Evidence for Different Fission Behavior of Hot Nuclei Formed in Central and Peripheral Collisions of ^(40)Ar+^(209)Bi Reaction at 25 MeV/u

Correlated fission fragments from the reaction of 25MeV/u ^(40)Ar+^(209)Bi and their further correlation with a par-tides have been studied for peripheral and central collisions simultaneously.The excitation energy at scission deduced from postscission multiplicity is about 1725 MeV.The fission timescale deduced from prescission multiplicity is about 4×10^(21)s.Systematic analysis of the mass and energy distributions of Hssion fragments as a function of the initial temperature of hot fissioning nuclei reveals the existence of different fission behavior of hot nuclei formed in central and peripheral collisions.Experimental data demonstrate the change of Hssion behavior at T~4MeV.

基于NF-κB信号通路探讨酸浆内酯B对溃疡性结肠炎的抗炎作用

目的:探究酸浆内酯B(PB)在溃疡性结肠炎(UC)中发挥的抗炎作用。方法:建立LPS诱导的斑马鱼炎症模型,分为对照组、模型组、吲哚美辛组、PB组,观察各组斑马鱼肠道中的中性粒细胞数量;DSS诱导的小鼠UC模型,分为对照组、模型组、美沙拉嗪组、PB组,连续监测各组小鼠体质量、粪便性状及隐血情况,比较肠道黏膜的病理改变及相关炎症因子的表达;LPS诱导的细胞炎症模型,分为对照组、LPS组、PB组,观察各组相关炎症因子蛋白表达水平。结果:斑马鱼模型:PB组斑马鱼中性粒细胞数量较模型组显著减少(P<0.01)。小鼠模型:PB组小鼠体质量、疾病活动度评分、结肠长度较模型组显著改善(P<0.01);炎症因子TNF-α、IL-1β及IL-6在蛋白水平上显著降低(P<0.01)。细胞模型:PB组相关炎症因子TNF-α、IL-1β表达较LPS组显著降低(P<0.05,P<0.01),NF-κB相关信号通路的蛋白表达水平也得到了抑制。结论:对于UC,PB可以发挥抗炎作用,与下调NF-κB信号通路、降低炎症因子的表达和中性粒细胞的水平有关。

SAPO-34分子筛的快速晶化及其NH3-SCR性能

相比单独采用三乙胺为模板剂,添加少量四乙烯五胺能明显加速SAPO-34分子筛的晶化过程,实现分子筛的快速合成。将快速合成的分子筛和商品分子筛经离子交换得到类似铜负载量的分子筛催化剂Cu/SAPO-34并进行NH3-SCR性能测试。测试结果表明,Cu/SAPO-34催化剂表现出较好的NH3-SCR活性,该类催化剂经750℃,10%H2O,48h水热老化后展现出较新鲜态催化剂更优异的低温反应活性。相比商品化分子筛,快速合成所得催化剂有更优的高温活性和稳定性,具有良好的应用前景。