参数具有对称性的等变分歧问题的通用开折

讨论分歧参数带有对称性的等变分歧问题在左右等价群的一个子群下的开折,分别给出了其开折是平凡和通用的充要条件.     

奇奇核^84Y的能谱统计

用粒子－转子模型计算奇奇核＾８４Ｙ低自旋下的能谱,重点研究不同自旋下能谱最近邻能级间距分布（ＮＮＳ）和能谱刚性度（△３）的特点,并就影响能谱统计特征的因素进行了分析。     

Helix H1 of the prion protein is rather stable against environmental perturbations: molecular dynamics of mutation and deletion variants of PrP(90–231)

We need to understand the underlying factors that promote or reverse the amyloid-type structure of the prion protein (PrP). In an earlier study, we showed that mutations within the first strand can extend the short sheet in the normal protein into a larger sheet at neutral pH. To determine the impact of the point mutation P102L and the deletion of either the first or the second strand on PrP, we performed further long molecular explicit water dynamics simulations. The trajectories show that all mutations do not exert a uniform effect on the dynamics of the N-terminal tail. The results of the deletion of the two strands confirm the idea that partially unfolded conformations are involved in the structural transition. In the deletion variants, the helices H2 and H3 are disordered, while helix H1 is either fully stable or partially disordered. This finding, consistent with recent spectroscopic analyses on peptides spanning helix H1 and flanking sequences, demonstrates that unfolding of the full domain containing helix H1 is not an early step in PrP interconversion. This result also raises questions regarding a current view of PrP^Sc structure that transforms helix H1 into a sheet conformation.Received 16 December 2003; received after revision 16 January 2004; accepted 21 January 2004     

基于碳化硼慢化体和涂硼微结构中子探测器的通用中子能谱仪设计和解谱方法研究

本文提出了一种基于碳化硼慢化体和涂硼微结构中子探测器的通用中子能谱仪设计方法, 获得了计算最优慢化体厚度和探测器响应函数的通用公式, 并用蒙特卡罗方法进行了验证和修正, 可实现对中子能谱仪的快速设计. 该类能谱仪可实现各中子响应函数之间的解耦, 使每个探测器对各个分立能量区间的中子最为敏感, 具有较强适用性和灵活性. 基于该方法, 我们设计了一个用于硼中子俘获治疗（BNCT）超热中子能谱测量的能谱仪, 通过Gravel算法实现了中子能谱解析, 并提出了一种具有良好普适性的基于响应函数的预置谱设置方法. 结果表明, 该能谱仪对单能中子的峰位解析精度约为1%, 对BNCT连续谱的解析均方差约为0.76%, 具有较大技术优势和可行性.     

具有非理想界面的双曲方程的均匀化问题（英文）

研究了二分区域上一类具有非周期系数的双曲问题.利用二分区域的时间相关的周期unfolding方法,得到了该问题的均匀化及其矫正结果,这一工作推广了带周期系数的双曲问题的结果.     

Molecular dynamics simulation of RNA pseudoknot unfolding pathway

Many biological functions of RNA molecules are related to their pseudoknot structures. It is significant for predicting the structure and function of RNA that learning about the stability and the process of RNA pseudoknot folding and unfolding. The structural features of mouse mammary tumor virus (MMTV) RNA pseudoknot in different ion concentration, the unfolding process of the RNA pseudoknot, and the two hairpin helices that constitute the RNA pseudoknot were studied with all atom molecule dynamics simulation method in this paper. We found that the higher cation concentration can cause structure of the RNA molecules more stable, and ions played an indispensable role in keeping the structure of RNA molecules stable; the unfolding process of hairpin structure was corresponding to the antiprocess of its folding process. The main pathway of pseudoknot unfolding was that the inner base pair opened first, and then, the two helices, which formed the RNA pseudoknot opened decussately, while the folding pathway of the RNA pseudoknot was a helix folding after formation of the other helix. Therefore, the unfolding process of RNA pseudoknot is different from the antiprocess of its folding process, and the unfolding process of each helix in the RNA pseudoknot is similar to the hairpin structure’s unfolding process, which means that both are the unzipping process.     

光滑映射芽的相对无穷小稳定性

刻画了光滑映射芽开折的相对无穷小稳定性,并给出了开折是相对无穷小稳定的充要条件。