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[en] The investigation results of the radioactive level in the houses made of cinder bricks of Xiangxi Gold Mine was presented. The measured results and dose assessment shows that the mean of γ external penetrating radiation dose rate including cosmic radiation in houses of cinder bricks is 33.4 x 10-8 Gyh-1 because the bricks have a higher concentration of natural radionuclide 226Ra. The additional annual collective effective dose equivalent to∼5250 persons in such houses is 20.9 man·Sv
[en] This paper reports the measured results of radon concentration in different environments with CSR solid track detectors. The results show that the radon concentrations are 15.6 Bq m-3 for ordinary buildings, 28.5, 31.6 and 71.1 Bq m-3 for the houses made of A,B and C types of coal-cinder-brick buildings respectively, and 36.1, 43.6 and 85.6 Bq m-3 indoors in residential quarters around Chengxi coal mine and near two uranium mines. (Author)
[en] Grafting copolymerization of acrylic acid to cotton cellulose by using pre-irradiating method was investigated. At lower concentration of monomer (10%) the relationship between grafting yield and total dose, dose rate, reaction time and reaction temperature was measured. It was found that in the temperature range of 294 K to 323 K the grafting yield decreased with increasing of grafting reaction temperature. The grafting yields as a function of above reaction conditions were given by the expression Gr% = 5.9 x 10-10De20.27/RT(1-e-0.313te-6.87/RT), where R 8.314 x 10-3kj·K-1·mol-1, D = irradiation dose, T = reaction temperature, and t = reaction time
[en] The paper is aimed at presenting the methodology for, and main findings of, surveying the environmental γ radiation doserate, the contents of naturally occurring radionuclides in environmental soils, bone coal, cinder and building materials, the annual average Rn concentration indoors and outdoors in mine area, the exhalation rate of Rn at the main release locations, and the contents of major non-radioactive elements in bone coal and in-plant soils at Nijiangkou Mine, Hunan Province. Furthermore, the calculation is made of additional doses to the local population living in the dwellings built with carbonized brick. (authors)
[en] We demonstrate the controlled synthesis of ZnO branched nanorod arrays on fluorine-doped SnO2-coated glass substrates by the hierarchical solution growth method. In the secondary growth, the concentration of Zn(NO3)2/hexamethylenetetramine plays an important role in controlling the morphology of the branched nanorod arrays, besides that of diaminopropane used as a structure-directing agent to induce the growth of branches. The population density and morphology of the branched nanorod arrays depend on those of the nanorod arrays obtained from the primary growth, which can be modulated though the concentration of Zn(NO3)2/hexamethylenetetramine in the primary growth solution. The dye-sensitized ZnO branched nanorod arrays exhibit much stronger optical absorption as compared with its corresponding primary nanorod arrays, suggesting that the addition of the branches improves light harvesting. The dye-sensitized solar cell based on the optimized ZnO branched nanorod array reaches a conversion efficiency of 1.66% under the light radiation of 1000 W/m2. The branched nanorod arrays can also be applied in other application fields of ZnO.
[en] Concentrations of radon and its daughters in typical houses made of different kinds of bricks and in uranium or coal mining regions in Hunan province were investigated with CSR track detector. The measured annual average concentration CRn in normal houses was 15.6 Bqm-3, in A, B and C category cinder brick made buildings 28.5, 31.6 and 71.1 Bqm-3 respectively, in dwellings around Chenxi coal mine (including power plant) and two uranium mines 36.1, 43.4 and 85.6 Bqm-3, respectively. Outdoor radon concentration decreased with increasing height, h, from the ground. The Rn concentration at h = 1.5m was 1.6 times of that at h = 3 m. The Rn concentration at the centre of a room was also decreasing with increasing height from the ground. The Rn concentration at the position of heads of sleeping people (near the wall) was 1.6-2.9 times of that just below the ceiling. The annual effective dose to residents of normal houses was 1.6 mSv, of which 1.1 mSv was from inhalation of Rn daughters, 2.2 times of that from γ external exposure (0.5 mSv). The additional average annual effective dose equivalent to residents in cinder brick made buildings from inhalation of Rn daughters was 1.6 mSv, 1.6 times of that from γ external exposure (1.0 mSv). The annual products of 38 coal cinder brick mills in Hunan caused an additional effective dose equivalent of 45 man · Sv, and their total products from commissioning 360 man · Sv
[en] Highlights: • Form-stable dodecane/fumed silica composite for cold storage is prepared. • A suggesting hypothesis that explains infiltration mechanism is proposed. • The performance of the composite phase change material is investigated. • Numerical simulation of system is carried out and results fit well. - Abstract: A kind of form-stable composite phase change materials used for cold thermal energy storage is prepared by absorbing dodecane into the hydrophobic fumed silica. With relatively suitable pore diameter and hydrophobic groups, hydrophobic fumed silica is beneficial to the penetration and infiltration of dodecane and the leakage problem solving. Scanned by electron micrographs and Fourier transformation infrared, the composite phase change material is characterized to be just physical penetration. Besides, the differential scanning calorimeter and thermo gravimetric analysis reveals the high enthalpy, good thermal stability and cycling performance of this composite phase change material. What’s more, Hot-Disk thermal constants analyzer demonstrates that the composite phase change material has low thermal conductivity which is desired in cold storage application. In the experiment, a cold energy storage system is set up and the results from the experiment show that the system has excellent performance of cold storage by incorporating composite phase change material. Apart from that, the experimental data is found to have a great agreement with the numerical simulation which is carried out by using the commercial computational fluid dynamics software FLUENT.
[en] A kinetic study was made on the pre-irradiation grafting of styrene onto cotton cellulose. The dependencies of the grafting yield on preirradiation (in air) dose, grafting reaction time and grafting temperature were investigated respectively. The grafting yields as a function of above reaction conditions were expressed by using approximate formulae. The results about the relation between the grafting yields with these grafting conditions calculated by the equations derived in this work were consistent with respective experimental data. It means that the experimental results are correct and the derived equations are reasonable