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Sulfate reducing bacterial community and in situ activity in mature fine tailings analyzed by real time qPCR and microsensor

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Journal of Environmental Sciences 2016年第6期28卷 141-147页

作者： Hong liu Shuying Tan tong Yu Yang liu Department of Civil and Environmental Engineering University of Alberta

Sulfate reducing bacteria（SRB） play significant roles in anaerobic environments in oil sands mature fine tailings（MFTs）. Hydrogen sulfide（H2S） is produced during the biological sulfate reduction process. The production of toxic H2S is one of the concerns because it may hinder the landscape remediation efficiency of oil sands tailing ponds. In present study, the in situ activity and the community structure of SRB in MFT and gypsum amended MFT in two settling columns were investigated. Combined techniques of H2S microsensor and dissimilatory sulfite reductase β-subunit（dsrB） genes-based real time quantitative polymerase chain reaction（qPCR） were applied to detect the in situ H2S and the abundance of SRB. A higher diversity of SRB and more H2S were observed in gypsum amended MFT than that in MFT, indicating a higher sulfate reduction activity in gypsum amended MFT; in addition, the activity of SRB varied as depth in both MFT and gypsum amended MFT： the deeper the more H2S produced. Long-term plans for tailings management can be assessed more wisely with the information provided in this study.

关键词： Sulfate reducing bacteria Hydrogen sulfide Oil sands tailing Molecular biology Microsensor

Adaptive Multiscale Method for Two-dimensional Nanoscale Adhesive Contacts

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Chinese Journal of Mechanical Engineering 2013年第3期26卷 606-612页

作者： tong Ruiting liu Geng liu Lan WU Liyan School of Mechanical Engineering Northwestern Polytechnical University

There are two separate traditional approaches to model contact problems: continuum and atomistic theory. Continuum theory is successfully used in many domains, but when the scale of the model comes to nanometer, continuum approximation meets challenges. Atomistic theory can catch the detailed behaviors of an individual atom by using molecular dynamics (MD) or quantum mechanics, although accurately, it is usually time-consuming. A multiscale method coupled MD and finite element (FE) is presented. To mesh the FE region automatically, an adaptive method based on the strain energy gradient is introduced to the multiscale method to constitute an adaptive multiscale method. Utilizing the proposed method, adhesive contacts between a rigid cylinder and an elastic substrate are studied, and the results are compared with full MD simulations. The process of FE meshes refinement shows that adaptive multiscale method can make FE mesh generation more flexible. Comparison of the displacements of boundary atoms in the overlap region with the results from full MD simulations indicates that adaptive multiscale method can transfer displacements effectively. Displacements of atoms and FE nodes on the center line of the multiscale model agree well with that of atoms in full MD simulations, which shows the continuity in the overlap region. Furthermore, the Von Mises stress contours and contact force distributions in the contact region are almost same as full MD simulations. The method presented combines multiscale method and adaptive technique, and can provide a more effective way to multiscale method and to the investigation on nanoscale contact problems.

关键词： adaptive multiscale method adhesive contact

Adaptive neural network tracking design for a class of uncertain nonlinear discrete-time systems with dead-zone

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Science China(Information Sciences) 2014年第3期57卷 276-287页

作者： liu YanJun liu Lei tong ShaoCheng College of Science Liaoning University of Technology

In this paper,the stability and control issues of a class of uncertain nonlinear discrete-time systems in the strict feedback form are *** dead-zone input in the systems,whose property is non-symmetric and discretized,is *** unknown functions in the systems are approximated by using the radial basis function neural networks(RBFNNs).Backstepping design procedure is employed in the controller and the adaptation laws *** analysis method is utilized to prove the stability of the closed-loop system.A simulation example is given to illustrate the efectiveness of the proposed approach.

关键词： adaptive control RBF neural network non-symmetric dead-zone backstepping design uncertain nonlinear systems

Spectral-spatial target detection based on data field modeling for hyperspectral data

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Chinese Journal of Aeronautics 2018年第4期31卷 795-805页

作者： da liu Jianxun LI School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University

Target detection is always an important application in hyperspectral image processing field. In this paper, a spectral-spatial target detection algorithm for hyperspectral data is *** spatial feature and spectral feature were unified based on the data filed theory and extracted by weighted manifold embedding. The novelties of the proposed method lie in two aspects. One is the way in which the spatial features and spectral features were fused as a new feature based on the data field theory, and the other is that local information was introduced to describe the decision boundary and explore the discriminative features for target detection. The extracted features based on data field modeling and manifold embedding techniques were considered for a target detection *** standard hyperspectral datasets were considered in the analysis. The effectiveness of the proposed target detection algorithm based on data field theory was proved by the higher detection rates with lower False Alarm Rates（FARs） with respect to those achieved by conventional hyperspectral target detectors.

关键词： data field modeling Feature extraction Hyperspectral data Spectral-spatial Target detection

Gravitational wave sensitivity curve of pulsar timing arrays affected by correlated noises

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Research in Astronomy and Astrophysics 2020年第11期20卷 293-302页

作者： Shu liu Ming-Lei tong National Time Center Chinese Academy of SciencesXi’an 710600China Key Laboratory of Time and Frequency Primary Standard Chinese Academy of SciencesXi’an 710600China University of Chinese Academy of Sciences Beijing 100049China

The detection of gravitational waves(GWs)by pulsar timing arrays(PTAs)is not only a very important supplementation of the verification of general relativity but also a new window to study the evolution of supermassive binary black holes and the early ***,so far the detection sensitivity of PTAs is not good enough to catch signals of GWs due to the disturbance of various *** this paper we explore the influences of the correlated noises caused by the reference clock errors and solar system ephemeris errors in pulsar timing on the detection of stochastic gravitational waves background(GWB).We demonstrate the power-law integrated sensitivity curves of GWB detection under the impacts from these correlated *** the simulated data,we find that the influence of different reference timescale is non-negligible,and the influence is even quite huge if one uses a very old version of solar system ***,the impact from these correlated noises on the sensitivity curve is very limited for the real observational data released by international pulsar timing arrays(IPTA).We also calculate the signalto-noise ratios based on the theoretical GW amplitude permitted by ***,we study how the detection sensitivity increases with more pulsar number and longer observation.

关键词： gravitational waves pulsars general time ephemerides

A Local Region Molecular Dynamics Simulation Method for Nanoscale Sliding Contacts

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Chinese Journal of Mechanical Engineering 2018年第5期31卷 119-126页

作者： Rui-Ting tong Geng liu Tian-Xiang liu Shaanxi Engineering Laboratory for Transmissions and Controls Northwestern Polytechnical University Xi’an 710072 China Institute for Mechanics and Fluid Dynamics TU Bergakademie Freiberg Lampadiusstr. 4 09596 Freiberg Germany

Computational e ciency and accuracy always conflict with each other in molecular dynamics(MD) simulations. How to enhance the computational e ciency and keep accuracy at the same time is concerned by each corresponding researcher. However, most of the current studies focus on MD algorithms, and if the scale of MD model could be reduced, the algorithms would be more meaningful. A local region molecular dynamics(LRMD) simulation method which can meet these two factors concurrently in nanoscale sliding contacts is developed in this paper. Full MD simulation is used to simulate indentation process before sliding. A criterion called contribution of displacement is presented, which is used to determine the e ective local region in the MD model after indentation. By using the local region, nanoscale sliding contact between a rigid cylindrical tip and an elastic substrate is investigated. Two two?dimensional MD models are presented, and the friction forces from LRMD simulations agree well with that from full MD simulations, which testifies the e ectiveness of the LRMD simulation method for two?dimensional cases. A three?dimensional MD model for sliding contacts is developed then to show the validity of the LRMD simulation method further. Finally, a discussion is carried out by the principles of tribology. In the discussion, two two?dimensional full MD models are used to simulate the nanoscale sliding contact problems. The results indicate that original smaller model will induce higher equivalent scratching depth, and then results in higher friction forces, which will help to explain the mechanism how the LRMD simulation method works. This method can be used to reduce the scale of MD model in large scale simulations, and it will enhance the computational e ciency without losing accuracy during the simula?tion of nanoscale sliding contacts.

关键词： Local region molecular dynamics simulation Nanoscale Sliding contacts Contribution of displacement

Effects of ultrasonic-assisted extraction on bioactive compounds,volatile flavors and antioxidant activities of vine tea water extracts

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Traditional Medicine Research 2025年第1期10卷 73-81页

作者： Xiao-Long Zhou Wei-Jin Jiang Ji Yu Mao-Jun Yao Yun-tong Li Hunan Provincial Key Laboratory of Research Resource Mining and High-valued Utilization on Edible&Medicinal PlantCollege of Chemistry and Chemical EngineeringJishou UniversityJishou 416000China Hunan Gaoge dairy Co. Ltd.Changsha 410000China

Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in *** vine tea processing,a large amount of broken tea is produced,which has low commercial ***:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea ***:A notable influence of extraction temperature on the yield of vine tea extracts(Pdant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid *** chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted ***,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE *** vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant ***:The findings suggest that extraction methods signi

关键词： vine tea dihydromyricetin ultrasonic-assisted extraction volatile aroma components

Monitoring Computer Numerical Control Machining Progress Based on Information Fusion

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Chinese Journal of Mechanical Engineering 2011年第6期24卷 1074-1082页

作者： tong Liang YAN Ping liu Fei State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing 400030China Chongqing Engineering Research Center of Networked Manufacturing Chongqing UniversityChongqing 400030China

To cope with the market demand dynamically,enterprise needs to obtain the production status of work in process real-timely,but the information of machining progress has feature of uncertainty and can not reflect the status of production field *** this work,to overcome the ineffectiveness of computer numerical control(CNC) machining progress information extraction and its application restriction in practice because of heterogeneous system of CNC machine,based on information fusion by analyzing multi-sources information,estimating CNC machining status and predicting the machining progress through tracking tool coordinates,a CNC machining progress monitoring method is *** multi-sources heterogeneous information includes machining path,real-time spindle power information,manual input data and tool *** the method of obtaining this multi-sources heterogeneous information,the method which helps explore numerical control(NC) program,monitor spindle power of CNC,collect human-computer interaction(HCI) information,obtain real-time tool coordinates and express the knowledge concerned in this field is analyzed; The decision rule of CNC machining status in the way of fusing multi-sources information in manufacturing process is summarized,as well as the machining progress tracking method in accordance with real-time tool coordinates and machining path is ***,the method discussed is proved feasible by the verification of machining progress tracking through simulation *** proposed research realizes the effective integration of CNC machining progress information,and enables enterprises an efficient way to share CNC information and configure CNC resources optimally.

关键词： machining progress information fusion machining path CNC machining process track

Highly efficient and stable 2D/3D perovskite solar cells based on surface reconstruction and energy level alignment

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Science China Chemistry 2024年第9期67卷 3083-3090页

作者： Qiaohui Li Hang liu tong Zhou Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-PlasticsQingdao University of Science and TechnologyQingdao 266042China The Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer Materials Institute of Polymer ChemistryCollege of ChemistryNankai UniversityTianjin 300071China

Realizing simultaneous adjustment of energy levels and work functions in two-dimensional/three-dimensional(2D/3D)perovskite solar cells(PSCs)is a ***,a pseudohalide 3,5-bis(trifluoromethyl)benzylammonium tetrafluoroborate(TFPMABF_(4))was used to react with unreacted Pb I2on the surface of 3D bulky perovskite to form a mixed halide of 2D perovskite denoted(TF-PMA)_(2)FA_(2)Pb_(3)I_(8)(BF_(4))_(2).This novel 2D/3D perovskite enables the simultaneous adjustment of energy levels and work functions on the surface of active *** to the significantly enhanced quality of 2D/3D perovskite film,decreased surface defects and increased charge carrier lifetime,the 2D/3D PSCs exhibit an outstanding power conversion efficiency(PCE)of 25.15%and a high V_(OC)of 1.194 ***,2D/3D PSCs exhibit remarkable enhancements in environmental stability,unencapsulated devices retaining more than 90%of their initial PCE at 50%humidity for 2,280 h.

关键词： 2D/3D perovskite perovskite solar cells organic spacers energy levels alignment