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温和条件下,苄胺与手性合成子5-(L)-孟氧基3-溴-2(5)呋喃酮通过串联的不对称迈克尔加成/分子内消除反应合成了一种新手性化合物:5-L-孟氧基-4-苄胺基丁烯内酯。产物经过IR、1H-NMR、MS谱学表征,并经X-ray单晶衍射测定了其结构。新化合物属于正交晶系,P212121空间群,a=5.2945(4),b=14.2829(10),c=26.0769(18),Mr=343.45,Z=4,V=1972.0(2)3,Dc=1.157g/cm3,μ(MoKα)=0.076mm-1,F(000)=744,R=0.0387,wR=0.0880。 相似文献
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A new coupled map car-following model considering drivers’ steady desired speed 总被引:2,自引:0,他引:2 下载免费PDF全文
Based on the pioneering work of Konishi et al., in consideration of the influence of drivers' steady desired speed ef/ect on the traffic flow, we develop a new coupled map car-following model in the real world. By use of the control theory, the stability condition of our model is derived. The validity of the present theoretical scheme is verified via numerical simulation, confirming the correctness of our theoretical analysis. 相似文献
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制备了一种阳离子含有萘基,阴离子分别为对 甲苯磺酸、甲磺酸及三氟甲磺酸的硫盐.它们有高的热解温度和在常用有机溶剂中较好的溶解性.测定了此类光产酸剂在水溶液及聚乙二醇固体膜层中的紫外吸收特性.结果表明,阴离子不含苯基时,在193nm处有很好的透明性.考察了其在低压汞灯照射下的光解性质,在254nm附近的吸收峰随光解进行迅速减弱.此类光产酸剂适用于氟化氩激光(193nm)等的化学增幅型光致抗蚀剂. 相似文献
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在表面活性剂存在下用T(4-TAP)P作显色剂导数光度法同时测定铜和锌 总被引:1,自引:0,他引:1
前言卟啉类试剂在光度法中作为高灵敏显色对金属离子的测定有很多报导,一般都采用常规光度法进行单个元素的测定,其ε值均在1×10~5—4×10~5之间。用卟啉作显色剂的导数光度法测定微量金属离子,文献曾报导过,但尚未见到在表面活性剂存在下,用卟啉作显示剂的导数光度进行二种金属离子用时测定的报道。导数光度法是测量吸光度对波长的导数输出信息d~n/dλ~n,对提高光度法的灵敏度、准确度、选择性,或实现多元素连测等方面都较常规光度法优越。本文试验表明:T(4-TAP)P 相似文献
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A new compound, Cochinchin (1), together with 7,4‘-dihydroxyflavone (2), 7-hydroxy-4‘-methoxyflavane (3),7-hydroxy-3-(4-hydroxybenzyl)chroman (4), 4‘-hydroxy-2,4-dirnethoxydihydrochalcone (5) and 4‘-hydroxy-2,4,6-trimethoxydihydrochalcone (6) was isolated from the resin (trivial name, “dragon‘s blood“) of Dracaena cochinchinensis (Lour.) S. C. Chert. The structure of 1 was elucidated on the basis of spectroscopic data as (2,3-trans)-6-allyl-2-(3,5-dimethoxyphenyl)-3-(4-hydroxyphenyl)-2,3-dihydrobenzo[1,4]dioxin which is a natural product possessing a new framework. 相似文献
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锰-meso-四(对磺基苯)卟啉高分子季铵盐胶束增敏显色反应的研究 总被引:5,自引:0,他引:5
本文研究了meso~-四(对磺基苯)卟啉(TPPS_4或H_2L~(4-))在高分子季铵盐存在下与锰的胶束增敏显色反应。探讨了一些有机碱对锰与TPPS_4作用增速的机理。实验表明,TPPS_4与高分子季铵盐在有辅助络合剂存在下,pH7.8-11.0的碱性介质中,可以与锰迅速地形成灵敏度极高(ε:3.2×10~5)的三元络合物。其最大吸收峰位于442nm。采用EDTA和TEA作掩蔽剂,45种金属离子和18种非金属物无干扰。本法为目前锰的光度法中灵敏度最高的方法。不需分离可直接测定化探样、矿石、生铁和合金钢中痕量的锰。 相似文献
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Based on the pioneering work of Konishi et al. [Phys. Rev. E (1999) 60 4000], a new feedback control scheme is presented to suppress traffic jams based on the coupled map car-following model under the open boundary condition. The effect of the safe headway on the traffic system is considered. According to the control theory, the condition under which traffic jams can be suppressed is analyzed. The results are compared with the previous results concerning congestion control. The simulations show that the suppression performance of our scheme on traffic jams is better than those of the previous schemes, although all the schemes can suppress traffic jams. The simulation results are consistent with theoretical analyses. 相似文献