The dynamic surface elasticity of the solution of carboxymethylchitosan (CMCH) and cetyltrimethylammonium bromide (C 16 TAB) was measured as a function of the surfactant concentration and the surface age by the oscillating drop method. The results showed that the surface layer of the CMCH/C 16 TAB solution transformed from loose to structured with the increase in the surfactant concentration. The surface elasticity versus the surface pressure curve during the adsorption showed different features at different surfactant concentration ranges, which was connected with the structural transformation of the surface layer. Our results show that the measurement of dynamic surface dilational properties is a powerful tool for studying the surface kinetics, which is helpful for dealing non-equilibrium systems in industry.

As a convenient, fast, reliable and economic value-added service, CDMA Short Message Service (SMS) becomes more and more popular in our daily work and lives. In this paper, the software package for sending and receiving short messages is realized, and it has simple interfaces and perfect functions. Based on WINCE 6.0, the USB port of Samsung S3C6410 is used as a virtual serial to realize the transmission of AT commands, and a specific realization of the processes and debugging results are given. The actual test results show that the software package can work stably. It can be used in the devices that support the WINCE 6.0.