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arXiv 2025年

作者： Hu, Chang Hu, Yifan Shen, Jiyuan College of Physics Science and Technology Hebei University Baoding071002 China Hebei Key Laboratory of High-precision Computation and Application of Quantum Field Theory Baoding071002 China Hebei Research Center of the Basic Discipline for Computational Physics Baoding071002 China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced Study UCAS Hangzhou310024 China University of Chinese Academy of Sciences Beijing100049 China Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China

In [1], we derived a direct expression for one-loop tensor reduction using generating functions and Feynman parametrization in projective space, avoiding recursive relations. However, for practical applications, this expression still presents two challenges: (1) While the final reduction coefficients are expressed in terms of the dimension D and Mandelstam variables, the given expression explicitly contains irrational functions;(2) The expression involves an auxiliary vector R, which can be eliminated via differentiation ∂/∂R , but the presence of irrational terms making differentiation cumbersome. (3) Most practical applications require the tensor form with Lorentz indices. In this paper, we provide a rational form of the reduction coefficients with Lorentz indices, free from recursion. Additionally, We provide a pure Wolfram Mathematica implementation of the code. Our practical tests demonstrate that this direct expression achieves significantly higher computational efficiency compared to the traditional Passarino-Veltman (PV) reduction or other recursion-based methods. © 2025, CC0.

关键词： Tensors

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Proportional Mean Residual Life Model with Varying Coefficients for Length-Biased and Right-Censored Data

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Acta Mathematica Sinica,English Series 2020年第5期36卷 578-596页

作者： Da XU Yong ZHOU Key Laboratory of Applied Statistics of MOE and School of Mathematics and Statistics Northeast Normal UniversityChangchun 130024P.R.China Key Laboratory of Advanced Theory and Application in Statistics and Data Science MOEAcademy of Statistics and Interdisciplinary SciencesEast China Normal UniversityShanghai 200062P.R.China Academy of Mathematics and Systems Sciences Chinese Academy of SciencesBeijing 100190P.R.China

Length-biased data are encountered in many fields,including economics,engineering and epidemiological cohort *** are two main challenges in the analysis of such data:the assumption of independent censoring is violated and the assumed model for the underlying population is no longer satisfied for the observed *** this paper,a proportional mean residual life varyingcoefficient model for length-biased data is considered and a local pseudo likelihood method is proposed for estimating the coefficient functions in the *** properties are investigated for the proposed *** finite sample performance of the proposed methodology is demonstrated by simulation ***,the method is applied to a real data set concerning the Academy Awards.

关键词： Length-biased data proportional hazards model mean residual life varying-coefficient model

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Nonparametrie Quantile Inference for Cause-specific Residual Life Function Under Length-biased Sampling

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Acta Mathematicae Applicatae Sinica 2020年第4期36卷 902-916页

作者： Fei-Peng ZHANG Cai-Yun FAN Yong ZHOU School of Economics and Finance Xi'an Jiaotong UniversityXi'an 710049China School of Statistics and Information Shanghai University of International Business and EconomicsShanghai 201620China Key Laboratory of Advanced Theory and Application in Statistics and Data Science MOE&Academy of Statistics and Interdisciplinary SciencesEast China Normal UniversityShanghai 200062China

This paper considers a competing risks model for right-censored and length-biased survival data from prevalent *** propose a nonparametric quantile inference procedure for cause-specific residual life distribution with competing risks *** also derive the asymptotic properties of the proposed estimators of this quantile *** studies and the unemployment data demonstrate the practical utility of the methodology.

关键词： Length-biased data competing risks quantile residual life estimating equation

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Optimal design approach of interpenetrating pre-stressed metal-ceramic composites based on deep learning neural network

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Composite Structures 2025年

作者： Kun Liu Xin Lai Lisheng Liu Jinyong Zhang Yifei Liu Hubei Longzhong Laboratory XiangYang 537134 PR China Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics Wuhan University of Technology Wuhan 430070 PR China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 PR China University of Rochester Rochester NY 14527 USA

In this work, we proposed a new pre-stressed metal-ceramic interpenetrating structure to improve the apparent tensile strength of ceramic. In addition, an optimization design framework was constructed by integrating machine learning and gradient descent optimization algorithm for the optimization design of ceramic interpenetrating composites. The optimized metal-ceramic interpenetrating structure can achieve a balance of the stress state of the ceramic phase between intensity and distribution by ingeniously control the confinement and topology of the metal phase. More specifically, the surrogate model we constructed through deep neural network (DNN) can efficiently predict the relationship between the structure and its stress state. The final result obtained can achieve excellent pre-stress effect while making the structure lightweight

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A class of admissible estimators of multiple regression coefficient with an unknown variance

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Statistical theory and Related Fields 2020年第2期4卷 190-201页

作者： Chengyuan Song Dongchu Sun Key Laboratory of Advanced Theory and Application in Statistics and Data Science-MOE School of StatisticsEast China Normal UniversityShanghaiPeople’s Republic of China Department of Statistics University of Nebraska-LincolnLincolnNEUSA

Suppose that we observe y|θ,τ∼N_(p)(Xθ,τ^(−1)I_(p)),where θ is an unknown vector with unknown precisionτ.Estimating the regression coefficient θ with known τ has been well ***,statistical properties such as admissibility in estimating θ with unknownτare not well ***[(2009).Topics in shrinkage estimation and in causal inference(PhD thesis).Warton School,University of Pennsylvania]appears to be the first to consider the problem,developing sufficient conditions for the admissibility of estimating means of multivariate normal distributions with unknown *** generalise the sufficient conditions for admissibility and apply these results to the normal linear regression model.2-level and 3-level hierarchical models with unknown precisionτare investigated when a standard class of hierarchical priors leads to admissible estimators of θ under the normalised squared error *** reason to consider this problem is the importance of admissibility in the hierarchical prior selection,and we expect that our study could be helpful in providing some reference for choosing hierarchical priors.

关键词： Admissible estimators unknown variance multivariate normal distributions hierarchical models

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A GMM approach in coupling internal data and external summary information with heterogeneous data populations

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Science China Mathematics 2024年第5期67卷 1115-1132页

作者： Jun Shao Jinyi Wang Lei Wang Key Laboratory of Advanced Theory and Application in Statistics and Data Science(East China Normal University) Ministry of EducationShanghai 200062China School of Statistics East China Normal UniversityShanghai 200062China Department of Statistics University of Wisconsin-MadisonWI 53706USA School of Statistics and Data Science KLMDASRLEBPS and LPMCNankai UniversityTianjin 300071China

Because of advances in data collection and storage,statistical analysis in modern scientific research and practice now has opportunities to utilize external information such as summary statistics from similar studies.A likelihood approach based on a parametric model assumption has been developed in the literature to utilize external summary information when the populations for external and main internal data are assumed to be the *** this article,we instead consider the generalized estimation equation(GEE)approach for statistical inference,which is semiparametric or nonparametric,and show how to utilize external summary information even when internal and external data populations are not the *** approach is coupling the internal data and external summary information to form additional estimation equations and then applying the generalized method of moments(GMM).We show that the proposed GMM estimator is asymptotically normal and,under some conditions,is more efficient than the GEE estimator without using external summary *** of the asymptotic covariance matrix of the GMM estimators are also *** results are obtained to confirm our theory and quantify the improvements by utilizing external *** example is also included for illustration.

关键词： adjustment for heterogeneity constraint data integration generalized method of moments summarystatistic

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Valence Bands Convergence in p-Type CoSb_(3) through Electronegative Fluorine Filling

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Chinese Physics Letters 2024年第7期41卷 87-94页

作者：黄写格李家良马浩钦李昌隆刘天乐段波翟鹏程李国栋 Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics Wuhan University of TechnologyWuhan 430070China School of Civil Engineering&Architecture Wuhan Polytechnic UniversityWuhan 430023China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China

Band convergence is considered to be a strategy with clear benefits for thermoelectric performance,generally favoring the co-optimization of conductivity and Seebeck coefficients,and the conventional means include elemental filling to regulate the ***,the influence of the most electronegative fluorine on the CoSb_(3) band remains *** carry out density-functional-theory calculations and show that the valence band maximum gradually shifts downward with the increase of fluorine filling,lastly the valence band maximum converges to the highly degenerated secondary valence bands in fluorine-filled skutterudites.

关键词： valence Convergence bands

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A Rate-Dependent Peridynamic Model for the Dynamic Behavior of Ceramic Materials

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Computer Modeling in Engineering & Sciences 2020年第7期124卷 151-178页

作者： Bufan Chu Qiwen Liu Lisheng Liu Xin Lai Hai Mei Department of Engineering Structure and Mechanics Wuhan University of TechnologyWuhan430070China Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics Wuhan430070China State Key Laboratory of Materials Synthesis and Processing Wuhan430070China

In this study,a new bond-based peridynamic model is proposed to describe the dynamic properties of ceramics under impact *** materials show pseudo-plastic behavior under certain compressive loadings with high strain-rate,while the characteristic brittleness of the material dominates when it is subjected to tensile *** this model,brittle response under tension,softening plasticity under compression and strain-rate effect of ceramics are considered,which makes it possible to accurately capture the overall dynamic process of *** enables the investigation of the fracture mechanism for ceramic materials,during ballistic impact,in more ***,a bond-force updating algorithm is introduced to perform the numerical simulation and solve the derived *** proposed model is then used to analyze the dynamic response of ceramics tiles under impact loading to assess its *** results of damage development in ceramic materials are calculated and compared with the experimental *** simulation results are consistent with the experiments,which indicates that the proposed rate-dependent peridynamic model has the capability to describe damage propagation in ceramics with good ***,based on a comparison between simulation and experimental results,it can be concluded that the damage results are in better agreement with experimental results than non-ordinary state-based peridynamic method.

关键词： Penetration ceramic peridynamics rate-dependency crack

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An Elastoplastic Fracture Model Based on Bond-Based Peridynamics

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2349-2371页

作者： Liping Zu Yaxun Liu Haoran Zhang Lisheng Liu Xin Lai Hai Mei Department of Engineering Structure and Mechanics Wuhan University of TechnologyWuhan430070China Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics Wuhan University of TechnologyWuhan430070China

Fracture in ductile materials often occurs in conjunction with plastic ***,in the bond-based peridynamic(BB-PD)theory,the classic mechanical stress is not defined *** makes it difficult to describe plasticity directly using the classical plastic *** address the above issue,a unified bond-based peridynamics model was proposed as an effective tool to solve elastoplastic fracture *** to the existing models,the proposed model directly describes the elastoplastic theory at the bond level without the need for additional calculation *** results obtained in the context of this model are shown to be consistent with FEM results in regard to force-displacement curves,displacement fields,stress fields,and plastic deformation *** model exhibits good capability of capturing crack propagation in ductile material failure problems.

关键词： Ductile materials plastic deformation bond-based peridynamics isotropic hardening fracture analysis

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Ultra-rapid assembly of graphene oxide macroscopic materials enabled by low-surface-tension solvent

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Surfaces and Interfaces 2025年 67卷

作者： Zhang, Long Chen, Pengfei Wang, Zhe Feng, Hao Li, Peng Qian, Wei Fu, Huaqiang Chen, Cheng Shi, Zuhao Lv, Yong Li, Shuxin He, Daping State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China Hubei Engineering Research Center of Radio Frequency Microwave Technology and Application School of Physics and Mechanics Wuhan University of Technology Wuhan 430070 China Hubei Key Laboratory of Theory and Application of Advanced Material Mechanics School of Physics and Mechanics Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Silicate Materials for Architectures Wuhan University of Technology Wuhan 430070 China

Two-dimensional (2D) nanomaterials assembled macroscopic materials via bottom-up approach are extensively utilized across various domains, attributable to their capacity to retain the desirable properties of individual nanosheets. However, the dense structure formed during assembly restricts solvent molecule passage, leading to prolonged preparation times. Traditional methods struggle to create larger and more solvent channels. Herein, we propose a strategy to achieve ultra-fast assembly of graphene oxide (GO) nanosheets by manipulating the solvent's surface tension to form a bouffant structure. This approach enables GO membrane assembly in only 10 s, which is 24,660 times faster than that of conventional water-based methods (over 2.85 days). Our analysis of solvents with varying surface tensions demonstrates that low surface tension, rather than solvent's relative molecular weight, significantly impacts the assembly rate. This rapid assembly process enables GO membranes to attain thicknesses of several centimeters, thereby overcoming the limitations of traditional bottom-up techniques. The resulting GO macro-materials exhibit considerable potential for diverse applications, from thin membranes for waste management to thick blocks for electromagnetic interference shielding and mechanical sensors. This work offers valuable insights into the rapid assembly of macroscopic structures from GO and potentially other 2D lamellar materials. © 2025

关键词： Graphene oxide Low surface tension Macroscopic material Solvent Ultra-rapid assembly

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