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3D MXene architectures as sulfur hosts for high-performance lithium-sulfur batteries

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Journal of Energy Chemistry 2022年第3期31卷 429-439,I0012页

作者： Yu-Hong Liu cao-Yu Wang Si-Lin Yang fei-fei cao Huan Ye College of Science Huazhong Agricultural UniversityWuhan 430070HubeiChina

Lithium-sulfur batteries(LSBs)are one of the most promising energy storage devices because of their high theoretical energy density;however,inherent issues including poor electrical conductivity and severe dissolution of S and its discharged products hinder their practical *** have metallic conductivity,ultra-thin two-dimensional(2D)structures,rich surface functional groups,and macrostructural adjustability and have been widely used to design advanced sulfur hosts.3D network structures assembled by 2D MXene nanosheets have shown superior performance for improving reaction kinetics,accommodating and dispersing sulfur at the micro-/nanoscale,and capturing polysulfides due to their porous interconnected ***,the applications of MXene architectures related to 2D layered structures,3D multilayered structures,and 3D spherical structures as sulfur hosts are *** structure-performance relationship,challenges for current designs,and opportunities for future 3D architectures for LSBs are also analyzed.

关键词： Lithium-sulfur batteries Cathodes Sulfur hosts MXenes 3D architectures

Lithiophilic interface guided transient infiltration of molten lithium for stable 3D composite lithium anodes

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Nano Research 2023年第6期16卷 8297-8303页

作者： Lan-Xing Li Yun-Nuo Li fei-fei cao Huan Ye College of Science Huazhong Agricultural UniversityWuhan 430070China

Fabricating three-dimensional(3D)composite lithium anodes via thermal infusion effectively addresses uncontrollable Li deposition and large volume ***,potential risks due to the long wetting time and high melting point remain a critical yet unconsidered ***,we report a stable 3D composite Li anode by infusing molten Li into a 3D scaffold within 3 s at 220℃.The key-enabling technique is the growth of a lithiophilic Mg-Al double oxide(LDO)nanosheet array layer on the *** in-situ formed lithiophilic alloy,combined with the capillary forces from the nanosheet arrays,enabled the transient infiltration of molten *** addition,the formed high ionic-conductivity Li phase can help construct a robust solid electrolyte interphase(SEI),stabilize the Li anode/electrolyte interface,and guide uniform Li *** 3D composite anode exhibited a long cycling life of 1,000 h under a current density of 1 mA·cm^(−2)and over 1,600 h under a current density of 2 mA·cm^(−2)with a high areal capacity of 4 mAh·cm^(−2)in Li/Li symmetric *** 3D composite anodes paired with high areal capacity LiFePO_(4)(LFP)and S cathodes demonstrate its practical application feasibility.

关键词： lithium metal battery composite Li anode interfacial layer thermal infusion long cycling life

Catalytic asymmetric synthesis of sulfur-containing atropisomers by C-S bond formations

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Science China Chemistry 2023年第12期66卷 3331-3346页

作者： Ren-fei cao Zhi-Min Chen School of Chemistry and Chemical Engineering Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsShanghai Jiao Tong UniversityShanghai 200240China

Chiral organosulfur compounds are not only widely distributed in bioactive natural products and pharmaceuticals,but also play a significant role in chiral ligands/*** the history of synthetic organic chemistry,chemists have been absorbed in the construction of centrally chiral organosulfur ***,there are relatively few reports on installing sulfur functional groups into axially chiral *** is one of the fundamental phenomena in nature,which ubiquitously exists in natural *** more than a century of development,atropisomers have been designed and extensively applied to pharmaceuticals,functional materials and chiral ligands/*** to the importance of chiral sulfurcontaining atropisomers,there is an increasing demand for enantioselective synthesis of ***,a diversity of approaches by C-S bond formations have been established for the construction of enantioenriched sulfur-containing atropisomers,however,there is no comprehensive review to summarize this great *** this mini-review,we summarize recent progress in catalytic asymmetric synthesis of sulfur-containing atropisomers by C-S bond formations,which includes sulfur nucleophilic reactions,sulfur electrophilic reactions and sulfur radical ***,the reaction mechanisms are also *** hope that this mini-review will enable more researchers to further explore this field.

关键词： atropisomers asymmetric catalysis C-S bond formations chiral organosulfur compounds

A 4H-SiC trench MOSFET structure with wrap N-type pillar for low oxide field and enhanced switching performance

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Chinese Physics B 2022年第7期31卷 629-636页

作者： Pei Shen Ying Wang fei cao The Key Laboratory of RF Circuits and Systems Ministry of EducationHangzhou Dianzi UniversityHangzhou 310018China The School of Mechanical and Electronic Engineering Pingxiang UniversityPingxiang 337055China

An optimized silicon carbide(SiC)trench metal-oxide-semiconductor field-effect transistor(MOSFET)structure with side-wall p-type pillar(p-pillar)and wrap n-type pillar(n-pillar)in the n-drain was investigated by utilizing Silvaco TCAD *** optimized structure mainly includes a p+buried region,a light n-type current spreading layer(CSL),a p-type pillar region,and a wrapping n-type pillar region at the right and bottom of the *** improved structure is named as *** side-wall p-pillar region could better relieve the high electric field around the p+shielding region and the gate oxide in the off-state *** wrapping n-pillar region and CSL can also effectively reduce the specific on-resistance(Ron,sp).As a result,the SNPPT-MOS structure exhibits that the figure of merit(Fo M)related to the breakdown voltage(V_(BR))and Ron,sp(V_(BR)^2R_(on,sp))of the SNPPT-MOS is improved by 44.5%,in comparison to that of the conventional trench gate SJ MOSFET(full-SJ-MOS).In addition,the SNPPT-MOS structure achieves a much fasterwitching speed than the full-SJ-MOS,and the result indicates an appreciable reduction in the switching energy loss.

关键词： 4H-silicon carbide(4H-SiC)trench gate MOSFET breakdown voltage(V_(BR)) specific onresistance(R_(on sp)) switching energy loss super-junction

The construction and approximation of feedforward neural network with hyperbolic tangent function

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Applied Mathematics(A Journal of Chinese Universities) 2015年第2期30卷 151-162页

作者： CHEN Zhi-xiang cao fei-long Department of Mathematics Shaoxing University Department of Mathematics China Jiliang University

In this paper, we discuss some analytic properties of hyperbolic tangent function and estimate some approximation errors of neural network operators with the hyperbolic tan- gent activation function. Firstly, an equation of partitions of unity for the hyperbolic tangent function is given. Then, two kinds of quasi-interpolation type neural network operators are con- structed to approximate univariate and bivariate functions, respectively. Also, the errors of the approximation are estimated by means of the modulus of continuity of function. Moreover, for approximated functions with high order derivatives, the approximation errors of the constructed operators are estimated.

关键词： Hyperbolic tangent function neural networks approximation modulus of continuity

The Ridge Function Representation of Polynomials and an Application to Neural Networks

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Acta Mathematica Sinica,English Series 2011年第11期27卷 2169-2176页

作者： Ting Fan XIE fei Long cao Department of Information and Mathematics Sciences China Jiliang University Hangzhou 310018 P. R. China

The first goal of this paper is to establish some properties of the ridge function representation for multivariate polynomials, and the second one is to apply these results to the problem of approximation by neural networks. We find that for continuous functions, the rate of approximation obtained by a neural network with one hidden layer is no slower than that of an algebraic polynomial.

关键词： Ridge function neural network polynomial approximation

The Rate of Approximation of Gaussian Radial Basis Neural Networks in Continuous Function Space

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Acta Mathematica Sinica,English Series 2013年第2期29卷 295-302页

作者： Ting Fan XIE fei Long cao Institute of Metrology and Computational Science China Jiliang University

There have been many studies on the dense theorem of approximation by radial basis feedforword neural networks, and some approximation problems by Gaussian radial basis feedforward neural networks （GRBFNs） in some special function space have also been investigated. This paper considers the approximation by the GRBFNs in continuous function space. It is proved that the rate of approximation by GRNFNs with nd neurons to any continuous function f defined on a compact subset K R^d can be controlled by w（f, n^-1/2）, where w（f, t） is the modulus of continuity of the function f.

关键词： Gaussian radial basis feedforward neural networks approximation rate of convergence modulus of continuity

Approximating and learning by Lipschitz kernel on the sphere

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Applied Mathematics(A Journal of Chinese Universities) 2014年第2期29卷 151-161页

作者： cao fei-long WANG Chang-miao Department of Mathematics China Jiliang University

This paper investigates some approximation properties and learning rates of Lipschitz kernel on the sphere. A perfect convergence rate on the shifts of Lipschitz kernel on the sphere, which is faster than O（n-1/2）, is obtained, where n is the number of parameters needed in the approximation. By means of the approximation, a learning rate of regularized least square algorithm with the Lipschitz kernel on the sphere is also deduced.

关键词： Approximation learning rate Lipschitz kernel sphere.

On a Problem of Hornik

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Acta Mathematica Sinica,English Series 2015年第7期31卷 1141-1148页

作者： Ting Fan XIE fei Long cao Department of Mathematics and Information Sciences China Jiliang University

In 1991, Hornik proved that the collection of single hidden layer feedforward neural net- works （SLFNs） with continuous, bounded, and non-constant activation function a is dense in C（K） where K is a compact set in Rs （see Neural Networks, 4（2）, 251-257 （1991））. Meanwhile, he pointed out ＂Whether or not the continuity assumption can entirely be dropped is still an open quite challenging problem＂. This paper replies in the affirmative to the problem and proves that for bounded and continuous almost everywhere （a.e.） activation function σ on R, the collection of SLFNs is dense in C（K） if and only if a is un-constant a.e..

关键词： Neural networks approximation activation function