Nonlinear Correlations of Protein Sequences and Symmetries of Their Structures

We investigate the nonlinear correlations of protein sequences by using the nonlinear prediction method developed in nonlinear dynamical theory. It is found that a lot of protein sequences show strong nonlinear correlations and have deterministic structures. Further investigations show that the strong nonlinear correlations of these protein sequences are due to the symmetries of their tertiary structures. Furthermore, the correlation lengths of the sequences are related to the degrees of the symmetries. These results support the duplication mechanism of protein evolution and also reveal one aspect how amino acid sequences encode their spatial structures.     

硫醚型芳香族二胺单体的合成及应用

以对氨基硫酸及４，４＇－二氯基二苯砜为原料合成了含硫醚键芳香族二胺单体：，用它制备的聚酰亚胺显示了良好的耐热性能。     

多路噪声测量系统的研制

本描述了多路噪声测量系统的建立,该系统是一以微机为中心的数字化系统,可实现对４路稳态宽带噪声的测量,测量参数是线性声压级和倍频带声压级。系统由微机、ＴＭＳ３２０Ｃ３０板、多路ＡＤ板、传感器、放大器等设备构成硬件系统,并通过编制Ｃ３０板嵌入式软件和微机主控程序实现系统功能。在软件编制中结合数字信号处理技术,并结合硬件特性优化程序设计,本系统测量方法简易,快捷和精度高,在噪声测量领域具有较高实用价值