This review introduces three green-solvent-processable strategies for realizing large-scale manufacture of organic photovoltaics.
Backgroundc-Jun NH2-terminal kinases (JNKs) are strongly activated by a stressful cellular environment, such as chemotherapy and oxidative stress. Autophagy is a protein-degradation system in which double-membrane vacuoles called autophagosomes are formed. The autophagy-related gene Beclin 1 plays a key role in this process. We previously found that autophagy was induced by dihydroartemisinin (DHA) in pancreatic cancer cells. However, little is known about the complex relationship between ROS, JNK activation, autophagy induction, and Beclin 1 expression.MethodsCell viability and CCK-8 assays were carried out to determine the cell proliferation; small interfering RNAs (siRNAs) were used to knockdown c-Jun NH2-terminal kinases (JNK1/2) genes; western blot was performed to detect the protein expression of LC3, JNK, Beclin 1, caspase 3 and β-actin; production of intracellular ROS was analyzed using FACS flow cytometry; autophagy induction was confirmed by electron microscopy.ResultsIn the present study, we explored the role of DHA and Beclin 1 expression in autophagy. DHA-treated cells showed autophagy characteristics, and DHA also activated the JNK pathway and up-regulated the expression of Beclin 1. Conversely, blocking JNK signaling inhibited Beclin 1 up-regulation. JNK activation was found to primarily depend on reactive oxygen species (ROS) resulting from the DHA treatment. Moreover, JNK pathway inhibition and Beclin 1 silencing prevented the induction of DHA-induced autophagy.ConclusionsThese results suggest that the induction of autophagy by DHA is required for JNK-mediated Beclin 1 expression.
To recognize the tender shoots for high-quality tea and to determine the picking points accurately and quickly, this paper proposes a method of recognizing the picking points of the tender tea shoots with the improved YOLO-v3 deep convolutional neural network algorithm. This method realizes the end-to-end target detection and the recognition of different postures of high-quality tea shoots, considering both efficiency and accuracy. At first, in order to predict the category and position of tender tea shoots, an image pyramid structure is used to obtain the characteristic map of tea shoots at different scales. The residual network block structure is added to the downsampling part, and the fully connected part is replaced by a 1 × 1 convolution operation at the end, ensuring accurate identification of the result and simplifying the network structure. The K-means method is used to cluster the dimension of the target box. Finally, the image data set of picking points for high-quality tea shoots is built. The accuracy of the trained model under the verification set is over 90%, which is much higher than the detection accuracy of the research methods.INDEX TERMS Image recognition, YOLO-v3, convolutional neural network, image pyramid, tea shoot.
The solutionprocessed perovskite is mostly polycrystalline with a large number of grain boundaries (GBs) that induce the fastest ion migration than other sites. [5][6][7][8][9] Meanwhile, the GBs are the dominating attack sites of water and oxygen, which will deteriorate the operation stability of PerSCs. [10][11][12][13][14] Therefore, high-grade perovskite films with high coverage, ideal crystal morphology, good crystallinity, and few defects are crucial for fabricating high-performance PerSCs. [15,16] Plentiful reports have shown that introducing functional additives into perovskite precursor solution can affect the nucleation rate, film morphology, grain size, and crystallinity of perovskite. Precursor additives, such as dimethyl sulfoxide, acids or 2D perovskite, play a vital role in the film formation of perovskite, determining the photovoltaic performance of PerSCs. [17][18][19][20][21] In 2015, Yan et al. revealed that the precursor of MAPbI 3 is a colloid state rather than a real solution. The addition of methylammonium iodide and methylamine chloride leads to a facilitated aggregation of lead iodide, which effectively improves the crystallinity of the perovskite film and ultimately yields promoted PCEs in PerSCs. [22] Ran et al. found that PbI 2 colloid has a wider particle size distribution and larger colloid under certain acidic conditions. [23] Liang et al. proposed an effective cosolvent strategy by introducing ethyl alcohol into the perovskite ink to construct high-performance, blade-coated PerSC modules. [4] Furthermore, the latest reports shed new light on controlling crystallization in 2D perovskites. A 2D (NpMA) 2 PbI 4 perovskite was incorporated into the PbI 2 precursor to modify the crystal growth process in 2D/3D perovskite film using a two-step deposition method. [24] Luo and his coworkers introduced highly oriented 2D (BDA)PbI 4 perovskites as seeds to chalk up large size colloids, which can optimize the growth kinetics of 3D perovskite and make its crystallization directly stride over the nucleation stage. [25] The introduction of these crystal auxiliary components has been proved to be a practical approach to modifying the grain size of perovskite films, while a synergistic function in inhibiting the formation of GBs Crystal growth regulation has become an effective solution to reduce the defects at grain boundaries (GBs) and surfaces of perovskite films for better photovoltaic performances. Oxime acid materials are maturely used as selective collectors in the flotation separation of oxide minerals. Such materials, showing a strong coordination effect and high selectivity with lead, may have great potential in controlling the crystal growth and passivating the defect of perovskite film, which are rarely applied in perovskite solar cells (PerSCs). Herein, an oxime acid-based material with multi-coordination sites, ethyl 2-(2-aminothiazole-4-yl)-2-hydroxyiminoacetate (EHA), is incorporated into the PbI 2 precursor solution to fabricate high-performance PerSCs using a two-step method. The ...
as a potential green energy-generating technology, proving to be a game-changer in photovoltaics. [1][2][3] Significant efforts, including material design, thin-film growth control, and interface engineering, have been devoted to promoting device performance. [4][5][6] Within only a few years, the power conversion efficiencies (PCEs) of single-junction PerSCs have been enhanced to 20% threshold. [7][8][9][10] Despite the leaps and bounds in efficiency, the stability of PerSCs, especially moisture/ water and thermal stability, is still a severe concern, since a long-term environmental atmosphere potentially makes degradation or phase transition of the perovskite. [11][12][13] Accordingly, device instability issues must be overcome along with the improvement of the PCE of PerSCs.Interface and grains control plays a vital role in achieving highly efficient and stable PerSCs. Nonradiative recombination caused by traps/defects existing at the interface and grain boundaries (GBs) impairs charge-density buildup and diminishes the photo-voltage of devices. [14][15][16] Moreover, these defects are the attack points of external factors such as water and thermal, resulting in the decomposition of perovskite. [17,18] Uncoordinated Pb 2+ ion is one typical ion defect on the surface and GBs of perovskite which seriously injures the device performance. [19] Previous studies have been carried out toward solving uncoordinated Pb 2+ ions in achieving high-efficiency PerSCs. [20] A series of organic molecules containing lone pair electrons on oxygen, sulfur, or nitrogen (such as pyridine, thiophene, benzoquinone, and crown ether) have been selected to reduce those defect sites by coordination bonds. [21][22][23] For instance, a series of crown ethers were employed to suppress uncoordinated surface defects, yielding an improved PCE exceeding 23% and achieving enhanced stability under ambient and operational conditions. [24] Moreover, as for the n-i-p structured PerSCs, SnO 2 has been regarded as a promising candidate for electron transport material. [25] However, surface traps/defects existing at the SnO 2 / perovskite interface are disadvantageous for charge transport. Therefore, optimizing the SnO 2 /perovskite interface to suppress the formation of surface traps/defects is vital to boosting device performance. [26,27] Generally, further modificationThe organic-inorganic halide perovskite solar cell (PerSC) is the state-of-theart emerging photovoltaic technology. However, the environmental water/ moisture and temperature-induced intrinsic degradation and phase transition of perovskite greatly retard the commercialization process. Herein, a dual-functional organic ligand, 4,7-bis((4-vinylbenzyl)oxy)-1,10-phenanthroline (namely, C1), with crosslinkable styrene side-chains and chelatable phenanthroline backbone, synthesized via a cost-effective Williamson reaction, is introduced for collaborative electrode interface and perovskite grain boundaries (GBs) engineering. C1 can chemically chelate with Sn 4+ in the SnO 2 electron transport...
Unlike conventional cellular networks where the evolved Node B (eNB) performs centralised scheduling, future relayenhanced cellular (REC) networks allow relay nodes (RNs) to schedule users independently. This decentralised nature of the REC networks brings about challenges to maintain fairness. In this study, we formulate the generalised proportional fair (GPF) resource allocation problem, where resource partition and routing are included as part of the overall radio resource management aiming to provide fairness across all users served by the eNB and its subordinate RNs. Although the traditional proportional fair scheduling algorithm is executed independently at the eNB and each RN to maintain local fairness, we propose efficient resource partition and routing algorithms to maintain global fairness by optimising the GPF objective for the whole relay-enhanced cell. Through system level simulations, the proposed algorithms are evaluated and compared with both non-relaying and relaying systems with benchmark resource partition and routing algorithms. The simulation results show that the proposed algorithms outperform the existing algorithms in providing a better trade-off between system throughput and fairness performance.
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