131 research outputs found
Transition Metal Promoted ZSM-5 Catalysts for the Conversion of Dimethyl Sulfide into Methanethiol
负载过渡金属的zSM-5催化剂用于催化甲硫醚(dMS)转化成甲硫醇(MT)的反应.实验结果表明,催化剂的甲硫醚转化率提高和甲硫醇选择性降低的趋势一样,都是以下顺序:CO/zSM-5>MO/zSM-5>nI/zSM-5>W/zSM-5.表征结果表明,由于过渡金属阳离子(W6+、nI2+、CO3+、MO6+)比Al3+活泼,而改性过程中W6+、nI2+、CO3+、MO6+分别代替了部分Al3+,使得改性催化剂对dMS和MT的化学吸附作用更强.过渡金属的引入使得zSM-5总酸度增强,提高了C―S键的裂解能力,从而改进了催化转化dMS的能力.研究结果发现,在转化dMS的过程中,金属活性位和酸性位之间通过强的协同效应起作用.ZSM-5-supported transition metal catalysts were prepared and used to catalyze the conversion of dimethyl sulfide(DMS) into methanethiol(MT).Test results indicated that the activities of the catalysts for the conversion of DMS increased as follows: Co/ZSM-5>Mo/ZSM-5>Ni/ZSM-5>W/ZSM-5.The decrease in MT selectivity followed the same trend.The characterization results showed that transition metal cations(W6 +, Ni2 +, Co3 +, Mo6 +) replaced some Al3 +sites leading to more active in chemiadsorption of DMS and MT since transition metal cations are more active than Al3 +.The incorporation of transition metals into ZSM-5enhances the total acidity of ZSM-5 and increases its capacity to rupture C―S bonds.This subsequently improves its catalytic behavior in the conversion of DMS.We found that the metal active sites and closely situated acidic sites have a strong synergistic effect when converting DMS
不断创新的电化学研究方法(厦门大学电化学研究工作简介之二)
不断创新的电化学研究方法(厦门大学电化学研究工作简介之二)林仲华,罗瑾,田中群,孙世刚,林昌健,毛秉伟,杨勇,林华水执笔(固体表面物理化学国家重点实验室,厦门大学化学系,厦门361005)1历史的回顾与自然科学的其它分支学科一样,电化学科学的建立和纵..
Study on the prothymosin α as vaccine adjuvant of P.yoelii
目的:研究胸腺素α原(PrOTHyMOSInα,PrOTα)作为约氏疟原虫疫苗免疫佐剂的作用。方法:提取P.yOElII-17Xnl全蛋白作为抗原,用胸腺素α原作为免疫佐剂,免疫小鼠。具体方案为:昆明小鼠分为4组,每组6只,A组免疫P.yOElII-17Xnl全蛋白+PrOTα;b组免疫P.yOElII-17Xnl全蛋白;C组只注射PrOTα;d组为空白对照,以相同体积的生理盐水代替。免疫结束后感染致死的P.yOElII-17Xl,1x107个虫/只小鼠。结果:感染后的前10天A组小鼠疟原虫血症平均值要低于其他三组,且最终有3只小鼠存活下来,存活率50%,C组有一只小鼠存活,b、d组小鼠全部死亡。结论:用P.yOElII-17Xnl全蛋白做抗原,用PrOTα作为佐剂,比单独用P.yOElII-17Xnl全蛋白对小鼠有更好的免疫保护作用,提示了PrOTα可以成为一种有潜力的蛋白疫苗。Objective:To investigate the function of prothymosin α(ProTα) as vaccine adjuvant of P.yoelii.Methods:The mice were immunized with the total protein extracted from P.yoelii-17XNL as antigen,together with prothymosin α as adjuvant.Programs:Kunming mice were divided into A,B,C and D group.A group was immunized with P.yoelii-17XNL total protein and ProTα;B group was immunized with P.yoelii-17XNL;C group was only injected with ProTα;D group was the control,only injected with physiological saline.And then,the mice of each group was infected with P.yoelii-17XL,the dosage was 1×107/mice.Results:The parasitemia of A group-mice was lower than the other three groups in the first 10 days after infection,and eventually there were three mice survived in A group,the survival rate was 50%,one mouse survived in C group,all of mice in B group and D group died.Conclusion:Mice immunized with P.yoelii-17XNL total protein as antigen together with ProTα as adjuvants,had better immune protection than those immunized with P.yoelii-17XNL protein only.The present results suggest that the ProTα can act as a potential adjuvant in protein vaccine.厦门市科技项目(3502Z20083004);国家“973”项目(2007CB513103)资
南海中深层动力格局与演变机制研究进展
南海是连接印度洋-太平洋的最大边缘海,在季风、海峡水交换以及复杂地形影响下,南海环流呈现出独特的三层结构以及远强于大洋的混合特征.理论与观测表明,南海内潮、内孤立波以及强风等过程是强混合的动力来源.在南海强混合作用下,南海发育了活跃的中深层动力系统,一方面促进了南海与大洋之间的水体交换,另一方面调控上层风生环流,使得南海环流显著区别于其他热带与副热带海盆.南海活跃的中深层环流所具有的物质搬运能力又显著影响着南海的地质沉积、生物地球化学循环等过程.中国对深海研究持续投入,在南海中深层环流动力学研究方面取得了显著的成果,文章就该方面进行总结,并对南海深海环流未来研究设想进行初步探讨
The Exponents of Convergence of Rational Functions of Meromorphic Functions Concerning Differences and Shifts
Development and Application of Soil and Water Plan System Based on GIS
以县南沟为例,结合小流域规划的特点及业务运作要求,讨论了开发基于GIS小流域规划系统的必要性,提出了规划系统的设计原则,进而讨论了系统各模块功能的实现方法
Existing Problems of Silt Arresters on the Loess Plateau
黄土高原地区自建国以来共建淤地坝1 .0 ×105 余座,淤地3 .8 ×105 hm 2 ,对黄土高原水土保持世界银行贷款项目区淤地坝的普查,充分证明了淤地坝在黄土高原水土保持上的作用以及经济和社会效益。但是,淤地坝建设与利用过程中仍存在种种问题,尤其表现在坝系规划布局不合理,病险坝多;设计标准偏低,易造成坝体破坏或垮坝;建坝施工质量差,工程不配套;坝体管理水平差,维护粗放;坝地利用率及经济效益偏低等5 个方面
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