Lignin-reinforced PVDF electrolyte for dendrite-free quasi-solid-state Li metal battery

Quasi-solid-state lithium metal batteries(QSSLMBs)assembled with polyvinylidene fluoride(PVDF)are a promising class of next-generation rechargeable batteries due to their safety,high energy density,and superior interfacial properties.However,PVDF has a series of inherent drawbacks such as low ionic conductivity,ease of crystallization,and hydrophobic character that leading to poor cell properties.To tackle these issues,a lignin-reinforced PVDF electrolyte is proposed in this work to solve these drawbacks of PVDF and enhance the comprehensive performance of QSSBs.The lithophilic polar groups of lignin can promote uniform deposition of Li on the electrodes.Cooperating with the improved mechanical properties can efficiently prevent Li dendrites penetration through the separator.In addition,more active sites provided by lignin can also enhance Li^(+)transport and lead to a faster electrochemical reaction kinetic.Benefitting from the ingenious design,Li symmetric cells with 5%lignin-PVDF quasi-solid-state electrolyte can operate for 900 h at a high current density/capacity of 5 mA·cm^(-2)/5 mAh·cm^(-2),while shortcircuiting occurs after 56 h for the counterpart(pure PVDF).Moreover,a full cell of Li/5%lignin-PVDF/LFP cell demonstrates a high capacity of 96.2 mAh·g^(-1)after 2000 cycles at 10 C.This work is expected to open up promising opportunities to develop other high-energy/power-density QSSLMBs.

Prediction of Listed Company Innovation Ability Based on Attention Mechanism

Innovation is the center of the enterprise development, which is the main driving force of enterprises’ competitiveness. To evaluate the enterprises’ innovation ability, we firstly establish an index system which aims at analyzing the enterprise innovation ability. We also retrieve the data of the listed companies in Wind database from 2015 to 2019 and label them using factor analysis method. Then, a new deep learning classificational framework with attention mechanism and LSTM is established. The results show that when attention mechanism and LSTM are added into the convolutional neural network(CNN), the model’s prediction performance is better improved, and the accuracy, recall, precision and F-score are 0.914, 0.914, 0.916 and 0.915, respectively. This indicates the strong generalization ability of our new model. Finally, we also find that patents and R &D expenditures are the most important factor affecting the corporate innovation ability through SHapley Additive exPlanations(SHAP). Companies with more patents and R &D expenditures are generally considered to be more innovative.

Photodamage to Pigment in the Photosystem Ⅱ Reaction Center D1/D2/Cytochrome b559 Complex

Strong light （800μmol photons/m^2 per s）-induced bleaching of the pigment in the isolated photosystem Ⅱ reaction center （PSII RC） under aerobic conditions （in the absence of electron donors or acceptors） was studied using high-pressure liquid chromatography （HPLC）, absorption spectra, 77K fluorescence spectra and resonance Raman spectra. Changes in pigment composition of the PSII RC as determined by HPLC after light treatment were as follows： with Increasing illumination time chlorophyll （Chl） a and β-carotene （β-car） content decreased. However, decreases in pheophytin （Pheo） could not be observed because of the mixture of the Pheo formed by degraded chlorophyll possibly. On the basis of absorption spectra, it was determined that, with a short time of illuminatlon, the initial bleaching occurred maximally at 680 nm but that with Increasing Illumination time there was a blue shift to 678 nm. It was suggested that P680 was destroyed Initially, followed by the accessory chlorophyll. The activity of P680 was almost lost after 10 mln light treatment. Moreover, the bleaching of Pheo and β-car was observed at the beginning of illumination. After Illumination, the fluorescence emission Intensity changed and the fluorescence maximum blue shifted, showing that energy transfer was disturbed. Resonance Raman spectra of the PSII RC excited at 488.0 and 514.5 nm showed four main bands, peaking at 1 527 cm^-1 （υ101）, 1 159 cm^-1 （υ2）, 1 006 cm^-1 （υ3）, 966 cm^-1 （υ4） for 488.0 nm excitation and 1 525 cm^-1 （υ1）, 1 159 cm^-1 （υ2）, 1 007 cm^-1 （υ3）, 968 cm^-1 （υ4） for 514.5 nm excitation. It was confirmed that two spectroscopically different β-car molecules exist In the PSII RC. After light treatment for 20 mln, band positions and bandwidths were unchanged. This indicates that carotenoid configuration Is not the parameter that regulates photoprotectlon in the PSII RC.

Synchronization in PT-symmetric optomechanical resonators

Synchronization has great impacts in various fields such as self-clocking,communication,and neural networks.Here,we present a mechanism of synchronization for two mechanical modes in two coupled optomechanical resonators with a parity-time(PT)-symmetric structure.It is shown that the degree of synchronization between the two far-off-resonant mechanical modes can be increased by decreasing the coupling strength between the two optomechanical resonators due to the large amplification of optomechanical interaction near the exceptional point.Additionally,when we consider the stochastic noises in the optomechanical resonators by working near the exceptional point,we find that more noises can enhance the degree of synchronization of the system under a particular parameter regime.Our results open up a new dimension of research for PT-symmetric systems and synchronization.