阵列纳米通道对微纳复合管道耗散作用的强化

微纳复合管道是目前微流控应用中的热点之一.该文分别模拟了单根纳米通道和纳米通道阵列对微纳管道结合部的离子耗散作用的影响,计算了两种管道系统内的离子浓度场、电势场、速度场及压力分布.计算结果表明:阵列纳米通道比单纳米通道的离子耗散强度提高了5倍;由Nernst-Planck方程分析得出电场梯度引起的电迁移在耗散过程中其主导作用;采用Navier-Stokes方程引入电场体积力模拟得出,阵列纳米通道连接的微纳管道耗散区存在多对涡漩.这增强了耗散区扩展的速度,使耗散区浓度值更低且扩展空间更大,从而解释了阵列纳米管道连接的微纳复合管道相比单纳米通道具有更强的耗散效应的原因.     

Observation of the induced pressure in a hybrid mlcro/nano-channel

This paper studies the flow characteristics in micro/nano-channels subjected to an applied electric field. The nano-channel flow was observed by means of the fluorescence Calcein. A Fluorescence Concentration Gradient Interface (FCGI) was observed across the nano-channel array. The front of the FCGI was shown to have an analogous parabolic shape. The propagation of this interface reflects indirectly the induced pressure at the micro/nano-channel junction, where the enrichment-depletion processes are known to take place. This induced pressure was predicted by numerical simulations, and this paper gives the first experimental evidence.     

用于水下测量的二分力天平

本文介绍一种用于水下测量的二分力天平，天平采用内式悬臂梁双变形结构，把力和力矩的测量分开，避免了力作用点变化对测量结果的影响，天平设计和严格的加工精度保证了二分力之间干扰系数接近零，天平防水层采用了特制涂料，使用该天平在水洞中进行了单柱水动力系数测量实验，并将实验结果与已有的数据作了比较。