Extensive 3-D model tests have been performed to study the effects of wave obliquity and multi-directionality on the wave loads acting on vertical breakwaters. The variation of horizontal and uplift forces acting on a...Extensive 3-D model tests have been performed to study the effects of wave obliquity and multi-directionality on the wave loads acting on vertical breakwaters. The variation of horizontal and uplift forces acting on an unit length of a breakwater with wave direction, the longitudinal distribution of wave forces, as well as the longitudinal load reduction are analyzed. Some empirical formulae of the longitudinal distribution coefficient and the longitudinal load reduction factor are presented for practical use.展开更多
In the upgrade project of Hefei Light Source（HLSⅡ）,a new digital longitudinal bunch-by-bunch feedback system will be developed to suppress the coupled bunch instabilities in the storage ring effectively.We design a...In the upgrade project of Hefei Light Source（HLSⅡ）,a new digital longitudinal bunch-by-bunch feedback system will be developed to suppress the coupled bunch instabilities in the storage ring effectively.We design a new waveguide overloaded cavity longitudinal feedback kicker as the feedback actuator.The beam pipe of the kicker is a racetrack shape so as to avoid a transition part to the octagonal vacuum chamber.The central frequency and the bandwidth of the kicker have been simulated and optimized to achieve design goals by the HFSS code.A higher shunt impedance can be obtained by using a nose cone to reduce the feedback power requirement.Before the kicker cavity was installed in the storage ring,a variety of measurements were carried out to check its performance.All these results of simulation and measurement are presented.展开更多
We report experiments on the observation of the ^1S0-^3P0 transition spectrum of ^88Sr in the Lamb-Dicke regime.After going through a two-stage magneto-optical trap（MOT）,88 Sr cold atoms with number of about 1 ×...We report experiments on the observation of the ^1S0-^3P0 transition spectrum of ^88Sr in the Lamb-Dicke regime.After going through a two-stage magneto-optical trap（MOT）,88 Sr cold atoms with number of about 1 × 10^5 and a longitudinal temperature of 8.4 μK are loaded into a one-dimensional（1D） optical lattice, which is realized with a semiconductor laser at 813.4 nm. Using the magnetic field-inducing ^3P1 state mixing into ^3P0 state, the spectroscopy of the1S0-3P0 transition with a linewidth of 180 Hz is detected.展开更多
文摘Extensive 3-D model tests have been performed to study the effects of wave obliquity and multi-directionality on the wave loads acting on vertical breakwaters. The variation of horizontal and uplift forces acting on an unit length of a breakwater with wave direction, the longitudinal distribution of wave forces, as well as the longitudinal load reduction are analyzed. Some empirical formulae of the longitudinal distribution coefficient and the longitudinal load reduction factor are presented for practical use.
基金Supported by Natural Science Foundation of China(11175173,11005105)
文摘In the upgrade project of Hefei Light Source（HLSⅡ）,a new digital longitudinal bunch-by-bunch feedback system will be developed to suppress the coupled bunch instabilities in the storage ring effectively.We design a new waveguide overloaded cavity longitudinal feedback kicker as the feedback actuator.The beam pipe of the kicker is a racetrack shape so as to avoid a transition part to the octagonal vacuum chamber.The central frequency and the bandwidth of the kicker have been simulated and optimized to achieve design goals by the HFSS code.A higher shunt impedance can be obtained by using a nose cone to reduce the feedback power requirement.Before the kicker cavity was installed in the storage ring,a variety of measurements were carried out to check its performance.All these results of simulation and measurement are presented.
基金supported by the National Nature Science Foundation of China (Nos. 61127901 and 11474282)the Key Project of the Chinese Academy of Sciences (No. KJZD-EW-W02)
文摘We report experiments on the observation of the ^1S0-^3P0 transition spectrum of ^88Sr in the Lamb-Dicke regime.After going through a two-stage magneto-optical trap（MOT）,88 Sr cold atoms with number of about 1 × 10^5 and a longitudinal temperature of 8.4 μK are loaded into a one-dimensional（1D） optical lattice, which is realized with a semiconductor laser at 813.4 nm. Using the magnetic field-inducing ^3P1 state mixing into ^3P0 state, the spectroscopy of the1S0-3P0 transition with a linewidth of 180 Hz is detected.
