Li-rich oxides are considered as the most commercial potential cathode materials due to the high theoretical specific discharge capacity. Here, ZrO_(2) in different crystalline states are applied as the coating layers...Li-rich oxides are considered as the most commercial potential cathode materials due to the high theoretical specific discharge capacity. Here, ZrO_(2) in different crystalline states are applied as the coating layers to enhance the electrochemical performance of hollow Li[Li_(0.2)Mn_(0.54)Ni_(0.13)Co_(0.13)]O_(2) materials.Meanwhile, a series of characterizations(XRD, SEM, TEM, EDX etc.) are conducted to compare the effects of ZrO_(2) coating layer with different crystalline states on the host material. The results elucidate that the Li-rich Mn-based material with the polycrystal ZrO_(2) coating layer has a slight advantage in rate performance, while the host material with the single crystal ZrO_(2)-coating layer has a better cycling performance and effectively suppresses voltage decay with the effect of excellently inhibiting layered to spinel-like phase transition and metal dissolution during charging and discharging process.展开更多
The sparse linear programming(SLP) is a linear programming problem equipped with a sparsity constraint, which is nonconvex, discontinuous and generally NP-hard due to the combinatorial property involved.In this paper,...The sparse linear programming(SLP) is a linear programming problem equipped with a sparsity constraint, which is nonconvex, discontinuous and generally NP-hard due to the combinatorial property involved.In this paper, by rewriting the sparsity constraint into a disjunctive form, we present an explicit formula of the Lagrangian dual problem for the SLP, in terms of an unconstrained piecewise-linear convex programming problem which admits a strong duality under bi-dual sparsity consistency. Furthermore, we show a saddle point theorem based on the strong duality and analyze two classes of stationary points for the saddle point problem. At last,we extend these results to SLP with the lower bound zero replaced by a certain negative constant.展开更多
This paper develops the Bernstein tensor concentration inequality for random tensors of general order,based on the use of Einstein products for tensors.This establishes a strong link between these and matrices,which i...This paper develops the Bernstein tensor concentration inequality for random tensors of general order,based on the use of Einstein products for tensors.This establishes a strong link between these and matrices,which in turn allows exploitation of existing results for the latter.An interesting application to sample estimators of high-order moments is presented as an illustration.展开更多
基金supported by the National Natural Science Foundation of China (No. 51604081 and 51974368)the Fundamental Research Funds for the Central Universities of Central South University (No. 2019zzts942)。
文摘Li-rich oxides are considered as the most commercial potential cathode materials due to the high theoretical specific discharge capacity. Here, ZrO_(2) in different crystalline states are applied as the coating layers to enhance the electrochemical performance of hollow Li[Li_(0.2)Mn_(0.54)Ni_(0.13)Co_(0.13)]O_(2) materials.Meanwhile, a series of characterizations(XRD, SEM, TEM, EDX etc.) are conducted to compare the effects of ZrO_(2) coating layer with different crystalline states on the host material. The results elucidate that the Li-rich Mn-based material with the polycrystal ZrO_(2) coating layer has a slight advantage in rate performance, while the host material with the single crystal ZrO_(2)-coating layer has a better cycling performance and effectively suppresses voltage decay with the effect of excellently inhibiting layered to spinel-like phase transition and metal dissolution during charging and discharging process.
基金supported by National Natural Science Foundation of China(Grant Nos.11431002,11771038 and 11728101)the State Key Laboratory of Rail Traffic Control and Safety,Beijing Jiaotong University(Grant No.RCS2017ZJ001)China Scholarship Council(Grant No.201707090019)
文摘The sparse linear programming(SLP) is a linear programming problem equipped with a sparsity constraint, which is nonconvex, discontinuous and generally NP-hard due to the combinatorial property involved.In this paper, by rewriting the sparsity constraint into a disjunctive form, we present an explicit formula of the Lagrangian dual problem for the SLP, in terms of an unconstrained piecewise-linear convex programming problem which admits a strong duality under bi-dual sparsity consistency. Furthermore, we show a saddle point theorem based on the strong duality and analyze two classes of stationary points for the saddle point problem. At last,we extend these results to SLP with the lower bound zero replaced by a certain negative constant.
基金supported by the National Natural Science Foundation of China(Grant No.11771038)the Beijing Natural Science Foundation(Grant No.Z190002)the Hong Kong Research Grant Council(Grant Nos.PolyU 15300715,15301716,15300717)。
文摘This paper develops the Bernstein tensor concentration inequality for random tensors of general order,based on the use of Einstein products for tensors.This establishes a strong link between these and matrices,which in turn allows exploitation of existing results for the latter.An interesting application to sample estimators of high-order moments is presented as an illustration.
