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On the transient models of the VITAS code:applications to the C5G7-TD pin-resolved benchmark problem

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Nuclear Science and Techniques 2023年第2期34卷 28-57页

作者： Wei xiao Han Yin xiao‑Jing Liu Hui he Teng‑Fei Zhang School of Nuclear Science and Engineering Shanghai Jiao Tong UniversityShanghai 2002040China

This article describes the transient models of the neutronics code VITAS that are used for solving time-dependent,pinresolved neutron transport *** uses the stiffness confinement method(SCM)for temporal discretization to transform the transient equation into the corresponding transient eigenvalue problem(TEVP).To solve the pin-resolved TEVP,VITAS uses a heterogeneous variational nodal method(VNM).The spatial flux is approximated at each Cartesian node using finite elements in the x-y plane and orthogonal polynomials along the *** discretization utilizes the even-parity integral approach at the nodes and spherical harmonic expansions at the *** further lower the computational cost,a predictor–corrector quasi-static SCM(PCQ-SCM)was *** the VNM framework,computational models for the adjoint neutron flux and kinetic parameters are *** direct-SCM and PCQ-SCM were implemented in VITAS and verified using the two-dimensional(2D)and three-dimensional(3D)exercises on the OECD/NEA C5G7-TD *** the 2D and 3D problems,the discrepancy between the direct-SCM solver’s results and those reported by MPACT and PANDAS-MOC was under 0.97%and 1.57%,*** addition,numerical studies comparing the PCQ-SCM solver to the direct-SCM solver demonstrated that the PCQ-SCM enabled substantially larger time steps,thereby reducing the computational cost 100-fold,without compromising numerical accuracy.

关键词： Stiffness confinement method Quasi-static method C5G7-TD benchmark Pin-resolved transient analysis

The Clustering Coefficient and the Diameter of Small-world Networks

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Acta Mathematica Sinica,English Series 2013年第1期29卷 199-208页

作者： Lei gu Hui Lin HUANG xiao Dong ZHANG School of Mathematical Sciences Fudan University College of Mathematics and Information Science Wenzhou University Department of Mathematics and MOE-LSC Shanghai Jiao Tong University

The small-world network, proposed by Watts and Strogatz, has been extensively studied for the past over ten years. In this paper, a generalized smMl-world network is proposed, which extends severM small-world network models. Furthermore, some properties of a special type of generalized small-world network with given expectation of edge numbers have been investigated, such as the degree distribution and the isoperimetric number. These results are used to present a lower and an upper bounds for the clustering coefficient and the diameter of the given edge number expectation generalized small-world network, respectively. In other words, we prove mathematically that the given edge number expectation generalized small-world network possesses large clustering coefficient and small diameter.

关键词： Generalized small-world network clustering coefficient diameter Laplacian spectra

In-depth analysis of the fatigue mechanism induced by inclusions for high-strength bearing steels

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International Journal of Minerals,Metallurgy and Materials 2021年第5期28卷 826-834页

作者： Chao gu Wen-qi Liu Jun-he Lian Yan-ping Bao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Department of Mechanical Engineering Aalto UniversityPuumiehenkuja 302150 EspooFinland

A numerical study of stress distribution and fatigue behavior in terms of the effect of voids adjacent to inclusions was conducted with finite element modeling simulations under different *** mechanisms were also analyzed *** results showed that the effects of inclusions on fatigue life will distinctly decrease if the mechanical properties are close to those of the steel *** the inclusions,which are tightly bonded with the steel matrix,when the Young’s modulus is larger than that of the steel matrix,the stress will concentrate inside the inclusion;otherwise,the stress will concentrate in the steel *** voids exist on the interface between inclusions and the steel matrix,their effects on the fatigue process differ with their positions relative to the *** void on one side of an inclusion perpendicular to the fatigue loading direction will aggravate the effect of inclusions on fatigue behavior and lead to a sharp stress *** void on the top of inclusion along the fatigue loading direction will accelerate the debonding between the inclusion and steel matrix.

关键词： inclusion high-strength bearing steel fatigue numerical study stress distribution

Generation of Sound by the Ultrashort Intense Laser Pulse in Water

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Chinese Physics Letters 1996年第5期13卷 370-373页

作者： FENG Shao-song WANG Run-tian he Hui-juan LI Yong-chun gu Sheng-ru ZHANG xiao-rong GAN Chang-ming Shanghai Acoustics Laboratory Chinese Academy of SciencesShanghai 200032 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800 Laboratory of Acoustics Nanjing University.Nanjing 210008

The ultrashort intense laser pulse transmitted by a Nd:YAG laser system is used to generate the sound in *** show that the light beam is cojiverged by an optical lens at two *** fact implies that,the time response is ... 详细信息

关键词： Nd:YAG optical laser

The Invariance Principle for p-■Chain

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Acta Mathematica Sinica,English Series 2007年第1期23卷 41-56页

作者： Di he HU Zheng Yan xiao School of Mathematics and Statistics Wuhan University Wuhan 430072 P. R. China School of Statistics Renmin University of China Beijing 100872 P. R. China

There are two parts in this paper. In the first part we construct the Markov chain in random environment（MCRE）, the skew product Markov chain and p-θ^→ chain from a random transition matrix and a two-dimensional probability distribution, and in the second part we prove that the invarianee principle for p-θ^→ chain, a more complex non-homogeneous Markov chain, is true under some reasonable conditions. This result is more powerful.

关键词： random transition matrix Markov chain in random environment skew product Markov chain p-θ^→ chain invariance principle

Multiplicity of Solutions for a Class of Kirchhoff Type Problems

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Acta Mathematicae Applicatae Sinica 2010年第3期26卷 387-394页

作者： xiao-ming he Wen-ming Zou School of Science Minzu University of China Beijing 100081 China Department of Mathematical Sciences Tsinghua University Beijing 100084 China

In this paper we apply the （variant） fountain theorems to study the symmetric nonlinear Kirch- hoff nonlocal problems. Under the Ambrosetti-Rabinowitz＇s 4-superlinearity condition, or no Ambrosetti- Rabinowitz＇s 4-superlinearity condition, we present two results of existence of infinitely many large energy solutions, respectively.

关键词： Kirchhoff nonlocal problems Multiple solutions Fountain theorems

Biocompatibility and biosafety of butterfly wings for the clinical use of tissue-engineered nerve grafts

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Neural Regeneration Research 2021年第8期16卷 1606-1612页

作者： Shu Wang Miao gu Cheng-Cheng Luan Yu Wang xiaosong gu Jiang-Hong he Key Laboratory for Neuroregeneration of Jiangsu Province and Ministry of Education Co-innovation Center of NeuroregenerationNantong UniversityNantongJiangsu ProvinceChina Department of Basic Medicine Chengde Medical CollegeChengdeHebei ProvinceChina

In a previous study, we used natural butterfly wings as a cell growth matrix for tissue engineering materials and found that the surface of different butterfly wings had different ultramicrostructures, which can affect the qualitative growth of cells and regulate cell growth, metabolism, and gene expression. However, the biocompatibility and biosafety of butterfly wings must be studied. In this study, we found that Sprague-Dawley rat dorsal root ganglion neurons could grow along the structural stripes of butterfly wings, and Schwann cells could normally attach to and proliferate on different species of butterfly wings. The biocompatibility and biosafety of butterfly wings were further examined through subcutaneous implantation in Sprague-Dawley rats, intraperitoneal injection in Institute of Cancer Research mice, intradermal injection in rabbits, and external application to guinea pigs. Our results showed that butterfly wings did not induce toxicity, and all examined animals exhibited normal behaviors and no symptoms, such as erythema or edema. These findings suggested that butterfly wings possess excellent biocompatibility and biosafety and can be used as a type of tissue engineering material. This study was approved by the Experimental Animal Ethics Committee of Jiangsu Province of China(approval No. 20190303-18) on March 3, 2019.

关键词： biocompatibility biomaterials biosafety butterfly wings dorsal root ganglion neurons Schwann cells tissue engineering

Performance Study of the MPC based on BPNN Prediction Model in Thermal Management System of Battery Electric Vehicles

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Journal of Thermal Science 2024年第6期33卷 2318-2335页

作者： he Lian'ge JING Haodong ZHANG Yan LI Pengpai gu Zihan Key Laboratory of Advanced Manufacture Technology for Automobile Parts(Chongqing University of Technology) Ministry of EducationChongqing 400054China Ningbo Shenglong Group Co. Ltd.Ningbo 315104China Chongqing Tsingshan Industrial Co. Ltd.Chongqing 402761China

In this paper,a model predictive control(MPC)based on back propagation neural network(BPNN)prediction model was proposed for compressor speed control of air conditioning system(ACS)and battery thermal management system(BTMS)coupling system of battery electric vehicle(BEV).In order to solve the problem of high cooling energy consumption and inferior thermal comfort in the cabin of the battery electric vehicle thermal management system(BEVTMS)during summer time,this paper combines the respective superiorities of artificial neural network(ANN)predictive modeling and MPC,and creatively combines the two methods and uses them in the control of ***,based on ANN and heat transfer theory,BPNN prediction model,ACS and BTMS coupling system were established and ***,a mathematical method of MPC was established to control the speed of the ***,the state parameters of the coupled system were predicted using a BPNN prediction model,and the predicted values were passed to the MPC,thus achieving accurate control of the compressor speed using the ***,the effects of PID control and MPC based on BPNN prediction model on thermal comfort of cabin and compressor energy consumption at different ambient temperatures were compared in simulation under New European Driving Cycle(NEDC)*** results showed for the constructed BPNN prediction model predicted and tested values of the selected parameters the mean squared error(MSE)ranged from 2.498%to 8.969%,mean absolute percentage error(MAPE)ranged from 4.197%to 8.986%,and mean absolute error(MAE)ranged from 3.202%to 8.476%.At ambient temperatures of 25℃,35℃ and 45℃,the MPC based on the BPNN prediction model reduced the cumulative discomfort time in the cabin by 100 s,39 s and 19 s,respectively,compared with the PID *** three NEDC conditions,the energy consumption is reduced by 1.82%,2.35%and 3.48%,*** the ambient temperature was 35℃,the MPC based on BPNN prediction model

关键词： air conditioning system battery thermal management system back propagation neural network model predictive control battery electric vehicle

Suppressing autoimmunity by TGF-β： not just through Treg cells

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Cellular & Molecular Immunology 2012年第5期9卷 371-372页

作者： Ming-xiao he You-Wen he Department of Immunology Duke University MedicalCenter Durham NC USA

Cellular ＆ Molecular Immunology （2012） 9,371-372; doi： 10.1038/cmi.2012.24; published online 13 August 2012Transforming growth factor-β （TGF-β） is a pleiotropic factor. It regulates manyaspects of T-cell biology including thymocyte development, T cell differentiation and effector T cell function.1 Previous work has shown that the loss of TGF-β signaling in the T-cell lineage leads to severe lymphopro- liferafive autoimmunity.2.3 Until now, it has been unclear to what extent the autoimmunity observed in those mice is driven by TGF- unresponsive conventional T cells, as TGF- is also crucial for the maintenance and function of regulatory T cells （Treg）. A recent study pub- lished in Nature Immunology revealed a novel role of TGF-β signaling in non-regulatory naive T cells. It was found that TGF-β controls lym- phopenia-driven T-ceU proliferation in neonatal mice, thereby preventing the development of autoimmtmity.

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