论美是理想的形式

美是以理想为核心的主体本质力量对象化的产物。美的本质是在人类社会实践基础上形成的既符合客观世界本质规律、又符合人类全面发展的长远目的即符合人类社会历史进步要求的理想关系。这种理想关系包含认识关系和伦理关系 ,又高于认识关系和伦理关系 ,是一种主体与客体、感性与理性、形式与内容、现实与未来辩证统一的更具创造性、超越性、前瞻性的本质关系 ,而美的事物则是这种真善统一、和谐自由的理想关系的感性显现。美的内容是形式化了的理想 ,美的形式是理想化了的形式。随着人类社会实践活动的推进 ,理想关系逐步向更高层次提升 ,美的事物也在保持相对恒久的同时 ,发展着革故鼎新的变易性。

汉语韵部、声调的变化及其对新诗的影响

现代汉语韵部数量处于历史"低值"且得益于通用语的普及,新诗用韵环境处于历史最为优越的时期。古、今汉语声调虽然发生了一些变化,但调类总数均为4个,就声调的特性来看,都可分为比较平稳、少起伏的高平调,以及起伏大、调值较低的仄声调两类,因而平仄规则在现代语境中仍然存在语言学的可能性。"美的形式"的缺失,可能损害内在精神的有效表达;"有意味的形式"可以传达言词、句子结构无法表达的某些情感或意义,有利于创作者在艺术层面更充分、更有力地表现丰富复杂的内心世界与现实世界。

Formal analysis of robust email protocol based on authentication tests

Based on the authentication tests and the strand space model, the robust email protocol with perfect forward secrecy is formally analyzed, and the security shortcomings of the protocol is pointed out. Meanwhile, the man-in-the-middle attack to the protocol is given, where the attacker forges the messages in the receiving phase to cheat the two communication parties and makes them share the wrong session keys with him. Therefore, the protocol is not ensured to provide perfect forward secrecy. In order to overcome the above security shortcomings, an advanced email protocol is proposed, where the corresponding signatures in the receiving phase of the protocol are added to overcome the man-in-the-middle attack and ensure to provide perfect forward secrecy. Finally, the proposed advanced email protocol is formally analyzed with the authentication tests and the strand space model, and it is proved to be secure in authentication of the email sender, the recipient and the server. Therefore, the proposed advanced email protocol can really provide perfect forward secrecy.