This paper aims to investigate the retarded Liénard-type equation+f 1(x)+f 2(x)(t-τ)+f 3(x)2+φ(x)+g(x(t-τ))=0,where τ is a nonnegative constant, f 1,f 2,f 3,φ and g are continuous functions on R. Using Liapu...This paper aims to investigate the retarded Liénard-type equation+f 1(x)+f 2(x)(t-τ)+f 3(x)2+φ(x)+g(x(t-τ))=0,where τ is a nonnegative constant, f 1,f 2,f 3,φ and g are continuous functions on R. Using Liapunov functional method, we establish a sufficient condition on the stability and boundedness of the solutions of above equation. This will generalize the main results of reference [2].展开更多
识别学科交叉研究的前沿主题,并对演化趋势进行分析,有助于揭示学科交叉融合的方向,为未来创新性、突破性研究提供参考。首先,基于引文视角构建测度论文学科交叉性的指标,识别具有学科交叉性的研究论文;其次,通过BERT-LDA模型识别研究主...识别学科交叉研究的前沿主题,并对演化趋势进行分析,有助于揭示学科交叉融合的方向,为未来创新性、突破性研究提供参考。首先,基于引文视角构建测度论文学科交叉性的指标,识别具有学科交叉性的研究论文;其次,通过BERT-LDA模型识别研究主题,利用余弦相似度计算主题之间的相似度,构建主题演化路径;最后,基于新颖度、增长性、关注度、影响力构建前沿主题识别指标体系,识别具有前沿性的学科交叉研究主题。以图书情报学(Library and Information Science,LIS)为例展开研究,研究结果显示,2004—2023年该学科领域的交叉研究主题呈现出逐渐细化和深入的特点,主要集中在信息挖掘与知识发现、互联网信息行为、医疗信息学3个方面;现阶段学科交叉研究前沿主题为医疗数据模型、舆情治理与情感分析、机器学习与深度学习;基于信息技术的研究方法和其在不同领域的应用研究具有良好的应用前景,有可能成为未来LIS领域的核心研究主题。展开更多
The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth.Resolving this issue will be key to achieving high-performance lithium metal batteries(LMBs).Herein...The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth.Resolving this issue will be key to achieving high-performance lithium metal batteries(LMBs).Herein,we construct a lithium nitrate(LiNO_(3))-implanted electroactiveβphase polyvinylidene fluoride-co-hexafluoropropylene(PVDF-HFP)crystalline polymorph layer(PHL).The electronegatively charged polymer chains attain lithium ions on the surface to form lithium-ion charged channels.These channels act as reservoirs to sustainably release Li ions to recompense the ionic flux of electrolytes,decreasing the growth of lithium dendrites.The stretched molecular channels can also accelerate the transport of Li ions.The combined effects enable a high Coulombic efficiency of 97.0%for 250 cycles in lithium(Li)||copper(Cu)cell and a stable symmetric plating/stripping behavior over 2000 h at 3 mA cm^(-2)with ultrahigh Li utilization of 50%.Furthermore,the full cell coupled with PHL-Cu@Li anode and Li Fe PO_(4) cathode exhibits long-term cycle stability with high-capacity retention of 95.9%after 900 cycles.Impressively,the full cell paired with LiNi_(0.87)Co_(0.1)Mn_(0.03)O_(2)maintains a discharge capacity of 170.0 mAh g^(-1)with a capacity retention of 84.3%after 100 cycles even under harsh condition of ultralow N/P ratio of 0.83.This facile strategy will widen the potential application of LiNO_(3)in ester-based electrolyte for practical high-voltage LMBs.展开更多
It is well accepted that a lithiophilic interface can effectively regulate Li deposition behaviors,but the influence of the lithiophilic interface is gradually diminished upon continuous Li deposition that completely ...It is well accepted that a lithiophilic interface can effectively regulate Li deposition behaviors,but the influence of the lithiophilic interface is gradually diminished upon continuous Li deposition that completely isolates Li from the lithiophilic metals.Herein,we perform in-depth studies on the creation of dynamic alloy interfaces upon Li deposition,arising from the exceptionally high diffusion coefficient of Hg in the amalgam solid solution.As a comparison,other metals such as Au,Ag,and Zn have typical diffusion coefficients of 10-20 orders of magnitude lower than that of Hg in the similar solid solution phases.This difference induces compact Li deposition pattern with an amalgam substrate even with a high areal capacity of 55 mAh cm^(-2).This finding provides new insight into the rational design of Li anode substrate for the stable cycling of Li metal batteries.展开更多
文摘This paper aims to investigate the retarded Liénard-type equation+f 1(x)+f 2(x)(t-τ)+f 3(x)2+φ(x)+g(x(t-τ))=0,where τ is a nonnegative constant, f 1,f 2,f 3,φ and g are continuous functions on R. Using Liapunov functional method, we establish a sufficient condition on the stability and boundedness of the solutions of above equation. This will generalize the main results of reference [2].
文摘识别学科交叉研究的前沿主题,并对演化趋势进行分析,有助于揭示学科交叉融合的方向,为未来创新性、突破性研究提供参考。首先,基于引文视角构建测度论文学科交叉性的指标,识别具有学科交叉性的研究论文;其次,通过BERT-LDA模型识别研究主题,利用余弦相似度计算主题之间的相似度,构建主题演化路径;最后,基于新颖度、增长性、关注度、影响力构建前沿主题识别指标体系,识别具有前沿性的学科交叉研究主题。以图书情报学(Library and Information Science,LIS)为例展开研究,研究结果显示,2004—2023年该学科领域的交叉研究主题呈现出逐渐细化和深入的特点,主要集中在信息挖掘与知识发现、互联网信息行为、医疗信息学3个方面;现阶段学科交叉研究前沿主题为医疗数据模型、舆情治理与情感分析、机器学习与深度学习;基于信息技术的研究方法和其在不同领域的应用研究具有良好的应用前景,有可能成为未来LIS领域的核心研究主题。
基金support from the National Science Foundation of China (No.51971249)the Natural Science Foundation of Shandong Province,China (No.ZR2020KE012)the Science and Technology Planning Project of Longkou City,China (No.2021KJJH025).
基金the financial support from the National Natural Science Foundation of China(Nos.22205191 and 52002346)the Science and Technology Innovation Program of Hunan Province(No.2021RC3109)+1 种基金the Natural Science Foundation of Hunan Province,China(No.2022JJ40446)Guangxi Key Laboratory of Low Carbon Energy Material(No.2020GXKLLCEM01)。
文摘The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth.Resolving this issue will be key to achieving high-performance lithium metal batteries(LMBs).Herein,we construct a lithium nitrate(LiNO_(3))-implanted electroactiveβphase polyvinylidene fluoride-co-hexafluoropropylene(PVDF-HFP)crystalline polymorph layer(PHL).The electronegatively charged polymer chains attain lithium ions on the surface to form lithium-ion charged channels.These channels act as reservoirs to sustainably release Li ions to recompense the ionic flux of electrolytes,decreasing the growth of lithium dendrites.The stretched molecular channels can also accelerate the transport of Li ions.The combined effects enable a high Coulombic efficiency of 97.0%for 250 cycles in lithium(Li)||copper(Cu)cell and a stable symmetric plating/stripping behavior over 2000 h at 3 mA cm^(-2)with ultrahigh Li utilization of 50%.Furthermore,the full cell coupled with PHL-Cu@Li anode and Li Fe PO_(4) cathode exhibits long-term cycle stability with high-capacity retention of 95.9%after 900 cycles.Impressively,the full cell paired with LiNi_(0.87)Co_(0.1)Mn_(0.03)O_(2)maintains a discharge capacity of 170.0 mAh g^(-1)with a capacity retention of 84.3%after 100 cycles even under harsh condition of ultralow N/P ratio of 0.83.This facile strategy will widen the potential application of LiNO_(3)in ester-based electrolyte for practical high-voltage LMBs.
基金supported by the National Key Research and Development Program of China(2019YFA0205700)Scientific Research Projects of Colleges and Universities in Hebei Province(JZX2023004)+2 种基金Research Program of Local Science and Technology Development under the Guidance of Central(216Z4402G)support from Ministry of Science and Higher Education of Russian Federation(project FFSG-2022-0001(122111700046-3),"Laboratory of perspective electrode materials for chemical power sources")support from"Yuanguang"Scholar Program of Hebei University of Technology
文摘It is well accepted that a lithiophilic interface can effectively regulate Li deposition behaviors,but the influence of the lithiophilic interface is gradually diminished upon continuous Li deposition that completely isolates Li from the lithiophilic metals.Herein,we perform in-depth studies on the creation of dynamic alloy interfaces upon Li deposition,arising from the exceptionally high diffusion coefficient of Hg in the amalgam solid solution.As a comparison,other metals such as Au,Ag,and Zn have typical diffusion coefficients of 10-20 orders of magnitude lower than that of Hg in the similar solid solution phases.This difference induces compact Li deposition pattern with an amalgam substrate even with a high areal capacity of 55 mAh cm^(-2).This finding provides new insight into the rational design of Li anode substrate for the stable cycling of Li metal batteries.
