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消逝的候鸟生命线
从亘古时代,候鸟从未改变过古老的旅行规则:跨越重洋,循环往复,一鼓作气.候鸟的万里迁徙,如同史诗般令人瞠目.以红腹滨鹬为例,每年四月,这种鸟儿从南半球起飞.在万里行程之前,它们会铆足了劲,先吃成大胖子,还会将一些暂不需要的生殖器官如子宫等萎缩,之后不停歇、不睡觉、不进食,沿着东亚-澳大利西亚一线连续飞行6000公里,历时7天抵达渤海湾后,只剩下约不到一半水蓝天 - 绿色中国文章来源: 万方数据 -
一类具有时滞的三种群食物链模型的定性分析及其仿真
在生态系统中,时滞对种群稳定性的影响一直是研究的重点内容之一.考虑了一类具有时滞的三种群食物链模型,利用微分不等式得到了种群的有界性;利用Matlab软件下的Simulink平台,对种群模型进行了数值仿真,得到了不同参数情况下的相空间轨迹,通过分岔图说明时滞对种群模型稳定性的影响.滕勇,李石涛 - 生物数学学报文章来源: 万方数据 -
不确定需求下跨国供应链数量折扣模型
本文研究了不确定需求下跨国供应链数量折扣问题.首先基于供应链系统的全局协调,得出了数量折扣率应满足的区间;然后分析了汇率和关税的变化对供应商和零售商利润所产生的影响;最后通过数值分析并得出结论:供应商提供数量折扣后,供应商和零售商的利润有了明显的改进;汇率减少时,供应商和零售商的利润也相应减少;另外,提高关税时,供应商和零售商的利润都相应减少.岳万勇,赵正佳 - 管理评论文章来源: 万方数据 -
养老设施内老年人休闲社交行为的影响因素研究
尝试用行为观察法,对上海市3家养老设施内195位老年人的日常生活行为进行调查,运用数量化I类,分析物质空间环境、管理环境、社会环境以及老年人个人基本属性对老年人休闲社交行为的影响程度,探讨通过改善这些影响因素,提高设施内老年人生活品质的策略和方法.李庆丽,李斌,李华 - 建筑学报文章来源: 万方数据 -
一类在污染环境中单种群模型的动力学行为(英文)
在种群的增长率满足广义logistic方程的情况下,建立了在污染环境中一类新的单种群模型,给出了该模型中种群一致持续生存和灭绝的充分条件.这里建立的模型是He和Wang[Appl.Math.Modell.31(2007)2227-2238]中模型的改进.吕世良,赵建东 - 生物数学学报文章来源: 万方数据 -
The role of behavior in tern conservation
Behavioral?research?has?long?had?an?important?role?in?the?conservation?of?terns?(Ayes:?Stemidae).?Habitat?management?and?restoration?of?breeding?colony?sites?depends?on?knowledge?of?the?cues?used?to?select?colony?and?nest?sites.?For?example,?conspecific?attraction?with?playback?and?decoys?is?commonly?used?to?bring?terns?to?suitable?colony?sites?and?habitat?modification?is?often?used?to?increase?the?availability?of?suitable?nest?sites.?Tern?colonies?are?interconnected?by?dispersal,?and?a?metapopulation?approach?is?needed?for?effective?management.?Population?dynamics?are?therefore?affected?by?behaviors?that?influence?the?frequency?of?movement?among?colony?sites:?site?fidelity,?natal?and?breeding?dispersal,?and?group?adherence.?The?monogamous?breeding?system?of?terns?should?keep?effective?population?size?similar?to?census?population?size,?but?variation?in?sex?ratios?(likely?resulting?from?sex?differences?in?behavior)?and?in?parental?quality?can?result?in?a?smaller?than?expected?effective?population?size.?In?addition?to?the?behavior?of?terns,?knowledge?of?the?behavior?of?predators?on?terns?contributes?to?management?plans,?because?predator?behavior?can?sometimes?be?manipulated?and?predation?is?often?performed?by?only?a?few?specialized?individuals.?Other?examples?of?links?between?tern?behavior?and?conservation?are?also?briefly?reviewed,?such?as?behavioral?toxicology?research?and?studies?of?behavioral?responses?to?human?disturbance?and?manmade?structures.?More?work?is?needed?on?the?behavior?of?migratory?terns?at?staging?sites,?stopover?sites?and?wintering?grounds,?and?on?the?behavior?of?less?well-studied?species?and?species?in?less?well-studied?geographic?regions?[Current?Zoology?60?(4):?500-514,?2014].Brian G. PALESTIS - 动物学报(英文版)文章来源: 万方数据 -
不同施药方式下吡虫啉对棉田绿盲蝽种群动态的影响
为探讨吡虫啉对绿盲蝽种群数量的控制作用,2011-2012年连续两年采用种子包衣、颗粒剂穴施和灌根处理棉花,并结合种植绿豆诱集带的方式,研究其对棉田绿盲蝽种群动态的影响.在吡虫啉有效成分用量为1 500 g/hm^2时,棉花颗粒剂穴施+绿豆诱集带颗粒剂穴施、灌根和颗粒剂穴施3种处理,对棉田绿盲蝽种群数量控制作用较好,自棉花苗期至8月中旬花铃期百株绿盲蝽数量分别为12、15、17、8、19头,均低于为害经济阈值,控制有效期接近110 d;在吡虫啉有效成分用量为900 g/hm^2时的棉花颗粒剂穴施、灌根处理以及吡虫啉有效成分用量为675 g/hm^2的棉花种子包衣+绿豆诱集带种子包衣处理,对棉田绿盲蝽种群数量控制作用次之,控制期在100 d左右.单一棉花种子包衣处理控制效果低于上述处理,持效接近90 d.各处理对棉叶受害指数减退率的影响与其对绿盲蝽种群数量的控制结果基本一致,表明棉田吡虫啉颗粒剂穴施及液体制剂灌根施药是控制绿盲蝽为害的有效施药手段.张小兵,王凯,王猛,王建美,慕卫 - 植物保护学报文章来源: 万方数据 -
新疆中哈边境阿拉山口口岸蚊虫调查研究
为了解中哈边境阿拉山口口岸地区蚊虫种群本底构成及生态习性,采用帐诱、挥网、灯诱采集蚊虫,进行形态学分类鉴定.2012与2013两年共采集成蚊16 317只、经随机抽样鉴定3 370只,隶属2科5属11种.2013年比2012年增加了2种,比历史资料记录的增加了5种,其中凶小库蚊占蚊虫总数的46.0%,为当地优势种.其生境季节变化从3月开始活动,5月达到高峰,8月为次高峰,至11月活动消失.调查结果显示应重视对优势蚊种的防控及携带病原的研究,识别外来物种的入侵、蚊媒疾病的监控提供了基础资料.尹小平,郑重,田延河,骄娃,徐军,张桂林 - 寄生虫与医学昆虫学报文章来源: 万方数据 -
Birds on the move: Special column on bird movement
Studying movements is essential for shedding light on a number of issues related to avian biology: behavioral aspects such as foraging, migratory routes and strategies, navigation and orientation mechanisms; ecological aspects such as metapopulation dynamics, insular biogeography, seed dispersal, disease spread; conservation biology such as the effects of habitat fragmentation, identification of key areas deserving protection, effects of climate change. Despite these relevant issues, the topic of "Movement ecology" on its own has only been highlighted recently (Nathan et al., 2008);although, the investigation of animal movements has always been one of the most fascinating topics for any zoologist and often is also quite a difficult task.Giuseppe BOGLIANI,Ugo MELLONE,Guest Editors - 动物学报(英文版)文章来源: 万方数据

