The development of offshore wind farms was originally carried out in shallow water areas with fixed （seabed mounted） structures. However, countries with limited shallow water areas require innovative floating platfo...The development of offshore wind farms was originally carried out in shallow water areas with fixed （seabed mounted） structures. However, countries with limited shallow water areas require innovative floating platforms to deploy wind turbines offshore in order to harness wind energy to generate electricity in deep seas. The performances of motion and mooring system dynamics are vital to designing a cost effective and durable floating platform. This paper describes a numerical model to simulate dynamic behavior of a new semi-submersible type floating offshore wind turbine （FOWT） system. The wind turbine was modeled as a wind block with a certain thrust coefficient, and the hydrodynamics and mooting system dynamics of the platform were calculated by SESAM soRware. The effect of change in environmental conditions on the dynamic response of the system under wave and wind loading was examined. The results indicate that the semi-submersible concept has excellent performance and SESAM could be an effective tool for floating wind turbine design and analysis.展开更多
In chronic stage of stroke, it is necessary to pay attention to the complex spatial movements training along with the traditional restoration of balance, strength of particular muscles, and paretic limb joints mobilit...In chronic stage of stroke, it is necessary to pay attention to the complex spatial movements training along with the traditional restoration of balance, strength of particular muscles, and paretic limb joints mobility. The aim of the study was to evaluate the effectiveness of robotic therapy in the recovery of upper limb function in the chronic stage of stroke. The study involved 52 patients with ischemic stroke in the middle cerebral artery. The patients were divided randomly into 2 groups. All patients （5 days/wk × 3 wk） got gymnastics by the standard technique, massage, laser, and pulsed currents therapy. Main group patients （n = 36） extra received complex spatial movements, speed, fluidity, precision and agility training by the robotic electromechanical device Multi Joint System （MJS） （40 minutes, 5 days/wk × 3 wk）. Analysis of the results of the study showed a statistically significant difference in improving ROM of the elbow and shoulder joints, speed and accuracy of movement in the main group compared with the control. Hardware recovery of complex spatial upper limb movements in the chronic stage of stroke increases the functionality and independence of the patient＇s domestic skills.展开更多
The counter-rotating type hydroelectric unit, which is composed of the axial flow type tandem runners and the peculiar generator with double rotational armatures, has been proposed. In the unit, the front and the rear...The counter-rotating type hydroelectric unit, which is composed of the axial flow type tandem runners and the peculiar generator with double rotational armatures, has been proposed. In the unit, the front and the rear runners counter-drive the inner and the outer armatures of the generator, respectively. Besides, the flow direction at the rear runner outlet must coincide with the direction at the front runner inlet, because the angular momentum change through the rear runner must coincides with that through the front runner. In this paper, the tandem runners work at on-cam conditions in keeping the induced frequency constant, to provide the hydroelectric unit for the power grid system. The output and the hydraulic efficiency are affected by the adjusting angles of the front and the rear blades. Both optimum angles giving the maximum output or efficiency were presented at the various discharge/head circumstances, accompanying with the turbine performances.展开更多
基金Foundation item： Supported by the 111 Project under Grant No.B07019, and the National Natural Science Foundation of China under Grant No.50979020.
文摘The development of offshore wind farms was originally carried out in shallow water areas with fixed （seabed mounted） structures. However, countries with limited shallow water areas require innovative floating platforms to deploy wind turbines offshore in order to harness wind energy to generate electricity in deep seas. The performances of motion and mooring system dynamics are vital to designing a cost effective and durable floating platform. This paper describes a numerical model to simulate dynamic behavior of a new semi-submersible type floating offshore wind turbine （FOWT） system. The wind turbine was modeled as a wind block with a certain thrust coefficient, and the hydrodynamics and mooting system dynamics of the platform were calculated by SESAM soRware. The effect of change in environmental conditions on the dynamic response of the system under wave and wind loading was examined. The results indicate that the semi-submersible concept has excellent performance and SESAM could be an effective tool for floating wind turbine design and analysis.
文摘In chronic stage of stroke, it is necessary to pay attention to the complex spatial movements training along with the traditional restoration of balance, strength of particular muscles, and paretic limb joints mobility. The aim of the study was to evaluate the effectiveness of robotic therapy in the recovery of upper limb function in the chronic stage of stroke. The study involved 52 patients with ischemic stroke in the middle cerebral artery. The patients were divided randomly into 2 groups. All patients （5 days/wk × 3 wk） got gymnastics by the standard technique, massage, laser, and pulsed currents therapy. Main group patients （n = 36） extra received complex spatial movements, speed, fluidity, precision and agility training by the robotic electromechanical device Multi Joint System （MJS） （40 minutes, 5 days/wk × 3 wk）. Analysis of the results of the study showed a statistically significant difference in improving ROM of the elbow and shoulder joints, speed and accuracy of movement in the main group compared with the control. Hardware recovery of complex spatial upper limb movements in the chronic stage of stroke increases the functionality and independence of the patient＇s domestic skills.
文摘The counter-rotating type hydroelectric unit, which is composed of the axial flow type tandem runners and the peculiar generator with double rotational armatures, has been proposed. In the unit, the front and the rear runners counter-drive the inner and the outer armatures of the generator, respectively. Besides, the flow direction at the rear runner outlet must coincide with the direction at the front runner inlet, because the angular momentum change through the rear runner must coincides with that through the front runner. In this paper, the tandem runners work at on-cam conditions in keeping the induced frequency constant, to provide the hydroelectric unit for the power grid system. The output and the hydraulic efficiency are affected by the adjusting angles of the front and the rear blades. Both optimum angles giving the maximum output or efficiency were presented at the various discharge/head circumstances, accompanying with the turbine performances.
