Vol.15,

Eight 500MHz cavities are applied in the storage ring of the Shanghai Synchrotron Radiation Factility (SSRF). In order to tune the cavities for different changing parameters and operation modes, the control system is essential for operations. The tuning is achieved by synchronizing the drive signal and the cavity probe signal. The error signal defined as their subtraction is amplified and used to drive a stepping motor, which in turn moves a metallic plunger in or out of the cavity by programmable logic controller (PLC). The tune speed is set to be 1kHz/s.

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Recent progress on nuclear liquid gas phase transition (LGPT) has been reviewed, especially for the signals of LGPT in heavy ion collisions. These signals include the power-law charge distribution, cluster emission rate, nuclear Zipf law, bimodality, the largest fluctuation of the fragments, Δ-scaling, caloric curve, phase coexistence diagram, critical temperature, critical exponent analysis, negative specific heat capacity and spinodal instability etc. The systematic works of the authors on experimental and theoretical LGPT are also introduced.

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In China, the firing and glazed red techniques of producing underglaze-red porcelain began early in the Yuan dynasty (AD1206~1368). This paper reports the results of the PIXE analysis of ancient Chinese underglaze-red porcelain produced at Kuan kiln (Jingdezhen, Jiangxi Province) in the Yuan dynasty. In this work the elemental composition analysis of the obtained samples was carried out using the PIXE facility of a 3 MeV tandem accelerator at Fudan University. The major, minor and trace elements of the clay body, white and red glazes were determined, and details of the results are presented. The obtained data can be used for identification of precious Chinese Yuan underglaze-red porcelain.

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TCTMP (1,4,8,11-tetraaza cyclotetradecyl-1,4,8,11-tetramethylene phosphonate) was synthesized and coupled with ¹⁸⁸Re. The ¹⁸⁸Re-TCTMP's coupling condition, stability and bio-distribution in mice were investigated. The results showed that satisfactory yield of ¹⁸⁸Re could be obtained under the conditions of media pH=2.0, 0.8~1.6mg of SnCl₂ and 50mg of ligand. ¹⁸⁸Re-TCTMP was stable (complexation yield >95%) in 8d without protection of N₂. The result of bio-distribution indicated that ¹⁸⁸Re-TCTMP had a strong affinity to skeleton and very low non-target tissue's uptake, and the amount of ¹⁸⁸Re-TCTMP in blood was (0.06±0.02)%ID/g 6h after injection, whereas the concentration of ¹⁸⁸Re-HEDP (1-hydroxy-ethylidene diphosphonate) in blood was (0.28±0.05)%ID/g 6 h after injection. Compared with ¹⁸⁸Re-HEDP, ¹⁸⁸Re-TCTMP exhibits better potential for the treatment of metastases.

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Experimental and numerical simulation were carried out on vertically upward air-water two-phase flow in the rod bundle with grid spacer. The related numerical simulation has been performed by using the Computational Fluid Dynamics code-CFX4.2, in which lateral interfacial effects based on a two-fluid model are accounted for. This model has been used to evaluate the velocity fields of gas and liquid phases, as well as phase distribution between elements in rod bundle by simulating 1/4 zone of experimental model, and mixing vanes of spacer in this area. Furthermore, this model has been used to predict the effects of spacer on flow and pressure drop along the rod bundle. The calculation results show that the mixing vane has significant influence on axial and lateral velocity. In order to obtain some experimental data to verify the numerical solutions, a series of tests, using a specially designed 3×3 rod bundle test section with AFA-2G structure spacer have been performed. An optical probe was used to measure local void fractions. At the same time, the pressure loss has been measured. A comparison between the calculated void profile and pressure loss and the measured results shows that the predicted void profiles are consistent at low gas apparent velocity. This research shows that the code CFX4.2 can be used to describe the 3-D air-water two-phase flow in the rod bundle channel with grid spacer.

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A plan of surveillance monitoring Qinshan Nuclear Power Plant (QNPP) has been implemented since 1992, the objective of which is to establish the database of environmental radiation information around QNPP, and to detect any unplanned discharge of radioactive materials from QNPP. This paper presents the monitoring results for radionuclide concentrations in the environmental matrices before and after QNPP operation. The radionuclide concentrations in vegetation, food, atmosphere, soil and littoral soil samples have been determined. After operation of QNPP, the mean values of ¹³⁷Cs, ⁹⁰Sr and ³H in water are 0.6, 4.9 mBq/L and 1.7 Bq/L, respectively; the mean values of ¹³⁷Cs in soil and littoral soil are 3.5 and 2.7 Bq/kg, respectively; the mean values of ¹³⁷Cs in rice, green cabbage, meat, mullet, milk and tea are 0.033, 0.039, 0.081, 0.069, 0.018 and 0.62 Bq/kg, respectively; the mean values of ⁹⁰Sr in rice, green cabbage and tea are 0.081, 0.315 and 4.1 Bq/kg, respectively; gross β activity in fallout is 0.9Bq·m^-2·d^-1. Compared with the data before QNPP's operation, no significant difference has heen observed in the radioactivity of ¹³⁷Cs, ⁹⁰Sr, ³H and the gross β activity in ambient environmental matrices from 1992 to 2001, and there are only some fluctuations within the range of background.

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