cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5 d]imidazole(BCHMX)is an advanced energetic compound that expected to spread worldwide in the near future.Since,no approved remote detection methods were reported in current ...cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5 d]imidazole(BCHMX)is an advanced energetic compound that expected to spread worldwide in the near future.Since,no approved remote detection methods were reported in current literature for this material,we performed hyper-spectral imaging and laser induced fluorescence(LIF)to a BCHMX sample under low laser fluence for determining the optimum laser wavelength used in any future BCHMX-LIF based remote detection systems.For this purpose,an experimental setup consisted of a sun spectrum lamp and hyper-spectral camera was built to illuminate and image white powder samples of BCHMX in comparison with the traditional explosives,HMX(1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane),RDX(1,3,5-trinitro-1,3,5-triazacyclohexane),PETN(2,2-Bis[(nitroxy)methyl]propane-1,3-diyldinitrate).The imaging reveals strong BCHMX sample absorption contrast among other samples at wavelength ranging from 400 to 410 nm.When light source was replaced by a 405 nm laser diode illuminator,a strong BCHMX sample LIF at the spectral range from 425 to 700 nm was observed under low laser fluence condition of 0.1 mJ/cm^(2).Finally,we demonstrated successfully the ability of the 405 nm LIF and the hyperspectral imaging technique to detect finger print traces of BCHMX on white cellulose fabric from a distance of 15 m and a detection limit of 1 mg/cm^(2).展开更多
Jet cooled CN radical beam was formed by cold cathode DC discharge of CH3CNunder molecular beam conditions. The cylindrical cold cathode was placed between the skimmerand the nozzle to prevent the nozzle from being cl...Jet cooled CN radical beam was formed by cold cathode DC discharge of CH3CNunder molecular beam conditions. The cylindrical cold cathode was placed between the skimmerand the nozzle to prevent the nozzle from being clogged by carbon particles. The pulsed photoncounting LIF measurement was seriously jeopardized by the high intensive scattering laser lightdue to CN(B2Z)’s short lifetime (70ns) and weak fiuorescence. By using an attenuator to reducelaser intensity or a polaroid to reduce the scattering laser intensity, we obtained LIF spectra withgood S/N ratio. With the theoretical simulasd spectra, the effects of laser p0larization on LIFwere discussed and the relative populations of CN rotational and vibrational states were obtained.展开更多
文摘cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5 d]imidazole(BCHMX)is an advanced energetic compound that expected to spread worldwide in the near future.Since,no approved remote detection methods were reported in current literature for this material,we performed hyper-spectral imaging and laser induced fluorescence(LIF)to a BCHMX sample under low laser fluence for determining the optimum laser wavelength used in any future BCHMX-LIF based remote detection systems.For this purpose,an experimental setup consisted of a sun spectrum lamp and hyper-spectral camera was built to illuminate and image white powder samples of BCHMX in comparison with the traditional explosives,HMX(1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane),RDX(1,3,5-trinitro-1,3,5-triazacyclohexane),PETN(2,2-Bis[(nitroxy)methyl]propane-1,3-diyldinitrate).The imaging reveals strong BCHMX sample absorption contrast among other samples at wavelength ranging from 400 to 410 nm.When light source was replaced by a 405 nm laser diode illuminator,a strong BCHMX sample LIF at the spectral range from 425 to 700 nm was observed under low laser fluence condition of 0.1 mJ/cm^(2).Finally,we demonstrated successfully the ability of the 405 nm LIF and the hyperspectral imaging technique to detect finger print traces of BCHMX on white cellulose fabric from a distance of 15 m and a detection limit of 1 mg/cm^(2).
基金Project supported by the"Twelfth Five-year"National Science and Technology Support Projects(2013BAK06B01)the National Science Foundation Project of China(51174258)+2 种基金the National Safe Production Critical Incident to Key Technologies Science and Technology Project(anhui-0001-2016AQ)the Provincial Natural Science Research Project(KJ2015A278,KJ2015A295)the College Young Talent Support Plan(gxyqzd2016194)
文摘Jet cooled CN radical beam was formed by cold cathode DC discharge of CH3CNunder molecular beam conditions. The cylindrical cold cathode was placed between the skimmerand the nozzle to prevent the nozzle from being clogged by carbon particles. The pulsed photoncounting LIF measurement was seriously jeopardized by the high intensive scattering laser lightdue to CN(B2Z)’s short lifetime (70ns) and weak fiuorescence. By using an attenuator to reducelaser intensity or a polaroid to reduce the scattering laser intensity, we obtained LIF spectra withgood S/N ratio. With the theoretical simulasd spectra, the effects of laser p0larization on LIFwere discussed and the relative populations of CN rotational and vibrational states were obtained.
