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Forming the transverse inner rib of a curved generatrix part through power spinning

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Advances in Manufacturing 2019年第1期7卷 105-115页

作者： Hong-Rui Zhang mei Zhan Jing Guo Xian-Xian Wang Peng-fei Gao fei Ma State Key Laboratory of Solidification Processing School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 People's Republic of China Shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 People's Republic of China Long March Machinery Factory China Aerospace Science and Technology Corporation Chengdu 610100 People's Republic of China

How to form high-quality transverse inner ribs through power spinning is a key issue for complicated integrated curved generatrix parts with transverse inner ribs. In this study, the forming characteristics and laws during the power spinning process were investigated using a finite element simulation based on the orthogonal design method. The results show that the transverse inner rib distributes homogeneously along the circumferential direction but inhomogeneously along the generatrix direction. Depressions occur easily in the middle zone of the rib (MZR). The roller nose radius is the most significant parameter of the MZR underfill degree. A larger roller nose radius is helpful to decrease the MZR underfill degree. Furthermore, the preformed billet thickness also plays a vital role in the underfill degree of the front zone of the rib and the back zone of the rib, as well as the depression degree of the outer surface of the rib. By combining the ribfilling characteristics and laws, the optimized forming process window for obtaining high-quality inner ribs was obtained by regression analysis, thus laying a basis for improving the forming quality of curved generatrix parts with transverse inner ribs in power spinning.

关键词： Power spinning Transverse inner rib Rib filling Process optimization

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

Boundedness of fractional integral operators on α-modulation spaces

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Applied Mathematics(A Journal of Chinese Universities) 2014年第3期29卷 339-351页

作者： WU xiao-mei CHEN Jie-cheng Xingzhi Colledge Zhejiang Normal University Department of Mathematics Zhejiang Normal University

In this paper, we obtain the boundedness of the fractional integral operators, the bilineax fractional integral operators and the bilinear Hilbert transform on α-modulation spaces.

关键词： α-modulation space fractional integral operator bilinear fractional integral operator bilinearHilbert transform.

Features of Motion of Soliton Transported Bio-energy in Aperiodic α-Helix ProteinMolecules with Three Channels

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Communications in Theoretical Physics 2009年第1期51卷 170-180页

作者： PANG xiao-Feng LIU mei-Jie Institute of High-Energy Electronics University of Electronic Science and Technology of China Chengdu 610065 China International Center for Materials Physics Chinese Academy of Sciences Shenyang 110015 China

The structure aperiodicities can influence seriously the features of motion of soliton excited in the α-helix protein molecules with three channels. We study the influence of structure aperiodicities on the features of the soliton in the improved model by numerical simulation and Runge-Kulta method. The results obtained show that the new soliton is very robust against the structure aperiodieities including large disorder in the sequence of mass of the amino acids and fluctuations of spring constant, coupling constant, dipole-dipole interactional constant, ground state energy and chain-chain interaction. However, very strong structure aperiodieities can also destroy the stability of the soliton in the α-helix protein molecules.

关键词： structure aperiodicity soliton stability protein bio-energy Runge-Kulta method

Equivalent Conditions of Complete Convergence and Complete Moment Convergence for END Random Variables

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Chinese Annals of Mathematics,Series B 2018年第1期39卷 83-96页

作者： Aiting SHEN mei YAO Benqiong xiao School of Mathematical Sciences Anhui University Hefei 230601 China. School of Mathematics Hefei University of Technology Hefei 230009 China School of Mathematics Shandong University Jinan 250100 China

In this paper,the complete convergence and the complete moment convergence for extended negatively dependent(END,in short) random variables without identical distribution are *** some suitable conditions,the equivalence between the moment of random variables and the complete convergence is *** addition,the equivalence between the moment of random variables and the complete moment convergence is also *** applications,the Marcinkiewicz-Zygmund-type strong law of large numbers and the Baum-Katz-type result for END random variables are *** results obtained in this paper extend the corresponding ones for independent random variables and some dependent random variables.

关键词： Extended negatively dependent random variables Complete convergence Complete moment convergence

Bio-energy in s-Helix Protein Molecules with Three Properties of Soliton-Transported Channels

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Communications in Theoretical Physics 2007年第2X期48卷 369-376页

作者： PANG xiao-Feng LIU mei-Jie Institute of Life Science and Technology University of Electronic Science and Technology of China Chengdu 610054 China International Center for Material Physics the Chinese Academy of Sciences Shenyang 110015 China

We study numerically the propagating properties of soliton-transported bio-energy excited in the a-helix protein molecules with three channels in the cases of the short-time and long-time motions and its features of collision at temperature T = 0 and biological temperature T = 300 K by the dynamic equations in the improved Davydov theory and fourth-order Runge-Kutta method, respectively. From these simulation experiments we see that the new solitons in the improved model can move without dispersion at a constant speed retaining its shape and energy in the cases of motion of both short-time or T = 0 and long time or T = 300 K and can go through each other without scattering in their collisions. In these cases its lifetime is, at least, 120 ps at 300 K, in which the soliton can travel over about 700 amino acid residues. This result is consistent with analytic result obtained by quantum perturbed theory in this model. In the meanwhile, the influences of structure disorder of a-helix protein molecules, including the inhomogeneous distribution of amino acids with different masses and fluctuations of spring constant, dipole-dipole interaction, exciton-phonon coupling constant and diagonal disorder, on the solitons are also studied by the fourth-order Runge-Kutta method. The results show that the soliton still is very robust against the structure disorders and thermal perturbation of proteins at biological temperature 300 K. Therefore we can conclude that the new soliton in the a-helix protein molecules with three channels is a possible carrier of bio-energy transport and the improved model is possibly a candidate for the mechanism of this transport.

关键词： bio-energy transport soliton protein molecule Runge-Kutta method thermal stabilization

Secure oblivious transfer protocol from indistinguishability obfuscation

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The Journal of China Universities of Posts and Telecommunications 2016年第3期23卷 1-10页

作者： Yuan Zheng Wang mei Feng xiao Beijing Electronic Science & Technology Institute Beijing 100070 China School of Telecommunications Engineering Xidian University Xi'an 710071 China

A new secure oblivious transfer （OT） protocol from indistinguishability obfuscation （iO） is proposed in this paper. The candidate iO and a dual-mode cryptosystem are the main technical tools of this scheme. Garg et al. introduced a candidate construction of iO in 2013. Following their steps, a new k-out-of-1 OT protocol is presented here, and its realization from decisional Diffie-Hellman （DDH） is described in this paper, in which iO was combined with the dual-mode cryptosystem. The security of the scheme mainly relies on the indistinguishability of the obf-branches （corresponding to the two modes in dual-mode model）. This paper explores a new way for the application of iO.

关键词： indistinguishability obfuscation (iO) oblivious transfer (OT) protocol dual-mode cryptosystem

Synthesis,Crystal Structure and Bioactivity Evaluation of a Heterocyclic Compound

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Chinese Journal of Structural Chemistry 2020年第10期39卷 1892-1897,1745页

作者： ZHANG Peng ZHAO xiao-mei School of Pharmacy Shaanxi University of Chinese MedicineXianyangShaanxi 712046China

The heterocyclic compound 2-amino-N-(2-chloro-6-methylphenyl)thiazole-5-carboxamide(1),designed using 2-chloro-6-methylaniline(2)as the start material,was successfully obtained via multiple synthesis route and finally characterized by IR,1H NMR,and single-cystal X-ray *** select the suitable candidates for tissue regeneration,the induction activity of the compound on the dental pulp mesenchymal stem cells(DP-MSCs)was ***,the DP-MSCs cells were isolated and the cell colon formation ability was measured after compound treatment with cell colony *** that,the RT-PCT assay was conducted and the relative expression level of the genes related with cell osteogenesis and proliferation was further detected.

关键词： heterocycles X-ray DP-MSCs RT-PCT assay

Reflected BSDEs with Random Default Time and Related Mixed Optimal Stopping-control Problems

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Acta Mathematicae Applicatae Sinica 2013年第1期29卷 165-178页

作者： Dong-mei Guo xiao-ming Xu School of Economics Central University of Finance and Economics Academy of Mathematics and Systems Science Chinese Academy of Sciences Institute of Mathematics School of Mathematical Sciences Nanjing Normal University

In this paper we study the one-dimensional reflected backward stochastic differential equations which are driven by Brownian motion as well as a mutually independent martingale appearing in a defaultable setting. Using a penalization method, we prove the existence and uniqueness of the solutions to these equations. As an application, we show that under proper assumptions the solution of the reflected equation is the value of the related mixed optimal stopping-control problem.

关键词： backward stochastic differential equation random default time mixed optimal stopping-controlproblem