摘要:The major performances of three high efficiency packings were studied in the enrichment of 13C using CO2/di-n-butylamine (DNBA) /triethylamine (TEA) system. These packings consisted of 2 × 2mm Dixon rings (phosphor bronze gauze, 100 mesh) , 1.5×1.5×0.12 mm triangular-section spirals (stainless steel wire ϕ0.12mm) and 1.6×1.6×1.5×0.2 mm rectangular-section spirals (i.e. Helipak packings, stainless steel wire ϕ0.12mm) .The results showed that the spiral packings are very suitable for the chemical exchange processes of isotope separation which require theoretically a large number of plates.
摘要:This paper deals with a timing SCA which has good timing characteristics for pulses from nuclear shaping amplifiers. With 0.4µs CR- (RC) 4 shaping pulses, while their amplitudes change from 10V to 1V,the timing walking is less than 1ns.
摘要:This paper describes the design outline, detecting principle, results obtained and some unsolved problem of this instrument. Specification: Measuring range, 1—104 cps; Fundamental error, ±40%; Response time, 18sec; Net weight 4kg.
摘要:A method for determining settling velocity of 113mIn labelled sands is presented. Experiments show that in distilled water the mean settling velocity of tracer particles with a diameter of 0.9 mm is 111.50±0.48 mm/s (theoretical value being 109.2 mm/s) . This method thus provides a laboratory mean for studying the velocity, the characteristics of sediment particles settling in muddy water, which could hardly be done hitherto.
摘要:The arrangement and method for reproducing the unit of roentgen with 10 to 50kV low energy X-rays were discribed. The correction factors and the error were given. The total uncertainty for single reproducing was 2.2% with the exposure rate being ±1~20 R/min.
摘要:The change of optical absorption in PE film is observed during irradiation. This effect can be used as a measure of radiation dose of 60Co γ-rays or electron beams at a range of 106~108 rad.
摘要:After irradiation, the thorium is rapidly extracted by TBP (15% in CC14) in NH4SCN solution (1.0M, pH=2.5) . The beta ray of 233Th was counted by liquid GM counter, without the α particles of 232Th and 228Th being detected. The whole process was finished in 15~20 min. Half-life of 233Th was determined as 22.1 min. The recovery of thorium was about 80%.This method was successfully used for the measurement of fast neutron capture cross-section of 232Th.
摘要:The in vivo kinetic distribution of [2,5,6-3H]-DL-DOPA, synthesized by us was investigated in mice. The experimental data showed that the radioactivity in adrenals and melanoma were high, and the eliminations from these tissues were slow. At 6 days after intravenous injection, the tissue uptakes were 2—4 times of other organs. But at such target/non-target ratio, the tumor can't be inhibited without other organs recieving doses exceeding maximum permissible level.
Yang Xi-zhen,Wu Jia-ping,He Rong-xia,Shen Ya-ying,Xu Xin-chuan,Zhang Man-da
1980, 03(6)
摘要:During the experiment of lymphocyte transformation with 3H-TdR, we found the counting rate of preparing sample using filter method was higher than that using chemical-digest method. Experiment showed the counting rate for 2 µCi was doubled in filter method than digest method.Moreover, when homemade 49 glass fiber disc was used in the filter method,the counting rate was markedly increased, in comparing with 0.8μ, 3μ, 5μ millipore filter. The filtering rate was quite rapid and gave reproducible results. The liquid scintillator after filter disc being removed could be used over again.
摘要:In this paper a parallel-plate avalanche counter for measuring Mössbauer emissionspectrum is described, the properties and the characteristics of the detector are discussed in detail. The results show that Mössbauer spectrum can be measured with a weak source about several tens of nCi.
摘要:This paper describes a method for thickness measurements of thin layer and foil by using the forward scattering of alpha particles from the cyclotron. By analyzing the scattering spectra, a thickness of a gold layer coated on kovar substrate and thickness of a carbon foil have been determined.