Interference microscopy Subject

As schematically shown by Fig. 46a, ferrierite contains two mutually intersecting arrays of channels. In comparison with the strictly one-dimensional MOF crystals considered in the previous section, their analysis is additionally complicated by the existence of two rooflike parts on either side of the platelike main crystal body. It turned out, however, that these features did in no way complicate the method of analysis. Contrary to the MOFs, which required an additional activation step after each uptake experiment, methanol in ferrierite proved to be an ideal host-guest system, where one and the same crystal could alternately be subjected to adsorption and desorption without any perceptible change in the sorbate profiles. It were these special conditions under which interference microscopy could be developed to a technique of diffusion measurement in nanoporous materials of unprecedented power [63,65,70,71,88,89]. 

The method avoids the use of nonvolatile surfactants and polymers, which may be adsorbed onto the silver nanocubes and interfere with their possible applications in catalysis and anal3d ical devices based on SERS spectroscopy. Figure 8.9 shows the transmission electron microscopy (TEM) image of the nanocube obtained using 310 M CaC. It is evident that the nanocube is composed of smaller silver nanoparticles. The nanocubes show good SERS activity in the presence of adsorbed 4-MBA with excitation at 632.8 nm, and the enhancement factor reaches 7.610 . The nanocubes are produced in a simple and cost-effective way, and they are expected to play an important role in the development of SERS-based anal3Aical devices. The method may represent a novel route for preparation of metal nanocubes, which is a subject of intense interest. 

As it can be seen from the above, considerable progress has been made in numerical simulation of mixed EHD lubrication of real rubbing surfaces. Conversely, only a few experimental studies on this subject can be found in the literature. The first attempt to obtain EHD film thickness map for random rough surface was made by Guangteng et al. [8] using advanced optical interference technique. Another form of this technique was recently used by Luo et al. [9] for the study of influence of operating conditions on the real contact area. Fluorescence microscopy [10] seems to be also promising tool for the study of mixed lubrication but it is still in nascent. 

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