Method of field survey for debris flow is classified into two types: regional survey and gully investigation.

Mountain Wulian Nature Reserve is located in the southeast coastal region of Shandong Province,to fully understand their community structure and species diversity,the author conducted a field survey,and obtained 11 standard samples,whose total area is 6 600 m2.

Finally the article also illustrates the external regulating method for enhancing extraction capacity of the non-regulated turbine.

The new type velocity sensor takes infrared modulation circuit to lower the effects of surrounding light on velocity measurement, and its the velocity data acquisition system is equipped with industrial pulse counting block.

Effect of chirp in external modulator on 10 Gbit/s dispersion compensation system;

The key points to design high speed burst mode external modulator are presented,the effects of extinction ratio and chirp on optical transmitter are discussed,then the matching technology is discussed in detail.