In this study, we explored relationships between plant biomass and emission of greenhouse-gases. The biomass of different plant community (Deyeuxia angustifolia、Carex lasiocarpa and Carex pseudocuraic ) and emission of CH4、N2O were studied in the typical freshwater wetland in sanjiang plain from June to September, 2003. The result suggests, the season variations of the aboveground biomass can be described by parabola model Y=a+bT+cT2. The emission of CH4 showed strong difference in the plant zones and the trend is reduction from center to brim in the sanjiang wetland. The emission of N2O of communities expresses the trend of “up-down-up”. But the first time of the top emission is earlier in the Deyeuxia angustifolia than Carex lasiocarpa and Carex pseudocuraic distinctly. By analyzed, the biomass of different plant community has the strong linear relation with the cumulated emission of CH4、N2O before the plants reaches its largest aboveground biomass during growing seasons. And it can be described by function Y=aX＋b, theirs R2 were almost over 0.89.
E-cash (Electronic cash) is an important Electronic payment tool, which is the bottleneck of e-commerce development. Most proposed e-cash schemes are unpractical although it has been studied more than two decades. One of the shortcomings is that the interest of e-cash between drawing and consuming is lost. An off-line interest countable electronic cash scheme is proposed in this paper. The e-cash’s interest can be counted from the time of customers drawing to paying in the scheme. The communication cost is reduced due to its off-line environment.