超声速气流中的斜爆震研究进展综述

对超声速气流中斜爆震波的起爆和驻定特性的研究进展进行总结,重点回顾了斜爆震波起爆准则和驻定条件的实验研究。随后对斜爆震过渡区结构及波面胞格结构的研究历程和发展现状进行了概述。此外,对爆震波与湍流边界层相互作用的研究现状进行概述,分析总结了当前斜爆震研究存在的问题,对后续的斜爆震研究内容和研究手段提出建议。

Vegetation landscape structure and dynamics in sandy forest-steppe ecotone

Sandy forest-steppe ecotone in Baiyinaobao Natural Reserve of Inner Mongolia Autonomous Region of China is one of the special landscape types in forest-steppe vegetation zone in China. Vegetation landscape types, landscape patches, and patch size were measured by the field investigation, forest photograph, and airscape. The structure of landscape patches in sandy forest-steppe ecotone, including composition structure, and size structure, was studied and the dynamics and transformation of landscape patches were analyzed. The data obtained in this study could provide theoretical basis for the research on vegetation landscape in forest-steppe ecotones and other vegetation types.

HNCX(X=O,S)和F反应机理及电子密度拓扑分析

采用G3B3//B3LYP/6-311++G(d,p)方法研究了HNCX(X=O,S)与F原子的反应机理.找到了六条可能的反应通道,计算结果表明,该反应的主产物为HF+NCX(X=O,S).对反应过程进行了电子密度拓扑分析,讨论了反应过程中化学键的断裂和生成规律,找到了HNCX(X=O,S)和F反应过程中的T型结构过渡态、三元环状结构过渡区和四元环状结构过渡区.

CH_3SS与XO(X=F,Cl,Br)反应过程的电子密度拓扑研究

利用MP2/6-311++G(d,p)//B3LYP/6-311++G(d,p)对CH3SS与XO(X=F,Cl,Br)的反应机理进行了研究.着重从电子密度拓扑分析角度讨论了化学键的生成和断裂.计算结果表明单线态反应为主要反应通道,且由于该通道的反应能垒低、放热明显,说明CH3SS与XO在大气中比较容易进行.电子密度拓扑分析表明,在单线态抽氢反应通道中存在着四元环状过渡结构,随着反应进行,此四元环状过渡结构通过一个T-型结构变为三元环状过渡结构,最后环状结构消失得到产物.