定量化评估未来气候变化条件下农田水分利用和作物产量变化,并探究适应气候变化的灌溉策略对水资源紧缺粮食主产区的农业可持续发展具有重要意义。该研究应用改进的SWAT(soil and water assessment tool)模型与CMIP6(coupled model inte...定量化评估未来气候变化条件下农田水分利用和作物产量变化,并探究适应气候变化的灌溉策略对水资源紧缺粮食主产区的农业可持续发展具有重要意义。该研究应用改进的SWAT(soil and water assessment tool)模型与CMIP6(coupled model intercomparison project phase 6)的大气环流模式(general circulation model, GCM)相结合的方法,在3种共享社会经济路径(SSP1-2.6, SSP2-4.5和SSP5-8.5)下评估了未来时期(2041-2070年)海河平原实际蒸散量、灌溉量、地下水净使用量(net groundwater use, NGU)和作物产量的变化情况,探究了未来气候情景中适宜的作物灌溉策略。结果表明:1)与历史时期(1971-2000年)相比,未来时期区域年实际蒸散量增加5.5%、年灌溉量和年地下水净使用量分别减少5.9%和25.8%。在SSP5-8.5情景下,年实际蒸散量的增幅最低,年灌溉量和年地下水净使用量的减幅最高。2)相较于历史时期,未来时期冬小麦和夏玉米产量分别增加14.3%和6.5%,其中夏玉米产量增幅随温室气体排放情景的增强而降低。3)在未来气候情景中,雨养夏玉米结合冬小麦拔节期进行灌溉(灌水定额为25 mm,根据自动灌溉系统确定灌水频率)或可最大限度地实现该区地下水资源恢复。从确保粮食安全的视角,推荐雨养夏玉米与冬小麦在拔节期和灌浆期灌溉相结合。研究结果可为区域农业水资源合理规划、可持续的粮食生产政策的制定提供参考。展开更多
The kinetics and mechanisms of p-nitrophenol （PNP） biodegradation by Pseudomonas aeruginosa HS-D38 were investigated. PNP could be used by HS-D38 strain as the sole carbon, nitrogen and energy sources, and PNP was m...The kinetics and mechanisms of p-nitrophenol （PNP） biodegradation by Pseudomonas aeruginosa HS-D38 were investigated. PNP could be used by HS-D38 strain as the sole carbon, nitrogen and energy sources, and PNP was mineralized at the maximum concentration of 500 mg/L within 24 h in an mineral salt medium （MSM）. The analytical results indicated that the biodegradation of PNP fit the first order kinetics model. The rate constant kpNp is 2.039 ×10^-2/h in MSM medium, KeNp＋N is 3.603 × 10^-2/h with the addition of ammonium chloride and KPNP＋c is 9.74 ×10^-3/h with additional glucose. The addition of ammonium chloride increased the degradation of PNP. On the contrary, the addition of glucose inhibited and delayed the biodegradation of PNP. Chemical analysis results by thin-layer chromatography （TLC）, UV-Vis spectroscopy and gas chromatography （GC） techniques suggested that PNP was converted to hydroquinone （HQ） and further degraded via 1,2,4-benzenetriol （1 ,2,4-BT） pathway.展开更多
基金supported by the National Natural Science Foundation of China(No.30771429)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20060511002)the Construction Fund for"211" Project of the Ministry of Education of China and the Excellent Middle-aged and Younger Talents Foundation of Hubei Province of China(No.Q200727005)
文摘The kinetics and mechanisms of p-nitrophenol （PNP） biodegradation by Pseudomonas aeruginosa HS-D38 were investigated. PNP could be used by HS-D38 strain as the sole carbon, nitrogen and energy sources, and PNP was mineralized at the maximum concentration of 500 mg/L within 24 h in an mineral salt medium （MSM）. The analytical results indicated that the biodegradation of PNP fit the first order kinetics model. The rate constant kpNp is 2.039 ×10^-2/h in MSM medium, KeNp＋N is 3.603 × 10^-2/h with the addition of ammonium chloride and KPNP＋c is 9.74 ×10^-3/h with additional glucose. The addition of ammonium chloride increased the degradation of PNP. On the contrary, the addition of glucose inhibited and delayed the biodegradation of PNP. Chemical analysis results by thin-layer chromatography （TLC）, UV-Vis spectroscopy and gas chromatography （GC） techniques suggested that PNP was converted to hydroquinone （HQ） and further degraded via 1,2,4-benzenetriol （1 ,2,4-BT） pathway.
