Background sky radiation means the spatial distribution of sunlight absorbed and scattered by particles in the atmosphere. It is important in scientific research and engineering applications. Kinds of ground-based instruments for measuring the background sky radiation are introduced. Algorithms of estimating the optical properties of atmospheric aerosol, the column density of water vapor, ozone and nitrogen dioxide as well as the spatial distribution of clouds are reviewed to illustrate the applications of background radiation in atmospheric optics research. It is the reference for the follow-up studies, according to the background spectra radiation in the atmosphere. Several research objectives about environmental perception and weather identification according to the all sky background spectra radiance are proposed.

For its low concentration indoor, formaldehyde is hard to degradation. The mechanism of nano-TiO2 photocatalysis degrading indoor formaldehyde gas is explored. To improve photo catalytic degradation rate of formaldehyde, the modification of TiO2 catalyst, the adoption of strong absorptive catalyst support, the improvement of avability ratio of light, the ultrasonic assisted catalytic and the combination with pulsed discharge plasma were discussed in detail as the proposed methods. The future tendency of degradation indoor formaldehyde by TiO2 in visible light was predicted.

Physical-optical properties of aerosols in the pollution haze weather are analyzed, and the main ingredients of PM2.5 is studied, including ammonium sulfate, sulfuric acid, ammonium nitrate and carbonaceous aerosol particles. The scattering characteristics of the particles in haze are studied by using Mie theory, and the properties of scattering, absorption, extinction efficiency factor and scattering phase function of the above four components are analyzed. Results show that ammonium sulfate, sulfuric acid and ammonium nitrate particles have strong-scattering effect, but slight absorbtion effect, and the scattering efficiency factor attenuates oscillatorily with the increase of size parameter, eventually close to constant 2, while the carbonaceous aerosol particles show a greater absorption effect. Finally, by comparing scattering phase functions of different particles with the different radius, it shows that the phase function of particle is more sensitive to size and complex refractive index, and the forward and backward scattering has a certain degree of symmetry. The results can be used for optical remote sensing monitoring of air pollution.

The automatic observation system of the near surface optical turbulence is composed with CSAT3 three-dimensional sonic anemometer and WXT520 multifunctional weather sensor. Solar power and wireless transmission are used to realize unattended operation, while the conventional meteorological parameters and atmospheric refractive index structure constant C2n can be measured simultaneously. It consists of a control center and three sub stations, which can be measured at the same time to three points. The real temperature is obtained from virtual temperature via humidity correction. The atmospheric refractive index structure parameter C2n is calculated by using the method of single point temperature fluctuation, and the calculated results are in good agreement with the experimental results. The system can adapt to the complex and harsh environment, the performance is stable and reliable, and the sub station can be extended.

As the exact measurement of airport road visibility range (RVR) is so difficult, a new method was proposed. A criterion lamp-house is set at proper range, and the minimum findable light intensity is manually observed, then the RVR at night is iteratively calculated. The new method is more elaborate than current ones, and its worked result is more appropriate for the true result. The reliability of the proposed method was verified by simulation experiment.

Using the data of World Data Center for Greenhouse Gases (WDCGG) and WMO, the concentrations of the main greenhouse gas CO2 in China and its surrounding countries and regions are preliminarily analyzed. The results show that: the CO2 concentrations in China mainland are close to Hong Kong in China, Japan, Russia, and South Korea; they all have the same trends. Higher CO2 concentrations are found in Hong Kong in China and South Korea, while lower CO2 concentrations in Japan, Russia, Waliguan in China. The results of many years observation show that the average concentration of CO2 in the northern hemisphere is increasing year by year, and the average annual variation of CO2 concentration is inversely proportional to the altitude of the observation station. The concentration and variation trend of CO2 in Waliguan Global Station is consistent with that in the Mauna Loa, Barrow, Trinidad Head global station. But the annual variation in Waliguan is slightly higher than in Mauna Loa, and lower than in Barrow. The changes of CO2 concentration in Shangdianzi Regional Background Station in China are more violent than in Waliguan, Mauna Loa, Barrow, Trinidad Head Stations, which shows that Shangdianzi Station is affected by the stronger regional emissions.

Laser Raman spectroscopy is widely applied in marine chemical environmental detection and analysis of substances, as an in－situ, real-time, multisubstance detection sensor technology. Charge-coupled devices (CCD) as the detector of Raman spectrometer are easily interfered by cosmic ray so that some spikes that have random location, intensity and peak width occur on Raman spectra. The presence of such spikes can damage spectral presentation, complicate interpretation, and impede further analyses. The method combined nearest neighbor comparison method (NNC) with median filter was used to detect and remove spike from the measured spectral data of seawater in laboratory. The Raman spectra were divided into two areas firstly: Raman peaks area and the area that has no Raman peaks. The NNC processed the area that has Raman peaks and the median filter processed the area that has no Raman peaks. The result shows that the combined method can remove spike of the full spectra completely on the premise that the intensity of Raman peaks remain unchanged. The method contributes to improving the accuracy and stability of qualitative and quantitative analysis for Raman spectra.

By using MODIS and MISR data, the spatiotemporal distribution characteristic of aerosols were studied for the period before, during and after Asia-Pacific Economic Cooperation (APEC) Conference 2014 (from November 3 to 12). Compared with the month before APEC, the aerosol optical depth (AOD) during APEC shows an apparent decrease in the region of Beijing-Tianjin-Hebei (36°N～41°N, 113.5°E～118.5°E), which decreases by 38.7% (36.4%) according to MODIS (MISR) data. And the AOD decreases more substantially in Beijing, which decreases by 64.6% ( 39.9%). The spatial distribution of the Angstrm exponent shows that in the most of the city of Beijing-Tianjin-Hebei region (e.g. Langfang, Baoding, Hengshui, etc.), the Angstrm exponent during APEC is relatively small, which indicates that the effective radius of the aerosol is relatively large. During APEC, the optical depth of the fine mode aerosol also decreases in comparison with the period before APEC, and it declines more significantly than the optical depth of the coarse aerosol in Beijing.

Solar UV radiation induces the dissociation of the chlorinated alkyl bromide with the product of free bromide radical and chlorine radical, which seriously damage the ozone layers. The molecular structure optimization and infrared spectra of chlorinated alkyl bromide CnH2nBrCl(n=1～16)were calculated by the[B3LYP/6-311++G(d, p)] basis set levels using density functional methods (DFT) approaches. Via comparison and discussion, the tendency of molecular structural parameters, like bond length, bond angle of CnH2nBrCl changing with the alkyl chain length increasing (n=1～16) are calculated. Meanwhile, the changing rules of C-Br and C-Cl vibration with the alkyl chain length increasing are also determined. Dependence of the molecular configuration and spectra of CnH2nBrCl on alkyl chain length (n) are obtained.

A new type of oscillation cavity is developed based on the optical characteristics of the combination of two rectangular prisms. The oscillation cavity consists of four rectangular prisms. The length of basic line and the number of oscillations were changed by adjusting the distances and locations of four rectangular prisms. So the optical length of the cell increased. The light intensity can be measured by photoelectric conversion, so a ratio and the new equation of calculating atmospheric visibility can be obtained. Because of the divergence angle of lasers, the diameter of the beam grows when the optical length increases. The situation is given by numerical simulation. The extinction coefficients corresponding with the different atmospheric visibilities are analyzed. The light intensities are calculated when the light passes the different optical lengths. This can provide reference for the selection of a detector.