in absence of light, the reaction kinetics of Mn(II) and Fe(III)-atalyzed oxidation ofS(IV) in unbuffered and buffered solutions were studied. An activation energy of 77.4kJ . mol￣(-1) forthe Mn(II)catalyzed oxidatio...in absence of light, the reaction kinetics of Mn(II) and Fe(III)-atalyzed oxidation ofS(IV) in unbuffered and buffered solutions were studied. An activation energy of 77.4kJ . mol￣(-1) forthe Mn(II)catalyzed oxidation of S(IV) is obtained. On the basis of the investigation of thecatalytic effects of Mn(II) and Fe(III) on the oxidation of S(IV), it has been elucidated that thecatalytic activity of Mn(II) is greater than that of Fet(III), and that Mn(II) and Fe(III) do not havea significant synergic effect on the catalytic oxidation of S (IV). The catalytic oxidation andautooxidation of S(IV) in unbuffered solution was also explored in the presence of light. The resultsshow that the reaction is first order with respect to S(IV) concentrations, the reaction rate increaseswith increasing light intensity and the concentrations of Fe(III) and Mn(II), and that the photoas-sisted catalytic activity of Fe(III) is greater than that of Mn(II).展开更多
Zeolites NaY and Ce（IV）Y were employed as adsorbents to remove organic sulfur compounds from model gasoline （MG） solutions with and without toluene in static adsorption experiments at room temperature （RT） and a...Zeolites NaY and Ce（IV）Y were employed as adsorbents to remove organic sulfur compounds from model gasoline （MG） solutions with and without toluene in static adsorption experiments at room temperature （RT） and atmospheric pressure. The adsorbents were characterized by XRD, XRF and pyridine infrared spectrum （IR）. The adsorption experiments show that the desulfurization performance of Ce（IV）Y is much better than that of NaY. The sulfur removal over both NaY and Ce（IV）Y decreases with the increase of toluene concentration in MG, however, the decline tendency on Ce（IV）Y is smooth, and it is steep on NaY. FT-IR spectra of thiophene adsorption indicate that thiophene molecules are mainly adsorbed on NaY via π electron interaction, but on Ce（IV）Y, in addition to the π electron interaction, both Ce^4＋-S direct interaction and protonation of thiophene also play important roles. Toluene molecules are adsorbed on NaY also via π electron interaction. Although the amount of Bronsted acid sites is increased due to the introduction of Ce^4＋ ions into NaY zeolite, it is not found to influence the adsorption mode of toluene over Ce（IV）Y. Compared with NaY zeolite, the improved desulfurization performance over Ce（IV）Y for removing organic sulfur compounds from MG solution, especially those containing large amount of aromatics, may be ascribed to the direct Ce（IV）-S interaction, which is much resistant to the influence resulted from toluene adsorption.展开更多
目的观察淫黄葛合剂对APP_(swe)/PS1_(dE9)小鼠行为及海马胱氨酸/谷氨酸反向转运体的表达影响。方法6只8月龄雄性C57BL/6J小鼠为正常组,18只8月龄雄性APP_(swe)/PS1_(dE9)小鼠随机分为模型组、合剂组、地拉罗司(deferasirox,DFX)组,每组...目的观察淫黄葛合剂对APP_(swe)/PS1_(dE9)小鼠行为及海马胱氨酸/谷氨酸反向转运体的表达影响。方法6只8月龄雄性C57BL/6J小鼠为正常组,18只8月龄雄性APP_(swe)/PS1_(dE9)小鼠随机分为模型组、合剂组、地拉罗司(deferasirox,DFX)组,每组6只。正常组、模型组给予蒸馏水灌胃,合剂组灌胃淫黄葛合剂(淫羊藿苷120 mg·kg^(-1)、黄芪甲苷80 mg·kg^(-1)、葛根素80 mg·kg^(-1)),DFX组灌胃DFX(100 mg·kg^(-1)),每日1次,干预2个月。利用八臂迷宫实验检测各组小鼠空间、学习记忆能力;免疫荧光观察正常组、模型组小鼠海马CA3区溶质载体家族7成员11(solute carrier family 7 member 11,SLC7A11)与溶质载体家族3成员2(solute carrier family 3 member 2,SLC3A2)的表达水平;Western blot和real time q-PCR检测各组小鼠海马SLC7A11、SLC3A2蛋白及mRNA表达水平。结果与正常组相比,模型组小鼠空间学习记忆能力下降,海马CA3区SLC7A11、SLC3A2表达下降(P<0.05),海马SLC7A11、SLC3A2蛋白及mRNA表达下降(P<0.05);与模型组相比,合剂组、DFX组空间学习记忆能力提升,海马SLC7A11、SLC3A2蛋白及mRNA表达上升(P<0.05);合剂组与DFX组各项指标差异无统计学意义(P>0.05)。结论淫黄葛合剂可以改善APP_(swe)/PS1_(dE9)小鼠的行为障碍,其机制与促进海马SLC7A11、SLC3A2的表达有关。展开更多
应用传统的压缩感知理论对天线阵列信号的波达方向(Direction-of-arrival,DOA)进行估计,存在基的失配问题。基于交替方向乘子法(Alternative Direction Method of Multiplier,ADMM)的无网格压缩感知(Grid-less Compressive Sensing)技...应用传统的压缩感知理论对天线阵列信号的波达方向(Direction-of-arrival,DOA)进行估计,存在基的失配问题。基于交替方向乘子法(Alternative Direction Method of Multiplier,ADMM)的无网格压缩感知(Grid-less Compressive Sensing)技术能够解决该问题,但仍存在收敛速度慢的缺陷。针对该缺陷,提出带自适应惩罚项的ADMM(ADMM with adaptive penalty,AP-ADMM)算法,即根据输入信号的噪声功率,自适应地选择惩罚项的初始值;同时在算法迭代求解的过程中,自适应地对目标函数的惩罚项进行调整。与传统算法相比,在保证收敛精度和DOA的恢复成功概率的条件下,带自适应惩罚项的ADMM算法收敛速率明显加快。仿真结果验证了新算法的有效性。展开更多
文摘in absence of light, the reaction kinetics of Mn(II) and Fe(III)-atalyzed oxidation ofS(IV) in unbuffered and buffered solutions were studied. An activation energy of 77.4kJ . mol￣(-1) forthe Mn(II)catalyzed oxidation of S(IV) is obtained. On the basis of the investigation of thecatalytic effects of Mn(II) and Fe(III) on the oxidation of S(IV), it has been elucidated that thecatalytic activity of Mn(II) is greater than that of Fet(III), and that Mn(II) and Fe(III) do not havea significant synergic effect on the catalytic oxidation of S (IV). The catalytic oxidation andautooxidation of S(IV) in unbuffered solution was also explored in the presence of light. The resultsshow that the reaction is first order with respect to S(IV) concentrations, the reaction rate increaseswith increasing light intensity and the concentrations of Fe(III) and Mn(II), and that the photoas-sisted catalytic activity of Fe(III) is greater than that of Mn(II).
基金supported by the Fundamental Research Funds for the Key Universities (Grant No. DUT10LK25)the National Natural Science Foundation of China (Grant No. 21106014)
文摘Zeolites NaY and Ce（IV）Y were employed as adsorbents to remove organic sulfur compounds from model gasoline （MG） solutions with and without toluene in static adsorption experiments at room temperature （RT） and atmospheric pressure. The adsorbents were characterized by XRD, XRF and pyridine infrared spectrum （IR）. The adsorption experiments show that the desulfurization performance of Ce（IV）Y is much better than that of NaY. The sulfur removal over both NaY and Ce（IV）Y decreases with the increase of toluene concentration in MG, however, the decline tendency on Ce（IV）Y is smooth, and it is steep on NaY. FT-IR spectra of thiophene adsorption indicate that thiophene molecules are mainly adsorbed on NaY via π electron interaction, but on Ce（IV）Y, in addition to the π electron interaction, both Ce^4＋-S direct interaction and protonation of thiophene also play important roles. Toluene molecules are adsorbed on NaY also via π electron interaction. Although the amount of Bronsted acid sites is increased due to the introduction of Ce^4＋ ions into NaY zeolite, it is not found to influence the adsorption mode of toluene over Ce（IV）Y. Compared with NaY zeolite, the improved desulfurization performance over Ce（IV）Y for removing organic sulfur compounds from MG solution, especially those containing large amount of aromatics, may be ascribed to the direct Ce（IV）-S interaction, which is much resistant to the influence resulted from toluene adsorption.
文摘目的观察淫黄葛合剂对APP_(swe)/PS1_(dE9)小鼠行为及海马胱氨酸/谷氨酸反向转运体的表达影响。方法6只8月龄雄性C57BL/6J小鼠为正常组,18只8月龄雄性APP_(swe)/PS1_(dE9)小鼠随机分为模型组、合剂组、地拉罗司(deferasirox,DFX)组,每组6只。正常组、模型组给予蒸馏水灌胃,合剂组灌胃淫黄葛合剂(淫羊藿苷120 mg·kg^(-1)、黄芪甲苷80 mg·kg^(-1)、葛根素80 mg·kg^(-1)),DFX组灌胃DFX(100 mg·kg^(-1)),每日1次,干预2个月。利用八臂迷宫实验检测各组小鼠空间、学习记忆能力;免疫荧光观察正常组、模型组小鼠海马CA3区溶质载体家族7成员11(solute carrier family 7 member 11,SLC7A11)与溶质载体家族3成员2(solute carrier family 3 member 2,SLC3A2)的表达水平;Western blot和real time q-PCR检测各组小鼠海马SLC7A11、SLC3A2蛋白及mRNA表达水平。结果与正常组相比,模型组小鼠空间学习记忆能力下降,海马CA3区SLC7A11、SLC3A2表达下降(P<0.05),海马SLC7A11、SLC3A2蛋白及mRNA表达下降(P<0.05);与模型组相比,合剂组、DFX组空间学习记忆能力提升,海马SLC7A11、SLC3A2蛋白及mRNA表达上升(P<0.05);合剂组与DFX组各项指标差异无统计学意义(P>0.05)。结论淫黄葛合剂可以改善APP_(swe)/PS1_(dE9)小鼠的行为障碍,其机制与促进海马SLC7A11、SLC3A2的表达有关。
文摘应用传统的压缩感知理论对天线阵列信号的波达方向(Direction-of-arrival,DOA)进行估计,存在基的失配问题。基于交替方向乘子法(Alternative Direction Method of Multiplier,ADMM)的无网格压缩感知(Grid-less Compressive Sensing)技术能够解决该问题,但仍存在收敛速度慢的缺陷。针对该缺陷,提出带自适应惩罚项的ADMM(ADMM with adaptive penalty,AP-ADMM)算法,即根据输入信号的噪声功率,自适应地选择惩罚项的初始值;同时在算法迭代求解的过程中,自适应地对目标函数的惩罚项进行调整。与传统算法相比,在保证收敛精度和DOA的恢复成功概率的条件下,带自适应惩罚项的ADMM算法收敛速率明显加快。仿真结果验证了新算法的有效性。
