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Linearized waveform inversion for vertical transversely isotropic elastic media:Methodology and multi-parameter crosstalk analysis

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Petroleum Science 2024年第1期21卷 252-271页

作者： Ke chen Lu Liu Li-Nan Xu Fei Hu Yuan Yang Jia-Hui zuo Le-Le Zhang Yang Zhao National Key Laboratory of Petroleum Resources and Engineering Unconventional Petroleum Research InstituteChina University of Petroleum(Beijing)Beijing102249China Aramco Beijing Research Center Aramco AsiaBeijing100102China University of Lausanne LausanneCH-1015Switzerland Bureau of Geophysical Prospecting China National Petroleum CorporationZhuozhou 072750HebeiChina

Seismic migration and inversion are closely related techniques to portray subsurface images and identify hydrocarbon *** migration aims at obtaining structural images of subsurface geologic *** specifically,seismic migration estimates the reflectivity function(stacked average reflectivity or pre-stack angle-dependent reflectivity)from seismic reflection *** the other hand,seismic inversion quantitatively estimates the intrinsic rock properties of subsurface *** seismic inversion methods are applicable to detect hydrocarbon reservoirs that may exhibit lateral variations in the inverted *** there exist many differences,pre-stack seismic migration is similar with the first iteration of the general linearized seismic ***,seismic migration and inversion techniques assume an acoustic or isotropic elastic *** reservoirs such as shale and tight sand formation have notable anisotropic *** present a linearized waveform inversion(LWI)scheme for weakly anisotropic elastic media with vertical transversely isotropic(VTI)*** is based on two-way anisotropic elastic wave equation and simultaneously inverts for the localized perturbations(ΔVp_(0)/Vp_(0)/Vs_(0)/Vs_(0)/,Δ∈,Δδ)from the long-wavelength reference *** proposed VTI-elastic LWI is an iterative method that requires a forward and an adjoint operator acting on vectors in each *** derive the forward Born approximation operator by perturbation theory and adjoint operator via adjoint-state *** inversion has improved the quality of the images and reduces the multi-parameter crosstalk comparing with the adjoint-based *** have observed that the multi-parameter crosstalk problem is more prominent in the inversion images for Thomsen anisotropy ***,the Thomsen parameter is the most difficult to *** also analyze the multi-parameter crosstalk using scattering radiation patte

关键词： Elastic Anisotropy Least-squares imaging Waveform inversion Computational geophysics

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Effective Ultra-High-Speed Identification Scheme of Lightning Strikes Suitable for VSC-Based DC Grids

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 548-561页

作者： Longlong chen Xiangyu Pei Xiaoguang wei Pengzhi Li Guangfu Tang North China Electric Power University(NCEPU) Beijing 102206China Changsha University of Science and Technology Changsha 410114China State Key Laboratory of Advanced Power Transmission Technology State Grid Smart Grid Research Institute Co.Ltd.Beijing 102209China

To ensure their sound and continuous operation to the greatest extent,VSC-based DC girds have extremely stringent requirements for transmission line relay *** terms of guaranteeing their reliability,accurate identification of lightning strikes on DC transmission lines is one of the urgent key problems to be *** effective ultra-high-speed identification scheme of lightning strikes suitable for the VSC-based DC grid is proposed in this ***,an 1-mode reverse voltage traveling wave(RVTW)is constructed applying the pole-mode transformation ***,fault traveling wave propagation characteristics along the DC transmission line are analyzed in depth utilizing Peterson's ***,differences of time-frequency electromagnetic transient characteristics of 1-mode RVTWs between disturbances and faults caused by lightning strikes are distinguished in detail by means of the classical wavelet transformation multi-resolution analysis ***,extensive simulations are carried out to evaluate the performance of the proposed identification scheme,and by which its excellent rapidity,reliability and robustness are *** Terms-Lightning-strike identification,Multi-resolution analysis,Relay protection,Traveling-wave protection,VsC-based DC grid,Wavelet transformation.

关键词： Lightning-strike identification Multi-resolution analysis Relay protection Traveling-wave protection VsC-based DC grid Wavelet transformation

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Coupling effect on the thermal hazard assessment of hazardous chemical materials via calorimetric technologies and simulation approaches

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Defence Technology（防务技术） 2024年第2期32卷 644-654页

作者： Yabei Xu Jiankun Shao wei Wang Shengliang Xu Dongping chen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Science and Technology on Aerospace Chemical Power Laboratory Hubei Institute of Aerospace ChemotechnologyXiangyang 441003China

The coupling effect of heat absorption and release exists in the thermal decomposition of a few chemical ***,the impact of the above coupling on thermal hazard assessment is not considered in the literature *** this work,nitroguanidine(NQ)and 1,3,5-trinitro-1,3,5-triazine(RDX)are selected as representative materials to explore the influence of the coupling effect on the thermal hazard assessment of chemical *** linear heating experiments of NQ and RDX are carried out by a microcalorimeter and synchronous thermal *** thermal decomposition curves are decoupled by advanced thermokinetics *** thermal decomposition and kinetic parameters before and after decoupling are *** results of TG experiment show that both NQ and RDX began to lose mass during the endothermic *** endothermic melting and exothermic decomposition of NQ and RDX are coupled within this *** coupling effect has different degrees of influence on its initial decomposition temperature and safety *** with the parameters in the coupling state,the initial decomposition temperature and adiabatic induction period after decoupling *** self-accelerating decomposition temperature increases,and internal thermal runaway time *** the thermal hazard assessment of chemical materials with coupling effects,the calculated parameters after decoupling should be taken as an important safety index。

关键词： Calorimetric technologies Kinetics Thermal hazard Phase transformation Thermal decomposition

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Observer-based robust high-order fully actuated attitude autopilot design for spinning glide-guided projectiles

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Defence Technology（防务技术） 2024年第4期34卷 282-294页

作者： wei Wang Yuchen Wang Shiwei chen Yongcang Guo Zhongjiao Shi School of Aerospace Engineering Beijing Institute of TechnologyBeijing 10081China Northwest Industries Group CO. Ltd.Xi'an 710043China

This paper investigates the design of an attitude autopilot for a dual-channel controlled spinning glideguided projectile(SGGP),addressing model uncertainties and external *** on fixed-time stable theory,a disturbance observer with integral sliding mode and adaptive techniques is proposed to mitigate total disturbance effects,irrespective of initial *** introducing an error integral signal,the dynamics of the SGGP are transformed into two separate second-order fully actuated ***,employing the high-order fully actuated approach and a parametric approach,the nonlinear dynamics of the SGGP are recast into a constant linear closed-loop system,ensuring that the projectile's attitude asymptotically tracks the given goal with the desired *** the proposed composite control framework,the ultimately uniformly bounded stability of the closed-loop system is rigorously demonstrated via the Lyapunov *** of the effectiveness of the proposed attitude autopilot design is provided through extensive numerical simulations.

关键词： Spinning glide-guided projectile Attitude control Sliding mode disturbance observer Fixed-time stable theory High-order fully actuated approach

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Colloid-facilitated release of polybrominated diphenyl ethers at an e-waste recycling site: evidence from undisturbed soil core leaching experiments

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Frontiers of Environmental Science & Engineering 2024年第2期18卷 91-101页

作者： Zebin Huo Mengjun Xi Lianrui Xu Chuanjia Jiang wei chen College of Environmental Science and Engineering Ministry of Education Key Laboratory of Pollution Processes and Environmental CriteriaTianjin Key Laboratory of Environmental Remediation and Pollution ControlNankai UniversityTianjin 300350China

Polybrominated diphenyl ethers (PBDEs), a class of persistent organic pollutants, have been frequently detected in soil at e-waste recycling sites. However, the key factors controlling the transport of PBDEs from surface soil to the vadose zone and groundwater are unclear. Here, colloid-enhanced leaching of PBDEs from undisturbed soil cores collected at an e-waste recycling site in Tianjin, China, is reported. Spatially heterogeneous release of colloids and PBDEs was observed in all the tested soil cores under chemical and hydrodynamic perturbations, indicating the presence of preferential flow paths. Colloid concentration in the effluent significantly increased as ionic strength decreased (from 10 to 0.01 mmol/L), probably due to the stronger electrostatic repulsion between colloidal particles and the soil matrix at lower ionic strength. In contrast, colloid mobilization was not significantly affected by the changes in pH of the influent (from 4.0 to 10.0) and flow rate (from a Darcy velocity of 1.5 to 6.0 cm/h). The concentrations of 2,2′,3,3′,4,4′,5,5′,6,6′-decabromodiphenyl ether (BDE-209), the predominant PBDE congener at the site, detected in the leachate (ranging from 1.09 to 3.43 ng/L) were much lower than previously reported results from packed column leaching tests, and were positively correlated with colloid concentrations. This indicates that remobilization of colloids at e-waste recycling sites can promote the leaching and downward migration of PBDEs from surface soil. The findings highlight the potential risk of surface soil PBDE contamination to groundwater quality and call for further understanding of colloid-facilitated transport for predicting the fate of PBDEs at e-waste recycling sites.

关键词： Polybrominated diphenyl ether Colloid-facilitated transport E-waste recycling site Undisturbed soil core Groundwater quality

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Prediction of maximum upward displacement of shield tunnel linings during construction using particle swarm optimization-random forest algorithm

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第1期25卷 1-17页

作者： Xiaowei YE Xiaolong ZHANG Yanbo chen Yujun wei Yang DING MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang UniversityHangzhou310058China Department of Civil Engineering Zhejiang UniversityHangzhou310058China Zhejiang Engineering Research Center of Intelligent Urban Infrastructure Hangzhou City UniversityHangzhou310015China

During construction,the shield linings of tunnels often face the problem of local or overall upward movement after leaving the shield tail in soft soil areas or during some large diameter shield *** floating will increase the initial stress on the segments and bolts which is harmful to the service performance of the *** this study we used a random forest(RF)algorithm combined particle swarm optimization(PSO)and 5-fold cross-validation(5-fold CV)to predict the maximum upward displacement of tunnel linings induced by shield tunnel *** mechanism and factors causing upward movement of the tunnel lining are comprehensively *** input variables were selected according to results from analysis of influencing *** prediction performance of two models,PSO-RF and RF(default)were *** Gini value was obtained to represent the relative importance of the influencing factors to the upward displacement of *** PSO-RF model successfully predicted the maximum upward displacement of the tunnel linings with a low error(mean absolute error(MAE)=4.04 mm,root mean square error(RMSE)=5.67 mm)and high correlation(R^(2)=0.915).The thrust and depth of the tunnel were the most important factors in the prediction model influencing the upward displacement of the tunnel linings.

关键词： Random forest(RF) Particle swarm optimization(PSO) Upward displacement of lining Machine learning prediction Shieldtunneling construction

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Characterization of Fe-containing particles in chengdu,southwest China,using single-particle aerosol mass spectrometry

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Journal of Environmental Sciences 2024年第2期136卷 110-120页

作者： Renjiang He Junke Zhang Luyao chen wei Zhang Yingwei Xi School of Public Health Southwest Medical UniversityLuzhou 646000China Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China Sichuan Environmental Monitoring Center Chengdu 610074China

Single-particle aerosol mass spectrometry was used to study the characteristics of Fecontaining particles during winter in chengdu,southwest *** mass concentrations of PM_(2.5)and PM_(10)during the study period were 64±38 and 89±49μg/m~3,respectively,and NO_(2)and particulate matter were high compared with most other regions of *** Fecontaining particles were divided into seven categories with different mass spectra,sources and aging *** highest contribution was from Fe mixed with carbonaceous components(Fe-C,23.1%)*** was more mixed with sulfate than nitrate and therefore the contribution of Fe mixed with sulfate(Fe-S,20.7%)particles was higher than that of Fe mixed with nitrate(Fe-N,12.5%)*** contributions from Fe-containing particles related to primary combustion were high in the small particle size range,whereas aged Fecontaining particles and dust-related particles were mostly found in the coarse particle size *** air masses mainly originated from the west and east of chengdu,and the corresponding PM_(2.5)concentrations were 79±36 and 55±36μg/m~3,*** west and east air masses showed stronger contributions of Fe-containing particles related to biomass burning(Fe-B)and fossil fuel combustion(Fe-C and Fe-S)particles,*** southwest area contributed the most Fe-containing *** assessments of the effects of Fe-containing particles during heavy pollution period should pay more attention to Fe-C and Fe-S ***-reduction of Fe-containing particles should consider both local emissions and short-distance transmission from the surrounding areas.

关键词： Fe-containing particles Particle composition Potential source areas Evolution chengdu

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Metal-to-insulator transitions in 3d-band correlated oxides containing Fe compositions

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 48-59页

作者： Yiping Yu Yuchen Cui Jiangang He wei Mao Jikun chen Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of EducationUniversity of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Institute of Industrial Science The University of Tokyo4-6-1 KomabaMeguro-kuTokyo 153-8505Japan

Metal-to-insulator transitions (MITs),which are achieved in 3d-band correlated transitional metal oxides,trigger abrupt variations in electrical,optical,and/or magnetic properties beyond those of conventional *** such material families,iron(Fe:3d^(6)4s^(2))-containing oxides pique interest owing to their widely tunable MIT properties,which are associated with the various valence states of *** potential electronic applications also show promise,given the large abundance of Fe on *** MIT properties triggered by critical temperature (TMIT) were reported for ReFe_(2)O_(4)(Fe^(2.5+)),ReBaFe_(2)O_(5)(Fe^(2.5+)),Fe_(3)O_(4)(Fe^(2.67+)),Re_(1/3)Sr_(2/3)FeO_(3)(Fe^(3.67+)),Re Cu_(3)Fe_(4)O_(12)(Fe^(3.75+)),and Ca_(1-x)Sr_(x)FeO_(3)(Fe^(4+))(where Re represents rare-earth elements).The common feature of MITs of these Fe-containing oxides is that they are usually accompanied by charge ordering transitions or disproportionation associated with the valence states of ***,we review the material family of Fe-containing MIT oxides,their MIT functionalities,and their respective *** the perspective of potentially correlated electronic applications,the tunability of the TMITand its resultant resistive change in Fe-containing oxides are summarized and further compared with those of other materials exhibiting MIT *** particular,we highlight the abrupt MIT and wide tunability of TMITof Fe-containing quadruple perovskites,such as Re ***,their effective material synthesis still needs to be further explored to cater to potential applications.

关键词： metal-to-insulator transitions Fe-containing oxides charge ordering charge disproportionation

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Nonlinear dynamics of a circular curved cantilevered pipe conveying pulsating fluid based on the geometrically exact model

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 261-276页

作者： Runqing CAO Zilong GUO wei chen Huliang DAI Lin WANG Department of Engineering Mechanics School of Aerospace EngineeringHuazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment Wuhan 430074China State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Due to the novel applications of flexible pipes conveying fluid in the field of soft robotics and biomedicine,the investigations on the mechanical responses of the pipes have attracted considerable *** fluid-structure interaction(FSI)between the pipe with a curved shape and the time-varying internal fluid flow brings a great challenge to the revelation of the dynamical behaviors of flexible pipes,especially when the pipe is highly flexible and usually undergoes large *** this work,the geometrically exact model(GEM)for a curved cantilevered pipe conveying pulsating fluid is developed based on the extended Hamilton's *** stability of the curved pipe with three different subtended angles is examined with the consideration of steady fluid *** attention is concentrated on the large-deformation resonance of circular pipes conveying pulsating fluid,which is often encountered in practical *** constructing bifurcation diagrams,oscillating shapes,phase portraits,time traces,and Poincarémaps,the dynamic responses of the curved pipe under various system parameters are *** mean flow velocity of the pulsating fluid is chosen to be either subcritical or *** numerical results show that the curved pipe conveying pulsating fluid can exhibit rich dynamical behaviors,including periodic and quasi-periodic *** is also found that the preferred instability type of a cantilevered curved pipe conveying steady fluid is mainly in the flutter of the second *** a moderate value of the mass ratio,however,a third-mode flutter may occur,which is quite different from that of a straight pipe system.

关键词： curved pipe conveying fluid pulsating fluid geometrically exact model(GEM) nonlinear dynamics parametric vibration flutter

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Energy budget of cold and hot gas-solid fluidized beds through CFD-DEM simulations

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Particuology 2024年第6期89卷 153-171页

作者： Lei Bi Yunpeng Jiao Chunjiang Liu Jianhua chen wei Ge School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

Direct energy budget is carried out for both cold and hot flow in gas–solid fluidization ***,the energy paths are proposed from thermodynamic *** consumption means total power input to the specific system,and it can be decomposed into energy retention and energy *** retention is the variation of accumulated mechanical energy in the system,and energy dissipation is the energy converted to heat by irreversible *** based on the Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)framework,different energy terms are quantified from the specific flow elements of fluid cells and particles as well as their interactions with the *** order to clarify the energy budget,it is important to identify which system is studied:the particle-fluid system or the particle *** the cold flow,the total energy consumption of the particle sub-system can well indicate the onset of bubbling and turbulent,while the variation of local energy consumption terms can reflect the evolution of heterogeneous *** the hot flow,different heat transfer mechanisms are analyzed and the solver is modified to reproduce the experimental *** impact of the heat transfer mechanisms and heat production on energy consumption is also *** proposed budget method has proven to be energy-conservative and easy to conduct,and it is hopeful to be applied to other multiphase flow systems.

关键词： Energy budget Gas-solid fluidization CFD-DEM Regime transition Heat transfer mechanism

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