点阴极电场辅助阳极连接中的紧密接触面积和电流

用等效电路的方法研究了点阴极情况下的电场辅助阳极连接效应，计算了连接电流，连接孕育期和紧密接触面积，本文结果表明，连接初期电流迅速衰减，随后缓慢变小，直至某一稳定值，孕育期随温度上升指数下降，连接温度高时，孕育期将难以观察到；待连接表面之间紧密接触面积随时间延长而非线性扩展，紧密接触区域增大时，其边界向外推进速度渐小，而接触面积增加渐快。     

Unfolding mechanism of rubredoxin from Pyrococcus furiosus

As part of our studies on the structural and dynamic properties of hyperthermostable proteins, we have investigated the unfolding pathways of the small iron-sulfur protein rubredoxin from Pyrococcus furiosus (RdPf) at pH 2. Unfolding has been initiated by temperature jump, triggered by manual mixing of a concentrated protein solution into a thermally preequilibrated buffer. The process has been followed in real time by absorption, tryptophan fluorescence emission, and far-UV circular dichroism. Unlike the case of the mesophilic rubredoxin from Clostridium pasteurianum (RdCp), RdPf displays a complex unfolding kinetics, pointing to the formation of at least three intermediates. All of the steps, including the one involving metal ion release, are extremely slow. However, hydrophobic core relaxation--not Fe3+ loss--is rate-determining for RdPf unfolding. This clearly rules out the fact that Fe3+ is solely responsible for the kinetic stability of RdPf. Results have been discussed in terms of sequential vs parallel pathways, and the possible role of irreversible phenomena has been taken into consideration. Aggregation does not appear to play a significant role in the observed kinetic complexities. According to a proposed sequential mechanism, partial release of secondary structure elements precedes iron loss, which is then followed by further loss of beta-sheet content and, finally, by hydrophobic relaxation. Although the main features of the RdPf unfolding mechanism remain substantially unchanged over the experimentally accessible temperature range, final hydrophobic relaxation gets faster, relative to the other events, as the temperature is decreased. A qualitative assessment of the unfolding activation parameters suggests that this arises from the very low activation energies (Ea) that characterize this step.     

生物质秸秆墙材—新型墙材的发展方向

秸秆是第二大“森林”资源，将秸秆制备成墙材，既找到大量秸秆资源化的出路，也填补了墙材即将面临短缺的难题。综述了生物质秸秆墙材的研究进展，讨论了目前秸秆墙材研究与应用中存在的问题，探讨了秸秆墙材将来研究的趋势。     

ACES尿素装置高压设备腐蚀情况研究

介绍ACES尿素工艺的特点及其设备选材,重点阐述了渭化ACES装置高压设备腐蚀和失效的基本规律,分析了腐蚀产生的原因,从结构设计、钢材选用、设计加工、运行维护和设备管理等方面提出了防范措施。     

改进行移编码的文本数字水印算法研究

研究了文本数字水印在追溯涉密纸质文档中的重要意义,介绍了常见的文本数字水印技术,分析了Brassil经典行移编码文本数字水印技术,在算法的标记策略中引入检验编码,文本行分割划段和引入基调行三个方面进行改进,改进后算法具有更大水印信息容量,更强的鲁棒性和可控的计算量.     

一种改进的智能卡数据传输安全策略

针对传统智能卡进行数据传输时仅支持单一模式的缺点,提出一种改进的基于模式控制字的数据传输安全策略。此模式控制字支持多种数据传输模式,数据可以采用明文、密文、明文MAC、密文MAC中的任一种方式进行传输,并通过基本文件(包含透明文件、线性文件)的读、写模式控制字,来规定文件进行读、写操作需要满足的传输安全条件。同时,还提出使用禁止添加、或禁止更新这两种写属性来限制基本文件的写入方式。用户可以根据自己的需求,将同一文件的读命令,和写命令采用的传输方式设置成不一样,从而选择不同的数据传输方式,进而提高数据传输的灵活性和安全性。