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Zhao G.,CAS Beijing National Laboratory for Molecular | Zhao G.,Henan Electric Power Research Institute | He Y.,CAS Beijing National Laboratory for Molecular | He C.,CAS Beijing National Laboratory for Molecular | And 3 more authors.
Solar Energy Materials and Solar Cells | Year: 2011

We report the photovoltaic properties of a DA copolymer, poly(benzothiadiazole-thiophene-co-bithiophene) (PBTTbT), containing the donor (D) unit of oligothiophene with a hexyl side chain and the acceptor (A) unit of 2,1,3-benzothiadiazole (BT) with a methyl side chain. The geometry, electronic and absorption spectroscopic properties of bithiophene-benzothiadiazole- thiophene monomer (M1) of the polymer were investigated theoretically by the density functional theory (DFT) method for deep understanding the relationship of the structure and properties of the polymer. Polymer solar cells (PSCs) were fabricated with PBTTbT as an electron donor blended with [6,6]-phenyl-C71- butyric acid methyl ester (PC70BM) as an electron acceptor. The power conversion efficiency (PCE) of PSC is 0.87% for an optimized PBTTbT:PC 70BM weight ratio of 1:3, under the illumination of AM 1.5, 100 mW/cm2. With the additive of 1% 1,8-dioctanedithiol and thermal annealing at 130 °C for 15 min, the PCE of the device was improved to 1.98%. The efficiency improvement of the device was ascribed to a better morphology of the PBTTbT:PC70BM active layer with the additive and thermal annealing. © 2010 Elsevier B.V. All rights reserved. Source

Liu Y.,Henan Electric Power Research Institute | Liu W.-Q.,Henan University of Science and Technology
Wuli Xuebao/Acta Physica Sinica | Year: 2011

We propose a method of obtaining peakon solution from bell-shape smooth soliton (or solitary wave) solution, i. e. constructing directly an ansatz solution of peakon according to the well-known bell-shape smooth soliton solution and then determining the coefficients in ansatz solution. The method is verified to be feasible for four nonlinear wave equations and one set of equations. The bell-shape smooth soliton (or solitary wave) solution and peakon solution can exist in the same expression and the expressions of peakon solutions include those of the bell-shape smooth soliton solutions and the latter are the special cases of the former. © Chinese Physical Society. Source

Ma W.,Henan Electric Power Research Institute
Lecture Notes in Electrical Engineering | Year: 2014

The problem that each cell's voltage is not equal in super capacitors series will affect the whole performance of series connected super capacitor strings. In order to solve this problem, an equalizing circuit is designed in this paper. This equalizing circuit uses inductances as energy storage elements, transfers energy from super capacitor with high voltage to the lower ones to achieve voltage balance. To prove the feasibility of this method, simulations and experiments have been done. The results show that this method can make each super capacitor's voltage tend to be equaled even when the discrepancy of the super capacitors' capacity is big. This method solves the voltage inequality in super capacitors series effectively and eliminates a difficult problem in engineering application. © Springer International Publishing Switzerland 2014. Source

Zhao G.,Henan Electric Power Research Institute | He Y.,CAS Beijing National Laboratory for Molecular | Peng B.,CAS Beijing National Laboratory for Molecular | Li Y.,CAS Beijing National Laboratory for Molecular
Chinese Journal of Chemistry | Year: 2012

Effect of the device fabrication conditions on photovoltaic performance of the polymer solar cells based on poly(3-hexylthiophene) (P3HT) as donor and indene-C 70 bisadduct (IC 70BA) as acceptor was studied systematically. The device fabrication conditions we studied include pre-thermal annealing temperature, active layer thickness, and the P3HT:IC 70BA weight ratios. For devices with a 188-nm-thick active layer of P3HT:IC 70BA (1:1, w:w) blend film and pre-thermal annealing at 150°C for 10 min, maximum power conversion efficiency (PCE) reached 5.82% with V oc of 0.81 V, I sc of 11.37 mA/cm 2, and FF of 64.0% under the illumination of AM1.5G, 100 mW/cm 2. Copyright © 2012 SIOC, CAS, Shanghai & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Yu L.,Henan Electric Power Research Institute
Chinese Physics B | Year: 2012

The solutions to a linear wave equation can satisfy the principle of superposition, i.e., the linear superposition of two or more known solutions is still a solution of the linear wave equation. We show in this article that many nonlinear wave equations possess exact traveling wave solutions involving hyperbolic, triangle, and exponential functions, and the suitable linear combinations of these known solutions can also constitute linear superposition solutions to some nonlinear wave equations with special structural characteristics. The linear superposition solutions to the generalized KdV equation K(2,2,1), the Oliver water wave equation, and the k(n, n) equation are given. The structure characteristic of the nonlinear wave equations having linear superposition solutions is analyzed, and the reason why the solutions with the forms of hyperbolic, triangle, and exponential functions can form the linear superposition solutions is also discussed. © 2012 Chinese Physical Society and IOP Publishing Ltd. Source

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