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Journal of Environmental Sciences 2009年第7期21卷 872-876页

作者： ZHANG Lizhu ma jun LI Xin WANG Shutao School of Science Harbin Institute of Technology Harbin 150090 China School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China

The effect of permanganate preoxidation on organic matter removal during the coagulation with aluminum chloride was investigated using tannic acid as a model compound. Results showed that a small amount of KMnO4 （0.75 mg/L） increased the removal efficiency of tannic acid up to 20%, as compared to the process of coagulation by aluminum chloride alone. The key factor enhancing the removal efficiency of tannic acid in preoxidation process was the in situ formation of a reductant manganese dioxide. The complexation model was used to describe the reaction between MnO2 and tannic acid. Under weak pH condition, tannic acid was difficult to be adsorbed by MnO2 due to the static electrical repulsive forces. The presence of Ca2＋ served as a bridge to hold the negative charged MnO2 and tannic acid together, which could be a crucial factor influencing tannic acid adsorption by in-situ manganese dioxide.

关键词： KMnO4 MnO2 adsorption coagulation oxidation tannic acid

Quantifying the Attractive Force Exerted on the Pinned Calcium Spiral Waves by Using the Adventive Field

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Chinese Physics Letters 2013年第11期30卷 199-202页

作者： QIU Kang TANG jun LUO Jin-Ming ma jun Department of mathematics and Physics Xuzhou Medical CollegeXuzhou 221004 College of Science China University of Mining and TechnologyXuzhou 221116 Department of Physics Lanzhou University of TechnologyLanzhou 730050

The cytosolic calcium system is inhomogenous because of the discrete and random distribution of ion channels on the ER *** is well known that the spiral tip can be pinned by the heterogenous area,and the field can detach the spiral from the *** use the adventive field to counteract the attractive force exerting on the calcium spiral wave by the heterogeneity,then the strength of the adventive field is used to quantify the attractive force *** factors determining the attractive force are *** is found that:(1)the attractive force sharply increases with size of the heterogeneity for small-size heterogeneity,whereas the force increases to a saturated value for large-size heterogeneity;(2)for large-size heterogeneity,the force almost remains constant unless the level of the heterogeneity vanishes,the force decreases to zero linearly and sharply,and for small-size heterogeneity,the force decreases successively with the level of the ***,it is found that the forces exist only when the spiral tip is very close to the heterogenous *** study may shed some light on the control or suppression of the calcium spiral wave.

关键词： wave attractive sharply

Multiple solutions and hysteresis in the flows driven by surface with antisymmetric velocity profile

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Chinese Physics B 2021年第9期30卷 83-88页

作者： Xiao-Feng Shi Dong-jun ma Zong-Qiang ma De-jun Sun Pei Wang Institute of Applied Physical and Computational mathematics Beijing 100094China Center for Applied Physics and Technology Peking UniversityBeijing 100871China Department of Modern Mechanics University of Science and Technology of ChinaHefei 230027China

Multiple steady solutions and hysteresis phenomenon in the square cavity flows driven by the surface with antisymmetric velocity profile are investigated by numerical simulation and bifurcation analysis.A high order spectral element method with the matrix-free pseudo-arclength technique is used for the steady-state solution and numerical *** complex flow patterns beyond the symmetry-breaking at Re≈320 are presented by a bifurcation diagram for Re<*** results of stable symmetric and asymmetric solutions are consistent with those reported in literature,and a new unstable asymmetric branch is obtained besides the stable branches.A novel hysteresis phenomenon is observed in the range of 2208

关键词： bifurcation and continuation symmetry-breaking hysteresis surface driven cavity flow

Integrated System for Combined Optical Coherence Tomography-Raman Spectroscopy of Neocaridina denticulate sinensis

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Journal of Ocean University of China 2021年第1期20卷 94-100页

作者： LIU Xiaoying ZHANG Xu ma jun SHI Xiaofeng Optics and Optoelectronics Laboratory Ocean University of ChinaQingdao 266100China

Optical coherence tomography(OCT)and Raman spectroscopy(RS)can be complementary biological tissue optical analysis *** study the internal structure and tissue compositions of biological samples,an OCT-RS system was built to carry out OCT section imaging and RS analysis in *** denticulate sinensis were collected regularly for morphological observation by OCT imaging and biochemical investigation based on the Raman *** internal structure of the *** sinensis was imaged by OCT,and the morphology of the tissues and the position in the body were distinguished according to the gray scale *** imaging depth along the vertical direction of Z-axis in *** sinensis is about 1.60 *** detection was selectively performed based on the OCT *** main Raman peaks of the rostrum,the cephalothorax,the abdominal segment,and the telson section are at 1006,1156,1447,1491 and 1515 cm-1,which are identified as proteins and amino *** presence of 1497 cm-1 at the cephalothorax is different from other parts,probably due to the presence of organs such as ovary,whose compositions are different from those of other *** combination of optical coherence tomography and Raman spectroscopy can provide information about morphological and biochemical features of tissues,and has potential applications in biomedical detection and imaging.

关键词： optical coherence tomography(OCT) Raman spectroscopy(RS) Neocaridina denticulate sinensis biological tissue

Differential coupling contributes to synchronization via a capacitor connection between chaotic circuits

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Frontiers of Information Technology & Electronic Engineering 2019年第4期20卷 571-583页

作者： Yu-meng XU Zhao YAO Aatef HOBINY jun ma Department of Physics Lanzhou University of Technology NAAM-Research Group Department of Mathematics King Abdulaziz University

Nonlinear oscillators and circuits can be coupled to reach synchronization and consensus. The occurrence of complete synchronization means that all oscillators can maintain the same amplitude and phase, and it is often detected between identical oscillators. However, phase synchronization means that the coupled oscillators just keep pace in oscillation even though the amplitude of each node could be different. For dimensionless dynamical systems and oscillators, the synchronization approach depends a great deal on the selection of coupling variable and type. For nonlinear circuits, a resistor is often used to bridge the connection between two or more circuits, so voltage coupling can be activated to generate feedback on the coupled circuits. In this paper, capacitor coupling is applied between two Pikovsk-Rabinovich(PR) circuits, and electric field coupling explains the potential mechanism for differential coupling. Then symmetric coupling and cross coupling are activated to detect synchronization stability, separately. It is found that resistor-based voltage coupling via a single variable can stabilize the synchronization, and the energy flow of the controller is decreased when synchronization is realized. Furthermore, by applying appropriate intensity for the coupling capacitor, synchronization is also reached and the energy flow across the coupling capacitor is helpful in regulating the dynamical behaviors of coupled circuits, which are supported by a continuous energy exchange between capacitors and the inductor. It is also confirmed that the realization of synchronization is dependent on the selection of a coupling channel. The approach and stability of complete synchronization depend on symmetric coupling, which is activated between the same variables. Cross coupling between different variables just triggers phase synchronization. The capacitor coupling can avoid energy consumption for the case with resistor coupling, and it can also enhance the energy exchang

关键词： Synchronization Voltage coupling Chaotic circuit Capacitor coupling

Structure and Function of N-Terminal Zinc Finger Domain of SARS-CoV-2 NSP2

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Virologica Sinica 2021年第5期36卷 1104-1112页

作者： jun ma Yiyun Chen Wei Wu Zhongzhou Chen State Key Laboratory of Agrobiotechnology and Beijing Advanced Innovation Center for Food Nutrition and Human Health College of Biological SciencesChina Agricultural UniversityBeijing 100193China Cherry Creek High School 9300 East Union AvenueGreenwood Village 80111USA

SARS-CoV-2 has become a global pandemic threatening human health and *** is urgent to find effective therapeutic agents and targets with the continuous emergence of novel mutant *** knowledge of the molecular basis and pathogenesis of SARS-CoV-2 in host cells requires to be understood *** unknown structure and function of nsp2 have hindered our understanding of its role in SARS-CoV-2 ***,we report the crystal structure of the N-terminal of SARS-CoV-2 nsp2 to a high resolution of 1.96?.This novel structure contains three zinc fingers,belonging to the C2 H2,C4,and C2 HC types,*** analysis suggests that nsp2 may be involved in binding nucleic acids and regulating intracellular signaling *** binding to single or double-stranded nucleic acids was mainly through the large positively charged region on the surface of nsp2,and K111,K112,K113 were key *** findings lay the foundation for a better understanding of the relationship between structure and function for *** is helpful to make full use of nsp2 as further research and development of antiviral targets and drug design.

关键词： Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) Crystal structure Zinc finger Electrophoretic mobility shift assays(EMSA) Small-angle X-ray scattering(SAXS)

Optimal Formation Reconfiguration Control of Multiple UCAVs Using Improved Particle Swarm Optimization

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Journal of Bionic Engineering 2008年第4期5卷 340-347页

作者： Hai-bin Duan Guan-jun ma De-lin Luo School of Automation Science and Electrical Engineering Beihang University Beijing 100191 P. R. China Provincial Key Laboratory for Information Processing Technology Suzhou University Suzhou 215006 P. R. China Center for Systems and Control Xiamen University Xiamen 361005 P. R. China

Optimal formation reconfiguration control of multiple Uninhabited Combat Air Vehicles （UCAVs） is a complicated global optimum problem. Particle Swarm Optimization （PSO） is a population based stochastic optimization technique inspired by social behaviour of bird flocking or fish schooling. PSO can achieve better results in a faster, cheaper way compared with other bio-inspired computational methods, and there are few parameters to adjust in PSO. In this paper, we propose an improved PSO model for solving the optimal formation reconfiguration control problem for multiple UCAVs. Firstly, the Control Parameterization and Time Diseretization （CPTD） method is designed in detail. Then, the mutation strategy and a special mutation-escape operator are adopted in the improved PSO model to make particles explore the search space more efficiently. The proposed strategy can produce a large speed value dynamically according to the variation of the speed, which makes the algorithm explore the local and global minima thoroughly at the same time. Series experimental results demonstrate the feasibility and effectiveness of the proposed method in solving the optimal formation reconfiguration control problem for multiple UCAVs.

关键词： uninhabited combat air vehicles particle swarm optimization control parameterization and time discretization optimal formation reeonfiguration

Immobilization of NZVI in polydopamine surface-modified biochar for adsorption and degradation of tetracycline in aqueous solution

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Frontiers of Environmental Science & Engineering 2018年第4期12卷 87-97页

作者： XiangyuWang Weitao Lian Xin Sun jun ma Ping Ning Faculty of Environmental Science and Engineering Kunming University of Science and Technology Kunming 650500 China School of Municipal and Environmental Engineering State Key Laboratory of Urban Water Resources and Environment Harbin Institute of Technology Harbin 150090 China＊

Polydopamine/NZVl@biochar composite （PDA/NZVI@BC） with high removal efficiency of tetracycline （TC） in aqueous solutions was successfully synthesized, The resultant composite demonstrated high reactivity, excellent stability and reusability over the reaction course. Such excellent performance can be attributed to the presence of the huge surface area on biochar （BC）, which could enhance NZVI dispersion and prolong its longevity. The carbonyl group contained on the surface of bioehar could combine with the amino group on polydopamine（PDA）. The hydroxyl groups in PDA is able to enhance the dispersion and loading of NZVI on BC. Being modified by PDA, the hydrophilicity of biochar was improved. Among BC, pristine NZVI and PDA/NZVI（L-BC, PDA/ NZVI（a-,BC exhibited the highest activity for removal of TC. Compared with NZVI, the removal efficiency of TC could be increased by 55.9c- by using PDA/NZVI@BC under the same conditions. The optimal modification time of PDA was 813, and the ratio of NZVI to BC was 1：2. In addition, the possible degradation mechanism of TC was proposed, which was based on the analysis of degraded praducts by LC-MS. Difli,-rent importanl /actors impacling on TC removal （including mass ratio of NZVI to BC/PDA, initial concentration, pH value and the initial temperature of the solution） were investigated as well. Overall, this study provides a promising alternative material and environmental pollution management option for antibiotic wastewater treatment.

关键词： Biochar Polydopamine NZVI Modification Tetracycline

Study on catalytic mechanisms of Fe_(3)O_(4)-rGO_(x) in three typical advanced oxidation processes for tetracycline hydrochloride degradation

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Chinese Chemical Letters 2023年第1期34卷 420-425页

作者： Heshan Zheng Yunying Hou Shuo Li jun ma jun Nan Nannan Wang College of Chemistry and Chemical Engineering Qiqihar UniversityQiqihar 161006China Urban Water Resources Development and Northern National Engineering Research Center Harbin 150090China School of Environment Harbin Institute of TechnologyHarbin 150090China Department of Environmental Engineering Beijing Institute of Petrochemical TechnologyBeijing 102617China

This study explored the catalytic mechanism and performance impacted by the materials ratio of Fe_(3)O_(4)-GO_(x) composites in three typical advanced oxidation processes(AOPs)of O_(3),peroxodisulfate(PDS)and photo-Fenton processes for tetracycline hydrochloride(TCH)*** ratio of GO in the Fe_(3)O_(4)-GO_(x) composites exhibited different trends of degradation capacity in each AOPs based on different ***_(3)O_(4)-rGO_(20wt%) exhibited the optimum catalytic performance which enhanced the ozone decomposition efficiency from 33.48%(ozone alone)to 51.83%with the major reactive oxygen species(ROS)of O_(2)·-.In PDS and photo-Fenton processes,Fe_(3)O_(4)-rGO_(5wt%) had the highest catalytic performance in PDS and H_(2)O_(2) decomposition for SO_(4)·–,and·OH generation,*** with using PDS alone,PDS decomposition rate and TCH degradation rate could be increased by 5.97 and 1.73 times under Fe_(3)O_(4)-rGO_(5wt%) *** the photo-Fenton system,Fe_(3)O_(4)-rGO_(5wt%) with the best catalyst performance in H_(2)O_(2) decomposition,and TCH degradation rate increased by 2.02 times compared with blank ***,the catalytic mechanisms in those systems of that the ROS produced by conversion between Fe^(2+)/Fe^(3+)were also analyzed.

关键词： Advanced oxidation progresses Fe_(3)O_(4) Graphene oxide Mechanism Reactive oxygen species

Uncertainty analysis and robust design optimization for the heat-assisted bending of high-strength titanium tube

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Science China(Technological Sciences) 2021年第10期64卷 2174-2185页

作者： ZHANG Zhao YANG JingChao HUANG WeiLiang ma jun LI Heng Taicang Yangtze River Delta Research Institute Northwestern Polytechnical UniversityTaicang 215400China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

Heat-assisted rotary draw bending(HRDB)is a promising technique for manufacturing difficult-to-form tubular components comprising high-strength titanium tubes(HSTTs)with small bending ***,as a multidie constrained and thermomechanical coupled process with many uncertainty factors,a high risk of several defects,such as cross-section distortion,over wall thinning,or even cracking,is *** the robust design optimization(RDO)of complex forming processes remains a nontrivial and challenging scientific ***,considering a high-strength Ti-3Al-2.5V titanium alloy tube as a case material,the five significant uncertainty factors in HRDB,i.e.,temperature distribution,tube geometrical characteristics,tube material parameters,tube/tool friction,and boost velocity had been ***,considering the preheating and HRDB of HSTT,a whole-process thermomechanical three-dimensional finite element model was established and validated for virtual ***,considering the maximum section distortion Q and maximum wall-thickness thinning t as the optimization objectives and the mean and variance of material and forming parameters,an RDO model was ***,the Pareto optimal solutions were obtained using the nondominated sorting genetic algorithm II,and a minimum distance selection method was employed to obtain the satisfactory *** show that the optimized solutions considering the uncertainty factors reduce the maximum section distortion rate of HSTT after bending by 38.1%and the maximum wallthickness thinning rate by 27.8%.

关键词： robust design optimization uncertainty factors heat-assisted bending high-strength titanium tube