ω -Bromopropylporphyrin ether synthesized from the raction of 1,3-dibromopropane as the bridge-linked reagent and 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin (H_2MHTPP) as the matrix reacts with 5,15-di(4- hydrox...ω -Bromopropylporphyrin ether synthesized from the raction of 1,3-dibromopropane as the bridge-linked reagent and 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin (H_2MHTPP) as the matrix reacts with 5,15-di(4- hydroxyphenyl)-10,20-diphenyl porphyrin( trans -H_2DHDPP) to give the title nanometer porphyrin trimer. The characterization was carried out by means of elemental analyses,UV-Vis,IR, 1H NMR and XRD.展开更多
A field experiment was conducted to investigate the variations in denitrification losses and N2O emissions from 4 different types of nitrogen fertilizers (urea, ammonium nitrate, ammonium bicarbonate, and calcium nitr...A field experiment was conducted to investigate the variations in denitrification losses and N2O emissions from 4 different types of nitrogen fertilizers (urea, ammonium nitrate, ammonium bicarbonate, and calcium nitrate) applied to the maize- fluvo-aquic soil system in the North China Plain by the method of intact soil core incubation and acetylene inhibition, and the responses of nitrogen fertilizers to maize grain yields. Results show that the denitrification loss from different nitrogen fertilizers ranged from 0.38-1.20 kg N ha-1, with no significant differences among different fertilizer treatments, and the N2O emission from 0.05-0.95 kg N ha-1, with a significant difference (P<0.05) among the treatments. The highest emission was from the treatment of ammonium nitrate, while the lowest from calcium nitrate. The nitrogen fertilizers increased the maize grain yield by 9.7-19.8% compared to control. But there were no significant differences in yield increase among the 4 types of nitrogen fertilizers. In comparison, urea had the best effect, whereas calcium nitrate had the least effect on increasing maize yield. The maize yield was 5.7% higher when urea was separately applied at 2 times than when it was applied at a time. In this case, however, the denitrification loss and the N2O emission were also increased by 4.05 and 1.84 kg N ha-1, respectively.展开更多
文摘ω -Bromopropylporphyrin ether synthesized from the raction of 1,3-dibromopropane as the bridge-linked reagent and 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin (H_2MHTPP) as the matrix reacts with 5,15-di(4- hydroxyphenyl)-10,20-diphenyl porphyrin( trans -H_2DHDPP) to give the title nanometer porphyrin trimer. The characterization was carried out by means of elemental analyses,UV-Vis,IR, 1H NMR and XRD.
基金The work was supported by the National Natural Sci-ence Foundation of China(49901010).
文摘A field experiment was conducted to investigate the variations in denitrification losses and N2O emissions from 4 different types of nitrogen fertilizers (urea, ammonium nitrate, ammonium bicarbonate, and calcium nitrate) applied to the maize- fluvo-aquic soil system in the North China Plain by the method of intact soil core incubation and acetylene inhibition, and the responses of nitrogen fertilizers to maize grain yields. Results show that the denitrification loss from different nitrogen fertilizers ranged from 0.38-1.20 kg N ha-1, with no significant differences among different fertilizer treatments, and the N2O emission from 0.05-0.95 kg N ha-1, with a significant difference (P<0.05) among the treatments. The highest emission was from the treatment of ammonium nitrate, while the lowest from calcium nitrate. The nitrogen fertilizers increased the maize grain yield by 9.7-19.8% compared to control. But there were no significant differences in yield increase among the 4 types of nitrogen fertilizers. In comparison, urea had the best effect, whereas calcium nitrate had the least effect on increasing maize yield. The maize yield was 5.7% higher when urea was separately applied at 2 times than when it was applied at a time. In this case, however, the denitrification loss and the N2O emission were also increased by 4.05 and 1.84 kg N ha-1, respectively.
