An STM study of the adsorption of Pb on Cu(100): formation of an ordered surface alloy

The adsorption of Pb on Cu(100) from 0 to 1 ML was investigated by UHV scanning tunneling microscopy. We obtained atomic resolution images of the different superstructures which appear at 300 K with increasing coverage (c(4 × 4), c(2 × 2) and c( √2)R45°). We confirm recent results and propose, partly on the basis of low temperature studies, new arguments in favour of an incorporation of lead atoms in the surface layer of copper for low coverage. We demonstrate that the c(4 × 4) superstructure corresponds to an ordered surface alloy of Pb₃Cu₄ composition, by investigating separately the alloying and de-alloying transitions. De-alloying occurs during the first-order transition between the c(4 × 4) and c(2 × 2) superstructures.     

金融衍生产品的力学方法分析（Ⅱ）—期权市场价格基本方程

类似固体力学建立基本方程方法，根据期权特点，采用一些假设，建立期权市场价格基本方程：hv0(t)=m1vo^-1(t)-n1vo(t) F,式中h,m1,n1,F为常数，主要假设有：期权市场价格vo(t)的升降由市场供求决定；影响v0(t)的因素如行使价，期限，波幅等用正或反比关系；买和卖用相反规律。文中给出不同情况下基本方程的解，并和期货市场价基本方程的解vf(t)相比较，以及用隐函数存在定理证明vf与v0(t)存在一一对应关系，为研究期货vf对期权价vo(t)的影响提供理论依据。     

Admissible solutions of k-extended finite state set and sequence compound decision problems

We treat situations in which independent structurally identical decision problems are to be faced either simultaneously or serially. Recent work on such compound decision problems has centered on finding procedures that satisfy the strengthened asymptotic optimality property of Gilliland and Hannan (Ann. Math. Statist.40 (1969), 1536–1541) and on providing decision rules that at once satisfy an admissibility property and the classical asymptotic optimality property. We suggest a simplified method of accomplishing the first of these goals in general situations and then provide decision rules for finite state components simultaneously admissible and satisfying the strengthened optimality property.     

关于复利率的连续计算方法——析国内外经管类数学教材中普遍存在的一种方法错误

高俊科．关于复利率的连续计算方法．数理统计与管理，１９９８，１７（２），３３～３４．本文分析了连续复利公式的形成背景，指出国内外经济、管理类数学教材中普遍存在的所谓复利率的连续计算的推导是错误的     

Photo-induced Conversion of Furylfulgide Single Crystal Under High Pressures

We have studied pressure effects on single crystal of photochromic furylfulgide for researching the possibility of photo-induced structural change. Pressure dependence of the absorption spectra was investigated up to 8.2 GPa at room temperature. Pressure-induced conversion to C-form molecules was observed at 8.2 GPa in single crystal composed only of E-form molecules, while at 5.7 GPa in single crystal containing small amount of C-form ones. Photochromic reaction was observed under high pressure as well as the ambient pressure. The dependence of absorption intensity due to C-form molecules suggests the possibly of cooperative structural change in furylfulgide single crystal at 5.5 GPa.     

Practical aspects of stop-loss calculations

This paper examines various methods of ‘arithmetizing’ the claim size distribution so that stop-loss premiums can be recursively calculated. Claim frequencies are assumed to be Poisson. A decision strategy for choosing a method when both error and computer costs are constrained is developed.     

On the expected discounted penalty function at ruin of a surplus process with interest

In this paper, we study the expected value of a discounted penalty function at ruin of the classical surplus process modified by the inclusion of interest on the surplus. The ‘penalty’ is simply a function of the surplus immediately prior to ruin and the deficit at ruin. An integral equation for the expected value is derived, while the exact solution is given when the initial surplus is zero. Dickson’s [Insurance: Mathematics and Economics 11 (1992) 191] formulae for the distribution of the surplus immediately prior to ruin in the classical surplus process are generalised to our modified surplus process.     

毛细管区带电泳法测定复方芦丁片中芦丁和维生素C的含量

考察了缓冲溶液的pH、背景电解质浓度及分离电压对芦丁、维生素C及苯甲酸分离的影响，建立了以苯甲酸为内标，毛细管区带电泳法快速测定复方芦丁片中芦丁和维生素C含量的新方法。以3g/L硼砂－4g/L硼酸(pH8.18）为运行缓冲液，苯甲酸为内标，在分离电压为25kV，检测波长为254nm的电泳条件下，芦丁、维生素C和内标可在5min实现分离。芦丁的线性方程为：y=2．65x＋0．095（r＝0．9994），线性范围为0．025mg/mL－0．4mg/mL，维生素C的线性方程为：y＝3．1343x＋0．565（r＝0．9991），线性范围0．125mg/mL－1．0mg/mL。方法可用于复方芦丁片的质量控制。     

在四种溶剂和萃取剂中研究硫氰酸钼(Ⅴ)络合物

在不同溶剂中研究了硫氰酸钼(Ⅴ)络合物的性质,络合物的最大配位数为3。分别测定了在四种不同溶剂中该络合物的稳定常数和摩尔吸光系数,用萃取法研究了在不同溶剂和不同萃取剂中对硫氰酸钼(Ⅴ)络合物的萃取效果及其生成机理。