中文摘要：

本文采用分子动力学方法模拟在常温常压下（1atm,298K）和在压水堆环境下（155atm,626K）,水分子数为256,联氨（N2H4）分子数为0,25,50,75等不同数目时,水和联氨粒子系统的动力性质和微观结构.同时探讨了联氨分子的引入对水中溶解氧的影响.从模拟结果可知,在常温常压下,当联氨的分子数为0,25,50,75时,粒子系统的均方位移会随联氨分子数的增加而增加;联氨分子数为0与为25,50,75比较时会少一个数量级;压水堆环境下,联氨分子数为50时的均方位移比常温常压下高出约4倍,但粒子系统的均方位移不随联氨的分子数增加而增加;联氨分子数为50时的均方位移高于分子数为25和75时的均方位移.此外,粒子系统的微观结构,从径向分布函数看,在常温常压下也会随着联氨分子浓度的增加而增加,这与联氨容易和水反应生成水合联氨的实际情况相符,而在压水堆环境下,联氨分子数为25,50与为0的水比较,径向分布均不会有大的变化,而分子数为75时会出现明显的增加.模拟数据表明,加入压水堆中的联氨对水中的溶解氧有明显的抑制作用,但并不是联氨的浓度越浓抑制作用就越强.对这种现象及其原因进行了较为全面的揭示.

英文摘要：

In this paper,we used molecular dynamics to simulate dynamic properties and micro-structure of the water-hydrazine particle system under various conditions： chamber condition of 1 atm,298 K; pressurized water reactor （ PWR ） environment of 155 atm,626 K; with number of water molecules of 256,numbers of hydrazine （N2H4） molecules of 0, 25,50 and 75. And we have also explored the impact on the dissolved oxygen in water when hydrazine molecule is added to the system. The simulation results show that in the chamber ambient,when the number of molecules of hydrazine varies from 0 to 25,50 and 75,the mean square displacement （ MSD） in the particle system will increase with the number of particles of the hydrazine. The MSD for hydrazine molecule of number 0 will be ten less than that of 25,50 and 75. Under the PWR environment,with hydrazine molecule number of 50,the MSD is about 4 times higher than that in chamber ambient. At the same time,under such condition,the MSD of particle system does not increase with the number of hydrazine molecules. The MSD with hydrazine molecule of 50 is higher than its counterpart with the number of molecules of 25 or 75. In addition,the micro-structure of particle systems,from the perspective of the radial distribution functions （RDF）,will increase with the increase of concentration of hydrazine in chamber ambient. This conclusion goes along with the fact that hydrazine is easy to react with water to generate hydrazine hydrate. While in the pressurized water reactor environment,the radial distributions of the water with the number of hydrazine molecules of 25,50 and 0 will have no big change. But the radial distributions with the number of hydrazine molecules of 75 increase significantly. It can be seen from simulation data that hydrazine added to PWR significantly inhibits the dissolved oxygen in water,but the inhibition does not increase in proportion to the increase of the concentration of hydrazine. This phenomenon and its causes are revealed comprehensively in this p