Residual fluoride self-activated effect enabling upgraded utilization of recycled graphite anode

Recycling graphite anode from spent lithium-ion batteries(SLIBs)is regarded as a crucial approach to promoting sustainable energy storage industry.However,the recycled graphite(RG)generally presents degraded structure and performance.Herein,the residual fluoride self-activated effect is proposed for the upgraded utilization of RG.Simple and low-energy water immersion treatment not only widens the interlayer spacing,but also retains appropriate fluoride on the surface of RG.Theoretical analysis and experiments demonstrate that the residual fluoride can optimize Li~+migration and deposition kinetics,resulting in better Li~+intercalation/deintercalation in the interlayer and more stable Li metal plating/stripping on the surface of RG,As a result,the designed LFP||RG full cells achieve ultrahigh reversibility(~100%Coulombic efficiency),high capacity retention(67%after 200 cycles,0.85 N/P ratio),and commendable adaptability(stable cycling without short-circuiting,0.15 N/P ratio).The energy density is improved from 334 Wh kg^(-1)of 1.1 N/P ratio to 367 Wh kg^(-1)of 0.85 N/P ratio(total mass based on cathode and anode).The exploration of RG by residual fluoride self-activated effect achieves upgraded utilization beyond fresh commercial graphite and highlights a new strategy for efficient reuse of SLIBs.

Sea surface temperature data from coastal observation stations:quality control and semidiurnal characteristics

Sea surface temperature(SST)data obtained from coastal stations in Jiangsu,China during 20102014 are quality controlled before analysis of their characteristic semidiurnal and seasonal cycles,including the correlation with the variation of the tide.Quality control of data includes the validation of extreme values and checking of hourly values based on temporally adjacent data points,with 0.15℃/h considered a suitable threshold for detecting abnormal values.The diurnal variation amplitude of the SST data is greater in spring and summer than in autumn and winter.The diurnal variation of SST has bimodal structure on most days,i.e.,SST has a significant semidiurnal cycle.Moreover,the semidiurnal cycle of SST is negatively correlated with the tidal data from March to August,but positively correlated with the tidal data from October to January.Little correlation is detected in the remaining months because of the weak coastal offshore SST gradients.The quality control and understanding of coastal SST data are particularly relevant with regard to the validation of indirect measurements such as satellite-derived data.

Influence of shape effect on dynamic surface charge transport mechanism of cellular electret after corona discharge

Surface charge accumulation and transport on cellular polypropylene play an important role in nanogenerators,which could have a potential impact on energy harvesting and wearable devices for zero carbon energy systems and the internet of things.Different shapes have different charge accumulation and decay characteristics of the polymer.Therefore,we studied the influence of the sample’s shape on the surface charge decay by experiment and modeling.The surface potential of square and circular cellular polypropylene was measured by a two-dimensional surface potential measurement system with electrostatic capacitive probe.The experimental result shows that the surface potential distribution of the square sample dissipates non-uniformly from the bell shape to a one-sided collapsed shape,while that of the circular sample dissipates uniformly from the bell shape to the crater-like shape.Moreover,the simulated results of the initial surface potential distributions of the square and circular cellular polypropylene are consistent with the experimental results.The investigation demonstrates that the charge transport process is correlated with the shape of the sample,which provides significant reference for designing electret material used for highly efficient nanogenerators.

The current pulses characteristics of the negative corona discharge in SF_(6)/CF_(4)mixtures

This paper presents the results of numerical investigation of the current pulses characteristics in SF_(6)/CF_(4)mixtures for the negative point-plane corona discharge.The pressure and the temperature of gas mixtures are 0.4 MPa and 300 K,respectively.The CF_(4)content varies from20%to 80%.The 2D axisymmetric geometry with point-plane electrodes is investigated,and the three drift-diffusion equations are solved to predict the characteristics of the negative corona discharge.In addition,Poisson’s equation is coupled with the above three continuity equations to calculate the electric field.In order to calculate the electron impact coefficients,including the Townsend ionization and attachment coefficients,as well as the mobilities and diffusion coefficients for electrons,the two-term Boltzmann equation is solved.The characteristics of three ionic species at five stages of the first current pulse in 60%SF_(6)-40%CF_(4)and20%SF_(6)-80%CF_(4)mixtures are selected to discuss the development mechanism of current pulses.Moreover,the reduced electric field strengths at the corresponding time instants are presented to help understand the discharge process.The current waveform and the total number of three species are compared in all the cases to analyze the effects of the CF_(4)content on the discharge.The reduced electric field strength is also helpful in understanding the effects of CF_(4)content.When the CF_(4)content increases to 80%,the discharge is more intensive and the pulse frequency also increases.

lpxL和lpxM基因对O1、O78血清型禽致病性大肠杆菌毒力的影响

【目的】为探究脂多糖对O1、O78血清型禽致病性大肠杆菌(Avian pathogenic Escherichia coli,APEC)致病作用的影响。【方法】选取负责脂质A生物合成相关基因lpx L和lpx M,利用λ噬菌体的Red同源重组系统分别构建APECE516(O1血清型)和APECE522(O78血清型)缺失株E516Δlpx L、E516Δlpx M、E516Δlpx LΔlpx M、E522Δlpx L、E522Δlpx M和E522Δlpx LΔlpx M,并通过体内外试验对其生物学特性及致病性进行研究。【结果】各菌株生长速度基本一致。E516Δlpx L、E516Δlpx LΔlpx M、E522Δlpx M和E522Δlpx LΔlpx M的抗血清补体杀菌能力和抗鸡巨噬细胞HD-11吞噬能力较野生株显著下降,而缺失株E516Δlpx M、E522Δlpx L与野生株相比无明显差异;半数致死剂量测定结果显示,除E516Δlpx M、E522Δlpx L外,各缺失株毒力降低1000倍左右;SPF鸡体内动态分布试验结果显示,各缺失株在鸡体内定殖能力较野生株显著下降,但回补株的毒力未能恢复至野生株水平。【结论】lpx L和lpx M基因与O1血清型APECE516株和O78血清型APECE522株的毒力有关,但是lpx L和lpx M基因对E516和E522菌株毒力的影响存在差异。

Multilayered regulation of secondary metabolism in medicinal plants

Medicinal plants represent a huge reservoir of secondary metabolites(SMs),substances with significant pharmaceutical and industrial potential.However,obtaining secondary metabolites remains a challenge due to their low-yield accumulation in medicinal plants;moreover,these secondary metabolites are produced through tightly coordinated pathways involving many spatiotemporally and environmentally regulated steps.The first regulatory layer involves a complex network of transcription factors;a second,more recently discovered layer of complexity in the regulation of SMs is epigenetic modification,such as DNA methylation,histone modification and small RNA-based mechanisms,which can jointly or separately influence secondary metabolites by regulating gene expression.Here,we summarize the findings in the fields of genetic and epigenetic regulation with a special emphasis on SMs in medicinal plants,providing a new perspective on the multiple layers of regulation of gene expression.