A wholly aromatic polypyrene was synthesized by direct chemical oxidative polymerization of pyrene with ferric chloride as oxidant in hexane/nitromethane. Successful synthesis of polypyrene was thoroughly confirmed by IR, UV/Vis, 1D (1)H NMR, 2D (1)H-(1)H COSY, 2D (1)H-(13)C HSQC, MALDI-TOF MS, elemental analysis, and X-ray diffraction methods. The results indicated that the polypyrene was formed mainly through dehydro coupling between 2- or 1- and 2'- or 1'-positions on pyrene rings having a degree of polymerization of around 24. The polypyrene was purified and then separated into THF-soluble (ca. 10 %) and THF-insoluble (ca. 90 %) fractions. Compared with insulating pyrene monomer, the polypyrene is a controllably conducting polymer that has low conductivity of 3.4x10(-8) S cm(-1) in its virgin state, moderate conductivity of 2.28x10(-4) S cm(-1) upon iodine doping, but much higher conductivity of up to 81.2 S cm(-1) after the insoluble polypyrene was heated up to 1300 degrees C in nitrogen with a high char yield of 70.6 %. In particular, the soluble polypyrene demonstrates much stronger visible color fluorescence and much lower toxicity than pyrene. The soluble polypyrene would be advantageous for detecting Fe(3+) with almost no interference of other metal ions. The soluble and insoluble polypyrene fractions have potential applications as intrinsically luminescent and highly conducting carbon materials, respectively.

Preventive diagnosis and maintenance of transformers have become more and more popular in recent times in order to improve the reliability of electric power systems. Dielectric testing techniques such as frequency domain spectroscopy (FDS) are being investigated as potential tools for condition assessment of transformer insulation. The FDS test has been affected by the factors, such as, the geometric, temperature, moisture content of insulation system. In this paper, those effect factors will be analyzed, according the field test data and laboratory model data.

In this paper, a 1-bit wideband electronically reconfigurable reflectarray (RRA) in Ku-band is proposed. In order to achieve the wideband and reconfigurable characteristics, the stacked microstrip structure and a 1-bit "microstrip line-slot line-microstrip line" phase shifter (MSMPS) were introduced in this design. A novel "receiving-phase shift-transmitting" unit cell was gotten by connecting two stacked microstrip structures using MSMPS. Due to the receiving and transmitting parts are perpendicular to each other, the polarization rotation characteristic was demonstrated. To avoid the blockage of the feed horn, it was placed above the reflecting surface array with an offset angle of 25° to the normal direction. A 16 × 16 obliquely-fed RRA was designed and fabricated. The measured 1-dB gain bandwidth of the RRA is 15.4%. The measured results show that the fabricated prototype can achieve beam scanning from -20° to 50° in the elevation plane, and ±50° beam scanning in the azimuth plane.

Wireless power transfer (WPT) technology has drawn much attention due to its advantages such as safety, convenience, and non-contact. For some movable devices such as intelligent inspection robot, the constant output voltage is very important to ensure its normal operation. In order to improve the system efficiency and steadiness of output voltage, a maximum efficiency tracking and constant voltage charging method is proposed for the dynamic WPT system. In this method, the mutual inductance and optimal input voltage can be estimated accurately no matter the coupling coefficient and equivalent load change or not. The simulation and experimental results have shown that the WPT system realize maximum efficiency tracking and constant voltage charging when the resistance is changed from 10Ω to 5Ω, and the same result was achieved when the mutual inductance is altered from 20μH to 10μH. INDEX TERMS Wireless power transfer, optimal input voltage matching, maximum efficiency tracking

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