The area of well rice in the sanjiang Plain is incresing recently.At the same time,the groundwater resource has been wasted.Thus,the resource of groundwater is shortening.More and more area appears the phenomenon of ...The area of well rice in the sanjiang Plain is incresing recently.At the same time,the groundwater resource has been wasted.Thus,the resource of groundwater is shortening.More and more area appears the phenomenon of “hanger pump” and “funnel”.According to these problems the paper adopts Chuang Ye farm as the research base,through handle the data of groundwater,applying GM(1,1) to forecasting the dynamic variation of groundwater.The writer hopes to provide some references about using groundwater resource of the area in the future for readers.展开更多
The paper builds up the forecasting model of air temperature according to the data (1994～1998) of Fu Jin area.At the same time,the writer inquires into the relation of water requirement of well irrigation rice (ET) a...The paper builds up the forecasting model of air temperature according to the data (1994～1998) of Fu Jin area.At the same time,the writer inquires into the relation of water requirement of well irrigation rice (ET) and average air temperature (T).Furthermore,the rice irrigation water requirement (ET) of Fu Jin area has been forecast in 1999.Thus,we can apply the model in irrigation management.展开更多
The optoelectronic telescope has two sets of control systems: azimuth one and elevation one, and both are driven by PWM power amplifier with high efficiency and wide speed regulation range. The diagram of the azimuth ...The optoelectronic telescope has two sets of control systems: azimuth one and elevation one, and both are driven by PWM power amplifier with high efficiency and wide speed regulation range. The diagram of the azimuth control system is demonstrated, the nonlinear factors is analyzed at low speed, and some related experiments are carried out. The results show that the positioning error with unipolar is 86 codes(106.21″), while 18 codes (22.23″) is with bipolar PWM driver.展开更多
基金China Postdoctoral Science Fund.The Youth Fund of Si Chuon University ( 4 3 2 0 2 8)
文摘The area of well rice in the sanjiang Plain is incresing recently.At the same time,the groundwater resource has been wasted.Thus,the resource of groundwater is shortening.More and more area appears the phenomenon of “hanger pump” and “funnel”.According to these problems the paper adopts Chuang Ye farm as the research base,through handle the data of groundwater,applying GM(1,1) to forecasting the dynamic variation of groundwater.The writer hopes to provide some references about using groundwater resource of the area in the future for readers.
基金Funditem:China Postdoctoral Science Fund(2 0 0 0 ).The Youth Fund of Sichuan U niversity.(43 2 0 2 8)
文摘The paper builds up the forecasting model of air temperature according to the data (1994～1998) of Fu Jin area.At the same time,the writer inquires into the relation of water requirement of well irrigation rice (ET) and average air temperature (T).Furthermore,the rice irrigation water requirement (ET) of Fu Jin area has been forecast in 1999.Thus,we can apply the model in irrigation management.
基金Natural Science Foundation from Science & Technology Department of Jilin Province(HJ2003013)
文摘The optoelectronic telescope has two sets of control systems: azimuth one and elevation one, and both are driven by PWM power amplifier with high efficiency and wide speed regulation range. The diagram of the azimuth control system is demonstrated, the nonlinear factors is analyzed at low speed, and some related experiments are carried out. The results show that the positioning error with unipolar is 86 codes(106.21″), while 18 codes (22.23″) is with bipolar PWM driver.
