[Er3+:Yb3+ co-doped nanocrystals BaGd2ZnO5 of up-conversion optical temperature sensing].

By far, the most efficient upconversion nanocrystals luminescence materials BaGd2ZnO5: 4%Yb3+ , 1%Er3+, with stable chemical performance, were prepared by using Sol-gel method. XRD pattern shows that the sample is pure phase, belongs to the orthogonal crystals, and space group is Pbnm; SEM micrograph shows that the prepared sample of the morphology sized around 150 nm is evenly distributed. Samples with 971 nm semiconductor laser excitation produce a strong green emission, visible to the naked eye, and uponversion strength and pump energy relation n = 1.

[Studies on laser induced dispersive fluorescence spectroscopy of SO2 molecule excited by two-photon].

The processes of excitation and complicated de-excitation of A-symmetric state in the first-excited band of SO2 molecule were studied experimentally with the techniques of two-photon laser induced dispersive fluorescence spectroscopy where a pulsed dye laser (579 nm) was used as excitation sources. The SO2 molecule which were excited from ground state X1A1 to the high vibrational levels of A1 A2 state by absorbing two photons, will realize the repopulation in several vibration-rotational energy levels of A1 A2, B1 B1 and alpha3 B1 states by internal energy conversion and collision relaxation. Because of transitions to the different vibrational levels of ground electronic state X1 A1 from the ground vibrational levels of A1 A2, B1 B1, and alpha3 B1, the fluorescence spectrum envelopes centered at 305 and 425 nm and the regular fluorescence lines centered at 347.

[Mollow profile with seven peaks under double coupling fields].

Transparency and absorption overlaping with Mollow profile in a lambda three-level scheme driven by two coupling fields was investigated. There are two degenerate hyperfine levels within ground state. A strong coupling field and a probing field interact with the same optical transition between the excited state level and the first ground state hyperfine level, and an additional weak coupling field interacts with the excited state level and the second ground state hyperfine level, which is named double coupling lambda three-level scheme.

[Study on the reaction mechanism of NO removal by pulse corona discharge].

Chemical reaction kinetics of NO removal by pulse corona discharge under the condition of normal atmospheric pressure was studied by using dispersive fluorescence spectrum and time-resomved spectrum. The fluorescence spectrum of NO pulse corona discharge was obtained. Moreover, dactylograms of NO, and those of the N+, O, N2, produced in the process of discharging were confirmed by attributing the fluorescence spectrum, and then the time behaviors of these particles were studied by analyzing these dactylograms.

[Self-absorption of NO fluorescence induced by two-photon].

The two-photon LIDFS of NO excited with 452.4 nm output of an optical parameter generator and optical parameter amplifier pumped by a Nd: YAG laser was obtained. The vibration frequency and the inharmonic coefficients of the ground electronic state of NO were calculated from the results of the spectral ascription.

[Spectrum of dielectric barrier discharge at atmospheric pressure intensified by mixing a little argon].

In this paper, the spectrum of dielectric barrier discharge at atmospheric pressure was measured by using the special setup with two water electrodes. The variation of spectrum was studied when a little argon was mixed. Nitrogen molecular spectrum (C3 IIu(v' = 0 ) --> B3 IIg(v" = 0-4)) and nitrogen atomic spectrum(4d(4) D7/2 --> 3p(4)P1/2(0)) were found in the range of 300-800nm.

[The 440-495 nm laser-induced fluorescence excitation spectrum of NO2].

Under the conditions of room temperature and low pressure, laser-induced fluorescence excitation spectrum of NQ2 in the wavelength region of 440-495 nm was obtained by using optical parameter generator (OPG) and amplifier (OPA) as an excitation source. The OPG/OPA was pumped by a Nd:YAG laser. The peaks of the spectrum are attributed to B2B1 <-- X2A1 transition.

[Laser induced dispersed fluorescence spectra of NO2 in the range of 550-740 nm].

Laser induced dispersed fluorescence spectra (LIDFS) of NO2 molecules, excited by second harmonic lines (the output wavelength is 532 nm) of a pulsed Nd: YAG laser at room temperature and at low and high NO2 pressures, were obtained and analyzed. The authors got vibronic progressions in the range of 550-740 nm at low pressure and ascribed them to the transitions from the first excitation electronic state A(2)B2 to the vibrational levels of the ground electronic state X(2)A1, and then calculated the harmonic frequencies of symmetry stretch and bond stretch: omega1 = 1300.72 cm(-1) and omega2 = 744.

[Study on the emission spectrum of B (3)pig state of N2 molecule].

DC glow discharge was used to study N2 molecule at low pressure (4 Torr). The emission spectrum was examined in the range of 320-470 nm in the discharge plasma of N2, which showed that the emission was composed of a series of spectral lines equidistant, and the relative emission intensity became weaker with longer wavelength, whose distribution accorded with Frank-Condon rule. It is attributed to the transition of C 3pi(u)-->B3pi(g).

[Laser fluorescence excited spectrum of NO via alpha2sigma<--chi2pi transition].

Two-photon fluorescence excited spectrum of NO induced by Nd: YAG laser pumped optical parameter generator/amplifier as excitation source was obtained in the range of 420-472 nm. With this technique, the structure of the energy levels of NO molecule in alpha2sigma electronic state was investigated. The peaks of the spectrum were attributed to alpha2sigma(v' = 0,1)<--chi2pi(v" = 0) transition.

[Mechanism of resonance-enhanced multiphoton ionization of NO molecule].

NO molecule is a diatomic molecule with different nucleus. It is a serious pollutant and is harmful to the health of the generation. It comes mainly from inflammation process using coal as burning material.

[Resonance-enhanced multiphoton ionization spectrum of NO by D2 sigma state].

NO is an important pollutant molecule, and plays a key role in generating photochemical smog and destroying O3 in the atmosphere. So researchers have always been interested in it. In our experiment, the optical parameter generator and amplifier (EKSPLA) pumped by Nd:YAG (Quantel) laser were used as the radiation source.

[Study on the formation of XeCl at low pressure].

Low pressure dielectric barrier discharge was used to study the formation of XeCl excimer in a mixture of Xe/Cl2 in the range of 70-1,330 Pa. The fluorescence emission spectra in the range of 285-315 nm at different pressure and ratio of Xe/Cl2 were measured. The results indicate that near 308 nm the emission intensities of XeCl formed under the experimental conditions varied with different total pressure and ratio of Xe/Cl2, and the formation efficiency of XeCl excimer reached maximum value at the ratio of 4:1.

[Spectroscopic diagnoses of glow discharge plasma for the carbon nitride growth process].

Plasma diagnostics is performed during dc. glow discharge plasma-enhanced chemical vapor deposition (PECVD) on nitride thin films using optical emission spectra. Several molecular bands such as the second positive series of N2 transitions, the first negative series of N2+ and the CN, NH violet bands are identified.

[The fluorescence emission spectrum of NO in dielectric barrier discharge (DBD) plasma].

Dielectric barrier discharge was used to study the NO molecules of the atmosphere pollution, and the fluorescence emission spectrum in the range of 210-280 nm at low pressure was obtained in this plasma. The spectrum shows obviously the structure of double apices, whose intensity distribution in accord with Frank-Condon principle and the maximum lies at 236 nm. The main lines are attributed to the A 2 sigma+ -->X 2 pi 1/2, 2/3 transition.