结果表明:两个半固定白刺群落格局都是白刺单种群控制的灌木格局。
The results showed that both the two half fixed Nitraria tanguiorum communities were shrub patterns controlled by single species.
应用干扰作用控制指数法评价了阿维菌素、蚜虱灭、蚜虱蓟净等杀虫剂对桃蚜种群控制的作用。
The interference index of population control, IIPC was used to evaluate the control effect of Avermectins, Yasimie and Yasimiejin on peach-aphid.
应用干扰作用控制指数法评价了阿维菌素、蚜虱灭、蚜虱蓟净等杀虫剂对桃蚜种群控制的作用。
An approximate variance estimator for index of population trend developed with delta-method and its application;
它是控制竞争种群规模的因素之一,在极端情况下,它可能导致一个竞争物种的灭绝。
It is one of the factors controlling the size of competing populations, and in extreme cases it may lead to the extinction of one of the competing species.
世卫组织完全同意粮农组织和国际兽疫局的观点,即在野鸟种群中控制禽流感感染既不可行也不应尝试。
WHO fully agrees with FAO and OIE that control of avian influenza infection in wild bird populations is not feasible and should not be attempted.
这些已发现和待发现的物质,可能是控制那些携带疾病的昆虫种群规模的有效工具。
These newly identified compounds, and others that remain to be discovered, might be effective in controlling populations of disease-carrying insects.
非法捕捞能在多大程度上得到控制也会对种群数量是否有机会恢复具有重大影响。
The extent to which illegal fishing can be brought under control will also have a big impact on whether the population has a chance of recovering.
这意味着大象种群数量需要得到控制。
This means that elephant populations will need to be managed.
为了食物和领地,邻近种群互相争斗,这些频繁发生的战斗帮助控制了蚂蚁的数量。
Neighboring colonies fight each other regularly for food and nest space. These frequent brawls help keep ant Numbers in check.
然而这套系统还需要一点建模来保证这种群体控制不会导致其他我们不想看到的情况。
But it will require a little more modelling to ensure that this kind of group control doesn't lead to other emergent behaviour that could be detrimental.
他补充说使我们作为一个种群能够生存进化成为可能的大部分原因是我们“控制和使用火,制造使用衣服的能力,新的打猎方式和新的石器工具的制造”。
He added that our success and progression as a species has been made possible, in large part, to our "controlled use of fire, the ability to use clothing, new hunting strategies and new stone tools."
本文中,像布拉德肖一样谈论相冲突的“人道的自我”("humaneself")和“奴役的自我”("Auschwitzself")【3】,一点不会有助于我们控制大象的种群数量。
In this context, it's hardly helpful to talk, as Bradshaw does, of a "humane self" and an "Auschwitz self" in conflict as we try to manage elephant populations.
如果,正像我们人类要控制自己的种群一样控制各种动物的种群数量,那么,我们既保护了它们,也可以少点儿麻烦,少点儿死亡,少点儿悲哀。
If we can control the amount of animal RACES as well as we control our population, then we both can protect animals and can be less trouble, less dead and less sad.
万利斯说,戈夫岛上的老鼠是令人沮丧的鸟类种群,如果不加以控制,会造成如特里斯坦信天翁等一些物种的灭绝。
Wanless says Gough Island mice are depressing bird populations and will cause some species, such as the Tristan albatross, to go extinct if left unchecked.
研究了一类半线性时变种群扩散系统的最优收获问题,证明了最优收获控制的存在性。
In this paper, the existence of the optimal harvesting control for a class of non-linear population system is proved.
以系统科学方法研究害虫种群系统的控制,具有明显的社会意义和实践意义。
Using system science methods to study the system control of pest insect population, has an obvious social significance and practical value.
通过不同的状态反馈控制研究了一个二维种群模型的永久持续生存问题,得到一些使被研究系统永久持续生存的充分条件。
The permanence of a two - species model are investigated by different state-feedback controls. Some sufficient conditions which make the model in question permanent are obtained.
讨论了一类具终端观测且与年龄相关的非线性时变种群扩散系统的最优分布控制问题。
In this paper, the optimal distributed control problems for a class of age-dependent non-linear population diffusion system with final state observation are studied.
深入地了解其独特的婚配行为机制、独特的繁殖发育机制,对有效地开展果蝠的保护工作、合理地控制种群数量有积极意义。
A detailed understanding to the particular mechanism of mating behavior, reproduction and development is effective to promote the protection of these fruit bats and to control their population.
目的调查长乐国际机场登革热媒介种群密度,预防和控制登革热暴发流行。
Objective By investigating population density and breeding characters of Dengue vectors in Fuzhou Changle International Airport to prevent and control Dengue fever.
终将舞毒蛾的种群密度控制在经济允许水平之下。
The species' density of the gypsy moth will be controlled under economic permitted level.
研究某一类改进的关于年龄结构的非线性种群系统的最优控制问题。
The present paper is concerned with the optimal control problem for an improved nonlinear age-dependent population dynamics.
讨论了一类时变种群扩散系统的最优分布控制问题,利用J。
This paper discusses the optimal distributed control problem for time-varying population system with spatial diffusion. By J.
生物种群可能要经历许多基因控制的步增发育。
The parasite population opposing vertical resistance may undergo stepwise development controlled by many genes.
研究了一类半线性时变种群扩散系统的最优收获问题,证明了最优收获控制的存在性。
This paper discusses the problem of the optimal harvesting control problem for a semilinear age-dependent population diffusion system.
研究了一类半线性时变种群扩散系统的最优收获问题,证明了最优收获控制的存在性。
This paper discusses the problem of the optimal harvesting control problem for a semilinear age-dependent population diffusion system.
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