P-methylbenzensulforate trace components were determined by derivative spectrophotometer and optimum derivativeorder and wavelength intervals were selected.
采用导《分光光度法研究了对甲苯磺酸痕量组分的测定方法，并选择了求导阶数、农导波长间距等最佳条件。
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Instead, when a company or an investor wants to buy a derivative contract for, say, oil or wheat or securitized mortgages, an order is placed with a trader at a bank.
We've done this before-- this is the conservation of energy, and in order to find the period of the simple harmonic oscillation, we take the time derivative.