本研究于2015—2016年进行野外控制试验,分析了不同施氮(N)水平(0、1、2、4、8、16 g N·m^(-2)·a^(-1))对青藏高原高寒草原根系生产、周转速率和现存量的影响及其调控因素。结果表明:随着施N量的增加,根系生产量和现存量呈线...本研究于2015—2016年进行野外控制试验,分析了不同施氮(N)水平(0、1、2、4、8、16 g N·m^(-2)·a^(-1))对青藏高原高寒草原根系生产、周转速率和现存量的影响及其调控因素。结果表明:随着施N量的增加,根系生产量和现存量呈线性或指数下降的趋势。与对照相比,16 g N·m^(-2)·a^(-1)处理根系生产量和现存量2年平均下降43.0%和45.7%。根系周转速率呈先上升后下降的趋势,2015年和2016年分别在2和4 g N·m^(-2)·a^(-1)处理达到峰值。线性混合模型结果显示,根系淀粉含量是调控根系生产量和周转速率的主要因素,分别解释二者变异的21.7%和25.4%;而根系现存量则受根系蛋白含量的影响,其解释率为20.8%。N富集对根系生产和现存量表现出抑制作用,低N促进而高N抑制根系周转速率,根系碳氮代谢指标是调控根系动态对N添加响应的主要因素。展开更多
Plants have diverse strategies to cope with phosphorus （P） deficiency. To better understand how maize responds to P deficiency, a field experiment with two P levels, 0 and 100 kg P205 ha-1 （P0 and P100, respectivel...Plants have diverse strategies to cope with phosphorus （P） deficiency. To better understand how maize responds to P deficiency, a field experiment with two P levels, 0 and 100 kg P205 ha-1 （P0 and P100, respectively）, was carried out as a part of a long-term Pfertilizer field trial. Plant and soil analyses showed that P-deficient maize reduced its growth rate, increased P use efficiency, and formed more thin roots with the diameter less than 0.6 mm at jointing and silking stages, compared to the plants treated with P100. Further, there were no differences in major inorganic P fractions （Ca2-P, Cas-P, Al-P, Fe-P, occluded P and Ca10-P） between the rhizospheric and bulk soils at each harvest, even when soil Olsen-P was only 1.38 mg kg-1. These results suggested that maize responded to P deficiency by reducing the internal P demand for growth and increasing P acquisition ability by favorable root morphological alteration at low carbon cost.展开更多
针对未来利用有人潜艇进行侦察型无人潜航器的投送问题,借鉴了相关求解方法,建立了类似有容量约束的车辆路径问题(Capacitated Vehicle Routing Problem,CVRP)模型,提出了一种利用编程软件(Linear Interactive and General Optimizer,LI...针对未来利用有人潜艇进行侦察型无人潜航器的投送问题,借鉴了相关求解方法,建立了类似有容量约束的车辆路径问题(Capacitated Vehicle Routing Problem,CVRP)模型,提出了一种利用编程软件(Linear Interactive and General Optimizer,LINGO)进行快速求解的实现方式。同时,通过假想具体算例,验证了求解方法的正确、有效。最后根据求解结果,思考了通过调整运载量差值来优化模型的方法,并阐述了在实际任务中的优选思路,为指战员提供了多样化决策方法。展开更多
文摘本研究于2015—2016年进行野外控制试验,分析了不同施氮(N)水平(0、1、2、4、8、16 g N·m^(-2)·a^(-1))对青藏高原高寒草原根系生产、周转速率和现存量的影响及其调控因素。结果表明:随着施N量的增加,根系生产量和现存量呈线性或指数下降的趋势。与对照相比,16 g N·m^(-2)·a^(-1)处理根系生产量和现存量2年平均下降43.0%和45.7%。根系周转速率呈先上升后下降的趋势,2015年和2016年分别在2和4 g N·m^(-2)·a^(-1)处理达到峰值。线性混合模型结果显示,根系淀粉含量是调控根系生产量和周转速率的主要因素,分别解释二者变异的21.7%和25.4%;而根系现存量则受根系蛋白含量的影响,其解释率为20.8%。N富集对根系生产和现存量表现出抑制作用,低N促进而高N抑制根系周转速率,根系碳氮代谢指标是调控根系动态对N添加响应的主要因素。
基金Supported by the National Basic Research Program (973 Program) of China (No. 2013CB127402)the Fundamental Research Funds for the Central Universities, China (No. 2012YJ054)the Innovative Research Group Grant of the National Natural Science Foundation of China (No. 31121062)
文摘Plants have diverse strategies to cope with phosphorus （P） deficiency. To better understand how maize responds to P deficiency, a field experiment with two P levels, 0 and 100 kg P205 ha-1 （P0 and P100, respectively）, was carried out as a part of a long-term Pfertilizer field trial. Plant and soil analyses showed that P-deficient maize reduced its growth rate, increased P use efficiency, and formed more thin roots with the diameter less than 0.6 mm at jointing and silking stages, compared to the plants treated with P100. Further, there were no differences in major inorganic P fractions （Ca2-P, Cas-P, Al-P, Fe-P, occluded P and Ca10-P） between the rhizospheric and bulk soils at each harvest, even when soil Olsen-P was only 1.38 mg kg-1. These results suggested that maize responded to P deficiency by reducing the internal P demand for growth and increasing P acquisition ability by favorable root morphological alteration at low carbon cost.
文摘针对未来利用有人潜艇进行侦察型无人潜航器的投送问题,借鉴了相关求解方法,建立了类似有容量约束的车辆路径问题(Capacitated Vehicle Routing Problem,CVRP)模型,提出了一种利用编程软件(Linear Interactive and General Optimizer,LINGO)进行快速求解的实现方式。同时,通过假想具体算例,验证了求解方法的正确、有效。最后根据求解结果,思考了通过调整运载量差值来优化模型的方法,并阐述了在实际任务中的优选思路,为指战员提供了多样化决策方法。
