高纯氧化钪中稀土杂质的电感耦合等离子体质谱法测定

研究了用电感耦合等离子体质谱法测定高纯氧化钪中１５个稀土杂质的方法。考察了基体效应及内标的作用，采用Ｉ或Ｃｓ为内标可很好补偿基体ＳＣ的影响。方法检测限为０．０１３－０．０８５ｎｇ／ｍｌ，加料回收率为９１．２％－１０５．７％，相对标准偏 １．４％－８．１％。     

Ideals in a perfect closure, linear growth of primary decompositions, and tight closure

This paper is concerned with tight closure in a commutative Noetherian ring of prime characteristic , and is motivated by an argument of K. E. Smith and I. Swanson that shows that, if the sequence of Frobenius powers of a proper ideal of has linear growth of primary decompositions, then tight closure (of ) `commutes with localization at the powers of a single element'. It is shown in this paper that, provided has a weak test element, linear growth of primary decompositions for other sequences of ideals of that approximate, in a certain sense, the sequence of Frobenius powers of would not only be just as good in this context, but, in the presence of a certain additional finiteness property, would actually imply that tight closure (of ) commutes with localization at an arbitrary multiplicatively closed subset of .

Work of M. Katzman on the localization problem for tight closure raised the question as to whether the union of the associated primes of the tight closures of the Frobenius powers of has only finitely many maximal members. This paper develops, through a careful analysis of the ideal theory of the perfect closure of , strategies for showing that tight closure (of a specified ideal of ) commutes with localization at an arbitrary multiplicatively closed subset of and for showing that the union of the associated primes of the tight closures of the Frobenius powers of is actually a finite set. Several applications of the strategies are presented; in most of them it was already known that tight closure commutes with localization, but the resulting affirmative answers to Katzman's question in the various situations considered are believed to be new.

     

Absorption Spectra of Gasolines in the Region 1090–1220 nm

The difference absorption spectra of different grades of gasoline (A-76, AI-92, and AI-95) with octane numbers lying within 76–85 have been investigated experimentally in comparison with hydrocarbons: isooctane, benzene, and n-heptane. The spectra obtained contain absorption bands of the CH₃, CH₂, and CH groups and supposedly of the olefin double bond. The possibility of determining the octane number of an unknown grade of gasoline by using the absorption of a measured difference spectrum at one selected wavelength is shown.     

On Pathwise Uniqueness of Stochastic Differential Equations Without Drift

We consider the stochastic differential equation: dX _t =(|X _t |)dB _t , where B is a Brownian motion and is a non-Hölder Borel function. A sufficient condition of pathwise uniqueness is given.     

On a kind of integrals of empirical processes concerning insurance risk

This paper proves the strong consistence and the central limit theorems for empirical right tail deviations.     

On existence of undominated pure strategy Nash equilibria in anonymous nonatomic games: a generalization

In this paper, we generalize the exitence result for pure strategy Nash equilibria in anonymous nonatomic games. By working directly on integrals of pure strategies, we also generalize, for the same class of games, the existence result for undominated pure strategy Nash equilibria even though, in general, the set of pure strategy Nash equilibria may fail to be weakly compact. Received August 2001     

Gas-chromatographic method of evaluation ofn-alkanol ability for self-association in pure liquid

The values of the gas-chromatographic indicator reflecting the capacity of analytes for self-association in pure liquids, δT _b.p., were estimated for C₁–C₉ and C₁₁ n-alkanols by capillary gas chromatography on a nonpolar stationary phase under isothermal conditions. The δT _b.p. values ofn-alkanols, found as the difference between the boiling points measured directly and those calculated from GC data, are correlated with thermodynamic characteristics of the formation ofn-alkanol associates in pure liquids. Usingn-alkanols as analytes with insignificant temperature increments of the retention indices, it was shown that the δT _b.p. values can be determined under conditions used in gas chromatography with temperature programming. In this way a single chromatographic run can be used to compare the capacities for self-association of analytes boiling over a wide temperature range. The C₂–C₉ n-alkanethiols, which are not associated in neat liquids, have negative δT _b.p. values. An interpretation of this finding is proposed. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 315–318 February, 2000.     

On the consistency of credibility premiums regarding Esscher principle

In this paper, we investigate the problems of convergence of experience-based ratemakings regarding the Esscher principle. In addition to the Bayes and the classical credibility premiums, we suggest a new credibility formula for the Esscher premium. Then we show the convergence of the Bayes and the newly defined credibility premiums towards the individual premium and point out that the classical credibility premium does not generally converge to the individual premium by presenting a sufficient and necessary condition under which the classical credibility Esscher premium converges to the individual premium. A simulation study is carried out to illustrate the theoretical conclusions.     

Sensitivity analysis of the moments of the profit on an Income Protection Policy

The main purpose of this paper is to perform a sensitivity analysis where we quantify and analyse the effects on the mean of the profit on an Income Protection policy and two risk measures of changing the values of the transition intensities. All the calculations carried out are based on a multiple state model for Income Protection proposed in Continuous Mortality Investigation Committee (Continuous Mortality Investigation Reports 1991; 12 ). Within this model, we derive a formula for the mean of the profit, which enables to evaluate it more efficiently. In order to calculate the two risk measures we use the numerical algorithms for the calculation of the moments of the profit proposed by Waters (Insurance: Mathematics and Economics 1990; 9 :101–113). We carry out the sensitivity analysis considering two different situations: in the first situation, we update the premium rates used to calculate the moments of the profit, according to the changes in the values of the transition intensities; in the second one, we do not update the premium rates. Both analyses are of practical interest to insurance companies selling Income Protection policies. Copyright © 2009 John Wiley & Sons, Ltd.