[3] GREZZI G, AYUSO R A, VIVO B D, et al.. Lead isotopes in soils and groundwaters as tracers of the impact of human activities on the surface environment: the Domizio-Flegreo Littoral (Italy) case study [J]. Journal of Geochemical Exploration, 2011, 109(1): 51-58.
[4] HOSONO T, WANG C, UMEZAWA Y, et al.. Multiple isotope (H, O, N, S and Sr) approach elucidates complex pollution causes in the shallow groundwaters of the Taipei urban area [J]. Journal of Hydrology, 2011, 397(1): 23-36.
[5] LASCIO A D, ROSSI L, TUCKER P C, et al.. Stable isotope variation in macroinvertebrates indicates anthropogenic disturbance along an urban stretch of the river Tiber (Rome, Italy) [J]. Ecological Indicators, 2013, 28: 107-114.
[6] KING L A, GORNUSHKIN I B, PAPPAS D, et al.. Rubidium isotope measurements in solid samples by laser ablation-laser atomic absorption spectroscopy [J]. Spectrochimica Acta Part B, 1999, 54: 1771-1781.
[7] SMITH B W, QUERNTMEIER A, BOLSHOV U M, et al.. Measurement of uranium isotope ratios in solid samples using laser ablation and diode laser-excited atomic fluorescence spectrometry[J]. Spectrochimica Acta Part B, 1999, 54: 943-958.
[8] WIZEMANN H D, NIEMAX K. Isotope selective element analysis by diode laser atomic absorption spectrometry [J]. Mikrochim. Acta, 1998, 129: 209-216.
[9] WIZEMANN H D, NIEMAX K. Measurement of 7Li/6Li isotope ratios by resonant Doppler-free two-photon diode laser atomic absorption spectroscopy in a low-pressure graphite furnace[J]. Spectrochimica Acta Part B, 2000, 55: 637-650.
[10] WAHL E H, FIDRIC B, RELLA C W, et al.. Applications of cavity ring-down spectroscopy to high precision isotope ratio measurement of 13C/12C in carbon dioxide [J]. Isotopes in Environmental and Health Studies, 2006, 42: 21-35.
[11] EWART P, O’LEARY S V. Measurement of relative extreme-wing absorption coefficients by excited-state degenerate four-wave mixing[J]. Optics Letters, 1986, 11: 279-281.
[12] SUN Z W, LI Z S, LI B, et al.. Detection of C2H2 and HCl using mid-infrared degenerate four-wave mixing with stable beam alignment: towards practical in situ sensing of trace molecular species[J]. Applied Physics B, 2010, 98: 593-600.
[13] WILLIAMS S, GREEN D S, SETHURAMAN S, et al.. Detection of trace species in hostile environments using degenerate four-wave mixing: CH in an atmospheric-pressure flame[J]. Journal of the American Chemical Society, 1992, 114: 9122-9130.
[14] PALOMBA S, ZHANG S, PARK Y, et al.. Optical negative refraction by four-wave mixing in thin metallic nanostructures[J]. Nature Materials, 2012, 11: 34-38.