We further find that anti - flow appears at certain large impact parameter , which seems to be more sensitive to 2 and might provide more definite information of the magnitude of 2 . the absorption effect of k - mesons is also studied , we find although there exists strong k - absorption , k - spectrum can still contain the messages of at " in nuclear medium 接着我们又研究了k ~ -介子的吸收问题，发现虽然有强烈的k ~ -吸收存在，其能谱在不太重的核系统的非中心碰撞中仍显示出对为的依赖，有可能提供k在核介质中性质的知识。
