Li Y.-X.,Beijing Normal University |
Zhang X.-L.,Beijing Normal University |
Li W.,Finnish Center for Radiation and Nuclear Safety |
Lu X.-F.,Beijing Normal University |
And 2 more authors.
Environmental Monitoring and Assessment | Year: 2013
To understand the residues and ecological risks of veterinary antibiotics (VAs) in animal faeces from concentrated animal feeding operations in northeastern China, 14 VAs were identified by high performance liquid chromatography, and the preliminary risks of six antibiotics were assessed using the hazard quotient (HQ). The investigated VAs occurred in 7.41 to 57.41 % of the 54 samples, and the levels ranged from 0.08 to 56.81 mg kg-1. Tetracyclines were predominant with a maximum level of 56.81 mg kg-1 mostly detected in pig faeces. Sulfonamides were common and detected with the highest concentration of 7.11 mg kg-1. Fluoroquinolones were more widely detected in chicken faeces rather than in pig or cow faeces, which contained the dominant antibiotic enrofloxacin. In comparison, the residue of tylosin was less frequently found. The risk evaluations of the six antibiotics revealed that tetracyclines, especially oxytetracycline, displayed the greatest ecological risk because of its high HQ value of 15.75. The results of this study imply that multiple kinds of VAs were jointly used in animal feeding processes in the study area. These medicine residues in animal faeces may potentially bring ecological risks if the animal manure is not treated effectively. © 2012 Springer Science+Business Media B.V.
Wang L.,Finnish Center for Radiation and Nuclear Safety |
Wang L.,Peking University |
Yang H.,Peking University
Advances in Atmospheric Sciences | Year: 2014
The equatorial response to subtropical Pacific forcing was studied in a coupled climate model. The forcings in the western, central and eastern subtropical Pacific all caused a significant response in the equatorial thermocline, with comparable magnitudes. This work highlights the key role of air-sea coupling in the subtropical impact on the equatorial thermocline, instead of only the role of the "oceanic tunnel". The suggested mechanism is that the cyclonic (anticyclonic) circulation in the atmosphere caused by the subtropical surface warming (cooling) can generate an anomalous upwelling (downwelling) in the interior region. At the same time, an anomalous downwelling (upwelling) occurs at the equatorward flank of the forcing, which produces anomalous thermocline warming (cooling), propagating equatorward and resulting in warming (cooling) in the equatorial thermocline. This is an indirect process that is much faster than the "oceanic tunnel" mechanism in the subtropical impact on the equator. © 2014 Chinese National Committee for International Association of Meteorology and Atmospheric Sciences, Institute of Atmospheric Physics, Science Press and Springer-Verlag Berlin Heidelberg.
Wang M.,Sichuan University |
Liu R.,Finnish Center for Radiation and Nuclear Safety |
Yang S.,Sichuan University
Nongye Jixie Xuebao/Transactions of the Chinese Society of Agricultural Machinery | Year: 2012
An optimal synthesis method of adjustable spherical four-bar mechanisms for multi-function generation was put forward. Different functions can be generated by the same mechanism through adjusting the length of the connecting frame poles. Based on the function relation between the input angle and the output angle of the spherical four-bar mechanism, the optimization model was established. The objective function was given with the aim of minimizing the maximum of the absolute structural error, and the constraints were given to ensure the crack existed and that the mechanisms have good transmission quality. After this, the immune genetic algorithm was chosen for multi-function generation of adjustable spherical four-bar mechanisms. The result of the synthesis example verified the effectiveness of the proposed method.
Lehto J.,University of Helsinki |
Vaaramaa K.,University of Helsinki |
Vaaramaa K.,Finnish Center for Radiation and Nuclear Safety |
Leskinen A.,University of Helsinki |
Leskinen A.,CEA Saclay Nuclear Research Center
Journal of Environmental Radioactivity | Year: 2013
Profiles of podzolic soil from boreal forests were sampled from eight sites in Finland and the distribution of 137Cs in the soil layers was determined. In addition, 239,240Pu and 241Am were determined from two soil profiles taken at one sampling site. Inventories of 137Cs in the soil profiles varied between 1.7 kBq/m2 and 42 kBq/m2, reflecting known variation in 137Cs fallout from the Chernobyl accident. The highest proportions of the radionuclides were found in the organic layer at a depth of less than 5 cm, which on average contained 47% of 137Cs, 76% of 239,240Pu and 79% of 241Am. In the litter, clearly higher proportions of 137Cs were found compared to 239,240Pu and 241Am, probably indicating its more effective recycling from the organic layer back to the surface. Only very minor proportions of 137Cs were recorded below 20 cm. The concentration of 137Cs in the soil profiles could be approximated with a declining logarithmic trend. The activity concentrations of 137Cs were determined for six wild mushroom species and three wild berry species at two sites, as well as the aggregated transfer factors and the distribution of 137Cs between their various parts. In addition, 239,240Pu and 241Am were determined in one mushroom and three berry species at one site. Very high concentrations of 137Cs, up to 20 kBq/kg (d.w.), were found in mushrooms, and their transfer factors were between 0.1 m2/kg and 1.0 m2/kg. In berries, the transfer factors were an order of magnitude lower. 137Cs accumulated more in the caps of mushrooms and in the fruits of berries than in other parts. Transfer factors for 239,240Pu and 241Am were two to three orders of magnitude lower than those of 137Cs. © 2012 Elsevier Ltd.
Ling L.-G.,Finnish Center for Radiation and Nuclear Safety
Jiliang Xuebao/Acta Metrologica Sinica | Year: 2014
The end-corner reflection test system is built basing on Z-scan ultrasonic detector, standards and reference blocks, as well as UltraVision ultrasonic signal acquisition and analysis software. Respectively, the end-corner reflection of 45°, 60° and 70° Ultrasonic transducers is tested. First, all reflection echo signal are sampled and analysed, and then the end-corner reflection echo signals is isolated basing on ultrasonic propagation law and the end-corner reflection waves mode conversion law. The relative reflectance of the above signal is computed at last. Test results show that 45° transverse wave transducer end-corner reflection close to the total reflection. The clutter from the end-corner reflection of longitudinal wave transducer is more than the transverse wave transducer. ©, 2014, Jiliang Xuebao/Acta Metrologica Sinica. All right reserved.
Feng S.,Finnish Center for Radiation and Nuclear Safety |
Rong P.,Finnish Center for Radiation and Nuclear Safety
Nuclear Engineering and Design | Year: 2016
According to a large-span half-steel–concrete (HSC) composited beam in the composited roof in the HTR-PM, a 1:3 scale specimen is investigated by the static load test. By analyzing the loading, deflection, strain and fracture development of the specimen in the process, studying the mechanical characteristics and failure pattern of such components. The ANSYS finite element software is utilized in this paper to analyze the nonlinearity behavior of the HSC beam specimen, and through comparing the experimental results and the numerical simulation, it can be illustrated that the finite element model can simulate the HSC beam accurately. From the test results, it can be concluded that by means of appropriate shear connection and anchorage length, steel plate and concrete can work together very well and the HSC beam has good load carrying capacity and ductility. These conclusions can serve as a preliminary design reference for the large span half-steel–concrete composite beam in NPP. © 2016 Elsevier B.V.
Zhou G.-L.,Finnish Center for Radiation and Nuclear Safety |
Li X.-J.,China Earthquake Administration |
Hou C.-L.,Finnish Center for Radiation and Nuclear Safety |
Li T.-P.,Finnish Center for Radiation and Nuclear Safety
Yantu Lixue/Rock and Soil Mechanics | Year: 2012
Using explicit finite element method and artificial transmitting boundary, the seismic response analysis of a 2D canyon model is performed under three incident SV seismic waves respectively with the assumptions of vertical incidence and oblique incidence at the angle of 30 degrees. The canyon surface ground motions have been compared and the distribution characteristics of ground motions are summarized. It indicates that canyon topography has significant influence on the distribution of ground motions. The peak ground accelerations (PGA) vary greatly from the bottom of the slope to the upper corners. Ground acceleration at high frequency band beyond 1 Hz has been more greatly amplified. And the canyon ground surface has been characterized by relative displacements (RD). It is also found that the incidence angle shows significant influences on the ground motions. Under oblique incident SV waves, the discrete degree of the PGA and RD observed at the canyon surface are much larger than that under vertical incident SV waves.
Ogawa T.,Research Group for Radiation Protection |
Morev M.N.,Finnish Center for Radiation and Nuclear Safety |
Sato T.,Research Group for Radiation Protection |
Hashimoto S.,Research Group for Radiation Protection
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2013
Fragmentation reaction cross-sections of lead bombarded by carbon ions below 400 MeV/u are measured and compared with those simulated with Monte-Carlo radiation transport code PHITS to pinpoint the problems of simulation based on the quantum molecular dynamics model and the statistical decay model. Cross-sections for 32 fragments from A = 24 to 85 and those from A = 121 to 175 are measured within a reasonable uncertainty. Contribution of secondary particles to production of measured fragments are generally less than 20%. Comparison shows production cross-sections for fragments from A = 20 to 60 and those from A = 110 to 130 are underestimated by one order of magnitude. Further simulation shows production of each group of fragments in simulation are attributed to evaporation of fission fragments and to evaporation of highly excited prefragments, respectively. The lower the energy is, the more this trend is pronounced. Observed underestimation indicates presence of nuclear reaction mechanisms not considered in the current simulation such as multi-fragmentation. © 2013 Elsevier B.V. All rights reserved.
Mo X.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research |
Guo R.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research |
Guo R.,Finnish Center for Radiation and Nuclear Safety |
Liu S.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research |
And 2 more authors.
Climatic Change | Year: 2013
As one of the key grain-producing regions in China, the agricultural system in the North China Plain (NCP) is vulnerable to climate change due to its limited water resources and strong dependence on irrigation for crop production. Exploring the impacts of climate change on crop evapotranspiration (ET) is of importance for water management and agricultural sustainability. The VIP (Vegetation Interface Processes) process-based ecosystem model and WRF (Weather Research and Forecasting) modeling system are applied to quantify ET responses of a wheat-maize cropping system to climate change. The ensemble projections of six General Circulation Models (GCMs) under the B2 and A2 scenarios in the 2050s over the NCP are used to account for the uncertainty of the projections. The thermal time requirements (TTR) of crops are assumed to remain constant under air warming conditions. It is found that in this case the length of the crop growth period will be shortened, which will result in the reduction of crop water consumption and possible crop productivity loss. Spatially, the changes of ET during the growth periods (ETg) for wheat range from -7 to 0 % with the average being -1.5 ± 1.2 % under the B2 scenario, and from -8 to 2 % with the average being -2.7 ± 1.3 % under the A2 scenario/consistently, changes of ETg for maize are from -10 to 8 %, with the average being -0.4 ± 4.9 %, under the B2 scenario and from -8 to 8 %, with the average being -1.2 ± 4.1 %, under the A2 scenario. Numerical analysis is also done on the condition that the length of the crop growth periods remains stable under the warming condition via breeding new crop varieties. In this case, TTR will be higher and the crop water requirements will increase, with the enhancement of the productivity. It is suggested that the options for adaptation to climate change include no action and accepting crop loss associated with the reduction in ETg, or breeding new cultivars that would maintain or increase crop productivity and result in an increase in ETg. In the latter case, attention should be paid to developing improved water conservation techniques to help compensate for the increased ETg. © 2013 Springer Science+Business Media Dordrecht.
Sun Z.,Finnish Center for Radiation and Nuclear Safety
Structural Health Monitoring and Integrity Management - Proceeding of the 2nd International Conference of Structural Health Monitoring and Integrity Management, ICSHMIM 2014 | Year: 2015
Earthquake events can be of a significant concern of nuclear safety, and the proper selection of input motions plays a very important role in a seismic analysis. When time histories of earthquake motions are used, two criteria should be satisfied from the safety point of view. One is for the response spectrum and the other is for the Power Spectral Density (PSD) function. Both industrial standards such as ASCE 4–98 and IEEE Std 344TM-2004 and nuclear regulatory documents such as NUREG 0800 specify various requirements on earthquake motion time histories used in safety-related structure or equipment for seismic analyses or tests. While there are relatively concrete requirements on the response spectra of time histories both for ground motion inputs and for support or floor motion inputs, there are still no clear specifications on PSD functions of time histories for support or floor motion inputs. This work starts from analyzing the implications and necessity of the PSD requirement in equipment seismic qualifications, and then explores proper ways to put the necessary requirement into practice. © 2015 Taylor & Francis Group, London.