羧甲基木薯淀粉和羧甲基壳聚糖混合物不仅可有效改善淀粉物化性质,还可引入抑菌性能好的羧甲基壳聚糖。以木薯淀粉、壳聚糖为原料,氯乙酸钠为醚化剂,氢氧化钠为催化剂,采用机械活化固相醚法制备羧甲基木薯淀粉和羧甲基壳聚糖混合物。以...羧甲基木薯淀粉和羧甲基壳聚糖混合物不仅可有效改善淀粉物化性质,还可引入抑菌性能好的羧甲基壳聚糖。以木薯淀粉、壳聚糖为原料,氯乙酸钠为醚化剂,氢氧化钠为催化剂,采用机械活化固相醚法制备羧甲基木薯淀粉和羧甲基壳聚糖混合物。以黏度为评价指标,通过单因素和正交试验设计优化确定最佳制备工艺,采用红外光谱(Fourier transform infrared spectroscopy,FTIR)、X-射线衍射(X-ray diffraction,XRD)、扫描电镜(Scanning electron microscope,SEM)对羧甲基淀粉的结构进行表征,并考察混合物的取代度和溶解度。结果表明,机械活化破坏了淀粉、壳聚糖的结晶结构,降低结晶度,醚化试剂更容易渗透到内部使淀粉、壳聚糖发生羧甲基化反应。最佳工艺参数为:淀粉与壳聚糖质量比0.5:0.5、淀粉与氯乙酸钠的摩比1:0.9、氢氧化钠质量分数18.8%(占淀粉干基质量)、球磨温度50℃、球磨时间60 min、转速380 r/min、磨球体积500 m L。在该试验条件下制备得到的羧甲基木薯淀粉和羧甲基壳聚糖混合物的黏度为1025 m Pa·s,其中羧甲基木薯淀粉的取代度为0.79,羧甲基壳聚糖的总取代度为1.17,溶解度为90.87%,且随着壳聚糖比例增大,混合物溶解度不断减小。FTIR、XRD、SEM进一步证实木薯淀粉、壳聚糖均发生了羧甲基化反应。展开更多
以邻二氟苯、甲醇钠为原料,甲苯、四氢呋喃为溶剂,一步醚化法制备了2-氟苯甲醚,用1 H NMR表征了该化合物结构。考察了不同原料配比、反应温度和反应溶剂对目标产物收率的影响,在优化条件下,目标产物的收率为84.8%。该路线操作简单,收率...以邻二氟苯、甲醇钠为原料,甲苯、四氢呋喃为溶剂,一步醚化法制备了2-氟苯甲醚,用1 H NMR表征了该化合物结构。考察了不同原料配比、反应温度和反应溶剂对目标产物收率的影响,在优化条件下,目标产物的收率为84.8%。该路线操作简单,收率高,对环境友好,适合工业化生产。展开更多
Catalytic combustion of dimethyl ether （DME） over hexaaluminate catalyst BaNi0.2Mn0.8Al11O19-δ has been investigated. The catalysts were prepared with the sol-gel method and reverse microemulsion method respectivel...Catalytic combustion of dimethyl ether （DME） over hexaaluminate catalyst BaNi0.2Mn0.8Al11O19-δ has been investigated. The catalysts were prepared with the sol-gel method and reverse microemulsion method respectively and characterized by thermogravimetry-differential thermal analysis, X-ray diffraction and transimission electron microscope. It was found that the formation of Mn, Ni modified hexaaluminate was a relatively slow process via two solid state reactions and spinel structure was a transition phase. At the same calcined temperature and time, the catalyst prepared with the reverse microemulsion method could form the hexaaluminate phase more easily than that prepared with the sol-gel method. The catalyst BaNi0.2Mn0.8Al11O19-δ prepared with the reverse micro-emulsion method appeared a plate-like morphology, while it appeared a needle-like morphology when using the sol-gel method. The catalytic activities of catalysts BaNi0.2Mn0.8Al11O19-δ prepared with two different methods for DME combustion were tested. It showed that catalyst prepared with the reverse microemulsion method had better catalytic activity, i.e. T10% of DME had decreased by 45℃, about 90% conversion of diemthyl ether at 380℃.展开更多
Isoamylene from the Fischer-Tropsch syncrude can be transformed to valuable fuel oxygenate additives through an equilibrium limited etherification reaction with methanol. A reactive distillation process is established...Isoamylene from the Fischer-Tropsch syncrude can be transformed to valuable fuel oxygenate additives through an equilibrium limited etherification reaction with methanol. A reactive distillation process is established to increase isoamylene conversion. Facing the challenge of improving product purity at the same time, an equilibrium stage model based design methodology is proposed and illustrated step-by-step for converting the Fischer-Tropsch C_5 olefins to tert-amyl methyl ether(TAME) process by using Aspen Plus. Under the guide of the proposed methodology, the design leads to a TAME product purity of higher than 95% and an isoamylene conversion of higher than 90%. The etherification kinetics over Amberlyst 35 is also studied within a temperature range of 60 ℃ to 75 ℃ to shed more light on the feasibility of process development. The methodology provides an effective reactive distillation column design to achieve the target reactant conversion and product purity simultaneously.展开更多
The solubilization of small molecules from coal by solvent extraction and the resulting effects on the pore distribution of a low rank coal were studied. Samples were extracted, in succession, with petroleum ether and...The solubilization of small molecules from coal by solvent extraction and the resulting effects on the pore distribution of a low rank coal were studied. Samples were extracted, in succession, with petroleum ether and with CS2. Extract and residue fractions collected during the solubilization process were analyzed by FTIR and by surface area and porosimetry. The results show that an obvious inflection point exists that allows separating the dissolution sequence into stages. Small molecules are first extracted from the free state, then molecules trapped in micropores are extracted and, finally, molecules trapped in the coal-matrix network are extracted. This is indicated from the extraction yield curves. Chain-like carbonyl compounds, -OH (or -NH) containing compounds that are hydrogen bonded and phenolics dominate the petroleum ether extracts. Chain-like carbonyl components and ether compounds (aliphatic ethers and aromatic ethers) dominate the CS2 extracts. A solvent dissolution mechanism and the effect of small molecule extraction on the pore structure are put forward. Diffusion, dissolution, pore opening, pore shrinking or even collapsing caused by swelling, creating of new micropores, pore opening and, finally, colloidallization of some micropores occurs. In the later stages of the extraction the internal structure of the coal is colloidallized due to swelling and the pore number or volume is greatly reduced.展开更多
Objective： To investigate the effects ofpenehyclidine hydrochloride on apoptosis of lung tissue cells and its mechanism in acute lung injury following blunt chest trauma in rats. Methods： Sprague Dawley （SD） r...Objective： To investigate the effects ofpenehyclidine hydrochloride on apoptosis of lung tissue cells and its mechanism in acute lung injury following blunt chest trauma in rats. Methods： Sprague Dawley （SD） rats （n=54） weighing （250-25） g were divided equally and randomly into three groups： normal control group （C group, n= 18）, trauma model group （T group, n= 18） and penehyclidine hydrochloride treatment group （P group, n=18）. Each group was further divided into three subgroups according to the time points of 3, 12 and 24 hours after experiment （at each time point, n=6 for each subgroup）. Rats of P group were intraperitoneally injected with penehyclidine hydrochloride for 2 mg/kg immediately after blunt chest trauma and rats in its 24 hours subgroup were once again injected with penehyclidine hy- drochloride in the same dose 12 hours after injury. Lung tissue samples were collected at every time point and cell apoptosis in lung tissues were measured by TUNEL. Apoptotic index （AI） was calculated, expressions of bax and bcl-2 were detected by immunohistochemical staining of SABC, and lung tissue sections were taken for light and electron microscopic observation. Results： As compared with C group, at every time point, AI and expressions ofbax and bcl-2 in T group were higher （P〈0.05）, and the ratio of bcl-2/bax markedly decreased （P〈0.05）, especially in the 24 hours subgroup. The ratio in T group （0.468±0.007） was lower than that in C group （1.382±0.058, t=12.5, P〈0.01）. Lung tissue injuries were significant under a light microscope, and the number of apoptotic cells increased obviously under a transmission electron microscope. As compared with T group at the same phase, AI and expression of bax decreased in P group （P〈0.05 and P〈0.01）, while the expression of bcl-2 increased significantly （P〈0.01）, and the ratio of bcl-2/bax markedly increased （P〈0.05）, especially in the 24 hours subgroup. The ratio in P group （1.012-0.070） was much higher than that in T group （0.468±0.007, t=-8.3, P〈0.01）. The injury of lung tissues was relieved, and apoptosis of cells decreased obviously under a transmission electron microscopic observation. Conclusions： Apoptosis and expressions ofbax and bcl-2 in lung tissues might be involved in the pathogenesis of lung injury induced by blunt chest trauma. Penehyclidine hydrochloride can alleviate lung injuries by inhibiting apoptosis of lung tissue cells, during which effects ofpenehyclidine hydrochloride on regulating expressions ofbax and bcl-2 may play an important role.展开更多
文摘羧甲基木薯淀粉和羧甲基壳聚糖混合物不仅可有效改善淀粉物化性质,还可引入抑菌性能好的羧甲基壳聚糖。以木薯淀粉、壳聚糖为原料,氯乙酸钠为醚化剂,氢氧化钠为催化剂,采用机械活化固相醚法制备羧甲基木薯淀粉和羧甲基壳聚糖混合物。以黏度为评价指标,通过单因素和正交试验设计优化确定最佳制备工艺,采用红外光谱(Fourier transform infrared spectroscopy,FTIR)、X-射线衍射(X-ray diffraction,XRD)、扫描电镜(Scanning electron microscope,SEM)对羧甲基淀粉的结构进行表征,并考察混合物的取代度和溶解度。结果表明,机械活化破坏了淀粉、壳聚糖的结晶结构,降低结晶度,醚化试剂更容易渗透到内部使淀粉、壳聚糖发生羧甲基化反应。最佳工艺参数为:淀粉与壳聚糖质量比0.5:0.5、淀粉与氯乙酸钠的摩比1:0.9、氢氧化钠质量分数18.8%(占淀粉干基质量)、球磨温度50℃、球磨时间60 min、转速380 r/min、磨球体积500 m L。在该试验条件下制备得到的羧甲基木薯淀粉和羧甲基壳聚糖混合物的黏度为1025 m Pa·s,其中羧甲基木薯淀粉的取代度为0.79,羧甲基壳聚糖的总取代度为1.17,溶解度为90.87%,且随着壳聚糖比例增大,混合物溶解度不断减小。FTIR、XRD、SEM进一步证实木薯淀粉、壳聚糖均发生了羧甲基化反应。
基金Supported by the Project of Science and Technology of Guangdong Province （2004B33401003, 2005B10201053）, the Natural Science Foundation of Guangdong Province （04205301, 06021468）, and the Special Functional Material Foundation of Shenzhen University （0602）.
文摘Catalytic combustion of dimethyl ether （DME） over hexaaluminate catalyst BaNi0.2Mn0.8Al11O19-δ has been investigated. The catalysts were prepared with the sol-gel method and reverse microemulsion method respectively and characterized by thermogravimetry-differential thermal analysis, X-ray diffraction and transimission electron microscope. It was found that the formation of Mn, Ni modified hexaaluminate was a relatively slow process via two solid state reactions and spinel structure was a transition phase. At the same calcined temperature and time, the catalyst prepared with the reverse microemulsion method could form the hexaaluminate phase more easily than that prepared with the sol-gel method. The catalyst BaNi0.2Mn0.8Al11O19-δ prepared with the reverse micro-emulsion method appeared a plate-like morphology, while it appeared a needle-like morphology when using the sol-gel method. The catalytic activities of catalysts BaNi0.2Mn0.8Al11O19-δ prepared with two different methods for DME combustion were tested. It showed that catalyst prepared with the reverse microemulsion method had better catalytic activity, i.e. T10% of DME had decreased by 45℃, about 90% conversion of diemthyl ether at 380℃.
基金financial support from the National High Technology Research and Development Program 863(2011AA05A204)National Natural Science Foundation of China(U1361202)
文摘Isoamylene from the Fischer-Tropsch syncrude can be transformed to valuable fuel oxygenate additives through an equilibrium limited etherification reaction with methanol. A reactive distillation process is established to increase isoamylene conversion. Facing the challenge of improving product purity at the same time, an equilibrium stage model based design methodology is proposed and illustrated step-by-step for converting the Fischer-Tropsch C_5 olefins to tert-amyl methyl ether(TAME) process by using Aspen Plus. Under the guide of the proposed methodology, the design leads to a TAME product purity of higher than 95% and an isoamylene conversion of higher than 90%. The etherification kinetics over Amberlyst 35 is also studied within a temperature range of 60 ℃ to 75 ℃ to shed more light on the feasibility of process development. The methodology provides an effective reactive distillation column design to achieve the target reactant conversion and product purity simultaneously.
基金Projects 50474066 and 50874108 supported by the National Natural Science Foundation of China107055 by the Scientific Research Key Project of Ministry of Education+1 种基金BK20070380 by the Natural Science Foundation of Jiangsu ProvinceCPEUKF06-03 and CPEUKF08-06 by the Open Fund of Key Laboratory of Coal Process and Clean Utilization of Ministry of Education,China
文摘The solubilization of small molecules from coal by solvent extraction and the resulting effects on the pore distribution of a low rank coal were studied. Samples were extracted, in succession, with petroleum ether and with CS2. Extract and residue fractions collected during the solubilization process were analyzed by FTIR and by surface area and porosimetry. The results show that an obvious inflection point exists that allows separating the dissolution sequence into stages. Small molecules are first extracted from the free state, then molecules trapped in micropores are extracted and, finally, molecules trapped in the coal-matrix network are extracted. This is indicated from the extraction yield curves. Chain-like carbonyl compounds, -OH (or -NH) containing compounds that are hydrogen bonded and phenolics dominate the petroleum ether extracts. Chain-like carbonyl components and ether compounds (aliphatic ethers and aromatic ethers) dominate the CS2 extracts. A solvent dissolution mechanism and the effect of small molecule extraction on the pore structure are put forward. Diffusion, dissolution, pore opening, pore shrinking or even collapsing caused by swelling, creating of new micropores, pore opening and, finally, colloidallization of some micropores occurs. In the later stages of the extraction the internal structure of the coal is colloidallized due to swelling and the pore number or volume is greatly reduced.
文摘Objective： To investigate the effects ofpenehyclidine hydrochloride on apoptosis of lung tissue cells and its mechanism in acute lung injury following blunt chest trauma in rats. Methods： Sprague Dawley （SD） rats （n=54） weighing （250-25） g were divided equally and randomly into three groups： normal control group （C group, n= 18）, trauma model group （T group, n= 18） and penehyclidine hydrochloride treatment group （P group, n=18）. Each group was further divided into three subgroups according to the time points of 3, 12 and 24 hours after experiment （at each time point, n=6 for each subgroup）. Rats of P group were intraperitoneally injected with penehyclidine hydrochloride for 2 mg/kg immediately after blunt chest trauma and rats in its 24 hours subgroup were once again injected with penehyclidine hy- drochloride in the same dose 12 hours after injury. Lung tissue samples were collected at every time point and cell apoptosis in lung tissues were measured by TUNEL. Apoptotic index （AI） was calculated, expressions of bax and bcl-2 were detected by immunohistochemical staining of SABC, and lung tissue sections were taken for light and electron microscopic observation. Results： As compared with C group, at every time point, AI and expressions ofbax and bcl-2 in T group were higher （P〈0.05）, and the ratio of bcl-2/bax markedly decreased （P〈0.05）, especially in the 24 hours subgroup. The ratio in T group （0.468±0.007） was lower than that in C group （1.382±0.058, t=12.5, P〈0.01）. Lung tissue injuries were significant under a light microscope, and the number of apoptotic cells increased obviously under a transmission electron microscope. As compared with T group at the same phase, AI and expression of bax decreased in P group （P〈0.05 and P〈0.01）, while the expression of bcl-2 increased significantly （P〈0.01）, and the ratio of bcl-2/bax markedly increased （P〈0.05）, especially in the 24 hours subgroup. The ratio in P group （1.012-0.070） was much higher than that in T group （0.468±0.007, t=-8.3, P〈0.01）. The injury of lung tissues was relieved, and apoptosis of cells decreased obviously under a transmission electron microscopic observation. Conclusions： Apoptosis and expressions ofbax and bcl-2 in lung tissues might be involved in the pathogenesis of lung injury induced by blunt chest trauma. Penehyclidine hydrochloride can alleviate lung injuries by inhibiting apoptosis of lung tissue cells, during which effects ofpenehyclidine hydrochloride on regulating expressions ofbax and bcl-2 may play an important role.
