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本文报道了7种新的N-烷基-N′-乙氧羰基甲基-N′-芳磺酰基-O-乙基磷酰二胺酯化合物的电子轰击质谱(EIMS)和化学电离质谱(CIMS,甲烷为反应气)。结果表明,无论是EIMS,还是CIMS均存在较多的骨架重排离子峰;取代基对谱图有较大的影响;EIMS中P—N键的断裂为重要质谱特征,CIMS中MH~+准分子离子为重要特征离子,还存在分子离子反应的产物。 相似文献
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For integer n > 0, let n.(x) denote the nth cyclotomic polynomialwhere is a primitive nib root of unity and (j, n) denotes the greatest common divisor of j andn.Although 4.(x) is irreducible over the integers, 4.(x) may be reducible over certain quadraticfield. Let n > 1 be an odd square-free number. Aurifeuille and Le Lasseur[1] proved thatLater on Schinzel[2] proved that (1) can be improved aswhere m|n,(3) denotes the Jacobi symbol, andwhere both Pn,m(x) and Qn,m(x) are polynomials with i… 相似文献
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The unimolecular dissociation reactions of doubly charged ions were reported,which resulted from a tandem mass spectrometer and a reversed geometry double focusing mass spectrometer by electron impact.Mass analyzed ion kinetic energy spectrometry(MIKES) was used to obtain the kinetic energy releases in charge separation reactions of doubly charged ions.The intercharge distances between the two charges at transition states can be calculated from the kinetic energy releases.Transition structures of unimolecular dissociation reactions were infered from MIKES and MS/MS. 相似文献
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For integer n>0, let n(x) denote the nth cyclotomic polynomial
n(x)=tackrel{01 be an odd square-free number.Aurifeuille and Le Lasseur[1] proved thatequationn(x)=An2(x)-(-1)n-12)nxBn2(x).equation 相似文献