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Kinetics study on photochemical oxidation of polyacrylamide by ozone combined with hydrogen peroxide and ultraviolet radiation

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Journal of Environmental Sciences 2006年第4期18卷 660-664页

作者： ren guang-meng SUN De-zhi CHUNG Jong Shik School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China Department of Chemical Engineering Pohang University of Science and Technology Pohang 790-784 South Korea

An investigation on the process of ozone combined with hydrogen peroxide and ultraviolet radiation has been carried out in order to establish the kinetics for photochemical oxidation of polyacrylamide （PAM） in aqueous solution. Effects of operating parameters, including initial PAM concentration, dosages of ozone and hydrogen peroxide, UV radiation and pH value on the photochemical oxidation of PAM, have been studied. There was an increase in photochemical oxidation rate of PAM with increasing of dosages of 03, H2O2 and ultraviolet radiation. Upon increasing of the initial PAM concentration, the photochemical oxidation rate of PAM decreased. Slight effect of pH value on the photochemical oxidation rate of PAM was observed in the experiments. The kinetics equation for the photochemical oxidation of PAM by the system has been established.

关键词： photochemical oxidation polyacrylamide kinetics ozone/hydrogen peroxide/ultraviolet radiation

A Two-Soliton Solution of Cubic Schrodinger Equation

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Chinese Physics Letters 1996年第1期13卷 17-19页

作者： YAN Jia-ren CHOU guang-hui WANG Xiao-gang Department of Physics Hu'nan Normal UniversityChangsha 410081

An exact two-soliton solution of cubic Schrodinger equation is derived by using the inverse scattering method,where the transmission coefficient has one pole of second order instead of two simple *** solution describes such a process that two infinitely separated solitons approach and then pass through each other and keep straight on infinitely.

关键词： infinitely straight soliton

An assessment of surrogate fuel using Bayesian multiple kernel learning model in sight of sooting tendency

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Frontiers in Energy 2022年第2期16卷 277-291页

作者： Lei ZHU Zhan GAO Xiaogang CHENG Fei ren zhen HUANG Key Laboratory for Power Machinery and Engineering of the Ministry of Education Shanghai Jiao Tong UniversityShanghai 200030China

An integrated and systematic database of sooting tendency with more than 190 kinds of fuels was obtained through a series of experimental investigations. The laser-induced incandescence (LII) method was used to acquire the 2D distribution of soot volume fraction, and an apparatus-independent yield sooting index (YSI) was experimentally obtained. Based on the database, a novel predicting model of YSI values for surrogate fuels was proposed with the application of a machine learning method, named the Bayesian multiple kernel learning (BMKL) model. A high correlation coefficient (0.986) between measured YSIs and predicted values with the BMKL model was obtained, indicating that the BMKL model had a reliable and accurate predictive capacity for YSI values of surrogate fuels. The BMKL model provides an accurate and low-cost approach to assess surrogate performances of diesel, jet fuel, and biodiesel in terms of sooting tendency. Particularly, this model is one of the first attempts to predict the sooting tendencies of surrogate fuels that concurrently contain hydrocarbon and oxygenated components and shows a satisfying matching level. During surrogate formulation, the BMKL model can be used to shrink the surrogate candidate list in terms of sooting tendency and ensure the optimal surrogate has a satisfying matching level of soot behaviors. Due to the high accuracy and resolution of YSI prediction, the BMKL model is also capable of providing distinguishing information of sooting tendency for surrogate design.

关键词： sooting tendency yield sooting index Bayesian multiple kernel learning surrogate assessment surrogate formulation

Reliable calculations of nuclear binding energies by the Gaussian process of machine learning

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Nuclear Science and Techniques 2024年第6期35卷 130-144页

作者： Zi-Yi Yuan Dong Bai zhen Wang Zhong-Zhou ren School of Physics Science and Engineering Tongji UniversityShanghai 200092China College of Science Hohai UniversityNanjing 211100China Key Laboratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China

Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the nuclear binding energies are modeled directly using a machine-learning method called the Gaussian process. First, the binding energies for 2238 nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ability of the Gaussian process in the studies of binding energies. Then, the predictive power of the Gaussian process is studied by calculating the binding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeably, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 834, 137484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding energies and α-decay properties.

关键词： Nuclear binding energies decay Machine learning Gaussian process

Stable Central Limit Theorems for Super Ornstein–Uhlenbeck Processes,Ⅱ

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Acta Mathematica Sinica,English Series 2022年第3期38卷 487-498页

作者： Yan Xia ren ren Ming SONG zhen Yao SUN Jian Jie ZHAO LMAM School of Mathematical Sciences&Center for Statistical Science Peking UniversityBeijing100871P.R.China Department of Mathematics University of Illinois at Urbana-ChampaignUrbanaIL61801USA School of Mathematics and Statistics Wuhan UniversityWuhan430072P.R.China The Faculty of Industrial Engineering and Management TechnionHaifa3200003Israel School of Mathematical Sciences Peking UniversityBeijing100871P.R.China

This paper is a continuation of our recent paper(***.,24(141),(2019))and is devoted to the asymptotic behavior of a class of supercritical super Ornstein-Uhlenbeck processes(X_(t))t≥0 with branching mechanisms of infinite second *** the aforementioned paper,we proved stable central limit theorems for X_(t)(f)for some functions f of polynomial growth in three different ***,we were not able to prove central limit theorems for X_(t)(f)for all functions f of polynomial *** this note,we show that the limiting stable random variables in the three different regimes are independent,and as a consequence,we get stable central limit theorems for X_(t)(f)for all functions f of polynomial growth.

关键词： Superprocesses Ornstein–Uhlenbeck processes stable distribution central limit theorem law of large numbers branching rate regime

A new epoch of quantum manipulation

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National Science Review 2014年第1期1卷 91-100页

作者： Yongjian Han zhen Wang guang-Can Guo Key Laboratory of Quantum Information University of Science and Technology of China Chinese Academy of Sciences

he behavior of individual microscopic particles,such as an atom(or a photon),predicted using quantum mechanics,is dramatically diferent from the behavior of classical particles,such as a planet,determined using classical *** can the counter-intuitive behavior of the microscopic particle be veriied and manipulated experimentally?David Wineland and Serge Haroche,who were awarded the Nobel Priz in physics in 2012,developed a set of methods to isolate the ions and photons from their environment to create a genuine quantum ***,they also developed methods to measure and manipulate these quantum systems,which open a path not only to explore the fundamental principles of quantum mechanics,but also to develop a much faster computer:a quantum computer.

关键词： quantum manipulation quantum computation optical clock ion trap cavity QED

Prescribed time control based on the periodic delayed sliding mode surface without singularities

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Science China(Information Sciences) 2024年第7期67卷 256-270页

作者： Bin ZHOU Yi DING Kang-Kang ZHANG guang-ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology

In this paper, nonsingular prescribed-time control is studied based on periodic delayed sliding mode surfaces. Different from the existing sliding mode control, where either singularity problems may appear or the convergence time depends on the initial state, the proposed sliding mode control approaches can achieve prescribed-time convergence without singularity. The proposed nonsingular sliding mode control approaches can be applied to both second-order and high-order nonlinear systems with prescribed-time convergence. As applications of the proposed sliding mode control approaches, the control of hypersonic vehicle systems is revisited. Numerical simulations on the nonlinear model of the hypersonic vehicle system show the effectiveness of the proposed methods.

关键词： prescribed-time control smooth periodic delayed feedback sliding mode control high-order nonlinear systems hypersonic vehicle systems

Analysis of the Load-Stress Response Characteristics of the Bogie Frame in Intercity Electric Multiple Unit

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Chinese Journal of Mechanical Engineering 2018年第2期31卷 227-237页

作者： Hua Zou Shou-guang Sun Qiang Li Zun-Song ren Engineering Research Center of Structure Reliability and Operation Measurement Technology of Rail Guided Vehicles of Ministry of Education Beijing Jiaotong University

Load spectra research for bogie frame requires establishing the load?stress relationship on working condition, which has been omitted by the researchers. With the load?stress of the bogie frame of an intercity Electric Multiple Unit(Hereinafter referred to as EMU) as the research object, an optimization model of the load?stress transfer relationship is established. The load?stress coe cient for EMU bogie frame was calibrated in the laboratory bench and online test was arranged on Dazhou?Chengdu line. Comparison of nonlinear and linear neural networks proves that the linear transitive relation between the load and stress of the bogie frame in the operating process is highly suitable. An optimization model of the load?stress transfer coe cient is obtained. The data calculated with the modified coe cient are closer to the dynamic stress results in the actual operating process than the data calculated with the calibration coe cient. The coe cient of the modified transitive relation is una ected by operating area, empty load, heavy load, or other conditions in the operating process of the intercity EMU. The real loads in actual situations are obtained. The model of online load?stress relationship that is highly suitable for line stress calculation is finally established. The research is helpful for further damage calculation and inferring the time history signal of the load in load spectra research.

关键词： Bogie frame Load Stress Transitive relation Neural network

Higher-order vibration of thick composite and sandwich plates based on an alternative higher-order model

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Chinese Journal of Aeronautics 2023年第3期36卷 406-420页

作者： Jinghui DENG Tangzhen WU zhen WU zhengliang LIU Xiaohui ren China Helicopter Research and Development Institute Jingdezhen 333001China School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China School of Mechanical Engineering Xi’an Aeronautical UniversityXi’an 710065China

The transverse stretching vibration of thick sandwich plates,which is attributed to largely different stiffness at the adjacent layers,is a challenging issue,and efficient approach for such issue is less reported in the published ***,natural frequencies corresponding to stretching vibration modes are generally neglected in engineering design,which might impact structural safety as frequencies of the exciting force are close to transverse stretching vibration *** paper proposes an alternative higher-order model for dynamic analysis corresponding to the higher-order vibration *** proposed model is classified in the displacement-based equivalent single-layer theory,as the number of displacement parameters in the proposed model is independent of the layer *** continuity of displacements and transverse shear stresses can be fulfilled at the interfaces between the adjacent layers of *** demonstrate the capability of the proposed model,typical examples are analyzed by utilizing the proposed model,the threedimensional finite element method and the chosen higher-order *** comparing with the exact three-dimensional elasticity solutions,it is found that the proposed model can yield more accurate natural frequencies corresponding to the higher-order displacement modes than the selected ***,the factors influencing reasonable prediction of the higher-order frequencies are investigated in detail,which can provide a reference for the accurate prediction of the higher-order frequencies.

关键词： Analytical solution Higher-order theory Natural frequency Sandwich plate Transverse stretching vibration