“j”的概念、定义、翻译、参考文献-科学参考

Mathematics

In the notation for complex numbers, some authors, especially engineers, use j instead of i.
A unit vector, usually in the direction of the y-axis or a vertical vector in the plane of a projectile’s motion.

Chemical Engineering

A symbol used by engineers to represent the square root of −1. It is an imaginary number which is distinguished from real numbers. For example, the solution of $x^{2} +1= 0$ is j and –j. Mathematicians tend to use the symbol i instead of j. See complex numbers.

Electronics and Electrical Engineering

1. A mathematical operator equivalent to a rotation through 90°.
2. Symbol for the square root of −1, √−1, which defines imaginary numbers. Formulas for electric and electronic circuits use j instead of i for this purpose because i is already used to indicate current flow.
If a current flows through a complex impedance, comprising a real resistive component and a reactive component, then the voltage across the resistive component will be in phase with the current, whereas the voltage across the reactance will be shifted in phase from the current by 90°. The resistance can therefore be denoted by a real value R, and the reactance by jX, the j signifying the 90° phase shift.

单词	j
释义	j Mathematics In the notation for complex numbers, some authors, especially engineers, use j instead of i. A unit vector, usually in the direction of the y-axis or a vertical vector in the plane of a projectile’s motion. Chemical Engineering A symbol used by engineers to represent the square root of −1. It is an imaginary number which is distinguished from real numbers. For example, the solution of $x^{2} +1= 0$ is j and –j. Mathematicians tend to use the symbol i instead of j. See complex numbers. Electronics and Electrical Engineering 1. A mathematical operator equivalent to a rotation through 90°. 2. Symbol for the square root of −1, √−1, which defines imaginary numbers. Formulas for electric and electronic circuits use j instead of i for this purpose because i is already used to indicate current flow. If a current flows through a complex impedance, comprising a real resistive component and a reactive component, then the voltage across the resistive component will be in phase with the current, whereas the voltage across the reactance will be shifted in phase from the current by 90°. The resistance can therefore be denoted by a real value R, and the reactance by jX, the j signifying the 90° phase shift.
随便看	arfvedsonite Arfwedson distribution arg Argand diagram Argand, Jean Robert (1768–1822) Argelander, Friedrich Wilhelm August Argelander, Friedrich Wilhelm August (1799–1875) Argelander step method argentic compounds Argentina Argentinean Space Agency argentite argentous compounds argic horizon argillaceous argillaceous limestone argillans argillic horizon argillite arginine Argo argon argon-40 Argo Navis argon(symbol: Ar)