At the Earth＇s magnetopause, the electron transport due to kinetic Alfvén waves（KAWs） is investigated in an ion-scale flux rope by the Magnetospheric Multiscale mission. Clear electron dropout around 90° ...At the Earth＇s magnetopause, the electron transport due to kinetic Alfvén waves（KAWs） is investigated in an ion-scale flux rope by the Magnetospheric Multiscale mission. Clear electron dropout around 90° pitch angle is observed throughout the flux rope, where intense KAWs are identified. The KAWs can effectively trap electrons by the wave parallel electric field and the magnetic mirror force, allowing electrons to undergo Landau resonance and be transported into more field-aligned directions. The pitch angle range for the trapped electrons is estimated from the wave analysis, which is in good agreement with direct pitch angle measurements of the electron distributions. The newly formed beam-like electron distribution is unstable and excites whistler waves,as revealed in the observations. We suggest that KAWs could be responsible for the plasma depletion inside a flux rope by this transport process, and thus be responsible for the formation of a typical flux rope.展开更多
锂离子电池健康状态(state of health,SOH)估计对确保能量存储系统的可靠性和安全性至关重要。然而,现有SOH估计方法在单一特征提取和固定充放电条件依赖方面存在局限性,难以适应多变的实际工作环境。为解决这一问题,本工作提出了一种...锂离子电池健康状态(state of health,SOH)估计对确保能量存储系统的可靠性和安全性至关重要。然而,现有SOH估计方法在单一特征提取和固定充放电条件依赖方面存在局限性,难以适应多变的实际工作环境。为解决这一问题,本工作提出了一种基于弛豫电压的并行多尺度特征融合卷积模型(multi-scale feature fusion convolution model,MSFFCM)结合极端梯度提升树(XGBoost)的SOH估计方法。MSFFCM通过多层堆叠卷积模块提取弛豫电压数据的深层特征,同时利用并行多尺度注意力机制增强了多尺度特征的捕捉能力,并将这些特征与统计特征进行融合,以提升模型的特征提取和融合能力。针对XGBoost模型,本工作应用贝叶斯优化算法进行参数调优,从而在多源融合特征基础上实现高精度SOH估计。实验验证基于两种商用18650型号电池的多温度和多充放电策略数据集,结果表明该方法的均方根误差(RMSE)和平均绝对误差(MAE)均小于0.5%,明显优于传统方法。本工作为锂电池健康管理提供了一种不依赖特定充放电条件的有效估计工具,有望在复杂的实际应用中发挥重要作用。展开更多
光合细菌是一类具有原始光能合成机制的原核生物,在多种环境中广泛分布,其在废水处理、饲料添加剂等领域的应用备受关注。然而,传统研究光合细菌的方法存在如过程复杂耗时费力、稳定性维持困难、可塑性差等诸多局限性。单细胞技术的发...光合细菌是一类具有原始光能合成机制的原核生物,在多种环境中广泛分布,其在废水处理、饲料添加剂等领域的应用备受关注。然而,传统研究光合细菌的方法存在如过程复杂耗时费力、稳定性维持困难、可塑性差等诸多局限性。单细胞技术的发展为其研究带来了新机遇。本文综述了单细胞水平下挖掘环境光合细菌资源的研究进展,包括纳米二次离子质谱技术(nano-scale secondary ion mass spectrometry,NanoSIMS)、单细胞拉曼光谱法及其与稳定同位素标记结合等技术在光合细菌资源挖掘和机理解析方面的应用。这些技术有助于深入理解光合细菌的光合机制、代谢途径及环境适应机制,为其在污水处理、生物能源生产等领域的应用提供了理论依据和技术支持,对推动环境保护和可持续发展具有重要意义。展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 41474145,41574159,41731070 and 41504114the Frontier Science Foundation of the Chinese Academy of Sciences under Grant No QYZDJ-SSW-JSC028+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No XDA15052500the Specialized Research Fund for State Key Laboratories of China
文摘At the Earth＇s magnetopause, the electron transport due to kinetic Alfvén waves（KAWs） is investigated in an ion-scale flux rope by the Magnetospheric Multiscale mission. Clear electron dropout around 90° pitch angle is observed throughout the flux rope, where intense KAWs are identified. The KAWs can effectively trap electrons by the wave parallel electric field and the magnetic mirror force, allowing electrons to undergo Landau resonance and be transported into more field-aligned directions. The pitch angle range for the trapped electrons is estimated from the wave analysis, which is in good agreement with direct pitch angle measurements of the electron distributions. The newly formed beam-like electron distribution is unstable and excites whistler waves,as revealed in the observations. We suggest that KAWs could be responsible for the plasma depletion inside a flux rope by this transport process, and thus be responsible for the formation of a typical flux rope.
文摘光合细菌是一类具有原始光能合成机制的原核生物,在多种环境中广泛分布,其在废水处理、饲料添加剂等领域的应用备受关注。然而,传统研究光合细菌的方法存在如过程复杂耗时费力、稳定性维持困难、可塑性差等诸多局限性。单细胞技术的发展为其研究带来了新机遇。本文综述了单细胞水平下挖掘环境光合细菌资源的研究进展,包括纳米二次离子质谱技术(nano-scale secondary ion mass spectrometry,NanoSIMS)、单细胞拉曼光谱法及其与稳定同位素标记结合等技术在光合细菌资源挖掘和机理解析方面的应用。这些技术有助于深入理解光合细菌的光合机制、代谢途径及环境适应机制,为其在污水处理、生物能源生产等领域的应用提供了理论依据和技术支持,对推动环境保护和可持续发展具有重要意义。
