Land and its size are important as the most basic factors of production in agriculture .Fragmentation is one of the main problems that rice producers of Mazandaran province are confronted with. Non-efficiency in farm management, inability in effective using of agriculture technology and machinery, and low range productivity of production are all related to land fragmentation. In order to overco...

Land and its size are important as the most basic factors of production in agriculture .Fragmentation is one of the main problems that rice producers of Mazandaran province are confronted with. Non-efficiency in farm management, inability in effective using of agriculture technology and machinery, and low range productivity of production are all related to land fragmentation. In order to overco...

boron nitride semiconducting zigzag swcnt, $b_{cb}$$n_{cn}$$c_{1-cb-cn}$, as a potential candidate for making nanoelectronic devices was examined. in contrast to the previous dft calculations, wherein just one boron and nitrogen doping configuration have been considered, here for the average over all possible configurations, density of states (dos) was calculated in terms of boron and nitrogen ...

پسماند چوبی درشت ) coarse woody debris ( یکی از اجزای مهم اکوسیستم جنگل است که نقش مهمی در فرآیندهای این اکوسیستم ایفا میکند. طی دهه اخیر توجه فراوانی به این جزء مهم بومسازگان توسط بوم- شناسان و جنگلشناسان شده است و روشهایی برای نمونهبرداری این جزء مهم اکوسیستم معرفی شده که همگی قطعات cwd را با احتمال نابرابر به عنوان نمونه انتخاب می نمایند. pds ( perpendicular distance sampling ،) dls ( dis...