基于多条件休眠的802.15.4网络能耗优化方法

针对802.15.4网络能耗优化问题,提出了一种基于多条件休眠模式的媒体接入控制(MAC)层信道接入机制。首先,建立该机制的马尔可夫模型;然后,基于模型对网络主要状态的稳态概率和协议参数进行推导;其次,分析了节点在每个超帧内的平均能耗;最后,研究了数据包到达率、退避次数、超帧指数和最小退避指数对节点主要状态的稳态概率、能耗和节点生存时间的影响。实验结果表明,与节点无休眠态的802.15.4网络相比,节点能耗降低了84.4%左右;与部分条件休眠的方法比较,节点能耗平均降低了62.8%,网络存活时间平均提高了70%。模型较好地描述了提出的网络信道接入机制,合理的网络参数设置能够优化网络能耗性能,也为无线传感器网络(WSN)的实际应用提供能耗优化参考。

盐生植物种子的休眠、休眠解除及萌发的特点

本文讨论了盐生植物种子的休眠、休眠解除及萌发的特点 ,主要内容有 :( 1 )盐生植物种子的休眠类型 ;( 2 )打破盐生植物种子休眠的必要条件 ;( 3)盐生种子萌发与土壤盐度的关系。并讨论了盐度抑制盐生植物种子的机理。最后 。

英国企业休眠制度及对我国商事制度的借鉴

新冠疫情对于我国经济特别是中小企业影响巨大,虽然政府出台了一系列扶持政策,但从长期看,我国的商事制度中仍然缺乏帮助中小企业渡过经营困境的制度性设计。英国企业休眠制度是一项由企业主动提出,以期在其暂停经营时最大限度降低其生存成本的制度。本文从对这一制度的介绍入手,阐述了企业休眠制度在中小企业持续经营、社会经济稳定发展、建设诚信体系等方面对于我国的积极借鉴意义,并从认定条件、程序设计、后续管理等几个方面对创设这一制度进行了初步的设想。

Studies on Mode of Expression of Apple （Malus x domestica Borkh.） Bud Dormancy under Tropical and Temperate Climatic Conditions

A study was conducted to describe the progression of bud dormancy in 1-year-old apple （Malus x domestica Borkh） shoots grown at two contrasting climatic conditions （Belgium, temperate and Ethiopia, tropics）. The experiment was carried out on ＂Golden＂ and ＂Gala＂ cultivars for two consecutive years （2010/2011 and 2011/2012）. Moreover, a validation experiment was conducted on ＂MM106＂ apple rootstock during 2010/2011 only in Ethiopia. Variations in inverse of time to 50% budburst were interpreted in terms of evolution of growth capacity of the buds. Despite differences observed with chilling accumulation later in winter or early in spring, depending on environments, depth of endodormancy intensity during winter can be summarized as follows： buds from pruned shoots were less endodormant than terminal buds of the intact shoots and terminal buds were more endodormant than the dormancy intensity of upper buds of the disbudded shoots, suggesting proximal buds can grow more readily than does terminal ones. Our results provide evidence for the existence of a considerably strong paradormancy inhibition by distal shoot parts and buds, which was more pronounced in Ethiopia than in Belgium, highlighting the importance of designing and applying appropriate pruning and dormancy avoidance strategies in mild-winter climates. Finally, as still there is knowledge gap on bud dormancy progression and its control mechanism especially under mild climates, our study highlights the need for further in-depth research using biological and biochemical tests.

极度濒危植物大果木莲种子的休眠与萌发

大果木莲种子具吸水性,胚未完全发育。新鲜种子25℃下的萌发率仅2%,在30/20℃和20/10℃的条件下30d内分别有27%和36%种子萌发。在20/10℃下,1000mg·L-1浓度的GA3可以有效打破种子休眠。冷层积120d的种胚生长不显著,大果木莲种子具有条件休眠特性,属于浅度简单型形态生理休眠。种子经冷层积60d的萌发率最高,而后下降,提示其可能有休眠循环现象。