可更换狭缝仪

第 21篇应用文章描述了用圆柱形孔作为案例，GCMC相比于NLDFT法能正确的评估孔径大小和孔体积。此文运用GCMC方法对狭缝孔活性炭纤维（ACFs）进行孔结构评价，并根据结果对孔形模型进行验证。

UV-1100紫外分光光度计的光谱带宽和狭缝宽度的区别UV-1100紫外分光光度计的光谱带宽和狭缝宽度的区别UV-1100紫外分光光度计的光谱带宽和狭缝宽度的区别

In this work the influence of the internal flow field on the liquid film was investigated. A strategy for reliablePIV measurements inside of nozzle channels with a height of only a few hundred micrometers and at flowvelocities of several m/s has been developed. These PIV measurements provided 2 dimensional snapshots of thevelocity field inside the nozzle as well as velocity- and fluctuation-profiles across the channel. The developmentof the channel flow could be observed along the channel length at laminar and partly turbulent flow conditions.Disturbances were introduced to the flow field by inserting a wire into the channel flow. PIV measurementsshowed the resulting change of the nozzle flow (in the wake of the wire and without wire, respectively). Theresulting effects on the free liquid film were observed using back-lit photographs and perpendicular lightsectionsthrough the film surface. In the case of the undisturbed nozzle, velocity fluctuations occurred mainly inthe boundary layer and the fluctuations in main streamwise direction were dominant. The free liquid film of thisnozzle was smooth at the exit and only at higher Re numbers the growth of surface waves could be observedfurther downstream. The nozzle with inserted wire showed a high level of velocity fluctuation in the center of theflow. Here, the fluctuations normal to the walls were of the same magnitude as the fluctuations in streamwisedirection. The liquid film of this nozzle was roughened directly below the nozzle exit, even at low Re numbers.The high level fluctuations normal to the wall are assumed to play the dominant role in this process. Thesemeasurements demonstrate the influence of the internal flow field on the liquid sheet. The results of the presentwork agree well with recent experiments of Heukelbach and Tropea [1] and supplement the existingexperimental data which for example can be used as input or validation of numerical simulations.