Comparison of temporal and Spatial Characteristics of Ozone Pollution at Ground Level in the Eastern China

Monitoring data from ozone（O3） automatic stations in three typical cities with different climatic areas in the southern and northern parts of eastern China are used to analyze temporal and spatial characteristics of ozone pollution at ground level. The results show that ozone pollution level has distinct regional differences and the concentration in the suburbs is higher than that in the urban areas. The seasonal variation of ozone concentration in different climatic areas is greatly affected by the variation of precipitation. Ozone concentration in Shenyang and Beijing , in the temperate zone, has one perennial peak concentration, occurring in early summer, May or June. Ozone concentration in Guangzhou, in sub-tropical zone, has two peak values year round. The highest values occur in October and the secondary high value in June. The ozone season in the south is longer than that in the north. The annual average daily peak value of ozone concentrations in different climates usually occur around 3 pm. The diurnal variation range of ozone concentration declines with the increase of latitude. Ozone concentration does not elevate with the increase of traffic flow. Ozone concentration in Guangzhou has a distinct reverse relation to CO and NOx. This complicated non-linearity indicates that the equilibrium of ozone photochemical reaction has regional differences. Exceeding the rate of Beijing＇s lh ozone concentration is higher than that of Guangzhou, whereas the average 8h ozone level is lower than that of Guangzhou, indicating that areas in low latitude are more easily affected by moderate ozone concentrations and longer exposure. Thus, China should work out standards for 8h ozone concentration.

Hydrogen Isotopes Recovery from Liquid Lithium under Dynamic Conditions

In the IFMIF （International Fusion Materials Irradiation Facility）, high-intensity deuteron ion beam is targeted at flowing liquid Li to produce neutron for long-time irradiation test of fusion materials. Radioactive tritium （T） will be produced as by-product of the D-Li reaction. Y hot trap is expected as an effective system to recover T from the liquid Li target loop. In the present study, absorption behavior of hydrogen isotopes in Y plates is experimentally and analytically investigated under stirring conditions of liquid Li. Experiments clarified that H2 absorption rates of solid Y immersed in Li are independent of the rotating rate in the range of 0 to 100 rpm and are in proportion to the inlet H2 concentration. The rate-determining step is H diffusion in Y. A mass-transfer coefficient is a useful parameter to correlate the overall H transfer from the gaseous phase through liquid Li to the solid Y plate. The effect of activation temperature on the overall performance when Y absorbs H is comparatively investigated. It is considered that heating at 673 K is effective to activate Y along with HF treatment.

Hydrophobic terminal group of surfactant initiating micellization as revealed by^1H NMR spectroscopy

The critical aggregation concentration（CAC） of four with three kinds of conventional surfactants, namely,two cationic surfactants [hexadecyltrimethyl ammonium bromide（CTAB） and tetradecyltrimethyl ammonium bromide（TTAB）], one anionic surfactant [sodium dodecyl sulfate（SDS）], and a nonionic surfactant [Triton X-100（TX-100）], were determined by variation of ^1H chemical shifts with surfactant concentrations. Results show that the CAC values of protons at different positions of the same molecule are different, and those of the terminal methyl protons are the lowest, respectively, which suggests that the terminal groups of the alkyl chains aggregates first during micellization. Measurement of the transverse relaxation time（T2） of different protons in SDS also show that the terminal methyl protons start to decrease with the increase in concentration first, which supports the above mentioned tendency.