نتایج جستجو برای: adopted by ecosystem conditions

تعداد نتایج: 7443738  

Journal: :journal of rangeland science 2013
gholam ali heshmati zahra mohebbi

the main objective of an ecosystem sustainable management is to preserve itscapacity to respond and adapt to current disturbances and/or future changes, and maintain theprovision of environmental goods and services. two very important properties linked to thisobjective are the ecosystem resilience and resistance to disturbance factors. the objective ofthis paper is to recommend conceptual modif...

براتی, محمد, رجبی, جلیل, عزیزی, مریم,

Introduction: Climate changes are one of the factors associated with human activities for the destruction of the ecosystem. This factor leads to global warming, changing rainfall patterns, increasing the amount and severity of climate factors such as storms, and rising sea levels. Parasites are also an integral part of this ecosystem; therefore, the present study considered the effect of climat...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - پژوهشکده علوم 1388

heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده ادبیات و زبانهای خارجی 1390

abstract the present thesis seeks to critically read george orwell’s nineteen eighty-four and animal farm in the light of louis althusser’s thought and theory. the present thesis proceeds to examine and demonstrate althusser’s major concepts including ideological state apparatuses (isas), repressive state apparatuses (rsas), the structure, the subject, and ideological interpellation which r...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تهران - دانشکده علوم 1370

تهیه ترکیب فسفرتری کلرید بااستفاده از واکنش فسفر سفید(زرد) و گاز کلر در فاز محلول و درمقیاس آزمایشگاهی موردمطالعه قرارگرفت .پس از انتخاب مناسبتر روش و انتخاب بهترین شرایط کوشش درجهت طراحی واحد نیمه صنعتی انجام شد و توانستیم دراین راستا به تولید 10 کیلوگرم درساعت باخلوص 99/5 درصد برسیم . abstract the preparation of phosphorous trichloride by the reaction of white phosphorous and chlorine gas in ...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد یزد - دانشکده شیمی 1392

in this study, a simple, rapid and selective method was developed for the determination of dexamethasone. the proposed method is based on inhibitory effect of dexamethasone on the oxidation of orange-g by bromate in sulfuric acid media. the reaction was followed spectrophotometrically at 478.5 nm (?max). under optimum experimental conditions, (72.6 ?mol l-1 of orange-g, 0.76 mol l-1 of h2so4, 0...

2013
Mo-Qian Zhang Hai-Qiang Guo Xiao Xie Ting-Ting Zhang Zu-Tao Ouyang Bin Zhao

Land-cover characteristics have been considered in many ecological studies. Methods to identify these characteristics by using remotely sensed time series data have previously been proposed. However, these methods often have a mathematical basis, and more effort is required to better illustrate the ecological meanings of land-cover characteristics. In this study, a method for identifying these ...

2004
Robert G Bailey

A map showing the upper four levels of Ecomap down to the section level has been published for the entire U.S. These upper levels are based on macroclimatic conditions and the plant formations determined by those conditions. Delineation of the remaining, finer-grained subdivisions has been left for local development. Within the same macroclimate, broad-scale landforms break up the climatic patt...

2000
James M. Vose

Fire is a potentially powerful tool for achieving desired conditions of forest ecosystems. From an ecological perspective, the use of fire requires affirmative answers to either of the following questions: (1) Does it increase ecosystem health and sustainability? and (2) Does it preserve or restore unique species or habitats? Health and sustainability can be measured and defined in terms of: (1...

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