Field measurements of wind effects on the world's tallest reinforced concrete building (CITIC Plaza, 391 m high) located in Guangzhou were made during Typhoon Damrey in 2005. The field-measured data such as wind speed, wind direction and acceleration responses were simultaneously and continuously measured from the super-tall building during the typhoon. Detailed analysis of the field data was conducted to investigate the wind characteristics and wind-induced vibration of the highrise structure. Based on the measured acceleration data, amplitude-dependent damping ratios of the building were estimated by the random decrement method. Dynamic characteristics obtained from the field measurements were compared with those calculated from the finite-element model of the structure. The serviceability of the tall building was then analysed based on the field measured results and design codes. Finally, a time-frequency analysis was carried out by the HilbertHuang technique to investigate the non-stationary features of the measured wind speed and acceleration response signals. The research output is expected to be of considerable interest and practical use to professionals and researchers involved in the design of super-tall buildings.

We report here the δ Scuti pulsation characteristics of low-amplitude oscillations of star V461 Per in the α Persei cluster. The 61 hr of high-quality light curve over seven nights have confirmed the low-amplitude oscillation characteristics of V461 Per. The amplitude spectra indicate a multiperiodic pulsation behavior, two pulsation frequencies f 1 ¼ 28:0433 cycle day À1 and f 2 ¼ 22:5973 cycle day À1 have been confidently identified, and three other frequencies (f 3 ¼ 4:5038, f 4 ¼ 28:3593, and f 5 ¼ 22:8838 cycle day À1 ) are probable. Explanation on the complicated frequency distribution requires a combination of both radial and nonradial modes. A preliminary comparison with models suggests that the observed modes would lie in the range of modes from high rank g to p 3 . The δ Scuti variable V461 Per has almost the same T eff and log g as the δ Scuti variable V459 Per in the same α Persei cluster. This suggests that it will be meaningful to have a comparison study of the two variables, and the pulsation characteristics discovered in the observations demonstrate that they share similar main frequency distribution style.