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The development of temperature-sensitive tunable metamaterials based on GST particles is one of the hot topics. These metamaterials have rich resonance properties and can be used in communication, optical control, coding, and other fields. However, it is still elusive how to achieve the tunability of metamaterials based on GST particles while maintaining the original resonance performance. In this paper, a tunable Terahertz (THz) metamaterial based on GST particles is verified and measured, which can maintain the original resonances with temperature increasing. Two absorption peaks (P1: 86% at 1.98 THz, P2: 51% at 5.88 THz) and a valley (V1) are achieved by this metamaterial at room temperature. The P1, P2, and V1 of the samples are temperature-sensitive, which are shifted to lower frequencies with temperature increasing. The maximum FOM value is 7651, and the maximum S value is 2190. Moreover, the resonance position of the P2 is always covered by the V1 with the temperature increasing. Therefore, this proposed temperature-sensitive tunable metamaterial realizes the absorption window conversion between P2 peak (or “ON”) and V1 valley (or “OFF”). This proposed metamaterial can be applied to crystallinity sensing.

In order to achieve the lightweight of fuel cell car, and through topology and size optimization on the current sub-frame, we have changed the original design structure under the premise of the requirements to meet the stiffness and strength in various operating conditions, which made the structure light weight and reliable. Analysis showed that the new sub-frame technology is feasible, which meet the technical and assembly requirements, and achieved the optimal goal.

Two new diterpenoid compounds, ginkgolide P (1) and ginkgolide Q (2), were isolated from the leaves of Ginkgo biloba L. Their structures were elucidated by various spectroscopic methods, and the structure of 1 was further confirmed by X-ray crystallographic analysis. The activities of the compounds were evaluated against platelet aggregation induced by platelet activating factor (PAF), and the preliminary structure-activity relationship was also discussed. [ABSTRACT FROM AUTHOR]

Abstract: Dynamics is one of the fundamentally important aspects of all space tether research. This paper derives the dynamic equations of electrodynamic tether system (EDT) in stationkeeping phase using Newton’s laws. This paper further analyzes the tether system motion rules under electrodynamic drag, gravity induced force, and tether tension. Numerical simulation of electrodynamic tether system in station-keeping phase is calculated using an approach that combines the central difference method, fourth-order Runge-Kutta method, and predictor-corrector method, among others. The simulation results show that the motion of electrodynamic tether in stationkeeping phase not only contains librations caused by the motion of endmass, but also contains vertical and longitudinal vibrations of tether. If the motion of endmass is ignored, it is much similar to the vibration of cable with two immovable pinned-supports, in which the mid-span has the largest amplitude of vibration. Based on this, the main satellite and the endmass at both ends of tether can be treated as immovable pinned-supports when the tether vibration and tension of electrodynamic tether system in impermanency are investigated.