The directed motion of a Brownian particle in a Bashing potential with various transition probabilities and waiting times in one of two states is studied. An expression for the average cycle period is proposed and the...The directed motion of a Brownian particle in a Bashing potential with various transition probabilities and waiting times in one of two states is studied. An expression for the average cycle period is proposed and the steady current J of the particle is calculated via Langevin simulation. The results show that the optimal cycle period (Tm), which takes the maximum of J, is shifted to a small value when the transition probability A from the potential on to the potential off decreases, the maximal current appears in the case of the average waiting time in the potential on being longer than in the potential off, and the direction of current depends on the ratio of the average times waiting in two states.展开更多
Topography around the Yellow River mouth has changed greatly in recent years, but studies on the current state of ma- rine dynamics off the Yellow River mouth are relatively scarce. This paper uses a two-dimension num...Topography around the Yellow River mouth has changed greatly in recent years, but studies on the current state of ma- rine dynamics off the Yellow River mouth are relatively scarce. This paper uses a two-dimension numerical model （MIKE 21） to reveal the tidal and wave dynamics in 2012, and conducts comparative analysis of the changes from 1996 to 2012. The results show that M2 amphidromic point moved southeastward by 11 kin. It further reveals that the tides around the Yellow River mouth are relatively stable due to the small variations in the tidal constituents. Over the study period, there is no noticeable change in the distribution of tidal types and tidal range, and the mean tidal range off the river mouth during the period studied is 0.5-1.1 m. However, the tidal currents changed greatly due to large change in topography. It is observed that the area with strong tidal currents shifted from the old river mouth （1976-1996） to the modem river mouth （1996-present）. While the tidal current speeds decreased continually off the old river mouth, they increased off the modem river mouth. The Maximum Tidal Current Speed （MTCS） reached 1.4 m s-1, and the maximum current speed of 50-year return period reached 2.8 m s-1. Waves also changed greatly due to change in topography. The significant wave height （H1/3） of 50-year return period changed proportionately with the water depth, and the ratio of Hi/3 to depth being 0.4-0.6. H1/3 of the 50-year return period in erosion zone increased continually with increasing water depth, and the rate of change varied between 0.06 and 0.07myr-1. Based on the results of this study, we infer that in the future, the modem river mouth will protrude gradually northward, while the erosion zone, comprising the old river mouth and area between the modern river mouth and the old river mouth （Intermediate region） will continue to erode. As the modem river mouth protrudes towards the sea, there will be a gradual increase in the current speed and decrease in wave height. Conversely, the old river mouth will retreat, with gradual decrease in current speed and increase in wave height. As more coastal constructions spring up around the Yellow River mouth in the future, we recommend that variation in hydrodynamics over time should be taken into consideration when designing such coastal constructions.展开更多
The lepton flavor violating process μ - eγ has been previously studied in a model of electroweak-scale right-handed neutrinos. In that work the decay amplitude was computed in unitarity gauge, augmented by some tech...The lepton flavor violating process μ - eγ has been previously studied in a model of electroweak-scale right-handed neutrinos. In that work the decay amplitude was computed in unitarity gauge, augmented by some technical considerations that correct the leading term thus obtained. This complication arises because the mixing matrices appearing in the weak charged currents are not unitary in the model. In this paper, we recalculate the amplitude in Re gauge. The cancellation of the ξ dependence in the final result serves as a useful check to both the obtained amplitude and the technical points made in the previous work.展开更多
文摘The directed motion of a Brownian particle in a Bashing potential with various transition probabilities and waiting times in one of two states is studied. An expression for the average cycle period is proposed and the steady current J of the particle is calculated via Langevin simulation. The results show that the optimal cycle period (Tm), which takes the maximum of J, is shifted to a small value when the transition probability A from the potential on to the potential off decreases, the maximal current appears in the case of the average waiting time in the potential on being longer than in the potential off, and the direction of current depends on the ratio of the average times waiting in two states.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41030856 and 41006024)the Foundation of Shandong Province (Grant No. BS2012HZ022)+1 种基金the Project of China Geological Survey (Grant No. GZH201100203)the Project of Taishan Scholar
文摘Topography around the Yellow River mouth has changed greatly in recent years, but studies on the current state of ma- rine dynamics off the Yellow River mouth are relatively scarce. This paper uses a two-dimension numerical model （MIKE 21） to reveal the tidal and wave dynamics in 2012, and conducts comparative analysis of the changes from 1996 to 2012. The results show that M2 amphidromic point moved southeastward by 11 kin. It further reveals that the tides around the Yellow River mouth are relatively stable due to the small variations in the tidal constituents. Over the study period, there is no noticeable change in the distribution of tidal types and tidal range, and the mean tidal range off the river mouth during the period studied is 0.5-1.1 m. However, the tidal currents changed greatly due to large change in topography. It is observed that the area with strong tidal currents shifted from the old river mouth （1976-1996） to the modem river mouth （1996-present）. While the tidal current speeds decreased continually off the old river mouth, they increased off the modem river mouth. The Maximum Tidal Current Speed （MTCS） reached 1.4 m s-1, and the maximum current speed of 50-year return period reached 2.8 m s-1. Waves also changed greatly due to change in topography. The significant wave height （H1/3） of 50-year return period changed proportionately with the water depth, and the ratio of Hi/3 to depth being 0.4-0.6. H1/3 of the 50-year return period in erosion zone increased continually with increasing water depth, and the rate of change varied between 0.06 and 0.07myr-1. Based on the results of this study, we infer that in the future, the modem river mouth will protrude gradually northward, while the erosion zone, comprising the old river mouth and area between the modern river mouth and the old river mouth （Intermediate region） will continue to erode. As the modem river mouth protrudes towards the sea, there will be a gradual increase in the current speed and decrease in wave height. Conversely, the old river mouth will retreat, with gradual decrease in current speed and increase in wave height. As more coastal constructions spring up around the Yellow River mouth in the future, we recommend that variation in hydrodynamics over time should be taken into consideration when designing such coastal constructions.
文摘The lepton flavor violating process μ - eγ has been previously studied in a model of electroweak-scale right-handed neutrinos. In that work the decay amplitude was computed in unitarity gauge, augmented by some technical considerations that correct the leading term thus obtained. This complication arises because the mixing matrices appearing in the weak charged currents are not unitary in the model. In this paper, we recalculate the amplitude in Re gauge. The cancellation of the ξ dependence in the final result serves as a useful check to both the obtained amplitude and the technical points made in the previous work.
