Monte Carlo Simulation of Chromatin Fiber Conformation Affected by Ionic Strength

我们通过建立核小体纤维模型，采用MonteCarlo方法模拟得出的核小体结构参数能与实验结果较好地符合，例如我们通过得出温度为300K的生理溶液浓度下核小体纤维的平均直径为24.3nm,与实验值32nm接近。而且我们模型还定性地显示了从低浓度到高浓度的过程中，核小体纤维从锯齿状到超螺旋结构的变化过程，这也与一系列地实验结果相吻合。我们还分析了静电能对核小体纤维结构形成的贡献，较好的解释了溶液浓度对核小体纤维状态的影响问题。可见此模型和方法对研究核小体纤维的形成机制有一定的合理性和适用性，可以得出某些定量的结果。Using Monte Carlo simulation, we model chromatin fiber and gain the structural parameters which well agree with the experiment results. For example, the average fiber diameter 24.3nm in the physiological ionic solution from our simulation is close to the experimental value 32nm. Furthermore, the simulation predicts the fiber transits from a breadlike state to a super helix state when we increase t...学位：理学硕士院系专业：物理与机电工程学院物理学系_理论物理学号：20012403

Monte Carlo simulation of chromatin fiber conformation affected by ionic strength

通过核小体纤维模型的构建,利用MontoCarlo方法模拟其在各种钠离子浓度的溶液中结构变化的过程.模拟结果显示当溶液的钠离子浓度增大时,核小体由锯齿状结构转变为螺旋状结构.在常温所得到的核小体结构参数与实验结果接近,较好地解释了溶液中的钠离子浓度对核小体纤维结构的影响.In this paper, using Monte Carlo simulation, we obtain different structures of chromatin fibers with different ionic concentration. The result shows that as the ionic concentration is increased, the fiber undergoes a conformational change from sawtooth state to super-helix state. The structural parameters obtained by simulation agree well with the experimental results, indicating that our model is useful in explaining the conformational change of chromatin fibers in different ionic solutions.国家自然科学基金(批准号:10225420,90206039,20021002)资助的课题~

Monte Carlo Simulation of Two-dimensional Magnetic Nanostructured Materials

【中文文摘】运用MonteCarlo模拟方法,通过分析系统自旋序参数与温度的变化关系了解纳米结构材料磁性的特征.计算模拟结果表明,磁性纳米材料具有比同等大小和平均密度的单晶低的居里温度,且在相变过程中往往会出现一些亚稳态.研究结果提供了一种解析金属纳米结构材料特性的重要方法. 【英文文摘】In this article, Monte Carlo simulation is applied to analyze the characteristics of twodimensional magnetic nanostructured materials. It is shown that nanostructured materials possess lower Curie temperature in comparison with crystalline materials with the same size and average densities. In addition, some mesoscopic states tend to appear in the transition processes of nanostructured materials. The result presented here gives an important approach to analyze nanostructured metal materials.国家自然科学基金纳米科技基础研究重大研究计划(90602039);; 中科院创新工程(K81045)资助项

Monte Carlo simulation of magnetic nanostructured thin films

Using Monte Carlo simulation, we have compared the magnetic properties between nanostructured thin films and two-dimensional crystalline solids. The dependence of nanostructured properties on the interaction between particles that constitute the nanostructured thin films is also studied. The result shows that the parameters in the interaction potential have an important effect on the properties of nanostructured thin films at the transition temperatures