Large Time Behavior of Solutions for General Navier-Stokes Systems in Multi-Dimension

Through the estimates for Greens function of linearized system, we obtain L p estimates of the asymptotic behavior of solutions of the Cauchy problem for the Navier Stokes systems of compressible flow in several space dimensions.

多重分形的振动信号故障特征提取方法

针对非线性振动信号故障特征提取问题,提出一种广义维数均值(MeanDq)联合多重分形谱参数(Δα和Δf)的动特征提取方法。首先分析了振动信号的多重分形特性,然后计算出MeanDq,Δα和Δf分别作为故障特征量,并将其应用于滚动轴承故障状态的检测。研究表明:MeanDq,Δα和Δf能够有效地反映滚动轴承振动信号的状态,并且特征量MeanDq和Δα较Δf具有更好的灵敏度。实践证明该方法在实际应用中切实可行。