نتایج جستجو برای: plant species restoration and animal selectivity in semi

تعداد نتایج: 21849927  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه لرستان - دانشکده علوم پایه 1389

abstract part one: the electrode oxidation potentials of a series of eighteen n-hydroxy compounds in aqueous solution were calculated based on a proper thermodynamic cycle. the dft method at the level of b3lyp-6-31g(d,p) was used to calculate the gas-phase free energy differences ,and the polarizable continuum model (pcm) was applied to describe the solvent and its interaction with n-hydroxy ...

2011
Vanesa Carbajo Bowy den Braber Wim H. van der Putten Gerlinde B. De Deyn

Restoration of species-rich grasslands on ex-arable land can help the conservation of biodiversity but faces three big challenges: absence of target plant propagules, high residual soil fertility and restoration of soil communities. Seed additions and top soil removal can solve some of these constraints, but restoring beneficial biotic soil conditions remains a challenge. Here we test the hypot...

2017
Lizet Solis-Gabriel Wendy Mendoza-Arroyo Karina Boege Ek Del-Val

Tropical dry forests (TDFs) have been widely transformed by human activities worldwide and the ecosystem services they provide are diminishing. There has been an urgent call for conservation and restoration of the degraded lands previously occupied by TDFs. Restoration experiences aim to recover species diversity and ecological functions. Different restoration strategies have been used to maxim...

Choosing management strategies are influencing the vegetation characteristics and plant diversity in rangelands. We have studied the effects of three management treatments including overgrazing, exclusure, and exclusure with restoration operations on vegetation characteristics of plant cover, composition, and diversity in Kiasar Chardange summer rangelands. In each management treatment, three r...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شاهد - دانشکده فنی و مهندسی 1387

abstract biometric access control is an automatic system that intelligently provides the access of special actions to predefined individuals. it may use one or more unique features of humans, like fingerprint, iris, gesture, 2d and 3d face images. 2d face image is one of the important features with useful and reliable information for recognition of individuals and systems based on this ...

Pejman tahmasebi Kohyani, Yousef askari

Semi-steppe rangelands are a complex, highly dynamic and often multi-layered mosaic of grassland, shrubland, and intermediate communities. A few recent studies have explicitly or implicitly developed synthetic hypotheses about how interactive effects of human made disturbances initiate dynamic changes in plant community composition to cause a shifting mosaic of vegetation pattern across the lan...

Pejman tahmasebi Kohyani, Yousef askari

Semi-steppe rangelands are a complex, highly dynamic and often multi-layered mosaic of grassland, shrubland, and intermediate communities. A few recent studies have explicitly or implicitly developed synthetic hypotheses about how interactive effects of human made disturbances initiate dynamic changes in plant community composition to cause a shifting mosaic of vegetation pattern across the lan...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1390

this work is presented in five parts. in the first part preparation of the starting complex [pt(c^n)cl(dmso)], 1, in which c^n = n(1),c(2?)-chelated, deprotonated 2-phenylpyridine, and dmso = dimethylsulfoxide, and its reaction with 1 equiv of the biphosphine ligands bis(diphenylphosphino)amine, dppa, or bis(diphenylphosphino)methane, dppm, to give the complex [pt(c^n)cl(dppa)], 2, or [pt(c^n)c...

پایان نامه :0 1370

all analytical methods are generally based on the measurement of a parameter or parameters which are somehow related to the concentration of the species.an ideal analytical method is one in which the concentration of a species can be measured to a high degree precision and accuracy and with a high sensitivity. unfortunately finding such a method is very difficult or sometimes even impossible.in...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز 0

a semi-empirical mathematical model for predicting physical part of ignition delay period in the combustion of direct - injection diesel engines with swirl is developed . this model based on a single droplet evaporation model . the governing equations , namely , equations of droplet motion , heat and mass transfer were solved simultaneously using a rung-kutta step by step unmerical method . the...

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