Based on the linear shallow water equations,an analytic solution of trapped waves over a symmetric parabolicprofile submerged ridge is derived.The trapped waves act as propagating waves along the ridge and as standing...Based on the linear shallow water equations,an analytic solution of trapped waves over a symmetric parabolicprofile submerged ridge is derived.The trapped waves act as propagating waves along the ridge and as standing waves across the ridge.The amplitude gets the maximum at the ridge top and decays gradually towards both sides.The decaying rate gets more gently with higher modes.Besides,an explicit first-order approximate dispersion relation is derived to simplify transcendental functions in the exact solution,which is useful to describe trapped waves over shallowly submerged ridges in reality.Furthermore,the trapping mechanism of the submerged ridge waveguides on the trans-oceanic tsunami propagation can be explained by the ray theory.A critical incident angle exists as a criterion to determine whether the wave is trapped.Besides,a trapped parameter γ is proposed to estimate the ratio of the energy trapped by the oceanic ridge if a tsunami is generated at its top.展开更多
大气压氮气和空气介质阻挡均匀放电属于Townsend放电,并且以一种反常的方式熄灭,即放电在气隙电压上升过程中熄灭。为了实验研究阻挡介质材料表面"浅位阱"(能级<1 e V)对大气压均匀放电的影响,探究"反常熄灭"现...大气压氮气和空气介质阻挡均匀放电属于Townsend放电,并且以一种反常的方式熄灭,即放电在气隙电压上升过程中熄灭。为了实验研究阻挡介质材料表面"浅位阱"(能级<1 e V)对大气压均匀放电的影响,探究"反常熄灭"现象的机理,研制了一套热刺激电流测量装置,可施加最高25 kV直流电压,电流测量精度达0.1 p A,具有良好的抗干扰能力和重复性。测量陶瓷和石英玻璃的热刺激电流曲线,发现2种材料表面均存在一定数量的"浅位阱"。陶瓷浅位阱能级0.37 e V,石英玻璃为0.63 e V,陶瓷浅位阱能级更低,更易被轰击成为种子电子;陶瓷陷阱电荷量315.3 n C,石英玻璃为20.7 n C,陶瓷表面浅位阱数量远远多于石英玻璃。这与陶瓷材料能够实现大气压均匀介质阻挡放电(dielectric barrier discharge,DBD)但石英玻璃只是细丝放电的实验现象一致。证实材料表面浅位阱能够为放电提供种子电子,且数量越多越有利于实现大气压均匀DBD。展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51579090 and 51425901)the Open Foundation of State Key Laboratory of Coastal and Offshore Engineering(Grant No.LP1405)+1 种基金the Open Foundation of the Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province(Grant No.2014SS02)the Fundamental Research Funds for the Central University(Hohai University,Grant No.2014B04114)
文摘Based on the linear shallow water equations,an analytic solution of trapped waves over a symmetric parabolicprofile submerged ridge is derived.The trapped waves act as propagating waves along the ridge and as standing waves across the ridge.The amplitude gets the maximum at the ridge top and decays gradually towards both sides.The decaying rate gets more gently with higher modes.Besides,an explicit first-order approximate dispersion relation is derived to simplify transcendental functions in the exact solution,which is useful to describe trapped waves over shallowly submerged ridges in reality.Furthermore,the trapping mechanism of the submerged ridge waveguides on the trans-oceanic tsunami propagation can be explained by the ray theory.A critical incident angle exists as a criterion to determine whether the wave is trapped.Besides,a trapped parameter γ is proposed to estimate the ratio of the energy trapped by the oceanic ridge if a tsunami is generated at its top.
文摘大气压氮气和空气介质阻挡均匀放电属于Townsend放电,并且以一种反常的方式熄灭,即放电在气隙电压上升过程中熄灭。为了实验研究阻挡介质材料表面"浅位阱"(能级<1 e V)对大气压均匀放电的影响,探究"反常熄灭"现象的机理,研制了一套热刺激电流测量装置,可施加最高25 kV直流电压,电流测量精度达0.1 p A,具有良好的抗干扰能力和重复性。测量陶瓷和石英玻璃的热刺激电流曲线,发现2种材料表面均存在一定数量的"浅位阱"。陶瓷浅位阱能级0.37 e V,石英玻璃为0.63 e V,陶瓷浅位阱能级更低,更易被轰击成为种子电子;陶瓷陷阱电荷量315.3 n C,石英玻璃为20.7 n C,陶瓷表面浅位阱数量远远多于石英玻璃。这与陶瓷材料能够实现大气压均匀介质阻挡放电(dielectric barrier discharge,DBD)但石英玻璃只是细丝放电的实验现象一致。证实材料表面浅位阱能够为放电提供种子电子,且数量越多越有利于实现大气压均匀DBD。
