This paper presents results of experimental and numerical investigations of a seesaw energy dissipation system （SEDS） using fluid viscous dampers （FVDs）. To confirm the characteristics of the FVDs used in the test...This paper presents results of experimental and numerical investigations of a seesaw energy dissipation system （SEDS） using fluid viscous dampers （FVDs）. To confirm the characteristics of the FVDs used in the tests, harmonic dynamic loading tests were conducted in advance of the flee vibration tests and the shaking table tests. Shaking table tests were conducted to demonstrate the damping capacity of the SEDS under random excitations such as seismic waves, and the results showed SEDSs have sufficient damping capacity for reducing the seismic response of flames. Free vibration tests were conducted to confirm the reliability of simplified analysis. Time history response analyses were also conducted and the results are in close agreement with shaking table test results.展开更多
In this paper,following the Occam’s razor principle,we have put forward a very simple form of the Dirac neutrino mass matrix M_(D) in the minimal seesaw model with the right-handed neutrino mass matrix being diagonal...In this paper,following the Occam’s razor principle,we have put forward a very simple form of the Dirac neutrino mass matrix M_(D) in the minimal seesaw model with the right-handed neutrino mass matrix being diagonal M_(R)=diag(M_(1),M_(2));it has one texture zero and only contains three real parameters,whose values can be determined from the neutrino oscillation experimental results.Such a model leads to a neutrino mass matrix M_(v)≃-M_(D)M_(R)^(-1)M_(D)^(T)that obeys the TM1 and μ-τ reflection symmetries simultaneously.In this way all the lepton flavor mixing parameters except for θ_(13) are predicted;the value of θ_(12) is predicted by the TM1 symmetry,while those of θ_(23),δ,ρ and σ by the μ-τ reflection symmetry.And the neutrino masses are predicted to be of the NO case with m_(1)=0,for which all three light neutrino masses will be pinned down with the help of the experimental results for the neutrino mass squared differences.For these results,the effective Majorana neutrino mass∣(M_(ν))_(ee)∣that controls the rate of the neutrinoless double beta decay is predicted to be 1.6 or 3.8 meV in the case of σ=0 or π/2.We have also studied the implications of the model for leptogenesis.It turns out that only in the two-flavor leptogenesis regime(which holds in the temperature range 10^(9)-10^(12) GeV)can leptogenesis have a chance to be successful.And a successful leptogenesis can be achieved at M_(1)≃1.2×10^(11) GeV in the case of σ=π/2,but not in the case of σ=0.展开更多
In Asaka et al(2021 Phys.Rev.D 103,015014),Asaka,Ishida and Tanaka put forward an interesting possibility that the neutrinoless double beta decay can be hidden in the minimal seesaw model with the two right-handed neu...In Asaka et al(2021 Phys.Rev.D 103,015014),Asaka,Ishida and Tanaka put forward an interesting possibility that the neutrinoless double beta decay can be hidden in the minimal seesaw model with the two right-handed neutrinos having a hierarchical mass structure:the lighter one is lighter enough than the typical Fermi-momentum scale of nuclei while the heavier one is sufficiently heavy to decouple from the neutrinoless double beta decay.Then,in the basis where the mass matrices of the charged leptons and right-handed neutrinos are diagonal,for some particular texture of the Dirac neutrino mass matrix M_(D),the neutrinoless double beta decay can be hidden.In this paper,on top of this specified model,we study the interesting scenario that M_(D)further obeys the TM1 symmetry orμ-τreflection symmetry which are well motivated by the experimental results for the neutrino mixing parameters.展开更多
Early studies suggested that the Aleutian–Icelandic low seesaw(AIS) features multidecadal variation. In this study, the multidecadal modulation of the AIS and associated surface climate by the Atlantic Multidecadal O...Early studies suggested that the Aleutian–Icelandic low seesaw(AIS) features multidecadal variation. In this study, the multidecadal modulation of the AIS and associated surface climate by the Atlantic Multidecadal Oscillation(AMO) during late winter(February–March) is explored with observational data. It is shown that, in the cold phase of the AMO(AMO|-),a clear AIS is established, while this is not the case in the warm phase of the AMO(AMO|+). The surface climate over Eurasia is significantly influenced by the AMO’s modulation of the Aleutian low(AL). For example, the weak AL in AMO|-displays warmer surface temperatures over the entire Far East and along the Russian Arctic coast and into Northern Europe,but only over the Russian Far East in AMO|+. Similarly, precipitation decreases over central Europe with the weak AL in AMO|-, but decreases over northern Europe and increases over southern Europe in AMO|+.The mechanism underlying the influence of AMO|-on the AIS can be described as follows: AMO|-weakens the upward component of the Eliassen–Palm flux along the polar waveguide by reducing atmospheric blocking occurrence over the Euro–Atlantic sector, and hence drives an enhanced stratospheric polar vortex. With the intensified polar night jet, the wave trains originating over the central North Pacific can propagate horizontally through North America and extend into the North Atlantic, favoring an eastward-extended Pacific–North America–Atlantic pattern, and resulting in a significant AIS at the surface during late winter.展开更多
The second EOF（EOF2） mode of interannual variation in summer rainfall over East China is characterized by inverse rainfall changes between South China（SC） and the Yellow River-Huaihe River valleys（YH）.However,un...The second EOF（EOF2） mode of interannual variation in summer rainfall over East China is characterized by inverse rainfall changes between South China（SC） and the Yellow River-Huaihe River valleys（YH）.However,understanding of the EOF2 mode is still limited.In this study,the authors identify that the EOF2 mode physically depicts the latitudinal variation of the climatological summer-mean rainy belt along the Yangtze River valley（YRRB）,based on a 160-station rainfall dataset in China for the period 1951-2011.The latitudinal variation of the YRRB is mostly attributed to two different rainfall patterns：one reflects the seesaw（SS） rainfall changes between the YH and SC（SS pattern）,and the other features rainfall anomalies concentrated in SC only（SC pattern）.Corresponding to a southward shift of the YRRB,the SS pattern,with above-normal rainfall in SC and below-normal rainfall in the YH,is related to a cyclonic anomaly centered over the SC-East China Sea region,with a northerly anomaly blowing from the YH to SC;while the SC pattern,with above-normal rainfall in SC,is related to an anticyclonic anomaly over the western North Pacific（WNP）,corresponding to an enhanced southwest monsoon over SC.The cyclonic anomaly,related to the SS pattern,is induced by a near-barotropic eastward propagating wave train along the Asian upper-tropospheric westerly jet,originating from the mid-high latitudes of the North Atlantic.The anticyclonic anomaly,for the SC pattern,is related to suppressed rainfall in the WNP.展开更多
Based on daily precipitation data from 163 meteorological stations, this study investigated precipitation changes in the mid-latitudes of the Chinese mainland（MCM） during 1960–2014 using the climatic trend coeffici...Based on daily precipitation data from 163 meteorological stations, this study investigated precipitation changes in the mid-latitudes of the Chinese mainland（MCM） during 1960–2014 using the climatic trend coefficient, least-squared regression analysis, and a non-parametric Mann-Kendall test.According to the effects of the East Asian summer monsoon on the MCM and the climatic trend coefficient of annual precipitation during 1960–2014, we divided the MCM into the western MCM and eastern MCM. The western MCM was further divided into the western MCM1 and western MCM2 in terms of the effects of the East Asian summer monsoon. The main results were as follows：（1） During the last four decades of the 20^（th） century, the area-averaged annual precipitation presented a significant increasing trend in the western MCM, but there was a slight decreasing trend in the eastern MCM, where a seesaw pattern was apparent. However, in the 21^（st） century, the area-averaged annual precipitation displayed a significant increasing trend in both the western and eastern MCM.（2） The trend in area-averaged seasonal precipitation during 1960–2014 in the western MCM was consistent with that in the eastern MCM in winter and spring. However, the trend in area-averaged summer precipitation during1960–2014 displayed a seesaw pattern between the western and eastern MCM.（3） On an annual basis,both the trend in rainstorms and heavy rain displayed a seesaw pattern between the western and eastern MCM.（4） The precipitation intensity in rainstorms, heavy rain, and moderate rain made a greater contribution to changes in the total precipitation than precipitation frequency. The results of this study will improve our understanding of the trends and differences in precipitation changes in different areas of the MCM. This is not only useful for the management and mitigation of flood disasters, but is also beneficial to the protection of water resources across the MCM.展开更多
In this paper, a calculation formula on spherical pattern of tide-isostasy model is established. The calculation indicated that for the oceanic crust plate which central angle is over 90°, a huge value(its equiva...In this paper, a calculation formula on spherical pattern of tide-isostasy model is established. The calculation indicated that for the oceanic crust plate which central angle is over 90°, a huge value(its equivalence is 108 N)of accumulative force moment in the crustal isostatic movement caused by tide can trigger off relative motion of plate, resulting in earthquake and volcanic eruption. The seismic wave features during the year 2001-2004 is an obvious example. The paracycles, i.e. 4, 12, 60, 36, 243, 372 and 396 years of tidal fluctuation can provide an explanation for some respective natural disasters. For example, La Madre paracycle about 60 years corresponds to the global disasters,earthquake and typhoon disasters.展开更多
文摘This paper presents results of experimental and numerical investigations of a seesaw energy dissipation system （SEDS） using fluid viscous dampers （FVDs）. To confirm the characteristics of the FVDs used in the tests, harmonic dynamic loading tests were conducted in advance of the flee vibration tests and the shaking table tests. Shaking table tests were conducted to demonstrate the damping capacity of the SEDS under random excitations such as seismic waves, and the results showed SEDSs have sufficient damping capacity for reducing the seismic response of flames. Free vibration tests were conducted to confirm the reliability of simplified analysis. Time history response analyses were also conducted and the results are in close agreement with shaking table test results.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.11605081,12142507 and 12147214the Natural Science Foundation of the Liaoning Scientific Committee under Grant No.2022MS-314
文摘In this paper,following the Occam’s razor principle,we have put forward a very simple form of the Dirac neutrino mass matrix M_(D) in the minimal seesaw model with the right-handed neutrino mass matrix being diagonal M_(R)=diag(M_(1),M_(2));it has one texture zero and only contains three real parameters,whose values can be determined from the neutrino oscillation experimental results.Such a model leads to a neutrino mass matrix M_(v)≃-M_(D)M_(R)^(-1)M_(D)^(T)that obeys the TM1 and μ-τ reflection symmetries simultaneously.In this way all the lepton flavor mixing parameters except for θ_(13) are predicted;the value of θ_(12) is predicted by the TM1 symmetry,while those of θ_(23),δ,ρ and σ by the μ-τ reflection symmetry.And the neutrino masses are predicted to be of the NO case with m_(1)=0,for which all three light neutrino masses will be pinned down with the help of the experimental results for the neutrino mass squared differences.For these results,the effective Majorana neutrino mass∣(M_(ν))_(ee)∣that controls the rate of the neutrinoless double beta decay is predicted to be 1.6 or 3.8 meV in the case of σ=0 or π/2.We have also studied the implications of the model for leptogenesis.It turns out that only in the two-flavor leptogenesis regime(which holds in the temperature range 10^(9)-10^(12) GeV)can leptogenesis have a chance to be successful.And a successful leptogenesis can be achieved at M_(1)≃1.2×10^(11) GeV in the case of σ=π/2,but not in the case of σ=0.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.11605081,12142507 and 12147214the Natural Science Foundation of the Liaoning Scientific Committee under grant NO.2022-MS-314。
文摘In Asaka et al(2021 Phys.Rev.D 103,015014),Asaka,Ishida and Tanaka put forward an interesting possibility that the neutrinoless double beta decay can be hidden in the minimal seesaw model with the two right-handed neutrinos having a hierarchical mass structure:the lighter one is lighter enough than the typical Fermi-momentum scale of nuclei while the heavier one is sufficiently heavy to decouple from the neutrinoless double beta decay.Then,in the basis where the mass matrices of the charged leptons and right-handed neutrinos are diagonal,for some particular texture of the Dirac neutrino mass matrix M_(D),the neutrinoless double beta decay can be hidden.In this paper,on top of this specified model,we study the interesting scenario that M_(D)further obeys the TM1 symmetry orμ-τreflection symmetry which are well motivated by the experimental results for the neutrino mixing parameters.
基金supported by the Research Council of Norway(Grant Nos.EPOCASA#229774/E10 and SNOWGLACE#244166)the National Natural Science Foundation of China(Grant No.41605059)the Young Talent Support Plan launched by the China Association for Science and Technology(Grant No.2016QNRC001)
文摘Early studies suggested that the Aleutian–Icelandic low seesaw(AIS) features multidecadal variation. In this study, the multidecadal modulation of the AIS and associated surface climate by the Atlantic Multidecadal Oscillation(AMO) during late winter(February–March) is explored with observational data. It is shown that, in the cold phase of the AMO(AMO|-),a clear AIS is established, while this is not the case in the warm phase of the AMO(AMO|+). The surface climate over Eurasia is significantly influenced by the AMO’s modulation of the Aleutian low(AL). For example, the weak AL in AMO|-displays warmer surface temperatures over the entire Far East and along the Russian Arctic coast and into Northern Europe,but only over the Russian Far East in AMO|+. Similarly, precipitation decreases over central Europe with the weak AL in AMO|-, but decreases over northern Europe and increases over southern Europe in AMO|+.The mechanism underlying the influence of AMO|-on the AIS can be described as follows: AMO|-weakens the upward component of the Eliassen–Palm flux along the polar waveguide by reducing atmospheric blocking occurrence over the Euro–Atlantic sector, and hence drives an enhanced stratospheric polar vortex. With the intensified polar night jet, the wave trains originating over the central North Pacific can propagate horizontally through North America and extend into the North Atlantic, favoring an eastward-extended Pacific–North America–Atlantic pattern, and resulting in a significant AIS at the surface during late winter.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41375086 and 41320104007)
文摘The second EOF（EOF2） mode of interannual variation in summer rainfall over East China is characterized by inverse rainfall changes between South China（SC） and the Yellow River-Huaihe River valleys（YH）.However,understanding of the EOF2 mode is still limited.In this study,the authors identify that the EOF2 mode physically depicts the latitudinal variation of the climatological summer-mean rainy belt along the Yangtze River valley（YRRB）,based on a 160-station rainfall dataset in China for the period 1951-2011.The latitudinal variation of the YRRB is mostly attributed to two different rainfall patterns：one reflects the seesaw（SS） rainfall changes between the YH and SC（SS pattern）,and the other features rainfall anomalies concentrated in SC only（SC pattern）.Corresponding to a southward shift of the YRRB,the SS pattern,with above-normal rainfall in SC and below-normal rainfall in the YH,is related to a cyclonic anomaly centered over the SC-East China Sea region,with a northerly anomaly blowing from the YH to SC;while the SC pattern,with above-normal rainfall in SC,is related to an anticyclonic anomaly over the western North Pacific（WNP）,corresponding to an enhanced southwest monsoon over SC.The cyclonic anomaly,related to the SS pattern,is induced by a near-barotropic eastward propagating wave train along the Asian upper-tropospheric westerly jet,originating from the mid-high latitudes of the North Atlantic.The anticyclonic anomaly,for the SC pattern,is related to suppressed rainfall in the WNP.
基金financially supported by the National Natural Science Foundation of China (91644226)the National Key Research Project of China (2016YFA0602004)Industry of National Public Welfare (Meteorological) Scientific Research (GYHY201206004)
文摘Based on daily precipitation data from 163 meteorological stations, this study investigated precipitation changes in the mid-latitudes of the Chinese mainland（MCM） during 1960–2014 using the climatic trend coefficient, least-squared regression analysis, and a non-parametric Mann-Kendall test.According to the effects of the East Asian summer monsoon on the MCM and the climatic trend coefficient of annual precipitation during 1960–2014, we divided the MCM into the western MCM and eastern MCM. The western MCM was further divided into the western MCM1 and western MCM2 in terms of the effects of the East Asian summer monsoon. The main results were as follows：（1） During the last four decades of the 20^（th） century, the area-averaged annual precipitation presented a significant increasing trend in the western MCM, but there was a slight decreasing trend in the eastern MCM, where a seesaw pattern was apparent. However, in the 21^（st） century, the area-averaged annual precipitation displayed a significant increasing trend in both the western and eastern MCM.（2） The trend in area-averaged seasonal precipitation during 1960–2014 in the western MCM was consistent with that in the eastern MCM in winter and spring. However, the trend in area-averaged summer precipitation during1960–2014 displayed a seesaw pattern between the western and eastern MCM.（3） On an annual basis,both the trend in rainstorms and heavy rain displayed a seesaw pattern between the western and eastern MCM.（4） The precipitation intensity in rainstorms, heavy rain, and moderate rain made a greater contribution to changes in the total precipitation than precipitation frequency. The results of this study will improve our understanding of the trends and differences in precipitation changes in different areas of the MCM. This is not only useful for the management and mitigation of flood disasters, but is also beneficial to the protection of water resources across the MCM.
文摘In this paper, a calculation formula on spherical pattern of tide-isostasy model is established. The calculation indicated that for the oceanic crust plate which central angle is over 90°, a huge value(its equivalence is 108 N)of accumulative force moment in the crustal isostatic movement caused by tide can trigger off relative motion of plate, resulting in earthquake and volcanic eruption. The seismic wave features during the year 2001-2004 is an obvious example. The paracycles, i.e. 4, 12, 60, 36, 243, 372 and 396 years of tidal fluctuation can provide an explanation for some respective natural disasters. For example, La Madre paracycle about 60 years corresponds to the global disasters,earthquake and typhoon disasters.
