Intermediate Layers in Tandem Organic Solar Cells

Tandem structures can boost the efficiency of organic solar cell to more than 15%, compared to the 10% limit of single layer bulk heterojunction devices. Design and fabricating of intermediate layers plays a very important role to achieve high device performance. This article will review the main experimental progresses of tandem organic solar cells, and focus on the intermediate layers (charge recombination layers) in both thermal evaporated and solution processed organic tandem solar cell devices

Intermediate Layers in Tandem Organic Solar Cells

Tandem structures can boost the efficiency of organic solar cell to more than 15%, compared to the 10% limit of single layer bulk heterojunction devices. Design and fabricating of intermediate layers plays a very important role to achieve high device performance. This article will review the main experimental progresses of tandem organic solar cells, and focus on the intermediate layers (charge recombination layers) in both thermal evaporated and solution processed organic tandem solar cell devices

Tax-induced earnings management, auditor conservatism, and tax enforcement

Prompted by the recent statutory corporate income tax-rate reduction in China, in this study I investigate whether the constraining effect that quality auditors have on tax-related discretionary current accruals (DCA) differs for two sub-groups of listed firms with tax incentives to manage earnings upward versus downward. I also explore whether the effectiveness of tax authority scrutiny (i.e. tax enforcement) on DCA differs for the same two groups. I find that the firms’ two external monitors are sensitive to the direction of managerial incentives for earnings management. Specifically, higher-quality auditors are associated with smaller amounts of reported DCA and this association is stronger for firms with incentives to manage earnings upward and weaker for those with incentives to manage earnings downward, although the accrual decisions for all of the firms are driven by the same tax reporting incentives. The results are consistent with the notion that due to concerns with legal liability and reputation loss, auditors have incentives to ensure that firms report earnings conservatively. I also find a significantly positive association between tax enforcement and reported DCA for firms with incentives to manage earnings downward. This suggests that tax authorities constrain corporate accruals management that is likely to result in tax revenue loss. Taken together, my results suggest that a spillover effect exists between auditors and tax authorities, such that the two monitoring bodies compensate for each other’s lack of monitoring in one direction of accruals management. My results are robust to a set of sensitivity tests and have implications for academic researchers, policy makers, and capital market investors

Diagnostics of reciprocating compressor fault based on a new envelope algorithm of empirical mode decomposition

Empirical mode decomposition (EMD), a self-adaptive time-frequency analysis methodology, is particularly suitable for processing the nonlinear and non-stationary time series, which can decompose a complicated signal into a series of intrinsic mode functions. Although it has the attractive features, the approach to construct the envelop-line in EMD has obvious shortcomings. A suggested improvement to EMD by adopting the optimized rational Hermite interpolation is proposed in this paper. In the proposed method, it adopts rational Hermite interpolation to compute the envelope-line, which has a shape controlling parameter compared with the cubic Hermite interpolation. In the meantime, one parameter determining criterion is introduced to guarantee the shape controlling parameter selection performs optimally. Besides the empirical envelope demodulation (EED) is introduced and utilized to analyze the IMFs derived from the improved EMD method. Hence, a new time-frequency method based on the optimized rational Hermite-based EMD combined with EED is proposed and the effectiveness was validated by the numerical simulations and an application to the reciprocating compressor fault diagnosis. The contributions of this paper are three aspects: Firstly, the definition of the best envelope is non-existent, some light is given about which envelope maybe better in this paper. Secondly, the optimal shape controlling parameter selection combined with rational Hermite interpolation is developed, leading to the significant performance enhancement. Thirdly, little research has been carried out on the fault diagnosis of the reciprocating compressor using EMD, the proposed method is a good start