校园网访问控制系统的应用研究

身份验证和权限分配一直是网络应用中的核心问题。该文设计了一种基于角色的访问控制系统,，改变以往静态授权的缺陷，设计了一个基于RBAC的动态权限配置应用到校园网中，设置了授权信息表，根据角色的改变而修改访问权限，引入筛选条件对记录进行控制，实现了资源细粒度访问控制，比传统的访问控制方式更为严格，，也具有更大的灵活性和普适性，有效提高了安全性，可广泛应用到各类局域网中。

Application of Campus Network Security Authentication System

The difference of sequencing batch biofilm reactor (SBBR) performance and nitrogen transformation mechanism which caused by four different influent patterns were researched. Through variance analysis of SBBR performance, microbial community structure and nitrogen transformation, the results indicated that, on the one hand the dispersed influent pattern displayed higher anti-load ability than the centralized one, under the same efficiency, COD and ammonia load of the dispersed M₄reached 2 540 mg·(L·d)^-1 and 540 mg·(L·d)^-1 respectively compared with 2 000 mg·(L·d)^-1 and 420 mg·(L·d)^-1 by the centralized M₁; on the other hand, considering the dispersed influent pattern, the closer influent mood was to the cycle mood of operation, the higher the nitrogen transformation efficiency was, which finally led residual nitrogen concentration declined.