近亲尖额溞Alona affinis(Leydig,1860)的若干生物学特征

本文测量计数了采自贵州省江口县凯土河边的154个近亲尖额溞的体长和怀卵量,并探讨了这个种群的一些生物学性状。根据形态特征,确定本种为指名模式亚种。

January to August temperature variability since 1776 inferred from tree-ring width of Pinus tabulaeformis in Helan Mountain

IEECAS SKLLQG

Dust weather records in Beijing during 1860-1898 AD based on the Diary of Tonghe Weng

IEECAS SKLLQG

Oscillatory Instabilities of Two-Layer Rayleigh-Marangoni-Benard Convection

The Rayleigh–Marangoni–Bénard convective instability (R–M–B instability) in the two-layer systems such as Silicone oil (10cSt)/Fluorinert (FC70) and Silicone oil (2cSt)/water liquids are studied. Both linear instability analysis and nonlinear instability analysis (2D numerical simulation) were performed to study the influence of thermocapillary force on the convective instability of the two-layer system. The results show the strong effects of thermocapillary force at the interface on the time-dependent oscillations at the onset of instability convection. The secondary instability phenomenon found in the real two-layer system of Silicone oil over water could explain the difference in the comparison of the Degen’s experimental observation with the previous linear stability analysis results of Renardy et al.

Relationships Between Initial Unloading Slope, Contact Depth, and Mechanical Properties for Conical Indentation in Linear Viscoelastic Solids

Using analytical and finite element modeling, we examine the relationships between initial unloading slope, contact depth, and mechanical properties for spherical indentation in viscoelastic solids with either displacement or load as the independent variable. We then investigate whether the Oliver-Pharr method for determining the contact depth and contact radius, originally proposed for indentation in elastic and elastic-plastic solids, is applicable to spherical indentation in viscoelastic solids. Finally, the analytical and numerical results are used to answer questions raised in recent literature about measuring viscoelastic properties from instrumented spherical indentation experiments.