方幂和中因子5的指数问题

设ｎ,ｘ,ｒ是正整数且ｒ＞１,ｎ＝５αｃ,５ｃ,给出方幂和中因子５的指数计算公式：Ｄ＝∑ｎ－１ｋ＝０（ｘ＋ｄｋ）ｒ,ｄ＝５ｓ＋１,ｓ≥０．     

闽东南晚中生代岩浆混合作用：平潭火成杂岩的岩石学证据

有关野外地质、岩相学和岩石地球化学等资料,证实福建平潭火成杂岩由高铝玄武岩浆和花岗岩浆经过不同程度的机械混合和化学混合形成。对这一火成杂岩体成因的认识,为研究中国东南部晚中生代钙碱性岩带中诸如基性岩石和酸性岩石的时空复合等问题,提供了一个新的思路。     

萘相分光光度法测定微量铁的研究

本文研究了铁－邻二氮菲（ｐｈｅｎ）－四苯硼酸钠（ＳＴＰＢ）－萘固相分光光度法。探讨了体系的最佳实验条件。铁量在０～１０μｇ／２０ｍＬ范围内服从比耳定律，本法将分离，富集，显色测定结合起来，选择性好，灵敏度比液相光度法提高１０倍，应用于自来水水中微量铁的测定。结果良好。     

手性双氨基醇-Et2Zn催化的不对称直接羟醛缩合反应

以1,3-二溴丙酮和(2'S)-(二苯基羟甲基)-四氢吡咯为原料,合成了两种新型手性氨基醇1,3-双[(2'S)-(二苯基羟甲基)-1-四氢吡咯基]丙酮(3)和1,3-双[(2'S)-(二苯基羟甲基)-1-四氢吡咯基]-2-丙醇(4),总产率分别为39%和35%.手性双氨基醇3-/4-Et2Zn可催化未修饰醛、酮的不对称直接羟醛缩合反应,对映体过量最高9%.     

GFAAS法基体改进剂对氯化物背景干扰清除及机理

本文探讨了石墨炉原子吸收光谱法(GFAAS)中的酒石酸、草酸和柠檬酸等七类基体改进剂在283.3nm波长氘灯测量方式对氯化物背景吸收干扰的清除效果,认为基体改进剂的作用是与干扰物形成了低沸点的挥发物,并讨论了其形成机理。     

Catalytic Spectrophotometric Determination of Ultratrace Amounts of Silver with Solubilizing Effect of Nonionic Surfactant

ＩｎｔｒｏｄｕｃｔｉｏｎＴｒｉａｚｅｎｅｒｅａｇｅｎｔｓａｒｅｉｎｔｅｒｅｓｔｉｎｇｂｅｃａｕｓｅｏｆｔｈｅｉｒｓｔｒｏｎｇｃｏｍｐｌｅｘａｔｉｏｎａｂｉｌｉｔｉｅｓｗｉｔｈｔｒａｎｓｉｔｉｏｎｍｅｔａｌｓ .1 6Ｈｏｗｅｖｅｒ,ｌｉｔｔｌｅｄｅｃｏｌｏｒａｔｉｏｎｏｆｔｈｅｍｃａｔａｌｙｚｅｄｂｙｓｉｌｖｅｒｉｏｎｈａｓｂｅｅｎｓｔｕｄｉｅｄｉｎａｎａｌｙｔｉｃａｌｃｈｅｍｉｓｔｒｙ .Ｍａｎｙａｎａｌ ｙｓｉｓｔｓｈａｖｅｒｅｐｏｒｔｅｄｔｈｅｕｓｅｏｆｃａｔａｌｙｔｉｃｒｅａｃｔｉｏｎｓｆｏｒｔ…     

FREE STANDING FILM OF POLYANILINE

A free standing film of polyaniline as large as 18 cm×18cm×0.002 cm can be obtained by evaporation of a solution of the chemically synthesized base in NMP. Its structure was examined by the elemental analysis, IR, U.V.-visible spectra, XPS, DSC, SEM and X-ray scattering and its conducting behavior as well as electrochemical properties were studied. Results show that the composition, structure of main chain, physical properties of the free standing film of polyanilme is similar to that of the powder. However, some differences in its electronic structure, conductivity at room temperature and potential of redox couple between the flee standing film and powder are observed, which may be due to cross-linking of the film of polyaniline.     

盐类对4-氯-4′-羟基二苯砜钾盐真空熔融聚合的影响

聚苯砜醚是一种综合性能比较好、可在180℃长期使用的热塑性工程塑料,在国内外受到一定的重视。我们与武汉化工原料厂协作,对4-氯-4′-羟基二苯砜钾盐真空熔融缩聚合成聚苯砜醚的途径进行过一些探索,得到了较好的结果。但是,在实践中发现,由于这一反应速度快,放出的热量大而集中,在真空中聚合热不易导出,随着单体用量     

双氮桥联1,10-菲咯啉大环化合物分子构型的从头算研究

应用规范不变原子轨道法(GIAO)在RHF/6-31G**和B3LYP/6-31G**水平上计算了质子化双氮桥联1,10-菲咯啉大环化合物(H4HAPP2+)C2h和C2h构型的1HNMR,并用TDDFT法计算了H4HAPP2+电子光谱.结果表明,B3LYP/6-31G*优化的C2h构型为较优构型,经谐振频率验证无虚频,C2h构型是H4HAPP2+合理的对称性构型.