نتایج جستجو برای: Chemical tree

تعداد نتایج: 544822  

Journal: :iranian journal of mathematical chemistry 0
r. rasi azarbaijan shahid madani university, tabriz, iran s. m. sheikholeslami azarbaijan shahid madani university, tabriz, iran a. behmaram institute for research in fundamental sciences, tehran, iran

in this paper we give sharp upper bounds on the zagreb indices and characterize all trees achieving equality in these bounds. also, we give lower bound on first zagreb coindex of trees.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده منابع طبیعی و علوم دریایی 1388

this research was conducted in two protect and destroy region in the middle zagros, in illam province. in order to identification of ecological species group and evaluate density of regeneration, effect of many factors such as protection, vegetation, physiographic factors, physical and chemical properties of soil in study locations were studied. to achieve these purpose number of 54 plots using...

Journal: :iranian journal of mathematical chemistry 2014
ž. k. vukićević g. popivoda

we give sharp upper bounds on the zagreb indices and lower bounds on the zagreb coindices of chemical trees and characterize the case of equality for each of these topological invariants.

1999
Roberto Aringhieri Pierre Hansen Federico Malucelli

The need to generate graphs representing chemical structures suggested the use of computer and as a consequence the delevopment of eecient enumerating algorithms. This paper considers the isomeric acyclic structures enumeration focusin on the alkane molecular family. Two new algorithms based on Reverse Search 7] 8] are presented. The main concern of this paper is to highlight the importance of ...

Journal: :Proceedings of the New Zealand National Weeds Conference 1951

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When aerial parts of the plants capable of storing absorbing mineral salts in their leaves fall, these dissolved materials are transferred to the soil surface, changing its physical and chemical properties. In this study, we have investigated the influence of the Haloxylon tree on the physical and chemical properties, and also humidity of the soil using two, 300 m long transects one canopy of t...

Journal: :caspian journal of environmental sciences 2010
r. zarkami

classification trees (j48) were induced to predict the habitat requirements of tench (tinca tinca). 306 datasets were used for the given fish during 8 years in the river basins in flanders (belgium). the input variables consisted of the structural-habitat (width, depth, gradient slope and distance from the source) and physic chemical (ph, dissolved oxygen, water temperature and electric conduct...

Journal: :جنگل و فرآورده های چوب 0
پدرام غدیری پور کارشناس ارشد پژوهش، مؤسسۀ تحقیقات جنگل ها و مراتع کشور، تهران، ایران خسرو ثاقب طالبی دانشیار پژوهش، مؤسسۀ تحقیقات جنگل ها و مراتع کشور، تهران، ایران محمد حسن صالحه شوشتری کارشناس پژوهش، مرکز تحقیقات کشاورزی و منابع طبیعی خوزستان، اهواز، ایران امید اسماعیل زاده استادیار، دانشگاه تربیت مدرس، دانشکدۀ منابع طبیعی و علوم دریایی، نور، ایران

in order to investigate some silvicultural and soil physico-chemical characteristics of christ's thorn (ziziphus spina christi l. desf.) natural stands, ten natural stands of the tree species which have similar climate and aspects were selected and altitude from sea level (asl), the thickest sprout collar diameter (tscd) and total tree height (th) of the tree species were measured in 1000 ...

Journal: :Journal of Experimental Botany 2018

This study aims at investigating the effect of distance from source, species type and soil physical chemical properties on the absorption ability of heavy metals by tree species around the Nahavand cement factory. In the present research, soil and tree leaf (Pseudoacacia L, Populus nigra L, Elaeagnus angustifolia L, Fraxinus excelsior and Thuja orientalis L) samples were taken from 300, 500, 80...

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