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Square antiprism. In geometry, the square antiprism is the second in an infinite family of antiprisms formed by an even-numbered sequence of triangle sides closed by two polygon caps. It is also known as an anticube. [1] If all its faces are regular, it is a semiregular polyhedron or uniform polyhedron .
Prentice's rule, named so after the optician Charles F. Prentice, is a formula used to determine the amount of induced prism in a lens: = where: P is the amount of prism correction (in prism dioptres) c is decentration (the distance between the pupil centre and the lens's optical centre, in millimetres)
Amblyopia. Anisometropia is a condition in which a person's eyes have substantially differing refractive power. [1] Generally, a difference in power of one diopter (1D) is the threshold for diagnosis of the condition . [2] [3] Patients may have up to 3D of anisometropia before the condition becomes clinically significant due to headache, eye ...
Examples. XeF 2− 8; IF − 8; ReF − 8; Square prismatic geometry and cubic geometry. Square prismatic geometry (D 4h) is much less common compared to the square antiprism. An example of a molecular species with square prismatic geometry (a slightly flattened cube) is octafluoroprotactinate(V), [PaF 8] 3–, as found in its sodium salt, Na 3 ...
Experimental electron energy loss spectrum, showing the major features: zero-loss peak, plasmon peaks and core loss edge. Electron energy loss spectroscopy ( EELS) is a form of electron microscopy in which a material is exposed to a beam of electrons with a known, narrow range of kinetic energies. Some of the electrons will undergo inelastic ...
Esophoria is an eye condition involving inward deviation of the eye, usually due to extra-ocular muscle imbalance. It is a type of heterophoria. Cause. Causes include: Refractive errors; Divergence insufficiency; Convergence excess; this can be due to nerve, muscle, congenital or mechanical anomalies.
Example: a retrograde star antiprism with regular star 7/5-gon bases (vertex configuration: 3.3.3.7/5) cannot be uniform. Also, star antiprism compounds with regular star p / q -gon bases can be constructed if p and q have common factors.
In chemistry, octahedral molecular geometry, also called square bipyramidal, [1] describes the shape of compounds with six atoms or groups of atoms or ligands symmetrically arranged around a central atom, defining the vertices of an octahedron. The octahedron has eight faces, hence the prefix octa. The octahedron is one of the Platonic solids ...
The video covers an area of 2.0 by 1.5 mm and was captured over 7.2 min. The interface between a crystal and its vapor can be molecularly sharp at temperatures well below the melting point. An ideal crystalline surface grows by the spreading of single layers, or equivalently, by the lateral advance of the growth steps bounding the layers.
The result for two conducting spheres in a solvent is the formula of Marcus G = ( 1 2 r 1 + 1 2 r 2 − 1 R ) ⋅ ( 1 ϵ opt − 1 ϵ s ) ⋅ ( Δ e ) 2 {\displaystyle G=\left({\frac {1}{2r_{1}}}+{\frac {1}{2r_{2}}}-{\frac {1}{R}}\right)\cdot \left({\frac {1}{\epsilon _{\text{opt}}}}-{\frac {1}{\epsilon _{\text{s}}}}\right)\cdot (\Delta e)^{2}}