Nanocomposite films comprising polymer‐functionalized single‐walled carbon‐nanotubes (SWNTs) and liquid crystal elastomers (LCEs) show a reversible IR‐induced strain (∼−30%) at very low SWNT loading levels (≤0.2 wt%). SWNTs can efficiently transform absorbed IR light into thermal energy, thereby serving as a nanoscale heat‐source and thermal‐ conduction pathway. The absorbed thermal‐energy induced a nematic– isotropic phase‐transition, generating a shape change in the nanocomposite film.

Abstract-This paper investigates the loss characteristics of rf magnetic materials for power conversion applications in the 10 MHz to 100 MHz range. A measurement method is proposed that provides a direct measurement of inductor quality factor QL as a function of inductor current at rf frequencies, and enables indirect calculation of core loss as a function of flux density. Possible sources of error in measurement and calculation are evaluated and addressed. The proposed method is used to identify loss characteristics of several commercial rf magnetic core materials. The loss characteristics of these materials, which have not previously been available, are illustrated and compared in tables and figures. The use of the method and data are demonstrated in the design of a magnetic-core inductor, which is applied in a 30 MHz inverter. The results of this paper are thus useful for design of magnetic components for very high frequency (VHF) applications.

Two layered iodoargentates, [HCP][Ag 2 I 3 ] (HCP + = NH-4-cyanopyridinium) (1) and [MCP][Ag 4 I 5 ] (MCP + = N-methyl-3-cyanopyridinium) (2) have been solvothermally synthesized. For 1, the inorganic layer is built up by 4-connected Ag 4 I 8 unit with cubane-type Ag 4 I 4 core via sharing peripheral μ 2 -I in ab plane, while the HCP + cations are located at the apertures and interlayer space. For 2, the inorganic layer is constructed from [Ag 6 I 6 ] n and [AgI 3 ] n 2n− chains via alternative corner-and edge-sharing modes along the b-axis, while the MCP + cations lie between neighboring layers. Compounds 1 and 2 exhibit reducing band gaps relative to the bulk β-AgI and remarkable thermochromism, which are ascribed to the intermolecular charge transfer (CT) and affected by electron affinity of pyridinium cations.

Five iodoargentate hybrids, {[MC][Ag 2 I 3 ]} n (1), {[EC][Ag 2 I 3 ]} n (2), {[PC] 2 [Ag 4 I 6 ]} n (3), {[BC] 2 [Ag 4 I 6 ]} n (4), and {[IPC] 2 [Ag 4 I 6 ]} n (5) (MC + = N-methyl-4-cyanopyridinium, EC + = N-ethyl-4-cyanopyridinium, PC + = N-propyl-4cyanopyridinium, BC + = N-butyl-4-cyanopyridinium, and IPC + = N-isopentyl-4-cyanopyridinium), have been solvothermally synthesized. Built up from μ-I bridging cubane-like Ag 4 I 4 nodes, 1 and 2 present similar two-dimensional grid-like layers with the MC + and EC + cations located at the apertures of inorganic layers and interlayer space, while 3, 4, and 5 possess threedimensional open frameworks with the PC + , BC + , and IPC + cations intercalated in the channels. 1−5 exhibit reducing band gaps with respect to the bulk β-AgI and interesting low temperature reversible thermochromism, which can be ascribed to the temperature effects directly on the population of intermolecular charge transfer. Variations in structure and property reveal delicate modulating effect of N-alkyl-4-cyanopyridinium cations and flexibility of iodoargentate frameworks.

This paper studies a single UAV-enabled secure data dissemination system, in which the UAV is employed as an aerial base station to secretly communicate with multiple ground users. To prevent confidential signal intended to scheduled users overhearing by unscheduled ones, artificial noise (AN) is introduced and the UAV transmits a mixture of intended signal and a priori knowledge of AN for scheduled user at each time slot. The trajectory and the AN power splitting factor of UAV as well as the user scheduling are jointly optimized to maximize the minimum average secrecy rate over a finite flight period. To address the non-convexity of the formulated problem, an efficient iterative algorithm is presented based on alternating optimization and successive convex optimization techniques, which can ensure convergence to at least a local optimal solution. Simulation results show significant secrecy gains of the proposed design over benchmark scheme with circular trajectory. INDEX TERMS physical layer security; UAV-enabled data dissemination; artificial noise; max-min secrecy rate; trajectory design