Abstract: A method for simultaneous determination of nitrogen and oxygen isotope compositions of natural nitrate and nitrite, which quantitatively converts natural nitrate and nitrite into an organic ester and a nitro-compounds respectively, and then nitrate and nitrite ?18O and ?15N are simultaneously determined by adopting a gas chromatography/pyrolysis/gas chromatography/isotope ratio mass spectrometry coupling technology (GC/Py/GC/IRMS). According to the method for simultaneously determining the nitrogen and oxygen isotope compositions of the natural nitrate salt and nitrite salt, the small amount of sample does not result in the loss, acquisition, exchange and fractionation of nitrogen and oxygen.

Abstract: The disclosure describes a method for simultaneous determination of nitrogen and oxygen isotope compositions of natural nitrate and nitrite, which quantitatively converts natural nitrate and nitrite into an organic ester and a nitro-compounds respectively, and then nitrate and nitrite ?18O and ?15N are simultaneously determined by adopting a gas chromatography/pyrolysis/gas chromatography/isotope ratio mass spectrometry coupling technology (GC/Py/GC/IRMS). According to the method for simultaneously determining the nitrogen and oxygen isotope compositions of the natural nitrate salt and nitrite salt, the small amount of sample does not result in the loss, acquisition, exchange and fractionation of nitrogen and oxygen.

Abstract: A fuel activation catalyzer for an energy saver of an internal combustion engine is provided, which including nanometer negative ions and far infrared materials, and carrier of the nanometer negative ions material selecting from the following material's: cordierite ceramic material and/or limestone, wherein the weight of the nanometer negative ions and far infrared materials to the total weight of the nanometer negative ions and far infrared materials and the carrier is 5 wt %-30 wt %. And a manufacture method of the catalyzer for an energy saver of an internal combustion engine and an energy saver of an internal combustion engine using the catalyzer are also provided. By using the energy saver, the oil circuits and gas circuits are improved, the combustion is promoted and the heat value of the fuel is enhanced.