杨乐不等式的推广及加强

本文首先利用凸函数基本不等式和平均值不等式推广并加强了杨乐不等式 ,然后利用 Jensen不等式给出了两个更为广泛的结果 .     

DNA damage induced by organotins on ­trout‐nucleated erythrocytes

The effect of tributyltin‐chloride (TBTC), dibutyltin‐chloride (DBTC) and monobutyltin‐chloride (MBTC) on rainbow trout (Salmo irideus) nuclear DNA, was investigated by means of single cell gel electrophoresis (‘comet’ assay). Our data show that TBTC presents a marked genotoxic effect, whereas the genotoxic effect is less pronounced for DBTC and it is completely absent for MBTC. These results could be important in evaluating the environmental risks deriving from the use of these molecules as a antifouling agents in marine paints and as agricultural biocides. Copyright © 2001 John Wiley & Sons, Ltd.

Abbreviations:

TBTC,

tributyltin‐chloride;

DBTC,

dibutyltin‐chloride;

MBTC,

monobutyltin‐chloride;

Hb,

hemoglobin.

     

On Liouville type theorems for fully nonlinear elliptic equations with gradient term

In this paper, we prove a Hadamard property and Liouville type theorems for viscosity solutions of fully nonlinear elliptic partial differential equations with a gradient term, both in the whole space and in an exterior domain.     

保险定价原则实证分析

本文根据失真保险定价原则 ,以我国某保险以同的某项机动车保险业务为例 ,对其保费进行了实证分析     

Co-ion dependence of DNA nuclease activity suggests hydrophobic cavitation as a potential source of activation energy

The source of the activation energy that allows cutting of DNA by restriction enzymes is unclear. A systematic study of the cutting efficiency of the type-II restriction endonuclease EcoRI, with varying background electrolyte ion pair and buffer reported here, shows only a modest dependence of efficiency on cation type. Surprisingly, efficiency does depend strongly on the presumed indifferent anion of the background salt. What emerges is that competition between the background salt anion and the buffer anion for the enzyme and DNA surfaces is crucial. The results are unexpected and counterintuitive from the point of view of conventional electrolyte theory. However, taken together with recent developments in surface chemistry, the results do fall into place and could also suggest a novel mechanism for enzyme activity as an alternative to metal-activated hydrolysis: microscopic cavitation in a hydrophobic pocket might be the source of activation energy. Received 19 June 2000 and Received in final form 17 October 2000