Variation in concentrations of the airborne particulate matters(PM)in three kinds of typical recreation forests in Baiwang Mountain,West Mountain area of Beijing were observed day and night in spring.Results showed th...Variation in concentrations of the airborne particulate matters(PM)in three kinds of typical recreation forests in Baiwang Mountain,West Mountain area of Beijing were observed day and night in spring.Results showed that:1)Diurnal variations of PM concentrations in three kinds of typical recreation forests in West Mountain of Beijing area in spring were all synchronous.Curves of diurnal variation of PM concentrations had two peaks and two vales,and two peaks presented at 7:00-9:00 and 21:00-1:00,and two vales presented at 15:00 and 3:00-5:00 respectively.In addition,the larger proportion finer particles took the heavier total particles were in a day;2)Comparatively,peaks in day and vales at night of finer particles presented earlier than that of coarser particles,however the peaks at night were later;3)Weather conditions had influences on PM,and the finer particles were more sensitive to the conditions than the coarse particles.In general,PM concentration was higher at the state of low air temperature,high air relative humidity and soft wind.They also increased at cloudy night,especially for finer particles.展开更多
Dry seeds of Populus ussuriensis collected from Heilongjiang area were carried by the recoverable satellite for mutagenesis.Then the growth traits and antioxidant enzymes activities of seedlings from the spaceflight-t...Dry seeds of Populus ussuriensis collected from Heilongjiang area were carried by the recoverable satellite for mutagenesis.Then the growth traits and antioxidant enzymes activities of seedlings from the spaceflight-treated seeds and controls were analyzed.The results showed that the growth traits of the seedlings after spaceflight varied to some degree,but most of the variation was not remarkable.There were no significant changes in soluble protein content,malondialdehyde(MDA)content and superoxide dismutase(SOD)activity in seedlings with response to spaceflight treatment.However,activities of ascorbate peroxidase(APX)and guaiacol peroxidase(POD)in the poplar seedlings after spaceflight were significantly higher than those from the ground control.It suggested that space condition altered the poplar traits in some degree,and the higher antioxidant enzymes might failitate themselves to avoid some damage from active oxygen.展开更多
文摘Variation in concentrations of the airborne particulate matters(PM)in three kinds of typical recreation forests in Baiwang Mountain,West Mountain area of Beijing were observed day and night in spring.Results showed that:1)Diurnal variations of PM concentrations in three kinds of typical recreation forests in West Mountain of Beijing area in spring were all synchronous.Curves of diurnal variation of PM concentrations had two peaks and two vales,and two peaks presented at 7:00-9:00 and 21:00-1:00,and two vales presented at 15:00 and 3:00-5:00 respectively.In addition,the larger proportion finer particles took the heavier total particles were in a day;2)Comparatively,peaks in day and vales at night of finer particles presented earlier than that of coarser particles,however the peaks at night were later;3)Weather conditions had influences on PM,and the finer particles were more sensitive to the conditions than the coarse particles.In general,PM concentration was higher at the state of low air temperature,high air relative humidity and soft wind.They also increased at cloudy night,especially for finer particles.
文摘Dry seeds of Populus ussuriensis collected from Heilongjiang area were carried by the recoverable satellite for mutagenesis.Then the growth traits and antioxidant enzymes activities of seedlings from the spaceflight-treated seeds and controls were analyzed.The results showed that the growth traits of the seedlings after spaceflight varied to some degree,but most of the variation was not remarkable.There were no significant changes in soluble protein content,malondialdehyde(MDA)content and superoxide dismutase(SOD)activity in seedlings with response to spaceflight treatment.However,activities of ascorbate peroxidase(APX)and guaiacol peroxidase(POD)in the poplar seedlings after spaceflight were significantly higher than those from the ground control.It suggested that space condition altered the poplar traits in some degree,and the higher antioxidant enzymes might failitate themselves to avoid some damage from active oxygen.
