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91.
金华 《四川畜牧兽医学院学报》2007,5(2):113-115
大学英语的教学目标是培养学生的英语综合运用能力,特别是听说能力。针对目前大学英语听说课中存在的实际问题,文章将以建构主义学习理论为基础探讨如何改进大学英语听说教学。 相似文献
92.
Cognition is recognized as an essential component of the living strategies of organisms and the use of cognitive approaches
based on an organismic-centered-view is discussed as a strategy to aid the advancement of landscape ecology to a more independent
scientific discipline. The incorporation of the theory of information, the theory of meaning and the Umwelt, and the biosemiotic models into the landscape ecology framework is described as the necessary step to create a common paradigmatic
background and operational tools to develop basis for a cognitive landscape ecology. Three cognitive landscapes (neutrality-based
landscape, individual-based landscape and observer-based landscape) have been described as the result of distinctive mechanisms
to extract information from a cognitive matrix based on a growing literature of (bio)semiotic exchange. The eco-field hypothesis
is presented as a new possibility to describe landscape processes according to an organismic-centered-view. The eco-field
is defined as a spatial configuration carrier of a specific meaning perceived when a specific living function is activated.
A species-specific cognitive landscape is composed of all the spatial configurations involved for all the living functions
for a particular organism. Eco-field hypothesis offers a detailed vision of (habitat) environmental requirements and creates
a novel conceptual bridge between niche, habitat, Umwelt and the methodological approaches of spatial ecology. Finally the eco-field hypothesis promises a new testing ground for
experimental investigations in landscape ecology and in related disciplines including environmental psychology, cognitive
ethology, cultural ecology, landscape aesthetics, design and planning. 相似文献
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94.
基于三维Copula函数的沙颍河流域水文干旱频率分析 总被引:2,自引:1,他引:1
为进一步研究水文干旱特征及其演变规律,选取沙颍河流域2个水文站1951—2008年逐月径流资料,采用游程理论提取水文干旱特征变量,选取4种对称Archimedean Copula函数和对应的非对称Archimedean Copula函数拟合干旱特征变量的联合分布并计算联合重现期和同现重现期。经拟合检验,Frank Copula对干旱特征变量二维联合分布的拟合效果最优,M3 Copula函数对三维干旱变量的联合分布拟合效果最优。干旱特征的单变量重现期值大于二、三维变量的联合重现期,小于二、三维变量的同现重现期。因此,Copula函数能够较好地拟合沙颍河流域水文干旱特征变量间的联合分布。 相似文献
95.
分析了环境设计以及生态理论的基本含义,探讨了在环境设计中按照生态理论进行设计的必要性,对相关理论进行了综述。 相似文献
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99.
有限元法钢丝滚道轴承接触问题研究 总被引:1,自引:1,他引:0
对钢丝滚道球轴承滚动体与钢丝滚道的点接触问题进行研究,由Hertz接触理论给出接触区的主要几何参数,应力极值以及接触体弹性趋近量的计算公式,并根据实际应用进行简化,计算出所研究轴承接触区的主要参数。在对钢丝滚道球轴承点接触理论分析的基础上,利用有限元法对钢丝滚道球轴承的接触问题进行仿真。对仿真的结果进行分析,并且与理论计算的结果和实际工作过程中的结果相比较,对其不同之处进行分析。 相似文献
100.
《Scandinavian Journal of Forest Research》2012,27(1-4):465-479
Two “classical” theories, both originating in Elias Melin's laboratory in Uppsala, have tried to explain the regulation of ectomycorrhiza formation. The carbohydrate theory, formulated by E. Björkman in 1942, identifies root carbohydrate concentrations as regulatory, while these are in turn considered to be strongly influenced by plant mineral nutrition and light conditions. The hormone theory, expounded by V. Slankis in the 1960s, claims auxin of fungal origin to be the key regulator, influencing root carbohydrate status, while the fungus itself may, to some extent, be affected by mineral nutrition. Both theories have been subject to much discussion and have led to further work, without ever having been conclusively proven experimentally. Recent results in Uppsala and elsewhere have shed new light on several of the key issues. The development of research in this field since 1942 is critically reviewed in light of later data, and a unifying theory is sketched on the basis of E. Hacskaylo's proposal from 1969 to reconcile contradictory results. 相似文献