Seismic Response Analysis of Long-Span Suspen-Dome under Multi-Support Excitations

A practical suspen-dome project, Changzhou Gym roof, is adopted as an example and its transient analysis based on the multi-support excitations of the earthquake wave is carried out. Compared with the single support excitation, the position and value of the maximum stress under multi-support excitations both change and the amount of elements with obvious changes is large and more than 70% of the total. Moreover, when other terms are not changed, this influence will decrease as the span decreases, but increa...

Effect of opening the Drake Passage on the oceanic general circulation:A box model study

The impacts of opening the Drake Passage(DP) on the oceanic general circulation are examined.When the DP is open,wind stress at mid-and high latitudes gives rise to a wind-driven gyre,which induces a meridional heat exchange between mid-and high latitudes in the Southern Ocean.After the opening of the DP,the Antarctic Circumpolar Current(ACC) forms and its associated strong temperature front blocks the heat transport from mid-latitudes to high latitudes.A simple box model is formulated,in which the effects of the wind stress(for the case of DP closed) and the thermal front(for the case of DP open) on the variability of Antarctic Bottom Water(AABW) and North Atlantic Deep Water(NADW) are explored.The sensitivity experiments demonstrate that:(1) When the DP is closed,the enhancement of the wind-driven gyre leads to the decline of AABW formation in the Southern Ocean and the increase of NADW formation in the North Atlantic.As a result,water in high latitudes of the Southern Ocean becomes warmer,so does the bottom water of global ocean.(2) When the DP is open,there is no formation of AABW until the intensity of thermal front along ACC exceeds a threshold value(it is 4.03℃ in our model).Before the formation of AABW,temperature in most of the oceans is higher than that after the formation of AABW,which usually leads to the cooling of high latitudes of the Southern Hemisphere and the bottom water in global ocean.When the strength of the thermal front is lower than the critical value,there is no AABW formation,and temperature in most of the oceans is slightly higher.These results demonstrate that during the opening of the DP,changes in wind stress and the formation of the thermal front in the Southern Ocean can substantially affect the formation of AABW and NADW,thus changing the state of meridional overturning circulation in the global ocean.

An effective description of a periodic one-dimensional hopping model

The periodic one-dimensional hopping model is useful for studying the motion of microscopic particles in the thermal noise environment. Based on the explicit formulations of mean velocity, mean first passage time and effective diffusion constant, a general N internal states or even infinite internal states model can be approximated by a one state model that retains the basic properties of the original process. This effective description aids the analysis of biochemical and biophysical problems. This effective description also implies that, to some extent, many processes can be well described by simple two-state models, or even one-state models.