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溶解性有机质对重金属在土壤中吸附和迁移的影响

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科学技术与工程 2016年第34期16卷 314-319页

作者：李小孟孟庆俊高波冯启言张英杰中国矿业大学环境与测绘学院徐州221116

溶解性有机质(DOM)是土壤中最具有活性的组分,可以与重金属发生吸附、解吸、络合等一系列作用,对重金属的迁移转化、生物有效性等产生一系列重要影响。通过实验研究溶解性有机质对重金属吸附和迁移的影响。吸附实验表明,重金属Cu、Pb、C... 详细信息

溶解性有机质(DOM)是土壤中最具有活性的组分,可以与重金属发生吸附、解吸、络合等一系列作用,对重金属的迁移转化、生物有效性等产生一系列重要影响。通过实验研究溶解性有机质对重金属吸附和迁移的影响。吸附实验表明,重金属Cu、Pb、Cr、Cd在土壤中吸附能力是不同的,土壤对重金属吸附能力的大小顺序为Pb>Cu>Cr>Cd。土柱实验表明,重金属Cu、Pb、Cd、Cr在土壤中的迁移规律相似,均为前期淋出液重金属含量较低,后期随时间的增大而增大,当达到吸附饱和后浓度趋于稳定。但不同重金属迁移速率各不相同,这与吸附实验结果相符。溶解性有机质的存在对重金属迁移的影响主要体现在迁移速率上,其穿透时间比去除有机质的情况短,有机质的存在有利于重金属离子向下迁移,但当达到饱和后对重金属迁移浓度影响不显著。

关键词：溶解性有机质土壤重金属吸附迁移

Local magnetic moment oscillation around an Anderson impurity on graphene

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 192-201页

作者： Shuai Li Zhen Ma Jin-Hua gao School of Science Hebei University of Science and Technology School of Electronics and Information Zhengzhou University of Light Industry School of Physics and Wuhan National High Magnetic Field Center Huazhong University of Science and Technology

We theoretically investigate the spin resolved Friedel oscillation （FO） and quasiparticle interference （QPI） in graphene induced by an Anderson *** the impurity becomes magnetic,the resulted FO becomes spin dependent,which gives rise to a local magnetic moment oscillation with an envelop decaying as r-2in real space in the doping ***,at half filling,the electron density and local magnetic moment will not oscillate but decay as *** spin resolved FO has both sublattice and spin ***,the local magnetic moment decay at half filling only occurs at one sublattice of graphene,which is quite like the phenomenon observed in the STM experiment (***ález-Herrero et al.,Science 352,437 （2016）).We further give an analytic formula about such spin dependent FO based on the stationary phase ***,we study the interference of quasiparticles around the magnetic impurity by calculating the spin dependent Fourier-transformed local density of states （FT-LDOS）.Our work gives a comprehensive understanding about the local magnetic moment oscillation around an Anderson impurity on graphene.

关键词： Friedel oscillation local magnetic moment graphene Anderson impurity

Influence of the Acoustic Liner in Large Eddy Simulation of Longitudinal Thermoacoustic Instability in a Model Annular Combustor

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Journal of Thermal Science 2024年第2期33卷 710-724页

作者： meng Sheng ZHANG Man gao Yi AECC Commercial Aircraft Engine Co. Ltd.Shanghai200241China School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai200240China

Although extensive efforts have been made to dampen the thermoacoustic instability,successfully controlling the pressure oscillations in modern gas turbines or aeroengines remains *** influence of the acoustic liner on the longitudinal thermoacoustic mode in a model annular combustor is investigated by Large Eddy Simulation(LES) in this *** result of the self-excited longitudinal thermoacoustic instability without the liner agrees well with the frequency and acoustic analysis of the pressure mode based on experimental *** different bias flow velocities of the liner located downstream of the combustor are then *** results reveal that the existence of the liner influences not only the acoustic field but also the flow *** the bias velocity is large,it leads to intense turbulence-induced fluctuations,and the pressure oscillation is modulated *** shows that the weak coupling between flow and pressure oscillations plays a significant role in the onset of the intermittency of a thermoacoustic *** on the dynamic analysis of the thermoacoustic system with the acoustic liner,this intermittency is caused by the influence of the flow field on the flame-acoustic ***,a low-order modeling method based on Van der Pol(VdP) oscillator with additive stochastic forcing is conducted to reproduce the evolving dynamics of the thermoacoustic *** the numerical cases demonstrated in this work are relatively simpler than those in a practical combustion system,the results are helpful for us to understand the effect of the acoustic liner and show the attractive potential to apply this device to suppress thermoacoustic instability.

关键词： thermoacoustic instability acoustic liner Large Eddy Simulation low-order modeling

Analysis of relationships between land surface temperature and land use changes in the Yellow River Delta

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Frontiers of Earth Science 2018年第2期12卷 444-456页

作者： Jicai NING Zhiqiang gao Ran meng Fuxiang XU meng gao Yantai Institute of Coastal Zone Research Chinese Academy of Sciences Yantai 264003 China Environmental & Climate Sciences Department Brookhaven National Laboratory Upton NY 11973 USA

This study analyzed land use and land coverchanges and their impact on land surface temperature usingLandsat 5 Thematic Mapper and Landsat 8 OperationalLand Imager and Thermal Infrared Sensor imagery of theYellow River Delta. Six Landsat images comprising twotime series were used to calculate the land surfacetemperature and correlated vegetation indices. The YellowRiver Delta area has expanded substantially because of thedeposited sediment carried from upstream reaches of theriver. Between 1986 and 2015, approximately 35% of theland use area of the Yellow River Delta has beentransformed into salterns and aquaculture ponds. Overall,land use conversion has occurred primarily from poorlyutilized land into highly utilized land. To analyze thevariation of land surface temperature, a mono-windowalgorithm was applied to retrieve the regional land surfacetemperature. The results showed bilinear correlationbetween land surface temperature and the vegetationindices （i.e., Normalized Difference Vegetation Index,Adjusted-Normalized Vegetation Index, Soil-AdjustedVegetation Index, and Modified Soil-Adjusted VegetationIndex）. Generally, values of the vegetation indices greaterthan the inflection point mean the land surface temperatureand the vegetation indices are correlated negatively, andvice versa. Land surface temperature in coastal areas isaffected considerably by local seawater temperature andweather conditions.

关键词： land surface temperature mono-window algo-rithm Yellow River Delta land use change vegetationindex

A complementary formulation for traffic equilibrium problem with a new nonadditive route cost

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Science China(Technological Sciences) 2011年第9期54卷 2525-2530页

作者： XU meng gao ZiYou MOE Key Laboratory for Urban Transportation Complex Systems Theory and Technology Beijing Jiaotong University Beijing 100044 China Institute of Systems Science School of Traffic and Transportation Beijing Jiaotong University Beijing 100044 China

Improviag transportation system is essential for all people in each city since transport plays a very important role. Using mathematical programming approach transport problem is an effective way to improve transportation system. In this paper, the traffic equilibrium problem （TEP） with a general nonadditive route cost function is studied. We formulate the route cost function for each route as a disutility function, which can evaluate route cost function flexibly and analyze the route toll conveniently. Furthermore, we present the TEP with a nonlinear complementary problem （NCP） formulation. The monotonicity and the existence with the NCP formulation are also given under relative assumptions.

关键词： traffic equilibrium problem nonadditive cost nonlinear complementarity problem

Efficient co-channel interference suppression in MIMO-OFDM systems

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Science China(Information Sciences) 2015年第2期58卷 116-130页

作者： meng Xin JIANG Bin gao XiQi National Mobile Communications Research Laboratory Southeast University

In this paper, we investigate channel frequency response(CFR) matrix and interference-plus-noise covariance matrix(ICM) estimation in multiple-input multiple-output(MIMO) and orthogonal frequency division multiplexing(OFDM) systems to suppress co-channel interference at the receiver side. We employ least square criterion to perform the initial CFR estimation. Then we estimate the autocorrelation function of interference-plus-noise in the time domain, instead of estimating the ICM in the frequency domain *** autocorrelation function estimation has two steps. Firstly, we present the inherent relationship between the expectation of the sample autocorrelation function of the residual(SAFR) and the true autocorrelation function, which is actually a linear transformation. Based on this, we propose a compensating method. This compensation brings significant performance gains when the pilot OFDM symbol number is small. Secondly,since the compensated SAFR cannot be guaranteed to be an autocorrelation sequence(ACS), which will make the obtained ICM loss the positive semidefinite property, we utilize semidefinite programming(SDP) to find an ACS that is the nearest to the compensated SAFR. The SDP is solved in its dual form, which yields a significant reduced complexity. Finally the estimated ICM is reutilized to revise the CFR estimation. The estimated CFR and ICM show excellent interference suppression performances when being applied in an interference rejection combining receiver.

关键词： MIMO-OFDM channel estimation co-channel interference interference-plus-noise covariance ma-trix moving average autocorrelation sequence semidefinite programming interference rejection combining

Stress distribution and surrounding rock control of mining near to the overlying coal pillar in the working face

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International Journal of Mining Science and Technology 2019年第6期29卷 881-887页

作者： Rui gao Bin Yu Xiangbin meng Key Laboratory of Deep Coal Resource Mining School of MinesMinistry of Education of ChinaChina University of Mining&TechnologyXuzhou 221116China Datong Coal Mine Group Co.Ltd. Datong 037000China

The occurrence of overlying coal pillar(OCP)exerts a strong effect on the stress and strain distribution of the surrounding rock in the *** this paper,the stress distribution characteristics are analyzed via the numerical calculation with the account of OCP presence or *** addition,this study revealed the joint effect of side pressure relief area of the goaf and stress concentration in OCP on the final stress ***,the rules of abutment stress distribution affected by three influencing factors,namely horizontal-vertical distances between OCP and working face and buried depth of OCP,are *** functional model linking the peak stress of surrounding rock with the above influencing factors is *** field application of the above results proved that the rib spalling and deformation of a 2.95 m-high and 5.66 m-wide roadway could be efficiently controlled by rationally adjusting working states of the support,and adopting the hydraulic prop coordinated with the p type metal beam and anchor cable to strengthen the surrounding rock of working face and roadway,*** proposed measures are considered appropriate to satisfy the safe operation requirements.

关键词： Overlying coal pillar(OCP) Stress distribution Influencing factors Surrounding rock control

Direct and rapid detection of serum amino acid and monoamine neurotransmitters to assist the diagnosis of panic disorder

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Science China Chemistry 2025年第1期 377-384页

作者： Shiwen Liu Xuerui Wan meng Zhao Jiaqi Wang Weilan Wu Linlin You Yonggui Yuan Qian Xu Rong gao Key Laboratory of Environmental Medicine Engineering Ministry of Education School of Public Health Southeast University Key Laboratory of Modern Toxicology of Ministry of Education Department of Hygienic Analysis and Detection School of Public HealthNanjing Medical University Department of Psychosomatics and Psychiatry Zhongda Hospital School of Medicine Southeast University

The measurement of amino acid and monoamine neurotransmitters（NTs） in serum plays a central role in the identification and monitoring of clinical panic disorder（PD）. However, the strong polarity and chemical heterogeneity of NTs make direct extraction and rapid detection extremely challenging. Herein, we developed a strategy that integrated solid phase extraction based on magnetic Fe3O4coated with polydopamine（Fe3O4@PDA） and direct analysis of mass spectrometry in real time（DART-MS） for quantification of 10 NTs. We systematically investigated the optimal conditions of this strategy to achieve good accuracy and precision. Compared with existing magnetic solid phase extraction methods for NTs detection in biological samples, this strategy could adsorb more targets while having similar adsorption efficiencies, and the total process time was reduced by an average of 69.42%. We rapidly determined the metabolic abnormality of 6 types of NTs in the serum of PD patients and demonstrated their diagnostic accuracy. In addition, an outstanding feature of PD in which tryptophan was more metabolized by the KYN pathway and the 5-hydroxytryptamine pathway was inhibited could be elucidated by this strategy. Our results highlighted the potential ability of Fe3O4@PDA coupled with DART-MS to assist in the clinical diagnosis of PD.

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Border collision bifurcations in 3D piecewise smooth chaotic circuit

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Applied Mathematics and Mechanics(English Edition) 2016年第9期37卷 1239-1250页

作者： Yinghui gao Xiangying meng Qishao LU School of Mathematics and System Sciences LMIB of the Ministry of EducationBeihang University Department of Biology University of Maryland School of Aeronautic Science and Engineering Beihang University

A variety of border collision bifurcations in a three-dimensional （3D） piecewise smooth chaotic electrical circuit are investigated. The existence and stability of the equilibrium points are analyzed. It is found that there are two kinds of non-smooth fold bifurcations. The existence of periodic orbits is also proved to show the occurrence of non-smooth Hopf bifurcations. As a composite of non-smooth fold and Hopf bifurcations, the multiple crossing bifurcation is studied by the generalized Jacobian matrix. Some interesting phenomena which cannot occur in smooth bifurcations are also considered.

关键词： electrical circuit border collision bifurcation multiple crossing