The growth of correlations in the matter power spectrum

We find statistically significant correlations in the cosmological matter power spectrum over the full range of observable scales. While the correlations between individual modes are weak, the band-averaged power spectrum shows strong non-trivial correlations. The correlations are significant when the modes in either one or both bands are in the non-linear regime, and approach 100 per cent for pairs of bands in which all the modes are non-linear. The correlations are weaker, but not absent, when computed in redshift space. As estimates of the power spectrum from galaxy surveys require band-averaging, the correlations must be taken into account when comparing a measured power spectrum with theoretical models.     

灰色聚类分析在煤矿瓦斯分区中的应用

以灰色理论为依据,结合南屯煤矿瓦斯分布规律的研究,探索了利用灰色聚类分析进行煤矿瓦斯分布规律研究的一般方法。      

Dynamics of ocean cables with local low-tension regions

A general set of 3-D dynamic field equations for a cable segment is derived based on the classical Euler-Kirchhoff theory of an elastica. The model includes flexural stiffness to remove the potential singularity when cable tension vanishes and can be reduced to the equations for a perfectly flexible cable. A hybrid model and a solution scheme by direct integration are then proposed to solve the oceanic cable/body system with a localized low-tension region. Numerical examples demonstrate the capability and validity of the formulation and the numerical algorithm.     

斜压海洋动力学的一种三维数值模式──Ⅱ.温度、盐度和垂直涡动粘性系数的计算

根据海水温度和盐度平流扩散方程给出一种数值计算方案并采用混合长度理论给出垂直涡动粘性系数的计算方法。对于温度和盐度方程,其平流过程采用了Lax－Wendroff格式,水平扩散采用显格式,垂直扩散采用隐格式。时间步长主要受平流过程的Courant-Friedrichs-Lewy条件限制。垂直涡动粘性系数计算依据Prandtl混合长度理论,并考虑了海水层化的抑制作用,因而其数值与流场及密度场结构有关。温度、盐度及垂直涡动粘性系数的计算与动力方程中内模态的计算同步进行。应用本模式模拟渤、黄、东海由潮流、密度流和风海流迭加而成的综合海流,得出了良好的结果。