Objective To investigate the specific activity of 24Na per unit neutron fluence,AB/Φ,in blood produced for Chinese reference man irratiaded by 252Cf neutron source,and to analyze the effects of scattering neutrons from ground,wall,and ceiling in irradiation site on it.MethodsA 252Cf neutron source of 3 × 108 n/s and the anthropomorphic phantom were used for experiments.The phantom was made from 4 mm thick of outer covering by perspex and the liquid tissue-equivalent substitute in it.The data of phantom dimensions fit into Chinese reference man.The weight ratios of H,N,O and C in substitute equal from source to long axis of phantom were 1.1,2.1,3.1 and 4.1 m,respectively.Both the neutron source and the position of xiphisternum of the phantom were 1.6 m above the floor.ResultsThe average specific activity of 24Na per unit neutron fluence was related to the irradiation-distances,d,and its The AB/ΦM corresponds to that of phantom irradiated by plane-parallel beams,and the value is about more 3% than that by BOMAB phantom reported in literature.It has shown that floor-( wall-)scattered neutrons in irradiation site have significant contribution to the specific activity of 24Na ,but they contributed relatively little to the induced neutron doses.Consequently,using the specific activity of 24 Na for assessing accidental neutron doses received by an individual,the contribution of scattered neutrons in accident site will lead dose to be overestimated,and need to be correct.

Objective To build a clinical key disciplines evaluation index system for county level hospitals in Chengdu city.Methods Literature meta analysis, focus group discussion, expert consultation method, boundary value method, brainstorming and hierarchy analysis method were comprehensively used.Results The clinical key disciplines evaluation index system for county level hospitals in Chengdu city comprises 5 level-1 indexes,1 6 level-2 indexes,47 level-3 indexes.Among the level-1 indexes,service capacity,medical quality,technical personnel,scientific research and education, and foundation of specialty was 0.474 6,0.202 7,0.148 2,0.097 7,0.076 8 respectively.Conclusion The clinical key disciplines evaluation index system for county level hospitals in Chengdu city is scientific, guiding and practical,which can be used to evaluate the status of the clinical key disciplines for county level hospitals in Chengdu city.