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Ratcheting Behavior of SA508-3 Steel at Elevated Temperature:Experimental Observation and simulation

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Acta Metallurgica Sinica(English Letters) 2017年第9期30卷 822-828页

作者： Jun Tian Yu Yang Li-Ping Zhang Xue-Jiao Shao Juan Du Qian-Hua Kan science and technology on Reactor System Design technology laboratory Nuclear Power Institute of China Applied Mechanics and Structure safety Key laboratory of Sichuan Province School of Mechanics and EngineeringSouthwest Jiaotong University

A series of monotonic uniaxial tensile tests, strain-controlled and stress-controlled cyclic tests of SA508-3 steel were conducted from 25 to 350℃. Results showed that the steel exhibited temperature-dependent cyclic softening characteristic and obvious ratcheting behavior, and dynamic strain aging was observed in the range of 250-350℃. Based on experimental observations, a temperature-dependent cyclic plastic constitutive model was proposed by introducing the nonlinear cyclic softening and kinematic hardening rules, and the dynamic strain aging was also considered into the constitutive model. Comparisons between experiments and simulations were carded out to validate the proposed model at elevated temperature.

关键词： Ratcheting Constitutive model Dynamic strain aging Cyclic loading Elevated temperature

Terahertz dual-beam leaky-wave antenna based on multi-mode spoof surface plasmon polariton waveguide

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Optoelectronics Letters 2025年

作者： BAI Yukun HAN Yuanqing Tianjin Key laboratory of Film Electronic and Communication Devices， Engineering Research Center of Optoelectronic Devices and Communication technology， Ministry of Education， School of Integrated Circuit science and Engineering， Tianjin University of technology

In this paper， a terahertz dual-beam leaky-wave antenna (LWA) based on a multi-mode spoof surface plasmon polariton (SSPP) waveguide is proposed. By dispersion engineering of the SSPP transmission line (SSPP TL)， multiple modes are excited on the SSPP TL. A dual-beam LWA is constructed based on the radiation from the first space harmonics of the guided fundamental mode and the first higher-order mode. The simulation results show that the antenna radiates frequency-dependent dual beams in the 1.9 ～ 2.6 THz operating frequency band. The average gains for the two beams are 12.9 dBi and 8.2 dBi， respectively. The compact dual-beam LWA is promising in the application of wireless communication and radar systems.

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Hydrothermal Syntheses of CuO, CuO/Cu2O, Cu2O, Cu2O/Cu and Cu Microcrystals Using Ionic Liquids

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Chemical Research in Chinese Universities 2016年第4期32卷 530-533页

作者： ZHANG Meng TU Xianneng WANG Jingyang FANG Tuo WANG Yanli XU Xiaodong ZHANG Milin CHEN Yitung fundamental science on nuclear safety and simulation technology laboratory Key laboratory of Superlight Materials and Surface technology Ministry of Education Harbin Engineering University Harbin 150001 P. R. China Department of Mechanical Engineering University of Nevada Las Vegas 4505 Maryland Parkway Box 454027 Las Vegas NV89154-4027 USA

In this paper, CuO, CuO/Cu2O, Cu2O, Cu2O/Cu and Cu microcrystals were synthesized via a hydrothermal method by mixing Cu（NO3）2·3H2O and NaOH together in the presence of an ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate（[BMIM]BF4） or 1-butyl-3-methylimidazolium chloride（[BMIM]Cl）. The structures and the morphologies of the obtained products were characterized by means of X-ray diffractometer（XRD）, field-emission scanning electron microscopy/energy-dispersive spectroscopy（FESEM/EDS）, transmission electron microscopy/selected area electron diffraction（TEM/SAED） and Raman spectroscopy. The result of XRD indicates that Cu2O and Cu microcrystals are cubic phase and the Raman spectra confirm the presence of carbon. The results of FESEM and TEM images show Cu2O microcrystals as rule cubes of 2μm in length and Cu particles of 5 μm in diameter. According to the difference between crystal structures, bi-eomponent and single component products were synthesized by adjusting the reaction conditions. A possible formation mechanism of Cu2O and Cu was proposed in [BMIM]BF4.

关键词： Ionic liquid Hydrothermal method Reducing agent Microstructure Crystal structure

Key Pose Frame Extraction Method of Human Motion Based on 3D Framework and X-Means

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Journal of Beijing Institute of technology 2017年第1期26卷 75-83页

作者： Sirui Zhao Yadong Wu Wenchao Yang Xiaowei Li School of Computer science and technology Southwest University of Science and Technology Mianyang 621010 China fundamental science on nuclear Wastes and Environmental Security laboratory Southwest University of Science and Technology Mianyang 621010 China

The key pose frames of a human motion pose sequence,play an important role in the compression,retrieval and semantic analysis of continuous human *** current available clustering methods in literatures are difficult to determine the number of key pose frames automatically,and may destroy the postures’ temporal relationships while extracting key *** deal with this problem,this paper proposes a new key pose frames extraction method on the basis of 3D space distances of joint points and the improved X-means clustering *** to the proposed extraction method,the final key pose frame sequence could be obtained by describing the posture of human body with space distance of particular joint points and then the time-constraint X-mean algorithm is applied to cluster and filtrate the posture *** experimental results show that the proposed method can automatically determine the number of key frames and save the temporal characteristics of motion frames according to the motion pose sequence.

关键词： human motion analysis key flame extraction 3D skeleton X-means clustering

The Implementation of Magnetic Islands in Gyrokinetic Toroidal Code

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Plasma science and technology 2016年第2期18卷 126-130页

作者：江澎林志宏 Ihor HOLOD 肖池阶 Fusion simulation Center and State Key laboratory of nuclear Physics and technology Peking University Department of Physics and Astronomy University of California

The implementation of magnetic islands in gyrokinetic simulation has been verified in the gyrokinetic toroidal code（GTC）.The ion and electron density profiles become partially flattened inside the *** density profile at the low field side is less flattened than that at the high field side due to toroidally trapped particles in the low field side,which do not move along the perturbed magnetic field *** the fraction of trapped particles decreases,the density profile at the low field becomes more flattened.

关键词： magnetic islands toroidal plasma confinement plasma gyrokinetics magnetic fields

Phase relations,microstructure,and valence transition studies on CaZr1-xCexTi2O7(0.0≤x≤1.0)system

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Journal of Rare Earths 2018年第11期36卷 1184-1189页

作者： Weimin Li Faqin Dong Liang Bian Hao Zou Mianxin Song Research Center of Laser Fusion China Academy of Engineering PhysicalMianyang 621900China fundamental science on nuclear Wastes and Environmental safety laboratory Southwest University of Science and TechnologyMianyang 621010China laboratory of Solid Waste Treatment and Resource Recycle Ministry of EducationSouthwest University of Science and TechnologyMianyang 621010China Hebei University of Geosciences Shijiazhuang 050000China

In this study, Ce-doped zirconolite was synthesized through high-temperature solid-state reaction at 1250 ℃ in air for 96 h. The crystal phase, microstructure and valence transition were studied by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and X-ray photoelectron spectroscopy （XPS）. Phase relations of CaZrl xCexTi207 systems were determined by XRD analyses and Rietveld refinements. Four different phases are identified, namely zirconolite, perovskite, pyrochlore, and cerianite. The phase transformation （2M-zirconolite → 4M-zirconolite →Ce-pyrochlore） is caused by cations rearrangement as cerium content increases. The solubility limit of cerium ions in CaZrl .xCexTi207 system is estimated to be approximately 0.80. Under sintering air atmosphere, partial reduction of Ce^4＋ in Ce^3＋ is detected in Ce 3d XPS soectra, and the ratio of Ce^3＋ and Ce^4＋ significantly decreases as cerium content increases.

关键词： Zirconolite Ce-pyrochlore Phase relations Valence transition Rare earths

Development of a scintillation detector for real-time measurement of space proton effective dose

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nuclear science and Techniques 2019年第5期30卷 48-58页

作者： Shou-Jie Zhang Xin-Biao Jiang Da Li Xiao-Ren Yu Liang-Liang Miao Xiao-Jing Song Yan Ma Northwest Institute of nuclear technology State Key laboratory of Intense Pulsed Radiation simulation and Effect Xi'an Jiaotong University

In this study, a scintillation detector was developed to measure the space proton effective dose for astronauts based on the proton effective dose conversion coefficients provided by International Commission on Radiological Protection Report No. 116. In the Monte Carlo N-Particle Transport Code X(version 2.6.0) simulation process, by modulating the depth and solid angle of truncated conical holes in an iron shell from lower-energy protons to higher-energy protons, the energy deposited in the scintillator by isotropic protons was nearly proportional to the corresponding effective dose, with a maximum relative deviation of 13.28% at thirteen energy points in the energy range of 10–400 MeV. Therefore, the detector can monitor proton effective dose indirectly in real time by measuring the deposited energy. We calibrated the photoelectric conversion efficiency of the detector at the cobalt source, tested the response of the detector in the energy range of 30–100 MeV in unidirectional proton field, and validated the simulation with the experimental results.

关键词： Effective dose Space proton Scintillation detector ICRP Report No. 116 Deposited energy

A theoretical study of fragmentation dynamics of water dimer by proton impact

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Chinese Physics B 2023年第3期32卷 219-227页

作者：王志萍许雪芬张丰收王旭 Department of fundamental Courses Wuxi Institute of TechnologyWuxi 214121China The Key laboratory of Beam technology and Material Modification of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China

To investigate the collision processes of proton with the water dimer(H_(2)O)_(2)at 50 e V,the time-dependent density functional theory coupled with molecular dynamics nonadiabatically is *** specific collision orientations with various impact parameters are *** reaction channels,the mass distribution and the fragmentation mass spectrum are *** all launched samples,the probability of the channel of non-charge transfer scattering and charge transfer scattering is about 80%,hinting that the probability of fragmentation is about 20%.The reaction channel of proton exchange process 2 is taken as an example to exhibit the detailed microscopic dynamics of the collision process by inspecting the positions,the respective distance,the number of loss of electrons and the evolution of the electron *** study of the mass distribution and the fragmentation mass spectrum shows that among all possible fragments,the fragment with mass 36 has the highest relative abundance of 65%.The relative abundances of fragments with masses 1,35,and 34are 20%,13%,and 1.5%,*** the total electron capture cross section,the present calculations agree with the available measurements and calculations over the energy range from 50 e V to 12 ke V.

关键词： time-dependent density functional theory water dimer collision proton

Theoretical investigations of collision dynamics of cytosine by low-energy (150-1000 eV) proton impact

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Chinese Physics B 2020年第2期29卷 262-268页

作者： Zhi-Ping Wang Feng-Shou Zhang Xue-Fen Xu Chao-Yi Qian Department of fundamental Courses Wuxi Institute of TechnologyWuxi 214121China The Key laboratory of Beam technology and Material Modification of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China

Using a real-space real-time implementation of time-dependent density functional theory coupled to molecular dynamics（TDDFT-MD） nonadiabatically,we theoretically study both static properties and collision process of cytosine by150-1000 eV proton impact in the microscopic *** calculated ground state of cytosine accords well with *** is found that proton is scattered in any case in the present *** bond break of cytosine occurs when the energy loss of proton is larger than 22 eV and the main dissociation pathway of cytosine is the breaks of C1 N2 and N8 *** the range of 150 eV≤Ek≤360 eV,when the incident energy of proton increases,the excitation becomes more violent even though the interaction time is *** in the range of 360 eV

关键词： time-dependent density functional theory cytosine collision proton