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The control of a typical extreme load with varying velocity and direction, i.e., International Electro-technical Commission Extreme Coherent Gust with Direction Change (ECD) load, was investigated on an Upwind/National Renewable Energy Laboratory 5 MW reference wind turbine using a newly developed smart blade system. The control action was implemented through the local perturbation of the Deformable Trailing Edge Flap (DTEF) on the blade surface and thus flow-blade system. The investigations were separately conducted within four time zones, depending on the complex yaw or/and pitching functions of the turbine. It was found that, without DTEF control, the flapwise root moment and tip deflection of the blades experienced rather complicated fluctuations due to the ECD load, together with the influence of blade yaw and pitching. On the other hand, the smart rotor control was very effective to reduce both blade flapwise root moment and tip deflection up to 30% and even more. The good control performance lied in the altered nature of the flow-blade interactions by the local controllable DTEF perturbation to change the in-phased fluid-structure synchronization into anti-phased collision at dominant load frequencies, thus significantly enhancing the damping of fluid-structure system and impairing their correlations. Consequently, the ECD load on the rotor and even drive-chain components would be greatly suppressed.

α decay Spin and parity Reduced α-decay width Quadrupole-octupole deformation Fine structure in the α decay of 223 U was observed in the fusion-evaporation reaction 187 Re( 40 Ar, p3n) by using fast digital pulse processing technique. Two α-decay branches of 223 U feeding the ground state and 244 keV excited state of 219 Th were identified by establishing the decay chain 223 U α1 −→ 219 Th α 2 −→ 215 Ra α 3−→ 211 Rn. The α-particle energy for the ground-state to ground-state transition of 223 U was determined to be 8993(17) keV, 213 keV higher than the previous value, the half-life was updated to be 62 +14 −10 µs. Evolution of nuclear structure for N = 131 even-Z isotones from Po to U was discussed in the frameworks of nuclear mass and reduced α-decay width, a weakening octupole deformation in the ground state of 223 U relative to its lighter isotones 219 Ra and 221 Th was suggested.

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