawa method was adopted to determine the kinetic parameters of the curing process as well. The activation energy is 78.8 kJ/mol and the reaction rate constant is in the range from 40.0 to 5.2 （K/min）＂ according to reaction temperatures. The Ozawa exponent decreases from 2.4 to 0.7 with the increase of reaction temperature, and curing mechanism is expounded briefly according to the results. TG result shows that the highest char yield of copolymers is 50.3%. The highest Tg of copolymers is 489 K, which is much higher than that of pure benzoxazine resin.
文摘Currently, multiple lines of cytotoxic chemotherapy for treatment of metastatic breast cancer are available, and Taxanes, used as monotherapy or in combination with anti-angiogenic drugs, such as Bevacizumab, are one of the most used schemes in clinical practice. These drugs have different side effects and the liver is one of the most affected organs. The objective of this paper is to report three cases of metastatic breast cancer with positive expression of hormone receptors and without amplification of HER-2 protein that were treated with Taxane and Bevacizumab, developed pseudocirrosis probably caused by these drugs and died due to liver failure. It can be drawn from the study that liver failure, as a pseudocirrhosis evolution, is an unusual but lethal event that may occur during the treatment of metastatic breast cancer with Taxanes and Bevacizumab. This warns the importance of diagnostic suspicion of this pathology.
