Showing papers by "Shanghai University published in 2015"

Thin-film preparation and characterization of Cs3Sb2I9: A lead-free layered perovskite semiconductor

Abstract: Computational, thin-film deposition, and characterization approaches have been used to examine the ternary halide semiconductor Cs3Sb2I9. Cs3Sb2I9 has two known structural modifications, the 0-D dimer form (space group P63/mmc, no. 194) and the 2-D layered form (P3m1, no. 164), which can be prepared via solution and solid-state or gas-phase reactions, respectively. Our computational investigations suggest that the layered form, which is a one-third Sb-deficient derivative of the ubiquitous perovskite structure, is a potential candidate for high-band gap photovoltaic (PV) applications. In this work, we describe details of a two-step deposition approach that enables the preparation of large grain (>1 μm) and continuous thin films of the lead-free layered perovskite derivative Cs3Sb2I9. Depending on the deposition conditions, films that are c-axis oriented or randomly oriented can be obtained. The fabricated thin films show enhanced stability under ambient air, compared to methylammonium lead(II) iodide per...

DeepContour: A deep convolutional feature learned by positive-sharing loss for contour detection

Abstract: Contour detection serves as the basis of a variety of computer vision tasks such as image segmentation and object recognition. The mainstream works to address this problem focus on designing engineered gradient features. In this work, we show that contour detection accuracy can be improved by instead making the use of the deep features learned from convolutional neural networks (CNNs). While rather than using the networks as a blackbox feature extractor, we customize the training strategy by partitioning contour (positive) data into subclasses and fitting each subclass by different model parameters. A new loss function, named positive-sharing loss, in which each subclass shares the loss for the whole positive class, is proposed to learn the parameters. Compared to the sofmax loss function, the proposed one, introduces an extra regularizer to emphasizes the losses for the positive and negative classes, which facilitates to explore more discriminative features. Our experimental results demonstrate that learned deep features can achieve top performance on Berkeley Segmentation Dataset and Benchmark (BSDS500) and obtain competitive cross dataset generalization result on the NYUD dataset.

A colour-tunable, weavable fibre-shaped polymer light-emitting electrochemical cell

Abstract: A fibre-shaped light emitting electrochemical cell that can be woven and integrated with textiles offers new opportunities for smart fabrics.

Multilayer CuO@NiO Hollow Spheres: Microwave-Assisted Metal–Organic-Framework Derivation and Highly Reversible Structure-Matched Stepwise Lithium Storage

Abstract: A unique CuO@NiO microsphere with three-layer ball-in-ball hollow morphology is successfully synthesized by Cu–Ni bimetallic organic frameworks. The beforehand facile microwave-assisted production of the Ni organic framework sphere is used as the template to induce the morphology control of bimetallic oxides. Designed by the controlled surface cationic exchange reactions between Cu and Ni ions, there is an elemental gradient (decreased amount of CuO but increased amount of NiO) from the shell to the core of the microsphere product. This ternary metal oxide hollow structure is found to be very suitable for solving the critical volume expansion problem, which is critical for all high-capacity metal oxide electrodes for lithium ion batteries. A reversible larger-than-theoretical capacity of 1061 mAh·g–1 can be retained after a repetitive 200 cycles without capacity fading compared to the initial cycle. These excellent electrochemical properties are ascribed to the step-by-step lithium insertion reactions ind...

Nickel-catalyzed reductive coupling of alkyl halides with other electrophiles: concept and mechanistic considerations

Abstract: The formation of C–C bonds directly by catalytic reductive cross-coupling of two different electrophiles represents one of the practical synthetic protocols that differs from the conventional nucleophile/electrophile coupling methods. Particularly the reductive coupling of alkyl electrophiles with other electrophiles is still a challenge. This report summarizes the advances in the formation of C(sp3)–C(sp3) bonds between two alkyl electrophiles, with emphasis on the control of chemoselectivity that is exceedingly challenging to achieve due to similar structures and reactivities of two unactivated alkyl halides. The coupling of alkyl halides with aryl or acyl electrophiles was also discussed based on the chemical approach developed by our group, followed by a brief overview of the reactions of tertiary alkyl halides. In the end, a brief overview of the challenges in this exciting field was illustrated. Whereas the reaction mechanisms generating alkyl–alkyl products are proposed to involve reactions of Ni(I) species with alkyl halides to generate Ralkyl–Ni(III)–Ralkyl intermediates through a radical/Ni cage-rebound process, the obtained evidence seemingly supports that the radical chain mechanism governs the acylation and arylation of alkyl halides. The latter features a cage-escaped alkyl radical.

Symmetry-based text line detection in natural scenes

Abstract: Recently, a variety of real-world applications have triggered huge demand for techniques that can extract textual information from natural scenes. Therefore, scene text detection and recognition have become active research topics in computer vision. In this work, we investigate the problem of scene text detection from an alternative perspective and propose a novel algorithm for it. Different from traditional methods, which mainly make use of the properties of single characters or strokes, the proposed algorithm exploits the symmetry property of character groups and allows for direct extraction of text lines from natural images. The experiments on the latest ICDAR benchmarks demonstrate that the proposed algorithm achieves state-of-the-art performance. Moreover, compared to conventional approaches, the proposed algorithm shows stronger adaptability to texts in challenging scenarios.

A novel approach for failure mode and effects analysis using combination weighting and fuzzy VIKOR method

Abstract: A novel FMEA approach is proposed using combination weighting and fuzzy VIKOR.Combination of fuzzy AHP and entropy method is applied for risk factor weighting.Fuzzy VIKOR method is used to determine the risk priorities of failure modes.An empirical example is offered to illustrate the effectiveness of the new method. Failure mode and effects analysis (FMEA) is one of the most popular reliability analysis tools for identifying, assessing and eliminating potential failure modes in a wide range of industries. In general, failure modes in FMEA are evaluated and ranked through the risk priority number (RPN), which is obtained by the multiplication of crisp values of the risk factors, such as the occurrence (O), severity (S), and detection (D) of each failure mode. However, the conventional RPN method has been considerably criticized for various reasons. To deal with the uncertainty and vagueness from humans' subjective perception and experience in risk evaluation process, this paper presents a novel approach for FMEA based on combination weighting and fuzzy VIKOR method. Integration of fuzzy analytic hierarchy process (AHP) and entropy method is applied for risk factor weighting in this proposed approach. The risk priorities of the identified failure modes are obtained through next steps based on fuzzy VIKOR method. To demonstrate its potential applications, the new fuzzy FMEA is used for analyzing the risk of general anesthesia process. Finally, a sensitivity analysis is carried out to verify the robustness of the risk ranking and a comparison analysis is conducted to show the advantages of the proposed FMEA approach.

Mechanistic Aspects of deNOx Processing over TiO2 Supported Co–Mn Oxide Catalysts: Structure–Activity Relationships and In Situ DRIFTs Analysis

Abstract: Anatase TiO2-supported manganese and cobalt oxide catalysts with different Co/Mn molar ratios were synthesized by a conventional impregnation method and used for selective catalytic reduction (SCR) of NOx with NH3. The catalysts were characterized by N2 adsorption/desorption, X-ray diffraction, X-ray photoelectron spectroscopy, and temperature-programmed desorption with NH3 and NOx. Characterization of the catalyst confirmed that by using Co3O4 over Mn/TiO2, we enhanced NO oxidation ability. From in situ diffuse reflectance infrared transform spectroscopy (DRIFTs) analysis of desorption and the transient reaction, we concluded that the addition of Co could remarkably lower the activation energy of NOx chemisorption on the catalyst surface. In addition, low-temperature SCR activity mainly results from a “fast SCR” reaction. We observed four NOx species (bidentate nitrates, gaseous NO2, linear nitrites, and monodentate nitrites) on the surface of Mn/TiO2 and Co–Mn/TiO2 catalysts that all participated in the...

Large-scale highly ordered Sb nanorod array anodes with high capacity and rate capability for sodium-ion batteries

Abstract: Na-ion batteries are a potential substitute to Li-ion batteries for energy storage devices. However, their poor electrochemical performance, especially capacity and rate capability, is the major bottleneck to future development. Here we propose a performance-oriented electrode structure, which is 1D nanostructure arrays with large-scale high ordering, good vertical alignment, and large interval spacing. Benefiting from these structural merits, a great enhancement in electrochemical performance could be achieved. Taking Sb as an example, we firstly report large-scale highly ordered Sb nanorod arrays with uniform large interval spacing (190 nm). In return for this electrode design, high ion accessibility, fast electron transport, and strong electrode integrity are presented here. Used as additive- and binder-free anodes for Na-ion batteries, Sb nanorod arrays showed a high capacity of 620 mA h g−1 at the 100th cycle with a retention of 84% up to 250 cycles at 0.2 A g−1, and a superior rate capability for delivering reversible capacities of 579.7 and 557.7 mA h g−1 at 10 and 20 A g−1, respectively. A full cell coupled by a P2-Na2/3Ni1/3Mn2/3O2 cathode and a Sb nanorod array anode was also constructed, which showed good cycle performance up to 250 cycles, high rate capability up to 20 A g−1, and large energy density up to 130 Wh kg−1. These excellent electrochemical performances shall pave the way for developing more applications of Sb nanorod arrays in energy storage devices.

Efficient Separation of Electron–Hole Pairs in Graphene Quantum Dots by TiO2 Heterojunctions for Dye Degradation

Abstract: Water-soluble, single-crystalline, and amine-functionalized graphene quantum dots (GQDs) with absorption edge at ∼490 nm were synthesized by a molecular fusion method, and stably deposited onto anatase TiO2 nanoparticles under hydrothermal conditions. The effective incorporation of the GQDs extends the light absorption of the TiO2 nanoparticles from UV to a wide visible region. Moreover, amine-functionalized GQD–TiO2 heterojunctions can absorb more O2 than pure TiO2, which can generate more ·O2 species for MO degradation. Accordingly, the heterojunctions exhibit much higher photocatalytic performance for degrading methyl orange (MO) under visible-light irradiation than TiO2 alone. At optimum GQD content (1.0 wt %), an apparent MO decomposition rate constant is 15 times higher than that of TiO2 alone, and photocurrent intensity in response to visible-light excitation increases by 9 times. Compared with conventional sensitization by toxic, photounstable quantum dots such as CdSe QDs, the sensitization by en...

Thermal Conductive and Mechanical Properties of Polymeric Composites Based on Solution-Exfoliated Boron Nitride and Graphene Nanosheets: A Morphology-Promoted Synergistic Effect.

Abstract: In this work, we reported a synergistic effect of boron nitride (BN) with graphene nanosheets on the enhancement of thermal conductive and mechanical properties of polymeric composites. Here, few layered BN (s-BN) and graphene (s-GH) were used and obtained by liquid exfoliation method. The polystyrene (PS) and polyamide 6 (PA) composites were obtained via solution blending method and subsequently hot-pressing. The experimental results suggested that the thermal conductivity (TC) of the PS and PA composites increases with additional introduction of s-BN. For example, compared with the composites containing 20 wt % s-GH, additional introduction of only 1.5 wt % s-BN could increase the TC up to 38 and 34% in polystyrene (PS) and polyamide 6 (PA) matrix, respectively. Meanwhile, the mechanical properties of the composites were synchronously enhanced. It was found that s-BN filled in the interspaces of s-GH sheets and formed s-BN/s-GH stacked structure, which were helpful for the synchronously improving TC and mechanical properties of the polymeric materials.

In Situ DRIFTs Investigation of the Low-Temperature Reaction Mechanism over Mn-Doped Co3O4 for the Selective Catalytic Reduction of NOx with NH3

Abstract: The Co3O4 and Mn-doped Co3O4 nanoparticle were synthesized by a co-precipitation method and used as selective catalytic reduction of NO with NH3 (NH3-SCR) catalysts. After the doping of manganese oxides, the NH3-SCR activity of Mn0.05Co0.95Ox catalyst is greatly enhanced. The NO oxidation ability of two catalysts is compared, and the X-ray diffraction results demonstrate that Mn has been successfully doped into the lattice of Co3O4. The X-ray photoelectron spectroscopy and temperature-programmed reduction with H2 results confirmed that there is a strong interaction between Mn and Co in the Mn0.05Co0.95Ox catalyst. Their adsorption and desorption properties were characterized by temperature-programmed desorption with NH3 or NO + O2 and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTs). These results indicated that the doping of manganese could provide more acid sites on the catalysts, and bidentate nitrates species originated from NOx adsorption are obviously activated on...

Chalcogenide perovskites for photovoltaics.

Abstract: Chalcogenide perovskites are proposed for photovoltaic applications. The predicted band gaps of CaTiS3, BaZrS3, CaZrSe3, and CaHfSe3 with the distorted perovskite structure are within the optimal range for making single-junction solar cells. The predicted optical absorption properties of these materials are superior compared with other high-efficiency solar-cell materials. Possible replacement of the alkaline-earth cations by molecular cations, e.g., (NH3NH3)(2+), as in the organic-inorganic halide perovskites (e.g., CH3NH3PbI3), are also proposed and found to be stable. The chalcogenide perovskites provide promising candidates for addressing the challenging issues regarding halide perovskites such as instability in the presence of moisture and containing the toxic element Pb.

An Interface‐Induced Co‐Assembly Approach Towards Ordered Mesoporous Carbon/Graphene Aerogel for High‐Performance Supercapacitors

Abstract: Hierarchically porous composites with mesoporous carbon wrapping around the macroporous graphene aerogel can combine the advantages of both components and are expected to show excellent performance in electrochemical energy devices. However, the fabrication of such composites is challenging due to the lack of an effective strategy to control the porosity of the mesostructured carbon layers. Here an interface-induced co-assembly approach towards hierarchically mesoporous carbon/graphene aerogel composites, possessing interconnected macroporous graphene networks covered by highly ordered mesoporous carbon with a diameter of ≈9.6 nm, is reported. And the orientation of the mesopores (vertical or horizontal to the surface of the composites) can be tuned by the ratio of the components. As the electrodes in supercapacitors, the resulting composites demonstrate outstanding electrochemical performances. More importantly, the synthesis strategy provides an ideal platform for hierarchically porous graphene composites with potential for energy storage and conversion applications.

Parametrization of Stillinger-Weber Potential Based on Valence Force Field Model: Application to Single-Layer MoS2 and Black Phosphorus

Abstract: We propose parametrizing the Stillinger-Weber potential for covalent materials starting from the valence force-field model. All geometrical parameters in the Stillinger-Weber potential are determined analytically according to the equilibrium condition for each individual potential term, while the energy parameters are derived from the valence force-field model. This parametrization approach transfers the accuracy of the valence force field model to the Stillinger-Weber potential. Furthermore, the resulting Stilliinger-Weber potential supports stable molecular dynamics simulations, as each potential term is at an energy-minimum state separately at the equilibrium configuration. We employ this procedure to parametrize Stillinger-Weber potentials for single-layer MoS2 and black phosphorous. The obtained Stillinger-Weber potentials predict an accurate phonon spectrum and mechanical behaviors. We also provide input scripts of these Stillinger-Weber potentials used by publicly available simulation packages including GULP and LAMMPS.

Spacetime symmetries of the quantum Hall effect

Abstract: We study the symmetries of nonrelativistic systems with an emphasis on applications to the fractional quantum Hall effect. A source for the energy current of a Galilean system is introduced and the nonrelativistic diffeomorphism invariance studied in previous work is enhanced to a full spacetime symmetry, allowing us to derive a number of Ward identities. These symmetries are smooth in the massless limit of the lowest Landau level. We develop a formalism for Newton-Cartan geometry with torsion to write these Ward identities in a covariant form. Previous results on the connection between Hall viscosity and Hall conductivity are reproduced.

Nickel-Catalyzed Reductive Coupling of Aryl Bromides with Tertiary Alkyl Halides

Abstract: A mild Ni-catalyzed reductive arylation of tertiary alkyl halides with aryl bromides has been developed that delivers products bearing all-carbon quaternary centers in moderate to excellent yields with excellent functional group tolerance. Electron-deficient arenes are generally more effective in inhibiting alkyl isomerization. The reactions proceed successfully with pyridine or 4-(dimethylamino)pyridine, while imidazolium salts slightly enhance the coupling efficiency.

Parametrization of Stillinger-Weber Potential Based on Valence Force Field Model: Application to Single-Layer MoS2 and Black Phosphorus

Abstract: We propose to parametrize the Stillinger-Weber potential for covalent materials starting from the valence force field model. All geometrical parameters in the Stillinger-Weber potential are determined analytically according to the equilibrium condition for each individual potential term, while the energy parameters are derived from the valence force field model. This parametrization approach transfers the accuracy of the valence force field model to the Stillinger-Weber potential. Furthermore, the resulting Stilliinger-Weber potential supports for stable molecular dynamics simulations, as each potential term is at energy minimum state separately at the equilibrium configuration. We employ this procedure to parametrize Stillinger-Weber potentials for the single-layer MoS2 and black phosphorous. The obtained Stillinger-Weber potentials predict accurate phonon spectrum and mechanical behaviors. We also provide input scripts of these Stillinger-Weber potentials used by publicly available simulation packages including GULP and LAMMPS.

Squaraine dyes for organic photovoltaic cells

Abstract: Recently, squaraine (SQ) dyes used as donor materials in organic photovoltaic (OPV) cells have received increasing attention because of their simple synthetic routes, high absorption coefficients with tunable bandgaps and bandwidths in the visible-near infrared region, as well as high photochemical and thermal stabilities. Using fullerenes or their derivatives as electron accepting materials, SQ:fullerene-based OPV devices have shown power conversion efficiencies as high as over 8%, which indicates the potential of SQ dyes for future solar cell applications. In this review, we briefly introduce the history of this group of materials, and present recent advances in SQ dye materials and their applications to OPV cells, including the major methodologies employed to exploit the full potential of these molecules as light harvesting materials in OPV devices. From the perspective of the current status of this field, we provide an overview of the primary issues affecting future development of OPV, as well as possible solutions.

Facile Hydrothermal Synthesis of VS2/Graphene Nanocomposites with Superior High-Rate Capability as Lithium-Ion Battery Cathodes.

Abstract: In this study, a facile one-pot process for the synthesis of hierarchical VS2/graphene nanosheets (VS2/GNS) composites based on the coincident interaction of VS2 and reduced graphene oxide (rGO) sheets in the presence of cetyltrimethylammonium bromide is developed for the first time. The nanocomposites possess a hierarchical structure of 50 nm VS2 sheets in thickness homogeneously anchored on graphene. The VS2/GNS nanocomposites exhibit an impressive high-rate capability and good cyclic stability as a cathode material for Li-ion batteries, which retain 89.3% of the initial capacity 180.1 mAh g–1 after 200 cycles at 0.2 C. Even at 20 C, the composites still deliver a high capacity of 114.2 mAh g–1 corresponding to 62% of the low-rate capacity. Expanded studies show that VS2/GNS, as an anode material, also has a good reversible performance with 528 mAh g–1 capacity after 100 cycles at 200 mA g–1. The excellent electrochemical performance of the composites for reversible Li+ storage should be attributed to t...

Internal Resonance Energy Harvesting

Abstract: Internal resonance is explored as a possible mechanism to enhance vibration-based energy harvesting. An electromagnetic device with snap-through nonlinearity is proposed as an archetype of an internal resonance energy harvester. Based on the equations governing the vibration measured from a stable equilibrium position, the method of multiple scales is applied to derive the amplitude–frequency response relationships of the displacement and the power in the first primary resonances with the two-to-one internal resonance. The amplitude–frequency response curves have two peaks bending to the left and the right, respectively. The numerical simulations support the analytical results. Then the averaged power is calculated under the Gaussian white noise, the narrow-band noise, the colored noise defined by a second-order filter, and the exponentially correlated noise. The results demonstrate numerically that the internal resonance design produces more power than other designs under the Gaussian white noise and the exponentially correlated noise. Besides, the internal resonance energy harvester can outperform the linear energy harvesters with the same natural frequencies and in the same size under Gaussian white noise.

A novel autophagy/mitophagy inhibitor liensinine sensitizes breast cancer cells to chemotherapy through DNM1L-mediated mitochondrial fission

Abstract: Autophagy inhibition has been widely accepted as a promising therapeutic strategy in cancer, while the lack of effective and specific autophagy inhibitors hinders its application. Here we found that liensinine, a major isoquinoline alkaloid, inhibits late-stage autophagy/mitophagy through blocking autophagosome-lysosome fusion. This effect is likely achieved via inhibiting the recruitment of RAB7A to lysosomes but not to autophagosomes. We further investigated the effects of autophagy inhibition by liensinine on the therapeutic efficacy of chemotherapeutic drugs and found that cotreatment of liensinine markedly decreased the viability and increased apoptosis in breast cancer cells treated with various chemotherapeutic agents. Mechanistically, we found that inhibition of autophagy/mitophagy by liensinine enhanced doxorubicin-mediated apoptosis by triggering mitochondrial fission, which resulted from dephosphorylation and mitochondrial translocation of DNM1L. However, blocking autophagosome/mitophagosome formation by pharmacological or genetic approaches markedly attenuated mitochondrial fission and apoptosis in cells with combinatatorial treatment. Moreover, liensinine was synergized with doxorubicin to inhibit tumor growth in MDA-MB-231 xenograft in vivo. Our findings suggest that liensinine could potentially be further developed as a novel autophagy/mitophagy inhibitor, and a combination of liensinine with classical chemotherapeutic drugs could represent a novel therapeutic strategy for treatment of breast cancer.

Wearable double-twisted fibrous perovskite solar cell.

Abstract: Wearable double-twisted fibrous perovskite solar cells are developed based on flexible carbon nanotube fiber electrodes, which exhibit a maximum power conversion efficiency of 3.03% and bending stability larger than 1000 cycles, and maintain 89% efficiency after 96 h in ambient conditions if sealed by a transparent polymer layer. The obtained superior performance can shed light on future self-powering e-textiles.

Biphen[n]arenes

Abstract: To design and exploit novel macrocyclic synthetic receptors is a permanent and challenging topic in supramolecular chemistry. Here we describe the one-pot synthesis, unique geometries and intriguing host–guest properties of a new class of supramolecular macrocycles – biphen[n]arenes (n = 3, 4), which are made up of 4,4′-biphenol or 4,4′-biphenol ether units linked by methylene bridges at the 3- and 3′- positions. The biphenarene macrocycles are conveniently accessible/modifiable and extremely guest-friendly. Particularly, biphen[4]arene is capable of forming inclusion complexes with not only organic cationic guests but also neutral π-electron deficient molecules. Compared with calixarenes, resorcinarenes, cyclotriveratrylenes and pillararenes with substituted mono-benzene units, the biphen[n]arenes reported here possess significantly different characteristics in both their topologic structures and their recognition properties, and thus can find broad applications in supramolecular chemistry and other areas.

Group multi-criteria supplier selection using an extended VIKOR method with interval 2-tuple linguistic information

Abstract: Propose an extended VIKOR method for group multi-criteria supplier selectionDiversity and uncertainty of decision makers' assessments are modeled using interval 2-tuplesMultiple and conflicting criteria are considered and evaluated by extended VIKOR methodThe new method is more suitable to handle the supplier selection problem under uncertain environment How to select the suitable suppliers in the supply chain is critical for an organization's success and has attracted much attention of both researchers and practitioners Supplier selection can be regarded as a complex group multiple criteria decision making problem requiring consideration of a number of alternative suppliers and quantitative and qualitative criteria Additionally, decision makers cannot easily express their judgments on the alternatives with exact numerical values in many practical situations, and there usually exists uncertain and incomplete assessments In response, this paper proposes an extended VIKOR method for group multi-criteria supplier selection with interval 2-tuple linguistic information The feasibility and practicability of the proposed interval 2-tuple linguistic VIKOR (ITL-VIKOR) method are demonstrated through three realistic supplier selection examples and comparisons with the existing approaches Results show that the ITL-VIKOR method being proposed is more suitable and effective to handle the supplier selection problem under vague, uncertain and incomplete information environment

Jasmonic acid promotes degreening via MYC2/3/4- and ANAC019/055/072-mediated regulation of major chlorophyll catabolic genes.

Abstract: Degreening caused by rapid chlorophyll (Chl) degradation is a characteristic event during green organ senescence or maturation. Pheophorbide a oxygenase gene (PAO) encodes a key enzyme of Chl degradation, yet its transcriptional regulation remains largely unknown. Using yeast one-hybrid screening, coupled with in vitro and in vivo assays, we revealed that Arabidopsis MYC2/3/4 basic helix-loop-helix proteins directly bind to PAO promoter. Overexpression of the MYCs significantly enhanced the transcriptional activity of PAO promoter in Arabidopsis protoplasts, and methyl jasmonate (MeJA) treatment greatly induced PAO expression in wild-type Arabidopsis plants, but the induction was abolished in myc2 myc3 myc4. In addition, MYC2/3/4 proteins could promote the expression of another Chl catabolic enzyme gene, NYC1, as well as a key regulatory gene of Chl degradation, NYE1/SGR1, by directly binding to their promoters. More importantly, the myc2 myc3 myc4 triple mutant showed a severe stay-green phenotype, whereas the lines overexpressing the MYCs showed accelerated leaf yellowing upon MeJA treatment. These results suggest that MYC2/3/4 proteins may mediate jasmonic acid (JA)-induced Chl degradation by directly activating these Chl catabolic genes (CCGs). Three NAC family proteins, ANAC019/055/072, downstream from MYC2/3/4 proteins, could also directly promote the expression of a similar set of CCGs (NYE1/SGR1, NYE2/SGR2 and NYC1) during Chl degradation. In particular, anac019 anac055 anac072 triple mutant displayed a severe stay-green phenotype after MeJA treatment. Finally, we revealed that MYC2 and ANAC019 may interact with each other and synergistically enhance NYE1 expression. Together, our study reveals a hierarchical and coordinated regulatory network of JA-induced Chl degradation.