Monotone trajectories of multivalued dynamical systems

Summary We prove existence of ? monotone trajectories ? for a class of discrete and continuous systems sufficiently general to include problems of some interest in economic and biological theory. We prove existence of critical points which are Pareto minima. We study stability properties of Pareto minima. Entrata in Redazione il 7 settembre 1976. Sponsored in part by ARO Grant DAHC04-74-60012, and NSF MCS75-21868.     

Structure of 72,74Se at high spin

Lifetimes of high spin states up to { }=22⁺ in the yrast positive parity bands have been measured to investigate the shape evolution with increasing spin in ^{72, 74}Se. The Q _t values derived from these measurements indicate that prolate shape stabilizes for ⁷²Se, while a triaxial shape develops for ⁷⁴Se at higher spins. Comparison of the observed trend in Q _t with spin for ^{72, 74}Se with that of the corresponding kryptones isotones emphasizes the stability provided by N=38 prolate shell gap even at high rotational frequency.     

The Cauchy problem in one-dimensional nonlinear viscoelasticity

The initial value problem for a nonlinear hyperbolic Volterra equation which models the motion of an unbounded viscoelastic bar is studied. Under physically motivated assumptions, the existence of a unique, globally defined, classical solution is established provided the initial data are sufficiently smooth and small. Boundedness and asymptotic behavior are also discussed. This analysis is based on energy estimates in conjunction with properties of strongly positive definite kernels.     

An abstract nonlinear Volterra integrodifferential equation

We study the nonlinear Volterra equation $\text{u′(t) + Bu(t) + ∫}{}_0{}^{\mathrm{t}}\text{a(t ? s) Au(s) ds ? F(t) (0 < t < ∞) (′ =}\text{d}\text{dt}\text{), u(0) = u}{}_0$, (¹) as well as the corresponding problem with infinite delay $\text{u′(t) + Bu(t) + ∫}{}_{\mathrm{?\infty }}{}^{\mathrm{t}}\text{a(t ? s) Au(s) ds ? ?(t) (0 < t < ∞), u(t) = h(t) (?∞ < t ? 0)}$. (⁷) Under various assumptions on the nonlinear operators A, B and on the given functions a, F, f, h existence theorems are obtained for (¹) and (⁷, followed by results concerning boundedness and asymptotic behaviour of solutions on (0 ? < ∞); two applications of the theory to problems of nonlinear heat flow with “infinite memory” are also discussed.     

抗坏血酸有机锗倍半氧化物的合成及抗癌活性研究

通过三氯锗仿与抗坏血酸分子的加成反应,合成了一种新型有机锗倍半氧化物,产物的结构通过元素分析、IR及UV光谱等方法进行了表征．生物活性实验表明合成物对小鼠S-180肿瘤生长具有显著的抑制作用．     

电感耦合等离子体原子发射光谱法测定钛酸钡纳米粉体中7种杂质元素

钛酸钡纳米粉体样品用盐酸溶解,在所得样品溶液中用电感耦合等离子体原子发射光谱法测定了以氧化物存在于样品中的7种杂质元素(包括镁、锶、钾、钠、铝、硅及铁),对测定的光谱条件进行了试验并优化达到上述各元素的测定上限为0.1%(质量分数).测得方法的检出限(3S/b)为(单位μg·L-1):2.0(铝),1.0(铁),20.0(钾),0.2(镁),4.0(钠),3.0(硅)及0.5(锶).应用此方法分析了两件实样,所得结果的相对标准偏差(n=6)小于等于2.0%,对其中4种杂质元素(镁、钾、钠和锶)同时用HG/T 3587-1999标准中的方法作分析校核,所得结果与此方法结果一致.