نتایج جستجو برای: nitrogen cycle
تعداد نتایج: 386826 فیلتر نتایج به سال:
مهندسان در طراحی های بزرگ و پیچیده، قبل از ساخت نمونه فیزیکی و برآورد هزینه و زمان ساخت آن احتیاج به شبیه سازی کامپیوتری سخت افزار دارند. از طرفی سرعت شبیه سازهای متداول برای حجم بزرگ مدار بسیار کند می شود و این به دلیل محاسبات زیادی است که برای بدست آوردن اطلاعات ریز زمانی مدار انجام می شود. اما در بسیاری از موارد یک طراح احتیاج به دیدن درستی عملکرد طرح خود دارد و نه اطلاعات ریز زمانی آن. در ا...
در این پایان نامه خصوصیات کلی شبیه سازی cycle-based معرفی شده و نحوه انجام شبیه سازی cycle-based در سطح گیت و سطح انتقال ثبات مورد بررسی موشکافانه قرار گرفته است . در این پایان نامه همچنین محدودیتهای شبیه سازی cycle-based معرفی شده و راه حلهایی برای این مشکلات ارائه شده است . به موازات این پایان نامه و برای اثبات صحت نظریه های مطرح شده و راه حلهای ارائه شده در آن، یک شبیه ساز cycle-based برای ز...
Absorption of ultraviolet light energy by nitrogen dioxide results in its dissociation into nitric oxide and an oxygen atom. The oxygen atoms, for the most part, react with atmospheric molecular oxygen (O2) to form ozone (O3). In general, nitric oxide will react with ozone to reform nitrogen dioxide, completing the cycle. A buildup of ozone above the equilibrium concentration defined by the rea...
Systems approaches have great potential for application in predictive ecology. In this paper, we present a range of examples, where systems approaches are being developed and applied at a range of scales in the field of global change and biogeochemical cycling. Systems approaches range from Bayesian calibration techniques at plot scale, through data assimilation methods at regional to continent...
Over the past decades, the Tibetan Plateau has experienced pronounced warming, yet the extent to which warming will affect alpine ecosystems depends on how warming interacts with other influential global change factors, such as nitrogen (N) deposition. A long-term warming and N manipulation experiment was established to investigate the interactive effects of warming and N deposition on alpine m...
Sediments play a key role in the marine nitrogen cycle and can act either as a source or a sink of biologically available (fixed) nitrogen. This cycling is driven by a number of microbial remineralization reactions, many of which occur across the oxic/anoxic interface near the sediment surface. The presence and activity of large burrowing macrofauna (bioturbators) in the sediment can significan...
Classical ecological theory predicts that changes in the availability of essential resources such as nitrogen should lead to changes in plant community composition due to differences in species-specific nutrient requirements. What remains unknown, however, is the extent to which climate change will alter the relationship between plant communities and the nitrogen cycle. During intervals of clim...
Population sizes and movement patterns of ungulate grazers and their predators have fluctuated dramatically over the past few centuries, largely owing to overharvesting, land-use change and historic management. We used δ(13)C and δ(15)N values measured from bone collagen of historic and recent gray wolves and their potential primary prey from Yellowstone National Park to gain insight into the t...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید