time-angle meaning in Chinese

时间角

In the last chapter , by introducing the isochronous center of real systems into complex planar and defining complex center and complex isochronous center , a concise linear recursion formula for period constants is given , necessary and sufficient conditions of complex isochronous center ( the time - angle difference theorem ) proved , conditions of real systems with linearizable center and saddle treated unitedly and the isochronous center conditions discussed fully for a class of real planar cubic systems
在第七章，通过把实系统等时中心引入复平面研究，定义了复中心和复等时中心，给出了等时中心周期常数计算的简明的线性递推公式，证明了等时中心判定的充分必要条件（时角差定理人统一地处理了实系统具有可线性化的中心和鞍点条件，并对一类实平面三次系统的等时中心条件进行了完整研究