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Formation and reactivation mechanisms of large-scale ancient landslides in the Longwu River basin in the northeast Tibetan Plateau, China

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Journal of Mountain Science 2022年第6期19卷 1558-1575页

作者： tian Jing-jing LI tian-tao PEI Xiang-jun DING Feng SUN Hao XIE Xian-gang GUO jian State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China College of Earth Sciences Chengdu University of TechnologyChengdu 610059China School of Earth System Science Tianjin UniversityTianjin 300072China Department of Civil Engineering Panzhihua UniversityPanzhihua 617000China

The northeastern Tibetan Plateau exhibits steep topography and strong internal or external dynamic geological effect and is frequently subjected to strong earthquakes and heavy rainfall. The geological evolution has resulted in a wide distribution of ancient landslides, which has become a hotspot for studying ancient landslide formation and reactivation. In recent decades, several ancient landslides on both banks of the Longwu River, Qinghai Province, China were reactivated, causing serious economic losses and casualties. This study conducted remote sensing interpretation and ground surveys on these ancient landslides. Totally 59 ancient landslides were identified, and the formation mechanism, evolution process, and resurrection mechanism of the Longwu Xishan No.2 ancient landslide were analyzed by means of a detailed field geological survey, drilling, and series of experimental tests such as the particle size distribution test, the Xray diffraction test and the mechanical properties test. The results show that the formation of these ancient landslides is closely associated with the uplift of the Tibetan Plateau and the erosion of the Longwu River. Firstly, the intermittent uplift of the Tibetan Plateau lead to the diversion and downcutting of the Longwu River basin, which forms the alternate slope topography with steep and slow slopes, thereby providing favourable topography and slope structure conditions for the formation of landslides. Secondly, 34.5% clay-mineral content in the Neoproterozoic mudstone with 32.7% particle size less than 0.005 mm, and the corrosion and softening effects of the Neogene mudstone with high clay mineral content under the erosion of water provides favourable material conditions for the formation of landslides. Thirdly, rainfall and human activities are the primary triggering factors for the revival of this ancient landslide group. It is revealed that the evolution process of the ancient landslides on both banks of the Longwu River can

关键词： Remote sensing interpretation Tectonic movement Ancient landslide Reactivation mechanism Formation process Tibetan Plateau

Superlinear Elliptic Equation with Mixed Boundary Value in Annular Domain

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Acta Mathematica Sinica,English Series 2021年第10期37卷 1549-1559页

作者： jian tian Yuan Hong WEI School of Mathematics Jilin UniversityChangchun 130012P.R.China

In this paper,we study superlinear elliptic equations with mixed boundary value conditions in annular *** is assumed that the nonlinearities depend on the derivative *** results about existence of solutions are establ... 详细信息

关键词： Mixed boundary value annular domain radial solution gradient term iterative method

Giant room temperature elastocaloric effect in metal-free thinfilm perovskites

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npj Computational Materials 2021年第1期7卷 1194-1201页

作者： Cheng Li Yu Hui Huang jian-jun Wang Bo Wang Yong jun Wu He tian Long-Qing Chen Zijian Hong Laboratory of Dielectric Materials School of Materials Science and EngineeringZhejiang UniversityHangzhouChina Department of Materials Science and Engineering The Pennsylvania State UniversityUniversity ParkPAUSA Cyrus Tang Center for Sensor Materials and Applications State Key Laboratory of Silicon MaterialsSchool of Materials Science and EngineeringZhejiang UniversityHangzhouChina Center of Electron Microscopy State Key Laboratory of Silicon MaterialsSchool of Materials Science and EngineeringZhejiang UniversityHangzhouChina

Solid-state refrigeration which is environmentally benign has attracted considerable ***(mC)materials,in which the phase transitions can be induced by mechanical stresses,represent one of the most promising types of solid-state caloric ***,we have developed a thermodynamic phenomenological model and predicted extraordinarily large elastocaloric(eC)strengths for the(111)-oriented metal-free perovskite ferroelectric[MDABCO](NH_(4))I_(3)*** predicted room temperature isothermal eC ΔS_(eC)/Δσ(eC entropy change under unit stress change)and adiabatic eCΔTeC/Δσ(eC temperature change under unit stress change)for[MDABCO](NH_(4))I_(3) are−60.0 J K^(−1)kg^(−1)GPa^(−1) and 17.9 K GPa^(−1),respectively,which are 20 times higher than the traditional ferroelectric oxides such as BaTiO_(3) thin *** have also demonstrated that the eC performance can be improved by reducing the Young’s modulus or enhancing the thermal expansion coefficient(which could be realized through chemical doping,etc.).We expect these discoveries to spur further interest in the potential applications of metal-free organic ferroelectrics materials towards next-generation eC refrigeration devices.

关键词： ferroelectric perovskite free

A new interacting capillary bundle model on the multiphase flow in micropores of tight rocks

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Petroleum Science 2024年第2期21卷 1099-1112页

作者： Wen-Quan Deng tian-Bo Liang Wen-Zhong Wang Hao Liu jun-Lin Wu Fu-jian Zhou National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China

Surfactants are widely used in the fracturing fluid to enhance the imbibition and thus the oil recovery rate. However, current numerical models cannot capture the physics behind capillary imbibition during the wettability alteration by surfactants. Although the interacting capillary bundle(ICB) model shows potential in characterizing imbibition rates in different pores during wettability alteration, the existing ICB models neglect the influence of wettability and viscosity ratio on the imbibition behavior, making it difficult to accurately describe the oil-water imbibition behavior within the porous media. In this work,a new ICB mathematical model is established by introducing pressure balance without assuming the position of the leading front to comprehensively describe the imbibition behavior in a porous medium under different conditions, including gas-liquid spontaneous imbibition and oil-water *** the pore size distribution of a tight rock is known, this new model can predict the changes of water saturation during the displacement process in the tight rock, and also determine the imbibition rate in pores of different sizes. The water saturation profiles obtained from the new model are validated against the waterflooding simulation results from the CMG, while the imbibition rates calculated by the model are validated against the experimental observations of gas-liquid spontaneous imbibition. The good match above indicates the newly proposed model can show the water saturation profile at a macroscopic scale while capture the underlying physics of the multiphase flow in a porous medium at a microscopic scale. Simulation results obtained from this model indicate that both wettability and viscosity ratio can affect the sequence of fluid imbibition into pores of different sizes during the multiphase flow, where less-viscous wetting fluid is preferentially imbibed into larger pores while more-viscous wetting fluid tends to be imbibed into smaller pores. Fur

关键词： Imbibition Multiphase flow Tight rock Interacting capillary bundle model Wettability

Cluster based hierarchical resource searching model in P2P network

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Journal of Systems Engineering and Electronics 2007年第1期18卷 188-194页

作者： Yang Ruijuan Liu jian tian Jingwen Inst. of Pattern Recognition and Artificial Intelligence Huazhong Univ. of Science and Technology Wuhan 430073 P. R. China Information and Command Automation Dept. Air Force Radar Academy Wuhan 430010 P. R. China

For the problem of large network load generated by the Gnutella resource-searching model in Peer to Peer （P2P） network, a improved model to decrease the network expense is proposed, which establishes a duster in P2P network, auto-organizes logical layers, and applies a hybrid mechanism of directional searching and flooding. The performance analysis and simulation results show that the proposed hierarchical searching model has availably reduced the generated message load and that its searching-response time performance is as fairly good as that of the Gnutella model.

关键词： Communication and information system Resource-searching model in P2P network Gnutella Cluster Hierarchical network

In situ analysis of dynamic evolution of the additive-regulated cathode processes in quasi-solid-state lithium-metal batteries

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Science China Chemistry 2023年第10期66卷 2921-2928页

作者： jian-Xin tian Hui-Juan Guo Jing Wan Gui-Xian Liu Rui Wen Li-jun Wan CAS Key Laboratory of Molecular Nanostructure and Nanotechnology CAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular ScienceInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The implementation of high-energy-density storage devices can be facilitated by the built-in situ cathode electrolyte interphase(CEI)between Ni-rich cathodes and gel polymer electrolytes,as it improves interfacial compatibility and enhances *** the interphase processes of cathode materials,including the structural evolution and the formation of cathode electrolyte interphase upon charging/discharging,is crucial for the design of solid-state lithium ***,we employed in situ atomic force microscopy(AFM)to investigate the effects of lithium difluoro(oxalato)borate(Li DFOB)on the dynamic evolution of the cathode *** the presence of Li DFOB,the adhesion of nanoparticles and a thin amorphous film on the cathode surface resulted in the formation of a homogeneous CEI,inducing the production of LixPFyas ***,the stable CEI formed between the cathode and electrolyte helps maintain the integrity of the composition and structure,reduces interfacial resistance,and improves the cycle stability of the *** visualization of in situ AFM in quasi-solid-state lithium-metal batteries provides valuable insights into the distinct nanostructures and growth dynamics of Li DFOB-mediated CEI on the LiNi_(6)Co_(2)Mn_(2)O_(2) cathode,thus offering a universal and convenient technique for interfacial analysis and a mechanistic understanding of solid-state batteries.

关键词： atomic force microscopy electrochemistry interfacial dynamics solid-state lithium batteries cathode electrolyte interphase

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A comparative survey of SSVEP recognition algorithms based on template matching of training trials

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International Journal of Intelligent Computing and Cybernetics 2023年第1期16卷 46-67页

作者： tian-jian Luo College of Computer and Cyber Security Fujian Normal UniversityFuzhouChina Digital Fujian Internet-of-Thing Laboratory of Environmental Monitoring Fujian Normal UniversityFuzhouChina

Purpose-Steady-state visual evoked potential(SSVEP)has been widely used in the application of electroencephalogram(EEG)based non-invasive brain computer interface(BCI)due to its characteristics of high accuracy and information transfer rate(ITR).To recognize the SSVEP components in collected EEG trials,a lot of recognition algorithms based on template matching of training trials have been proposed and applied in recent *** this paper,a comparative survey of SSVEP recognition algorithms based on template matching of training trails has been ***/methodology/approach-To survey and compare the recently proposed recognition algorithms for SSVEP,this paper regarded the conventional canonical correlated analysis(CCA)as the baseline,and selected individual template CCA(ITCCA),multi-set CCA(MsetCCA),task related component analysis(TRCA),latent common source extraction(LCSE)and a sum of squared correlation(SSCOR)for ***-For the horizontal comparative of the six surveyed recognition algorithms,this paper adopted the“Tsinghua JFPM-SSVEP”data set and compared the average recognition performance on such data *** comparative contents including:recognition accuracy,ITR,correlated coefficient and R-square values under different time duration of the SSVEP stimulus *** on the optimal time duration of stimulus presentation,the author has also compared the efficiency of the six compared *** measure the influence of different parameters,the number of training trials,the number of electrodes and the usage of filter bank preprocessing were compared in the ablation ***/value-Based on the comparative results,this paper analyzed the advantages and disadvantages of the six compared SSVEP recognition algorithms by considering application scenes,realtime and computational ***,the author gives the algorithms selection range for the recognition of real-world online SSVEP-BCI.

关键词： Non-invasive brain-computer interface EEG signals Template matching of training trials Steadystate visual evoked potential Optimal projection vector

Efficient Fingerprint Matching Algorithm for Integrated Circuit Cards

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Journal of Computer Science & Technology 2004年第4期19卷 510-520页

作者： jian-WeiYang Li-FengLiu tian-Zijiang NationalLaboratoryofPatternRecognition InstituteofAutomationTheChineseAcademyofSciencesBeijing100080P.R.China

Fingerprint matching is a crucial step in fingerprint identification. Recently, a variety of algorithms for this issue have been developed. Each of them is application situation specific and has its advantages and disadvantages. It is highly desired to develop an efficient fingerprint verification technology for Integrated Circuit (IC) Cards or chips. IC cards have some special characteristics, such as very small storage space and slow processing speed, which hinder the use of most fingerprint matching algorithms in such situations. In order to solve this problem, the paper presents an improved minutia-pattern (minutiae-based) matching algorithm by employing the orientation field of the fingerprint as a new feature. Our algorithm not only inherits the advantages of the general minutia-pattern matching algorithms, but also overcomes their. disadvantages. Experimental results show that the proposed algorithm can greatly improve the performance of fingerprint matching in both accuracy and efficiency, and it is very suitable for applications in IC cards.

关键词： fingerprint matching minutia-pattern matching ridge-based matching IC cards orientation field FAR

Preparation of Au/Ag Multilayers via Layer-by-Layer Self-assembly in Spherical Polyelectrolyte Brushes and Their Catalytic Activity

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Chinese Journal of Polymer Science 2015年第10期33卷 1421-1430页

作者： Fei Zhao 李莉 Yu-chuan tian jian-jia Liu jian-jun Wang Zhi-ming Zhou 吕春祥 Xu-hong Guo School of Chemical Engineering East China University of Science and Technology National Engineering Laboratory for Carbon Fiber Technology Key Laboratory of Xinjiang Uygur Autonomous Region and Engineering Research Center of Xinjiang Bingtuan of Materials-oriented Chemical Engineering Shihezi University

Spherical polyelectrolyte brushes （SPBs） consisting of polystyrene （PS） core and poly（2-aminoethyl methacrylate hydrochloride）（PAEMH） shell were prepared by photo-emulsion polymerization. Au nanoparticles （Au-NPs） with controlled size and size distribution were synthesized in situ using SPBs as nanoreactors. Via layer-by-layer deposition technique on the surface of SPBs, nano-composite particles with Au/Ag-NPs bilayer and Au/Ag/Au-NPs trilayer were prepared. The structures of the as-prepared Au/Ag multilayer SPBs were characterized by UV-Vis spectroscopy, TEM, ICP-AES and DLS. The charge reversal of the nano-composite particles observed by zeta potential confirmed the success of layer-by-layer assembly. The Au/Ag-NPs bilayer nano-composite particles showed high catalytic efficiency with an apparent activation energy of about 41.2 kJ/mol in the reduction reaction of 4-nitrophenol to 4-aminophenol in the existence of sodium borohydride monitored. The catalytic activity ofAu/Ag-NPs multilayer SPBs close to that of Au-NPs SPBs and much higher than that of Ag-NPs SPBs reveals its potential applications in cost-effective catalysts with high-performance.

关键词： Layer-by-layer self-assembly Spherical polyelectrolyte brushes Catalytic activity