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13.1 December 23, 2022: Free BSD 3-clause (aka new) Automatic differentiation makes it well suited to complex minimization problems Analytica: Lumina Decision Systems 1982 (Demos) 4.6 May 2015: Free (Analytica Free 101), $995 (professional), $2795 (enterprise) Proprietary
Given a system transforming a set of inputs to output values, described by a mathematical function f, optimization refers to the generation and selection of the best solution from some set of available alternatives, [1] by systematically choosing input values from within an allowed set, computing the value of the function, and recording the best value found during the process.
The α phase has one third of the electrical resistivity [29] and a much lower superconducting transition temperature T C relative to the β phase: ca. 0.015 K vs. 1–4 K; mixing the two phases allows obtaining intermediate T C values. [30] [31] The T C value can also be raised by alloying tungsten with another metal (e.g. 7.9 K for W-Tc). [32]
Wolframite is an iron, manganese, and tungstate mineral with a chemical formula of (Fe,Mn)WO 4 that is the intermediate mineral between ferberite (Fe 2+ rich) and hübnerite (Mn 2+ rich). [4] Along with scheelite , the wolframite series are the most important tungsten ore minerals.
Scheelite is a calcium tungstate mineral with the chemical formula Ca W O 4. It is an important ore of tungsten (wolfram). Scheelite is originally named after Swedish chemist Carl Wilhelm Scheele (1742–1786). Well-formed crystals are sought by collectors and are occasionally fashioned into gemstones when suitably free of flaws.
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Tungsten hexacarbonyl (also called tungsten carbonyl) is an organometallic compound with the formula W(CO) 6. This complex gave rise to the first example of a dihydrogen complex. [2] Like its chromium and molybdenum analogs, this colorless compound is noteworthy as a volatile, air-stable derivative of tungsten in its zero oxidation state.
Tungsten(VI) oxytetrachloride is the inorganic compound with the formula W O Cl 4. This diamagnetic solid is used to prepare other complexes of tungsten. The red crystalline compound is soluble in nonpolar solvents but it reacts with alcohols and water and forms adducts with Lewis bases.