Rotifera recorded from China, 1893-1997, with remarks on their composition and distribution

A search of the literature on rotifers recorded from China, includes today 477 valid species names and 42 subspecies or infrasubspecific variants in 84 genera and 28 families recorded since 1893. Chinese rotifera research is reviewed, and all recorded species are listed with current taxonomic status and their first localities in China. Most of the named taxa are widely distributed or cosmopolitan, with only a small number (about 3%) possibly restricted to China. This fauna exhibits 15 endemic taxa. The composition and distribution of Chinese Rotifera are briefly analyzed. It is likely that considerably more rotifers remain to be described from China as further study to be carried on and taxonomic resolution improves.

安全ARP的Clark-Wilson模型化

ARP协议漏洞严重威胁着TCP／IP的安全，一些基于对称或非对称密钥机制的安全ARP协议被相继提出。本文介绍了ARP协议攻击的原理和几个最出名的基于对称或非对称密钥机制的安全ARP协议，引入Clark-wilson商业模型对ARP的完整性状态进行了分析，把改进协议Clark-Wilson模型化，在模型化的过程中找到了它们不能通过Clark-Wilson商业模型验证规则的关键点，并根据Clark-Wilson商业模型提出的经典场景，给出了相应的攻击场景。

基于Biba和Clark-Wilson策略的混合强制完整性模型

商业应用需要实施完整性策略保护.Biba模型提供了一种简洁的多级完整性控制方案,但是需要引入可信主体来保证实施的可用性.而Clark-Wilson模型通过可监控的状态转换提供了一种完备的完整性保护,但其复杂性影响了该模型的完整实现.提出的模型以Biba严格完整性策略为基础,同时根据可信主体在其生命周期所属的状态实施Biba低水标策略.对可信主体在其生命周期发生的状态转换及相应的低水标参数调整,采用Clark-Wilson模型来进行监控.在有效解决了Biba策略的可用性问题和Clark-Wilson模型监控量过大给系统带来的配置和运行负担问题的同时,继承它们的优点.证明了该策略融合方案是可行的、安全的.