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Adsorption of phosphorus in sediment re-suspension under sudden expansion flow conditions

Journal of Hydrodynamics 2013年第1期25卷 112-117页

作者： LIANG Wen WANG Ze JIAO Zeng-xiang WAN Jun College of Mechanics and Materials Hohai University State Key Laboratory for Turbulence and Complex System Department of Mechanics and Aerospace Engineering Peking University

Based on the study of hydraulic characteristics of the sudden expansion water flow of an annular flume, this paper determines the vertical velocity distribution and the turbulence intensity distribution in the mainstream and the recirculation regions to analyze the basic features of this flow field. The adsorption of the phosphorus in the sediment is studied by adding the bacteriostatic agent. The results show that the flow speed in the mainstream region is higher than that in the recirculation region. However, the turbulence intensity in the recirculation region increases more than that in the mainstream region. The adsorption of the phosphorus in the sediment includes the physisorption and the biosorption, and the former is stronger than the latter. With the biosorption in the phosphorus removal process, the phosphorus released by the sediment is mainly completed by the poly-P bacteria in the anaerobic condition. The adsorption of the phosphorus in the sediment in the mainstream region of a sudden expansion water flow is strong and stable, whereas the adsorption in the sediment in the recirculation region is largely fluctuated.

关键词： sudden expansion flow sediment phosphorus adsorption effect

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Wave propagation in a magneto-electro- elastic plate

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Science China(Physics,Mechanics & Astronomy) 2008年第6期51卷 651-666页

作者： WEI JianPing SU XianYue State Key Laboratory for Turbulence and Complex System and Department of Mechanics and Aerospace Engineering Peking UniversityBeijing 100871China

The wave propagation in a magneto-electro-elastic plate was studied. Some new characteristics were discovered: the guided waves are classified in the forms of the Quasi-P, Quasi-SV and Quasi-SH waves and arranged by the standing wavenumber; there are many patterns for the physical property of the magneto-electro-elastic dielectric medium influencing the stress wave propagation. We proposed a self-adjoint method, by which the guided-wave restriction condition was derived. After the corresponding orthogonal sets were found, the analytic dispersion equa-tion was obtained. In the end, an example was presented. The dispersive spectrum, the group velocity curved face and the steady-state response curve of a mag-neto-electro-elastic plate were plotted. Then the wave propagations affected by the induced electric and magnetic fields were analyzed.

关键词： magneto-electro-elastic plate guided-wave restriction condition dispersive equation dispersive spectrum group velocity curved face steady-state response curve

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Calculating models of mass action concentrations for structural units or ion couples in RbCl-H_2O binary system and RbCl-RbNO_3-H_2O ternary system

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Transactions of Nonferrous Metals Society of China 2010年第6期20卷 1112-1120页

作者：郭汉杰杨学民赵伟洁 School of Metallurgical and Ecological Engineering University of Science and Technology Beijing State Key Laboratory of Multiphase Complex System Institute of Process Engineering Chinese Academy of Sciences

Thermodynamic models of calculating mass action concentrations for structural units or ion couples in RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions were developed based on the ion and molecule coexistence theory at 298.15 K.A transformation coefficient is needed to compare the calculated mass action concentration and the reported activity because they are obtained at different standard states and concentration *** results show that the transformation coefficients between the calculated mass action concentrations and the reported activities of the same structural units or ion couples in RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions change in a very narrow *** transformed mass action concentrations of structural units or ion couples in RbCl-H2O binary system are in good agreement with the reported activities. The transformed mass action concentrations of RbCl and RbNO3 in RbCl-RbNO3-H2O ternary solution are also in good agreement with the reported activities,aRbCl and 3RbNOa,with different total ionic strengths as 0.01,0.05,0.1,0.5,1.0,1.5,2.0,3.0 and 3.5 mol/kg,*** those results mean the developed thermodynamic model of strong electrolyte aqueous solutions can reflect structural characteristics of RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions and the mass action concentration also strictly follows the mass action law.

关键词： mass action concentration activity ion and molecule coexistence theory RbCl-H2O RbCl-RbNO3-H2O structural unit ion couple

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Sub/supercritical carbon dioxide induced phase switching for the reaction and separation in ILs/methanol

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Green Energy & Environment 2016年第2期1卷 144-148页

作者： Jiayu Xin Dongxia Yan Ruimei Cao Xingmei Lu Huixian Dong Suojiang Zhang Beijing Key Laboratory of Ionic Liquids Clean Process State Key Laboratory of Multiphase Complex System Institute of Process Engineering Chinese Academy of Sciences

Separation of products from ionic liquid(IL) solvents is one of the main challenges that hinder their utilizations. In this study, the production of γ-valerolactone(GVL) by selective hydrogenation of α-angelica lactone(AL) and separation of the products from the IL solvent were carried out by using subcritical CO_2 as a "switch" at room temperature. After the mixture was separated into two phases by subcritical CO_2, AL and nano Pd/C catalyst were only found in the lower IL-rich phase, GVL was produced with quantitative yield and enriched in the upper methanolrich phase. Pure GVL can be obtained by depressurizing to release CO_2 and evaporation to remove methanol of the upper phase, the lower phase containing IL, catalyst and methanol can be recycled for the next reaction. The strategy may provide a new approach to produce and separate products from IL solvents at mild conditions.

关键词： Separation Ionic liquids Selective hydrogenation Mild condition Subcritical CO2

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Angstrom science:Exploring aggregates from a new viewpoint

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Green Energy & Environment 2016年第1期1卷 75-78页

作者： Suojiang Zhang Feng Huo Beijing Key Laboratory of Ionic Liquids Clean Process State Key Laboratory of Multiphase Complex SystemInstitute of Process EngineeringChinese Academy of Sciences

A small aggregate is composed of several or tens of molecules or ions, with at least one dimension in the range from a few to dozens of angstroms. Here, we named such aggregate system as Angstrom Aggregates(AA). AA with the specific size in angstrom meter might possess unique structure activity relationship. Unlike molecular level, nano system and the bulk, AA, an aggregate in angstrom scale is firstly proposed,its arrangement in order, electronic effect, surface interaction, confinement effect, is still unclear. However, recently, the structure and activity relationship of such aggregate in angstrom scale has attracted increasing interest in many areas, such as in ionic liquids, aqueous solution,catalytic system, and bio-system. As the physical and chemical propeties of AA strongly depends on its structure, the in situ characterizzation technique combined with theoretical methods should be developed to understand the exact interaction between the component of the clusters, the assembly formations, the special features, and the reaction activities. It has great scientific meaning to detect, represent and regulate the structure and function of AA precisely, facilitating in its application. A systematic and thorough research on AA in angstrom scale will promote the development of fundamental science and the progress of technology significantly.

关键词： Angstom science Aggregates Aqueous system Bio-system Ionic liquids

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Lightweight GPU-Accelerated Parallel Processing of the SCHISM Model Using CUDA Fortran

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Journal of Marine Science and engineering 2025年第4期13卷 662-662页

作者： Zhang, Hongchun Cao, Qian Wu, Changmao Xu, Guangjun Liu, Yuli Feng, Xingru Jin, Meibing Dong, Changming State Key Laboratory of Climate System Prediction and Risk Management Nanjing210044 China International Geophysical Fluid Research Center Nanjing210044 China Nanjing University of Information Science and Technology Nanjing210044 China School of Marine Sciences Nanjing University of Information Science and Technology Nanjing210044 China Institute of Software Chinese Academy of Sciences Beijing100190 China School of Electronics and Information Engineering Guangdong Ocean University Zhanjiang524088 China Key Laboratory of Ocean Circulation and Waves Institute of Oceanology Chinese Academy of Sciences Qingdao266071 China Zhuhai519000 China

The SCHISM model is widely used for ocean numerical simulations, but its computational efficiency is constrained by the substantial resources it requires. To enhance its performance, this study develops GPU–SCHISM, a GPU-accelerated parallel version of SCHISM using the CUDA Fortran framework, and this study evaluates its acceleration performance on a single GPU-enabled node. The research results demonstrate that the GPU–SCHISM model achieves computational acceleration while maintaining high simulation accuracy. For small-scale classical experiments, a single GPU improves the efficiency of the Jacobi solver—identified as a performance hotspot—by 3.06 times and accelerates the overall model by 1.18 times. However, increasing the number of GPUs reduces the computational workload per GPU, which hinders further acceleration improvements. The GPU is particularly effective for performing higher-resolution calculations, leveraging its computational power. For large-scale experiments with 2,560,000 grid points, the GPU speedup ratio is 35.13;however, CPU has more advantages in small-scale calculations. Moreover, a comparison between CUDA and OpenACC-based GPU acceleration shows that CUDA outperforms OpenACC under all experimental conditions. This study marks the first successful GPU acceleration of the SCHISM model within the CUDA Fortran framework, laying a preliminary foundation for lightweight GPU-accelerated parallel processing in ocean numerical simulations. © 2025 by the authors.

关键词： Acceleration

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Novel polarimetric detector for target detection in heterogeneous clutter

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Journal of systems engineering and Electronics 2016年第6期27卷 1135-1141页

作者： Xu Cheng Longfei Shi Yuliang Chang Yongzhen Li Xuesong Wang State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System College of Electronic Science and Engineering National University of Defense Technology

A detection of static or slowly moving targets in the inhomogeneous clutter of polarimetric radar is researched and a new detector without exploiting the training set is developed, which has a good performance against the inhomogeneous clutter. The decision rule ensures the constant false alarm rate (CFAR) with respect to the disturbance covariance matrix. Numerical results show the robustness of the proposed method against the inhomogeneous clutter. © 2016 Beijing Institute of Aerospace Information.

关键词： Clutter (information theory) Covariance matrix Numerical methods Polarimeters Radar Radar clutter Radar signal processing Signal processing

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An efficient adaptive space partitioning algorithm for electromagnetic scattering calculation of complex 3D models

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Journal of systems engineering and Electronics 2021年第5期32卷 1071-1082页

作者： HUANG Minjie ZHOU Yaoming WANG Yongchao LIU Zhongtie School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Key Laboratory of Complex Aviation System Simulation Beijing 100076China

The space partitioning algorithm based on the rounding and addressing operations has been proved to be an efficient space partitioning algorithm with the potential for real-time *** improvement on this kind of space partitioning algorithms for solving complex 3D models is *** examples show that the efficiency of the improved algorithm is better than that of the original *** the size of most target elements is smaller than the size of spatial grids,the efficiency of the improved method can be more than four times of that of the original *** adaptive method of space partitioning based on the improved algorithm is developed by taking the surface element density or the curvature as the threshold for deep partitioning and conducting the deep partitioning using the octree method.A computer program implementation for applying the method in some typical applications is discussed,and the performance in terms of the efficiency,reliability,and resource use is *** testing shows that the results of the adaptive spacing partitioning are more convenient for the follow-up use than that of the basic uniform space ***,when it is used to calculate the electromagnetic scattering of complex targets by the ray tracing(RT)method,the adaptive space partitioning algorithm can reduce the calculation time of the RT process by more than 40%compared with the uniform space segmentation algorithm.

关键词： adaptive space partitioning computer graphics binary space partitioning ray tracing(RT)method stealth technology

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Numerical Simulation of Random Close Packing with Tetrahedra

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Chinese Physics Letters 2008年第5期25卷 1724-1726页

作者：李水乡赵健周璇 College of Engineering Peking University Beijing 100871 State Key Laboratory for Turbulence and Complex System Study Peking University Beijing 100871

The densest packing of tetrahedra is still an unsolved problem. Numerical simulations of random close packing of tetrahedra are carried out with a sphere assembly model and improved relaxation algorithm. The packing density and average contact number obtained for random close packing of regular tetrahedra is 0.6817 and 7.21 respectively, while the values of spheres are 0.6435 and 5.95. The simulation demonstrates that tetrahedra can be randomly packed denser than spheres. Random close packings of tetrahedra with a range of height are simulated as well. We find that the regular tetrahedron might be the optimal shape which gives the highest packing density of tetrahedra.

关键词： supernova explosion proto-neutron star shock wave

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Large-scale synthesis of hierarchical MnO_2 for benzene catalytic oxidation

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Particuology 2014年第3期12卷 71-75页

作者： Dongyan Li Genli Shen Wenxiang Tang Haidi Liu Yunfa Chen State Key Laboratory of Multi-phase Complex System Institute of Process EngineeringChinese Academy of Sciences University of Chinese Academy of Sciences

Hierarchical sea-urchin-shaped manganese oxide microspheres were synthesized via a facile method based on the reaction between KMnO4 and MnSO4 in HNO3 solution at 50℃. The average diameter of the microspheres is -850 nm. The microspheres consist of a core of diameter of -800 nm and nanorods of width -50 nm. The nanorods exist at the edge of the core, The Brunauer-Emmett-Teller surface area of the sea-urchin-shaped microspheres is 259.4 m^2/g. A possible formation mechanism of the hierarchical sea-urchin-shaped microspheres is proposed. The temperature for 90% conversion of benzene （T90%） on the hierarchical urchin-shaped MnO2 microspheres is about 218 ℃.

关键词： Manganese oxide Hierarchical Catalyst Benzene

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