نتایج جستجو برای: wiener and simpson and richness indices
تعداد نتایج: 16837873 فیلتر نتایج به سال:
abstract: the potato tuberworm, phthorimaea operculella (zeller), is an important insect pest of potato (solanum tuberosum l.) in the storage and field in most parts of the world especially in tropical and subtropical regions due to its close relationship with the host, high reproductive potential and high economic losses. information on host preference, life table parameters and digestive en...
The aim of this study was to investigate the flora, life form, chrotype, diversity and evenness of accompanying species of Artemisia melanolepis Boiss. and Artemisia aucheri Boiss. in the south east of Sabalan. Species were collected and identified. Overall, 82 identified plant species was belonging to 23 families and 61 genera. Asteraceae, Fabaceae, Lamiaceae and Poaceae families were the domi...
drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...
the predatory mites of suborder prostigmata are important natural enemies of spider mites. in this study abundance and biodiversity of predatory mites of super families of raphignathoidea, bdelloidea and erythraeoidea in pomefruit orchards of mashhad) educational orchard of agricultural college of ferdowsi unuversity of mashhad, agricultural research centre of torogh and laeen, torghabe and sha...
whereas there is an exact linear relation between the wiener indices of kenograms and plerograms of isomeric alkanes, the respective terminal wiener indices exhibit a completely different behavior: correlation between terminal wiener indices of kenograms and plerograms is absent, but other regularities can be envisaged. in this article, we analyze the basic properties of terminal wiener indices...
Diversity estimates play a key role in ecological assessments. Species richness and abundance are commonly used to generate complex diversity indices that are dependent on the quality of these estimates. As such, there is a long-standing interest in the development of monitoring techniques, their ability to adequately assess species diversity, and the implications for generated indices. To dete...
Rangeland ploughing and cultivation using dry land farming crops may be amajor reason for the destruction of natural resources in the semiarid and sub-humid regionswhich may significantly change the composition and reduce the stability of the affectedcommunities. In present research, an abandoned ploughed site was compared with a nearbyreference site in the semiarid rangelands of Baharkish, Quc...
gradual decrease of biodiversity related to the rapid industrialization and urbanization is stimulating the fundamental research towards a better understanding of the relationships between biodiversity and ecosystem functioning. present study emphasizes the nature and status of floral diversity in the vicinity of integrated industrial estate-pantnagar, uttarakhand, india (iie-pantnagar).three m...
the padmakar-ivan (pi) index is a first-generation topological index (ti) based on sums overall edges between numbers of edges closer to one endpoint and numbers of edges closer to theother endpoint. edges at equal distances from the two endpoints are ignored. an analogousdefinition is valid for the wiener index w, with the difference that sums are replaced byproducts. a few other tis are discu...
Whereas there is an exact linear relation between the Wiener indices of kenograms and plerograms of isomeric alkanes, the respective terminal Wiener indices exhibit a completely different behavior: Correlation between terminal Wiener indices of kenograms and plerograms is absent, but other regularities can be envisaged. In this article, we analyze the basic properties of terminal Wiener indices...
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