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A New Explicit Symplectic Fourier Pseudospectral Method for Klein-Gordon-Schrodinger Equation

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Advances in Applied Mathematics and Mechanics 2018年第1期10卷 242-260页

作者： Yanhong Yang yongzhong song Haochen Li Yushun Wang Jiangsu Key Laboratory for NSLSCS Institute of MathematicsSchool of Mathematical SciencesNanjing Normal UniversityNanjing 210023China Department of Mathematics College of TaizhouNanjing Normal UniversityTaizhou 225300China LMAM CAPT and School of Mathematical SciencesPekingUniversityBeijing 100871China

In this paper,we propose an explicit symplectic Fourier pseudospectral method for solving the Klein-Gordon-Schr odinger *** key idea is to rewrite the equation as an infinite-dimensional Hamiltonian system and discrete the system by using Fourier pseudospectral method in space and symplectic Euler method in *** composing two different symplectic Euler methods for the ODEs resulted from semi-discretization in space,we get a new explicit scheme for the target equation which is of second order in space and spectral accuracy in *** canonical Hamiltonian form of the resulted ODEs is presented and the new derived scheme is proved strictly to be *** new scheme is totally explicitwhereas symplectic scheme are generally implicit or *** stability analysis is carried and a necessary Courant-Friedrichs-Lewy condition is *** numerical results are reported to test the accuracy and efficiency of the proposed method in long-term computing.

关键词： Klein-Gordon-Schr odinger equation Fourier pseudospectral method symplectic scheme explicit scheme

A New Understanding of Channel Patterns and Facies Models of the Shallow Lake Delta Facies of Fuyu Oil Reservoir in songliao Basin,China

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Acta Geologica Sinica(English Edition) 2008年第3期82卷 596-609页

作者： LI Yanping CHEN Shumin song yongzhong ZHANG Erhua SHEN Jiagang ZHENG Jianbin College of Marine Geosciences Ocean University of China Qingdao Shandong 266100 Qinhuangdao School of Daqing Petroleum College Qinhuangdao Hebei 066004 Exploration and Development Institute ofDaqing Oilfield Co. Ltd. Daqing Heilongjiang 163712

In the Fuyu Reservoir of songliao Basin, there occur a series of well-developed peculiar shallow lake delta facies, which can be divided to such three ones as the upper delta plain subfacies, the lower delta plain subfacies, and the delta front subfacies. Among them the upper delta plain subfacies mainly grows proximal distributary channels; the lower delta plain subfacies mainly grows distal ones. The entire Fuyu Reservoir has mainly developed 7 kinds of distributary channel patterns： proximal/ distal meandering type distributary channels, proximal/distal low-sinuosity type distributary channels, proximal/distal straight type distributary channels, and subaqueous distributary channels. Among these patterns, the proximal and distal meandering type distributary channels have bigger thickness of point bar and better sorting and low content of mud; moreover, they are the major reservoirs and occur in the bottom of Quan-4th member. The sandbars of the subaqueous distributary channels have higher mud content, and serve as the poorer reservoirs, and mainly occur in the top of Quan-4th member.

关键词： Fuyu Reservoir shallow lake delta lower delta plain proximal/distal distributary channels

Explicit One-Step P-Stable Methods for Second Order Periodic Initial Value Problems

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Numerical Mathematics A Journal of Chinese Universities(English Series) 2006年第3期15卷 237-247页

作者： Qinghong Li yongzhong song School of Mathematics and Computer Science Nanjing Normal University Naniina 210097 China Department of Mathematics Chuzhou College Chuzhou 239000 China.

In this paper, we present an explicit one-step method for solving periodic initial value problems of second order ordinary differential equations. The method is P-stable, and of first algebraic order and high phase-lag order. To improve the algebraic order, we give a composition second order scheme with the proposed method and its adjoint. We report some numerical results to illustrate the efficiency of our methods.

关键词：周期初值问题周期间隔 P-稳定相位滞后

Using NH_(2)-MIL-125(Ti)for efficient removal of Cr(Ⅵ)and Rh B from aqueous solutions:Competitive and cooperative behavior in the binary system

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Journal of Environmental Sciences 2024年第2期136卷 437-450页

作者： Lei Zheng Lixia Sun Jiangbo Qiu Junling song Luyi Zou Yue Teng yongzhong Zong Hongyan Yu School of Environmental and Civil Engineering Jiangnan UniversityWuxi 214122China School of Chemical and Material Engineering Jiangnan UniversityWuxi 214122China Kunming South Water Co. Ltd.Kunming 650501China Jiangsu Key Laboratory of Anaerobic Biotechnology Jiangnan UniversityWuxi 214122China

The coexistence of inorganic and organic contaminants is a challenge for real-life water treatment ***,in this research,we used NH_2-MIL-125(Ti)to evaluate the single adsorption of hexavalent chromium(Cr(Ⅵ))or Rhodamine B(RhB)in an aqueous solution and further investigate simultaneous adsorption experiments to compare the adsorption behavior *** main influencing factors,for example,reaction time,initial concentration,reaction temperature,and pH were studied in *** all reaction systems,the pseudo-second-order kinetic and Langmuir isotherm models were well illuminated the adsorption progress of Cr(Ⅵ)and *** studies showed that the adsorption process was spontaneous and *** compared to the single system,the adsorption capacity of Cr(Ⅵ)in the binary system gradually decreased as the additive amount of RhB increased,whereas the adsorption capacity of RhB in the binary system was expanded *** the binary reaction system contained 100 mg/L Cr(Ⅵ),the removal rate of RhB increased to 97.58%.The formation of Cr(Ⅵ)-RhB and Cr(Ⅲ)-RhB complexes was the cause that provided facilitation for the adsorption of *** findings prove that the interactions during the water treatment process between contaminants may obtain additional benefits,contributing to a better adsorption capacity of co-existing contaminant.

关键词： Adsorption Heavy metal ion Organic dye Simultaneous removal Mechanism studies

WAVEFORM RELAXATION METHODS AND ACCURACY INCREASE

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Annals of Differential Equations 1995年第4期11卷 440-454页

作者： song yongzhong (Nanjing Normal University,) Nanjing Normal University 210024

In this paper we propose some waveform relaxation (WR) methods for solving large systems of initial value problems. Nonlinear ODEs, linear ODEs, semi-explicit DAEs and linear DAEs are discussed. The accuracy increase ... 详细信息

关键词： ordinary differential system differential-algebraic system waveform relaxation method accuracy increase

Analysis and Monitoring of Indoor Radon Concentrations of 37 Kindergartens — Beijing Municipality, China, 2023

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China CDC weekly 2024年第13期6卷 272-276页

作者： Meinan Yao Kuke Ding Xiaozhe Tang Yunyun Wu Yanchao song Shuyuan Liu Bin Bai Li Zhang yongzhong Ma Institute for Radiation Hygiene Protection Beijing Center for Disease Prevention and ControlBeijingChina Chinese Center for Disease Control and Prevention BeijingChina Key Laboratory of Radiological Protection and Nuclear Emergency&National Institute for Radiological Protection Chinese Center for Disease Control and PreventionBeijingChina

Introduction:Radon(222Rn or 222radon)is a radioactive gas emitted from building materials,foundations,and *** are especially susceptible to radon exposure,underscoring the need to assess indoor radon levels in *** study monitored radon concentrations in 37 Beijing kindergartens from June to October ***:A random sample of 37 kindergartens was selected from 18 administrative districts in *** indoor radon concentration was measured using the solid track accumulation method,with radon detectors continuously monitored over a 3-month ***:The mean indoor radon level in 37 kindergartens,observed at 252 monitoring points,was 84.3 Bq/m3,with values varying from 12.9 to 263.5 Bq/*** 20.2%of points showed radon levels between 100.0 and 200.0 Bq/m3,while 2.4%exceeded 200.0 Bq/***,radon levels were significantly elevated on the ground floor compared to the upper ***:Indoor radon levels in 37 kindergartens remained below the national standard limit of 300.0 Bq/m3 for buildings(GB/T 16146-2015).Nonetheless,18.9%of the kindergartens exceeded the 100.0 Bq/m3 limit set for new *** is advised to improve radon monitoring in kindergartens and consider developing a national standard for maximum permissible radon levels in such facilities.

关键词： Radon limit floor