نتایج جستجو برای: Plant distribution

تعداد نتایج: 981981  

Journal: :journal of agricultural science and technology 2014
m. r. nematollahi y. fathipour a. a. talebi j. karimzadeh m. zalucki

to estimate population density of the cabbage aphid, brevicoryne brassicae (l.), a stratified random sampling was conducted in two unsprayed canola fields in isfahan (central iran) during 2011-2012. population density was determined for apterous, and alates, as well as the total population, at two plant growth phases (pgp1: from plant emergence to the end of rosette, and pgp2: from the beginnin...

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

مدل روزنه های موازی موج دار (corrugated oarallel bundle model) برای تعریف اثر ساختمان روزنه ها در نفوذ-واکنش (diffusion and reaction) در کاتالیستهای متخلخل بکار می رود. در مدل روزنه های موج دار، از یک دسته روزنه های اصلی (pore) استفاده شده است . هر یک از این روزنه های اصلی دارای یکسری عناصر روزنه می باشد که هر عنصر دارای یک شعاع تعیین شده به صورت اتفاقی از یک توزیع اندازه روزنه ها (pore size di...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1391

in this work, a novel and fast method for direct analysis of volatile compounds (davc) of medicinal plants has been developed by holding a filament from different parts of a plant in the gc injection port. the extraction and analysis of volatile components of a small amount of plant were carried out in one-step without any sample preparation. after optimization of temperature, extraction time a...

One of the major issues examined in the quantitative ecology is the spatial distribution pattern of plant species. Knowledge of the spatial distribution patterns is essential to measure the level of uniformity in the surrounding environment, plant reproduction, and distribution of the seedlings, plant behavioral patterns, coexistence, allelopathic relations, and competition. Therefore, the aim ...

Journal: :مرتع و آبخیزداری 0
بهرام قلی نزاد استادیار گروه مرتع و آبخیزداری دانشکده منابع طبیعی، دانشگاه کردستان محمد جعفری استاد دانشکده منابع طبیعی دانشگاه تهران محمد علی زارع چاهوکی دانشیار دانشکده منابع طبیعی دانشگاه تهران حسین آذرنیوند استاد دانشکده منابع طبیعی دانشگاه تهران حسن پوربابایی دانشیار دانشکده منابع طبیعی دانشگاه گیلان

this research has been done with the aim of explaining environmental and managerial factors that affects on rangeland vegetation distribution in saral rangelands of kurdistan province. after selecting plant types as working area were done sampling from plant types and determined some of plants parameters such as kind and number of plants and cover percentage. various environmental factors such ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1996
N C Ellstrand R Whitkus L H Rieseberg

Natural hybridization is a relatively common feature of vascular plant species and has been demonstrated to have played an important role in their evolution. Nonetheless, it is not clear whether spontaneous hybridization occurs as a general feature of all plant families and genera or whether certain groups are especially prone to spontaneous hybridization. Therefore, we inspected five modern bi...

Journal: :Journal of Agricultural Meteorology 1967

Journal: :The Geographical Journal 1909

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید