遗传余代数的特征

从同调代数的角度引入了遗传余代数的概念，并给出了它的几个重要的特征。     

疲劳裂纹扩展过载延迟效应微观机理的研究

应用自制的扫描电镜加载台,对60Si_2Mn弹簧钢过载后疲劳裂纹扩展的延迟效应进行了扫描电镜的直接观察.分析和讨论了延迟效应的微观机理.结果表明,拉伸过载引起的裂尖钝化及裂纹扩展方向的偏转都会导致延迟效应。     

偏序集拟阵中的三类算子及十四滤子定理

在具有逆序对舍对应的有限偏序集上的偏序集拟阵中定义了闭包、内部和取补3种算子，研究了这3种算子的一些性质，最后证明了偏序集拟阵中的十四滤子定理。     

A new Planetary Boundary Layer model and its application to heavy rain modeling

A new Planetary Boundary Layer （PBL） model （namely MY-4 in this paper） was developed with reference to Mellor-Yamada＇s Level 4 turbulent closure concept. Having been coupled with a meso-scale model MM5, MY-4 was utilized to simulate a heavy-rain process, which took place over South China during June 8-9, 1998. Its model outputs indicated that the rainfall process was well captured in terms of its intensity and geographical distribution. More importantly, in comparison with MM5＇s original boundary layer models, MY-4 made the following improvements： （1） MY-4 not only simulated the major weather systems like low vortexes and low-level jets more accurately, thus improving the general weather pattern of the rainfall process, but it was also capable of restraining the occurrence of false rainfall centers with maximum precipitation amounts exceeding 160 mm. （2） Having been compared with the wind profile observed at Hong Kong, it revealed that MY-4 could reproduce the wind speed fluctuations in a short time scale reasonably well, which was not yet achieved in the original PBL models in MM5. Furthermore, a more detailed comparative study was made on the results simulated by MY-4 and a PBL model （which is based on Mellor-Yamada＇s Level 2.5 concept） respectively. It showed that the contributions of turbulences generated by the two categories of PBL models to the wind fields at a lower atmosphere were increasingly different even in the first 1-2 hours of integrations. As the analysis demonstrated, under the nonlinear interactions within the meso-seale MM5 model, it was the turbulences in the boundary layer that had the most important impacts on the final model outputs and MY-4 seemed to better reflect this turbulent process, hence leading to the aforementioned improvements.     

大跨度PC连续刚构桥合拢施工措施

连续刚构桥一般都做成超静定的结构形式,因此砼收缩、徐变和温度变化等因素都会在结构内产生附加内力,因此对结构产生不利影响.介绍了大跨度预应力混凝土连续刚构桥减少营运期砼收缩徐变的新的合拢施工措施———主跨静置4个月后合拢,并用理论计算分析了该种合拢方式与常规合拢方式之间徐变影响的不同,为连续刚构桥的徐变控制提供了科学依据.     

从Warshall算法到求模糊矩阵传递闭包的一个简捷算法

模糊矩阵传递闭包的计算在模糊聚类中起着关键的作用,而模糊矩阵传递闭包与普通集合论中传递闭包是有密切联系的。从普通集合论中求关系闭包的Warshall算法和模糊关系图出发,论述并实现了一种求模糊矩阵传递闭包的有效算法。与经典的求模糊矩阵传递闭包的算法———平方法比较,该算法简捷,运算量小。最后分析了一个利用传递闭包法进行模糊聚类的实例。     

Rattling系统的一种随机模型

研究了一个叠加噪声的Rattling系统.代替常用的数值分析方法,采用非高斯截断技术导出一个由平均映射描述的离散随机模型．实例指出该模型能揭示浑沌随机性质,可用于模拟齿轮箱噪声源     

具半局部根的模与拟遗传代数

证明下面结论：设Ａ是有限维代数，Ａ的根的为Ｎ．设Ｍ是Ｌｏｅｗｙ长度为ｍ＋１的Ａ－模，并且对任意的ｉ，０≤ｉ≤ｍ，ＮｉＭ是半局部模，则ＥｎｄＡ（ｍｉ＝１ＮｉＭ）是拟遗传代数     

累积矩删去法分析过滤白噪声地震输入的随机响应

分析了地基土－非线性结构相互作用体系在过滤白噪声地震输入下的随机响应，在控制运动方程中增加一个过滤方程，再把它们转化成伊藤方程，并应用伊藤微分规则即可建立矩方程，采用累积矩删去法可使原来的无穷系列矩方程组成为闭合方程组，从而求出各阶统计矩，数例表明，用本方法所算得的均方根响应与用Ｗｉｅｎｅｒ－Ｈｅｒｍｉｔｅ展开式方法所算得的结果非常接近，这说明本方法可应用于求解工程实际问题并具有足够的精度。     

随机参变激励下系统的稳定性分析

本文介绍随机稳定性的基本概念,应用高斯截断法分析随机参变激励下系统的均方稳定性,给定了响应的均方稳定条件并讨论其数值计算结果.