In this paper, the coupled thermo-mechanical （TM） processes in the AEspoe Pillar Stability Experiment （APSE） carried out by the Swedish Nuclear Fuel and Waste Management Company （SKB） were simulated using both c...In this paper, the coupled thermo-mechanical （TM） processes in the AEspoe Pillar Stability Experiment （APSE） carried out by the Swedish Nuclear Fuel and Waste Management Company （SKB） were simulated using both continuum and discontinuum based numerical methods. Two-dimensional （2D） and three- dimensional （3D） finite element method （FEM） and 2D distinct element method （DEM） with particles were used. The main objective for the large scale in situ experiment is to investigate the yielding strength of crystalline rock and the formation of the excavation disturbed/damaged zone （EDZ） during excavation of two boreholes, pressurizing of one of the boreholes and heating. For the DEM simulations, the heat flow algorithm was newly introduced into the original code. The calculated stress, displacement and temperature distributions were compared with the ones obtained from in situ measurements and FEM simulations. A parametric study for initial microcracks was also performed to reproduce the spalling phenomena observed in the APSE.展开更多
Differential and total cross sections of the γp→π0p and the γd→π0pn reaction were measured for photon energies between 640 and 1 150 MeV. The data have been compared with SAID and MAID model calculations. π0 ph...Differential and total cross sections of the γp→π0p and the γd→π0pn reaction were measured for photon energies between 640 and 1 150 MeV. The data have been compared with SAID and MAID model calculations. π0 photoproduction on the deuteron shows a strong suppression of the 2nd resonance which is clearly seen in the γp→π0p reaction.展开更多
We have developed an event mixing technique to observe Bose-Einstein correlations （BEC） between two identical neutral pions produced in photo-induced reactions in the non-perturbative QCD energy region. It is found ...We have developed an event mixing technique to observe Bose-Einstein correlations （BEC） between two identical neutral pions produced in photo-induced reactions in the non-perturbative QCD energy region. It is found that the missing-mass consistency cut and the pion-energy cut are essential for the event mixing method to effectively extract BEC observables. A Monte Carlo （MC） simulation is used to validate these constraints and confirms the efficiency of this method. Our work paves the way for similar BEC studies at lower energies where the multiplicity of emitted bosons is limited.展开更多
Small-sized axial fans are used as air cooler for electric equipments.But there is a strong demand for higher power of fans according to the increase of quantity of heat from electric devices.Therefore,higher rotation...Small-sized axial fans are used as air cooler for electric equipments.But there is a strong demand for higher power of fans according to the increase of quantity of heat from electric devices.Therefore,higher rotational speed design is conducted,although,it causes the deterioration of efficiency and the increase of noise.Then,the adoption of contra-rotating rotors for the small-sized axial fan is proposed for the improvement of performance.In the case of contra-rotating rotors,it is necessary to design the rotor considering the unsteady flow condition of each front and rear rotor.In the present paper,the fan performance of the contra-rotating small-sized axial fan with 100mm diameter at a designed and a partial flow rates is shown,and the unsteady flow conditions at the inlet and the outlet of each front and rear rotor are clarified with unsteady numerical results.Furthermore,the relation between the performance and the unsteady flow condition of the contra-rotating small-sized axial fan is discussed and the methods to improve the performance are considered.展开更多
Type I X-ray bursts are the most frequently observed thermonuclear explosions in nature[1].They take place on the surface of accreting neutron star in low-mass X-ray binary systems.
Ⅰ. GEOLOGYSamples studied were collected by LUO Xiang-jun from Kangsulake, Yutiantown. Geology of this area has been given by LIU Jia-qi. Two lava layers can be recognized. The upper layer is 1.1 Ma BP and the lower ...Ⅰ. GEOLOGYSamples studied were collected by LUO Xiang-jun from Kangsulake, Yutiantown. Geology of this area has been given by LIU Jia-qi. Two lava layers can be recognized. The upper layer is 1.1 Ma BP and the lower is 1.4 Ma BP (LUO Xiang-jun, personal communication, 1987). A K-Ar age of 1.24 Ma was obtained by the authors (1988), which is in agreement with the result reported by LIU Jia-qi.展开更多
基金conducted within the context of the international DECOVALEX Project (DEvelopment of COupled models and their VALidation against EXperiments)financed by Japan Atomic Energy Agency (JAEA) who was also one of the Funding Organizations of the projectChrister Anders-son from Swedish Nuclear Fuel and Waste Management Co.(SKB),Sweden
文摘In this paper, the coupled thermo-mechanical （TM） processes in the AEspoe Pillar Stability Experiment （APSE） carried out by the Swedish Nuclear Fuel and Waste Management Company （SKB） were simulated using both continuum and discontinuum based numerical methods. Two-dimensional （2D） and three- dimensional （3D） finite element method （FEM） and 2D distinct element method （DEM） with particles were used. The main objective for the large scale in situ experiment is to investigate the yielding strength of crystalline rock and the formation of the excavation disturbed/damaged zone （EDZ） during excavation of two boreholes, pressurizing of one of the boreholes and heating. For the DEM simulations, the heat flow algorithm was newly introduced into the original code. The calculated stress, displacement and temperature distributions were compared with the ones obtained from in situ measurements and FEM simulations. A parametric study for initial microcracks was also performed to reproduce the spalling phenomena observed in the APSE.
文摘Differential and total cross sections of the γp→π0p and the γd→π0pn reaction were measured for photon energies between 640 and 1 150 MeV. The data have been compared with SAID and MAID model calculations. π0 photoproduction on the deuteron shows a strong suppression of the 2nd resonance which is clearly seen in the γp→π0p reaction.
基金Supported by Ministry of Education and Science of Japan(19002003)JSPS KAKENHI(24244022,26400287)
文摘We have developed an event mixing technique to observe Bose-Einstein correlations （BEC） between two identical neutral pions produced in photo-induced reactions in the non-perturbative QCD energy region. It is found that the missing-mass consistency cut and the pion-energy cut are essential for the event mixing method to effectively extract BEC observables. A Monte Carlo （MC） simulation is used to validate these constraints and confirms the efficiency of this method. Our work paves the way for similar BEC studies at lower energies where the multiplicity of emitted bosons is limited.
基金supported by Japan Science and Technology Agency and University of Tokushima and Komiya research aid
文摘Small-sized axial fans are used as air cooler for electric equipments.But there is a strong demand for higher power of fans according to the increase of quantity of heat from electric devices.Therefore,higher rotational speed design is conducted,although,it causes the deterioration of efficiency and the increase of noise.Then,the adoption of contra-rotating rotors for the small-sized axial fan is proposed for the improvement of performance.In the case of contra-rotating rotors,it is necessary to design the rotor considering the unsteady flow condition of each front and rear rotor.In the present paper,the fan performance of the contra-rotating small-sized axial fan with 100mm diameter at a designed and a partial flow rates is shown,and the unsteady flow conditions at the inlet and the outlet of each front and rear rotor are clarified with unsteady numerical results.Furthermore,the relation between the performance and the unsteady flow condition of the contra-rotating small-sized axial fan is discussed and the methods to improve the performance are considered.
基金National Key Research and Development Program of China(2016YFA0400503)。
文摘Type I X-ray bursts are the most frequently observed thermonuclear explosions in nature[1].They take place on the surface of accreting neutron star in low-mass X-ray binary systems.
文摘Ⅰ. GEOLOGYSamples studied were collected by LUO Xiang-jun from Kangsulake, Yutiantown. Geology of this area has been given by LIU Jia-qi. Two lava layers can be recognized. The upper layer is 1.1 Ma BP and the lower is 1.4 Ma BP (LUO Xiang-jun, personal communication, 1987). A K-Ar age of 1.24 Ma was obtained by the authors (1988), which is in agreement with the result reported by LIU Jia-qi.
