Convex function than convex or strictly convex functions, since they are a smaller class. Like strictly convex functions, strongly convex functions have unique minima on compact sets. A uniformly convex function, with modulus formula_70, is a function that, for all "x", "y" in the domain and , satisfies where formula_70 is a function that is non-negative and vanishes only at 0. This is a generalization of the concept of strongly convex function; by taking formula_73 we recover the definition of strong convexity. Convex function In mathematics, a real-valued function defined on an "n"-dimensional interval is called convex (or convex downward or concave
Compound refractive lens Compound refractive lens A Compound refractive lens (CRL) is a series of individual lenses arranged in a linear array in order to achieve focusing of X-rays in the energy range of 5-40 keV. They are an alternative to the KB mirror. For all materials the refractive index for X-rays is close to 1, hence a single conventional lens for X-rays has an extremely long focal length (for practical lens sizes). In addition, X-rays attenuate as they pass through a material so that conventional lenses for X-rays have long been considered impractical. The CRL gets its reasonably short focal length, on