针对无线传感器网络的经典LEACH算法中存在的簇头选取不合理、分簇不均以及能量损耗过大的问题,提出改进算法REC(Region Energy Clustering)。算法首先通过对网络内节点设置分层模型,然后根据动态的簇头数量对网络进行分区成簇,在选取...针对无线传感器网络的经典LEACH算法中存在的簇头选取不合理、分簇不均以及能量损耗过大的问题,提出改进算法REC(Region Energy Clustering)。算法首先通过对网络内节点设置分层模型,然后根据动态的簇头数量对网络进行分区成簇,在选取簇头时,根据节点所在层级,通过引入能量影响因子和距离影响因子综合选取,最后在数据传输时分层传输数据。上述算法改善了经典LEACH算法中成簇过多、分簇不匀的问题,采用的分层选取和分层传输方式,也降低了网络中数据通信时的能量损耗。经仿真结果表明,与LEACH及同类改进算法相比,REC算法有效的均衡了网络中能量损耗,延长了网路生存时间。展开更多
In order to explore the technology and effects of reducing nitrogen and potassium fertilizer applications in double-cropping rice,a field plot experiment was conducted to study the effects of optimized application of ...In order to explore the technology and effects of reducing nitrogen and potassium fertilizer applications in double-cropping rice,a field plot experiment was conducted to study the effects of optimized application of nitrogen and potassium fertilizers combined with returning Chinese milk vetch and straw to fields on yield,fertilizer utilization efficiency,net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO_(2) concentration(Ci),chlorophyll content(SPAD value)and soil physical and chemical properties in late rice harvest period.The results showed that the optimized application of nitrogen and potassium fertilizers combined with the integrated technology of Chinese milk vetch and straw co-returning to the field could enhance the photosynthetic efficiency of double-cropping rice,increase rice yield,and enhance soil biological activity,especially T4 treatment involving the returning of Chinese milk vetch and straw to the field instead of 30%nitrogen fertilizer achieved the highest rice yield,fertilizer use efficiency,net photosynthetic rate and soil biological activity.Compared with the conventional fertilization treatment T2,the total rice yield of T4 treatment increased by 4.1%,among which the early rice and late rice increased by 6.3%and 2.4%,respectively;Pn,Gs and SPAD values of flag leaves at full heading stage significantly increased,and the contents of soil active organic carbon,alkali hydrolyzed nitrogen,available phosphorus and readily available potassium significantly increased.展开更多
文摘针对无线传感器网络的经典LEACH算法中存在的簇头选取不合理、分簇不均以及能量损耗过大的问题,提出改进算法REC(Region Energy Clustering)。算法首先通过对网络内节点设置分层模型,然后根据动态的簇头数量对网络进行分区成簇,在选取簇头时,根据节点所在层级,通过引入能量影响因子和距离影响因子综合选取,最后在数据传输时分层传输数据。上述算法改善了经典LEACH算法中成簇过多、分簇不匀的问题,采用的分层选取和分层传输方式,也降低了网络中数据通信时的能量损耗。经仿真结果表明,与LEACH及同类改进算法相比,REC算法有效的均衡了网络中能量损耗,延长了网路生存时间。
文摘In order to explore the technology and effects of reducing nitrogen and potassium fertilizer applications in double-cropping rice,a field plot experiment was conducted to study the effects of optimized application of nitrogen and potassium fertilizers combined with returning Chinese milk vetch and straw to fields on yield,fertilizer utilization efficiency,net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO_(2) concentration(Ci),chlorophyll content(SPAD value)and soil physical and chemical properties in late rice harvest period.The results showed that the optimized application of nitrogen and potassium fertilizers combined with the integrated technology of Chinese milk vetch and straw co-returning to the field could enhance the photosynthetic efficiency of double-cropping rice,increase rice yield,and enhance soil biological activity,especially T4 treatment involving the returning of Chinese milk vetch and straw to the field instead of 30%nitrogen fertilizer achieved the highest rice yield,fertilizer use efficiency,net photosynthetic rate and soil biological activity.Compared with the conventional fertilization treatment T2,the total rice yield of T4 treatment increased by 4.1%,among which the early rice and late rice increased by 6.3%and 2.4%,respectively;Pn,Gs and SPAD values of flag leaves at full heading stage significantly increased,and the contents of soil active organic carbon,alkali hydrolyzed nitrogen,available phosphorus and readily available potassium significantly increased.
