一类芳香族偶氮化合物的合成及表征

采用重氮偶合反应合成了一系列不同对位取代的4-[N，N-(二羟乙基)]氨基偶氮苯化合物，其结构用元素分析，IR，1HNMR，DSC，DSC等进行表征和确认。     

Lifetime of Antibaryon Bound in Finite Nuclei

The study of finite nuclei containing antibaryon（s） in addition to nucleons is an interesting topic in nuclear physics. The calculation of the lifetime of an antibaryon embedded in a nucleus was performed in the framework of the standard quantum field theory. It was shown that the annihilation probability of the antibaryon in nuclei is strongly dependent on the effective masses of mesons involved in the annihilation channels. The contribution of the Dirac sea to the annihilation probability makes the lifetime of the antibaryon short. If the Dirac sea effect is neglected, the lifetime of the bound antibaryon tends to be longer with the nuclear density increasing. Particularly, when the nuclear density is larger than a critical value, the antibaryon may exist stably in a nucleus.