A practical optical fiber differential pressure sensor is presented at first. Then the techniques of light source feedback, set up of reference channel, proportional measurement and other methods to improve the stabil...A practical optical fiber differential pressure sensor is presented at first. Then the techniques of light source feedback, set up of reference channel, proportional measurement and other methods to improve the stability of the system as well as to reduce the interference with same nature are emphatically discussed. Finally, the experiment results of the developed instrument are given.展开更多
The paper studied the photosynthetic and water physiological characteristics of Cinnamomum septentrionale.The results indicated that the light saturation point of C.septentrionale was 1 301 μmol·m-2·s-1,and...The paper studied the photosynthetic and water physiological characteristics of Cinnamomum septentrionale.The results indicated that the light saturation point of C.septentrionale was 1 301 μmol·m-2·s-1,and the light compensation point was only approximately 17 μmol·m-2·s-1.It had a quite low light compensation point and a higher saturation point.It belongs to a heliophytic tree species,but it also could tolerate shade,and was suitable to a multiple light condition.The utilization efficiency of water of C.septentrionale reached 3.476×10-3 g·g-1,more than those of Celtis sinensis,Ulmus gaussenii,Pteroceltis tatarinowii and Zelkova schneideriana and 1.88 times higher than that of Pterocarya stenoptera.The results suggested that the water utilization efficiency of C.septentrionale is high and has a similar drought-resistant ability with Ulmaceae plant.展开更多
文摘A practical optical fiber differential pressure sensor is presented at first. Then the techniques of light source feedback, set up of reference channel, proportional measurement and other methods to improve the stability of the system as well as to reduce the interference with same nature are emphatically discussed. Finally, the experiment results of the developed instrument are given.
文摘The paper studied the photosynthetic and water physiological characteristics of Cinnamomum septentrionale.The results indicated that the light saturation point of C.septentrionale was 1 301 μmol·m-2·s-1,and the light compensation point was only approximately 17 μmol·m-2·s-1.It had a quite low light compensation point and a higher saturation point.It belongs to a heliophytic tree species,but it also could tolerate shade,and was suitable to a multiple light condition.The utilization efficiency of water of C.septentrionale reached 3.476×10-3 g·g-1,more than those of Celtis sinensis,Ulmus gaussenii,Pteroceltis tatarinowii and Zelkova schneideriana and 1.88 times higher than that of Pterocarya stenoptera.The results suggested that the water utilization efficiency of C.septentrionale is high and has a similar drought-resistant ability with Ulmaceae plant.