网络安全操作系统关键技术研究

 本文针对安全操作系统开发和安全操作系统网络适应性方面涉及的关键问题进行研究。从信息系统整体来看，安全操作系统是解决各种安全威胁的基础。在网络环境中，计算机系统面临复杂、多样的安全威胁，尤其是机密信息泄露的威胁。网络环境对安全操作系统的研究和开发实践提出了新的挑战和要求：1) 网络环境中需要多层次安全策略实施框架，而以安全内核为基础的安全操作系统总是将安全功能集中在最小的安全内核中；2) 安全操作系统机密性策略导致的单向信息流动与网络环境下的双向信息交互之间存在冲突，需要引入大量的可信主体；3) 网络环境中独立的节点间缺少必要的信任。

    本文对上述几个方面的关键问题进行研究，并取得如下的创新：

    第一，针对网络环境中多层次安全策略实施要求，探索基于虚拟机环境的安全操作系统体系结构。提出一种基于虚拟机的双内核体系结构，这种体系结构以隔离作为基础，将操作系统分解为可以单独设计、开发、测评的组件。还提出一种基于消息的策略体系结构来约束组件的开发和设计。分析了虚拟机环境下动态内存管理的隔离性问题，提出一种基于BLP模型的安全的内存管理方案。

    第二，对安全操作系统的可信主体进行了研究。 该研究涉及到判定可信主体、确定可信主体的安全需求以及评估可信主体对于整个系统的安全风险等多个方面。本文以信息流分析为基础，利用TE安全规范与MLS策略间的信息流冲突定位可信主体，确定可信主体的安全标签范围，采用风险分析法确定每个可信主体的安全保障级指派。

    第三，针对网络环境中信任缺乏的问题，研究建立远程信任的平台证明技术，尤其关注平台证明的隐私保护问题。本文提出一种隐私隐藏的度量体系结构，并给出了相应的远程平台证明方案，改进了基于TCG的IMA度量体系结构    存在的配置隐私泄露问题。在此基础上，提出一种二进制证明与属性证明结合的混合证明方案。该方案既具有平台配置隐私保护能力又不需要属性证明所必须的在线可信第三方。

    第四，对属性证明的配置隐私保护能力进行研究。本文提出了几种可以被用来攻击属性证明隐私保护的方法：奇异属性法、增量分析法和统计分析法，证实了属性证明并不具有完全的配置隐私保护能力， 需要在设计中满足一定条件才具有隐私保护能力。上述研究也可为属性证明的设计提供参考。

Effect of compatibilization on the properties of HIPS/PA1010 blends

Blends consisting of high-impact polystyrene (HIPS) as the matrix and polyamide 1010 (PA1010) as the dispersed phase were prepared by mixing. The grafting copolymers of HIPS and maleic anhydride (MA), the compatibilizer precursors of the blends, were synthesized. The contents of the IMA in the grafting copolymers are 4.7 wt % and 1.6 wt %, and were assigned as HAM and LMA, respectively. Different blend morphologies were observed by scanning electron microscopy (SEM); the domain size of the PA1010 dispersed phase in the HIPS matrix of compatibilized blends decreased comparing with that of uncompatibilized blends. For the blend with 25 wt % HIPS-g-MA component, the T-c of PA1010 shifts towards lower temperature, from 178 to 83 degrees C. It is found that HIPS-g-MA used as the third component has profound effect on the mechanical properties of the resulting blends. This behavior has been attributed to the chemical reaction taking place in situ during the mixing between the two components of PA1010 and HIPS-g-MA. (C) 2000 John Wiley & Sons, Inc.

Studies on polyepichlorohydrin-based polyurethane/poly(MMA-co-St) IPNs

Interpenetrating polymer networks of polyepichlorohydrin-based polyurethane/poly(MMA-co-St) have been prepared with simultaneous mettled by changing the weight fraction of MMA(W-MMA) in copolymer of MMA with styrene. The IPNs have been studied by DSC, TEM and dynamic mechanical spectroscopy(DMS). The results show that the IPNs have only one T-g, when W-MMA is greater than 0. 6. But when W-MMA IMA is less than 0. 4, the IPNs have two T(g)s, and phase separation is observed on TEM. The phenomenon is explained according to the solubility parameters(delta) and the fraction of hydrogen bond(delta(h)) of P (MMA-co-St). The study reveals that there is a close correlation among the delta, domain size and mechanical properties of PU (PECH)/P(MMA-co-St) IPN.

青藏高原东缘新生代富钾碱性岩的年龄与岩石地球化学特征

The Cenozoic high-Potassium alkaline magma rocks are widely distributed in the eastern margin of Qinghai-Xizang (Tibet) plateau, such as Mangkang, Deqin, Jianchuan, Haidong in the western Yunnan Province, Yanyuan, Muli in the western Sichuan province, including syenite, minette and trachyte and lamprophyres, which formaed a large alkaline-rich magmatic rock zone along the Jinshajiang-Ailaoshan fault. Here we present detailed Geochemical and Geochronology study for the Cenozoic high-K alkline magma rocks from Mangkang, Deqin, Jianchuan, Haidong and Muli, Yanyuan, Yanbian, Yaoan (western Yangtze craton). Rocks of our target area include syenite, minette and trachyte. Geochronologic dating and compilation of existing age data suggest magmatism occurred at 32-38Ma and distribute along the Jinsha suture, from Jinping, Daping, Zhenyuan to Haidong, Jianchuan, Deqin, Mangkang, Zaduo to Qiangtang Bandaohu, Zhentouya. They all share same geochemical features such as rich in potassium and alkaline, rich in LREE, slightly negative Eu anomalies, negative anomalies in Nb, Ta, Ti,. These indicate they come from EMU mantle. Geochronologic dating on western Yangtze craton minette surgest minette in Haidong, Yanyuan, Yanbian, Yaoan, Deqin ocurred at 30-37Ma, well minette in Muli ocurred at IMa. Need more detailed geology study to find differece of these two episode magmatism.