Vol.11,

A new 14.5 GHz Electron Cyclotron Resonance (ECR) ion source has been constructed over the last two years. The source was designed and tested by making use of the latest results from ECR ion source development, such as high mirror magnetic field, large plasma volume, and biased probe. 140µA of O7+, 185µA of Ar¹¹⁺ and 50µA of Xe²⁶⁺ could be produced with a RF power of 800W. The intense beams of highly charged metallic ions are produced by means of the method of a metal evaporation oven and volatile compound through axial access. The test results are 130μA of Ca¹¹⁺, 70µA of Ca¹²⁺ and 65µA of Fe¹⁰⁺. The ion source has been put into operation for the cyclotron at the Institute of Modern Physics (IMP).

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An 18-year-long (1981-1998) study was conducted in Hainan Island waters (22°20＇N, 110°39＇E) to determine the relationship between δ¹⁸O in skeletal aragonite carbonate and sea surface temperature (SST) in porites lutea of reef-building corals. δ¹⁸O values in skeletal aragonite carbonate were measured by means of mass spectrometry. Coral samples grew at 5m depth at Longwan Bay. Monthly measurements of the SST from 1960 to 1998 were taken at Qinglan Bay adjacent to the place of the collected samples. The thermometer shows that SST=-4.16 δ18O^PDB + 4.9 (r=0.80) and dδ¹⁸O/dT=-0.24 permil/℃. The δ¹⁸O thermometer is strongly influenced by the rainfall and runoff. Using the thermometer, the SST in the past hundred years with monthly resolution will be reconstructed and the climatic change in the northern area of South China Sea will be hindcasted

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Predictions on the leaching behaviour of microconstituents from dumped, stored, or immobilised wastes are based on estimates of the effective diffusion coefficients involved, which usually range from ~10^-6 to ~10^-12 cm²•s^-1. Radioanalysis, especially radiotracer procedures, can be applied to determine these parameters on small (field) samples of granular material and test specimens of immobilised wastes. A summary of standard experiments for both types of material under non-steady state and steady state conditions is presented

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Alternative versions of the ZM model are extended to asymmetric nuclear matter by including ρ meson degree of freedom in the Lagrangian. The extended models are then used to study the thermodynamical properties of asymmetric nuclear matter at finite temperature. The critical temperature for a liquid- gas phase transition in nuclear matter and its dependence on asymmetry parameter are calculated. The limiting temperature T_lim, which reflects Coulomb instability of hot nuclei, is studied. The calculated results are compared with that given by the original ZM model.

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Angular correlation of excitation functions in dissipative heavy ion collision ²⁷Al+²⁷Al has been measured. The incident beam energies ranged from 114 MeV to 127 MeV in steps of 200 keV. The angular analysis region was continuous from 50° to 90° in the center of mass system. An angular coherent width, at least 40°, was obtained. This long-range angular correlation could not be interpreted in the framework of the standard statistical reaction theory with state of equilibrium or near equilibrium, maybe it reveals the formation of a new kind of dissipative structure in the reaction of ²⁷Al+²⁷Al with the state that is far from equilibrium.

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A study of dilepton spectra, in intermediate mass region (IMR), from main background sources, quark phase, and secondary processes in hadronic phase on the basis of a relativistic hydrodynamic model has been carried out. The comparison between these results indicates that in this mass region the contribution from the background sources dominates, and due to the effect of the phase boundary on the evolution of the system the contribution from the quark phase becomes more important than that from secondary processes.

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Analyzing powers and differential cross sections have been measured for elastic scattering of 22 MeV polarized protons from ⁴⁰Ca, ¹⁶O and ¹²C, and differential cross sections for inelastic scattering of 22 MeV protons from 3^-(3.736 MeV) and 5^-(4.491 MeV) states of ⁴⁰Ca have also been measured. The experimental data for polarized proton elastic scattering have been analyzed with a phenomenological optical potential parameters, the experimental data and theoretical values are in good agreement. In the theoretical frame of microscopic single scattering model, transition densities extracted from electron inelastic scattering and M3Y and Halderson's effective interactions have been utilized to analyze the experimental data of 22 MeV proton inelastic scattering from ⁴⁰Ca. Overall, it seems that Halderson's effective interaction can better describe the experimental data than M3Y although the degree of agreement between experimental and theoretical values needs to be improved.

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The liquid-liquid extraction behavior of uranium(VI) from nitric acid aqueous solution with n-octyldodecylsulfoxide(ODSO) has been studied over a wide range of conditions. The extracted species appear to be UO²(NO₃)₂•2ODSO. It was found that the extraction was increased with increasing sodium nitrate concentration. Extracting also increases with increasing extractant concentration. The influence of temperature and nitric acid concentration on extraction equilibrium was also investigated and the enthalpy of the extraction reaction was obtained.

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