منابع مشابه
investigation of effective parameters on the rigidity of light composite diaphragms (psscb) by fem
در این رساله با معرفی سقف های psscb متشکل از ترکیب ورق های فولادی ذوزنقه ای و تخته های سیمانی الیافی به عنوان سقف های پیش ساخته (سازگار با سیستم سازه ای قاب های فولادی سبک) به بررسی پارامترهای موثر بر صلبیت سقف، پرداخته می شود. در تحقیق حاضر ابتدا به مدل سازی دو نمونه سقف آزمایش شده، به روش اجزاء محدود با استفاده از نرم افزار تحلیلی abaqus ver 6.10 پرداخته شده است. نمونه های ساخته شده تحت اعما...
Casting light on the darkening of colors in historical paintings.
The degradation of colors in historical paintings affects our cultural heritage in both museums and archeological sites. Despite intensive experimental studies, the origin of darkening of one of the most ancient pigments known to humankind, vermilion (α-HgS), remains unexplained. Here, by combining many-body theoretical spectroscopy and high-resolution microscopic x-ray diffraction, we clarify ...
متن کاملMoving Colors in the Lime Light
The ability of humans and macaques to perceive color arises from the existence of three types of cone photore-ceptors in the eye, which are maximally sensitive to long (L), medium (M), and short (S) wavelengths of light. The signals from the L, M, and S cones are thought to be combined at the postreceptoral level to form three inde-The degree to which the primate motion system makes pendent col...
متن کاملThe Photodynamic Action of Light on Hydra.
Hydra were known to react to light as early as 1744 when Trembley first described their movement towards a light source. This migration of the animal was then further elucidated by Wilson in 1891, who found that Hydra viridis and fusca are maximally sensitive to blue light. Haug ( ' 3 3 ) found that Hydra will react to a light stimulus by contracting first and then orienting; and Rushforth, Bur...
متن کاملEffects of prenatal exposure to different colors on offsprings mood
Objective(s):There is much evidence indicating that depression is influenced by the levels of neurotransmitters such as dopamine, GABA and adrenaline. The current study we designed to investigate the effect of exposure of pregnant rats to different colors on neurotransmitters level, as indicators of mood disorders in off springs. Materials and Methods:Five groups of pregnant female Wistar rats ...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1892
ISSN: 0036-8733
DOI: 10.1038/scientificamerican02061892-13421bsupp