Spectroscopic remote techniques are hi-tech atmospheric pollution mon-itoring with their special advantages over other methods in many aspects，such as high sensitivity multi-analytical，fast and on line supervision etc．Four spectroscopic methods are introduced in this paper： Fourier Transform Infrared Spectroscopy,(FTIR)，Diferetial Optical Absorption Spectroscopy(DOAS) Laser Long—path Absorption and Diferetia1 Absorption Lidar (DIAL) based on 1asers．Basic measurement principle．operation way，each advantages and shortcomes，and applicaion are also discussed．

In this paper，the temporal averaging which is used to prepare efective pure states and has been suggested by Gershenfeld et al．，is extended to prepare 3-qubit efective pure states in a homonuclear system．We have prepared 3-qubit efective pure states by NMR simulators aald validate this method．

W e report here a high efficient diode pumped Nd：YV04 laser emitting at 1342 nm． The dependence of output power and efficiency on cavity length transmittance of the output mirrors and doped density of Nd ion in YVO4 crystals was investigated，a maximum output power of 3 W was obtained．

We consider the effect of the partially coherent finite duration of excitation laser pulse and instrumental finite response time oil the data fit of quantum beats in isolated molecules．By using a Gauss response mode1 we can simulate the efect of both partially coherent laser pulse and instrumnental response time．We show that Gauss response has the biggest efect oil the first severel peaks of the quantum beat decay．but less Oil the subsequent peaks if quantum beat period js mnch greater than Gauss response width．This approach is applied to analyze quantum beats of S02 in the range of 224~235 nm We find that these quantum beats come from the couple of SO2C(1B2) state with the high vibrational state of the ground state．

The photoelectron energy spectra and the coherence population trapping of a two channel photoionization system are studied． The results show that the energv spectra and th coherence trapping are not only decided by the phase of the photonization field，but also have a close relationship with the phase and the intensitv of the modulated electromagnatic field．

The nonclassical properties of odd and even coherent states in a finite dimensional Hilbert spaces (FDHS) case are studied by numerical method． It is found that，no squeezing but antibunching efects exist in odd coherent states,both quadrature squeezing and antibunching efects are exist in even coherent states．with the number ofdimension reducing．the quadrature fluctuation is increased and the antibunching efects are Enhanced in odd coherent states； and the squeezing effects are weakened but the antlbunchlng efects aTe Enhanced iu even coherent stares

In this paper,evolution of the field entropy have been studied by use of the Jaynes-Cummings mode1． Trinsition probability between every two levels of atom with binomial stage for radiation field interacting is also studied． The influence of field parameters Drl the trallsition pl。obability，and evolution of the field are discussed．

L625 Rayleigh scattering lidar made the measurements of air density and temperature over the altitudes of 30~43 km at Hefei (31.9。N／117.17。E)，two laser beams with 355 rim and 532 nm were employed，respectively The results of lidar agreed well with ones of NOAA／NMC and NASA／HALOE．Generally,the differences of density were about 10％ and temperature biases were less than 2 K between the altitude 34 km and 43 km．but a 1ittle larger below 34 km．