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Migration time prediction and assessment of toxic fumes under forced ventilation in underground mines

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Underground Space 2024年第5期18卷 273-294页

作者： Jinrui zhang tingting zhang Chuanqi Li School of Resources&Civil Engineering Northeastern UniversityShenyang 110819China Laboratory 3SR CNRS UMR 5521Grenoble Alpes UniversityGrenoble 38000France

This study aims to predict the migration time of toxic fumes induced by excavation blasting in underground *** reduce numerical simulation time and optimize ventilation design,several back propagation neural network(BPNN)models optimized by honey badger algorithm(HBA)with four chaos mapping(CM)functions(i.e.,Chebyshev(Che)map,Circle(Cir)map,Logistic(Log)map,and Piecewise(Pie)map)are developed to predict the migration time.125 simulations by the computational fluid dynamics(CFD)method are used to train and test the developed *** determination coefficient(R2),the variance accounted for(VAF),the Willmott’s index(WI),the root mean square error(RMSE),the mean absolute percentage error(MAPE),and the sum of squares error(SSE)are utilized to evaluate the model *** evaluation results indicate that the CirHBA-BPNN model has achieved the most satisfactory performance by reaching the highest values of R2(0.9945),WI(0.9986),VAF(99.4811%),and the lowest values of RMSE(15.7600),MAPE(0.0343)and SSE(6209.4),*** wind velocity in roadway(Wv)is the most important feature for predicting the migration time of toxic ***,the intrinsic response characteristic of the optimal model is implemented to enhance the model interpretability and provide reference for the relationship between features and migration time of toxic fumes in ventilation design.

关键词： Migration time Underground mines Honey badger algorithm Chaos mapping Back propagation neural network

Performance analysis of an indoor UWB ranging system

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Journal of Systems Engineering and Electronics 2009年第3期20卷 450-456页

作者： zhang tingting zhang Qinyu zhang Naitong Xu Hongguang School of Electrical and Information Harbin Inst. of Technology Harbin 150001 P. R. China Harbin Inst. of Technology Shenzhen Graduate School Shenzhen 518055 P. R. China

To evaluate the ranging performance of impulse radio ultra wideband （IR-UWB） signals, an experiment is performed in a typical indoor environment. In order to mitigate the ranging error caused by theoretical algorithm and practical circuits, one way-time difference of the arrival （OW-TDOA） ranging method and corresponding approaches are proposed and carried out according to the structure of UWB transceivers. Generalized maximum likelihood （GML） estimator based on energy detection is applied for the time of arrival estimation. The obtained results show that this UWB ranging system can achieve a relative high ranging accuracy in a multipath environment （e.g. about 5 cm at ranges up to 6 m）, which is practical and meaningful for many sensor applications.

关键词： ranging impulse radio ultra wideband time of arrival energy detection multipath

Interfacial Morphology and Bonding Mechanism of Explosive Weld Joints

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Chinese Journal of Mechanical Engineering 2021年第2期34卷 201-212页

作者： tingting zhang Wenxian Wang Zhifeng Yan Jie zhang Advanced Forming and Intelligent Equipment Research Institute Taiyuan University of TechnologyTaiyuan 030024China College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024China College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China

Interfacial structure greatly affects the mechanical properties of laminated ***,the critical material properties that impact the interfacial morphology,appearance,and associated bonding mechanism of explosive welded plates are still *** this paper,the same base plate(AZ31B alloy)and different flyer metals(aluminum alloy,copper,and stainless steel)were used to investigate interfacial morphology and *** and TEM results showed that typical sine wave,wave-like,and half-wave-like interfaces were found at the bonding interfaces of Al/Mg,Cu/Mg and SS/Mg clad plates,*** different interfacial morphologies were mainly due to the differences in hardness and yield strength between the flyer and base *** results of the microstructural distribution at the bonding interface indicated metallurgical bonding,instead of the commonly believed solid-state bonding,in the explosive welded clad *** addition,the shear strength of the bonding interface of the explosive welded Al/Mg,Cu/Mg and SS/Mg clad plates can reach up to 201.2 MPa,147.8 MPa,and 128.4 MPa,*** proposed research provides the design basis for laminated composite metal plates fabrication by explosive welding technology.

关键词： Interfacial structure Bonding mechanism Explosive welding Metallurgical bonding Magnesium alloy

Interfacial bonding characteristics and mechanical properties of H68/AZ31B clad plate

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International Journal of Minerals,Metallurgy and Materials 2022年第6期29卷 1237-1248页

作者： tingting zhang Wenxian Wang Jie zhang Zhifeng Yan Advanced Forming and Intelligent Equipment Research Institute Taiyuan University of TechnologyTaiyuan 030024China College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024China College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of EducationTaiyuan 030024China Shanxi Key Laboratory of Advanced Magnesium-based Materials Taiyuan 030024China

Interfacial bonding,microstructures,and mechanical properties of an explosively-welded H68/AZ31B clad plate were systematically *** to the results,the bonding interface demonstrated a“wavy-like”structure containing three typical zones/layers:(1)diffusion layer adjacent to the H68 brass plate;(2)solidification layer of melted metals at the interface;(3)a layer at the side of AZ31B alloy that experienced severe *** copper,CuZn_(2),andα-Mg phases were observed in the melted-solidification *** polygonal grains with twins were found at the H68 alloy side,while fine equiaxed grains were found at the AZ31B alloy side near the interface due to *** results revealed the formation of brittle intermetallic CuZn_(2) phases at the bonding *** interface was bonded well through metallurgical reactions due to diffusion of Cu,Zn,and Mg atoms across the interface and metallurgic reaction of partially melted H68 and AZ31B alloys.

关键词： explosive welding interfacial bonding numerical simulation nanoindentation dissimilar metal composite

Distributed adaptive prescribed-time orbit containment control for satellite cluster flight

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Chinese Journal of Aeronautics 2024年第8期37卷 342-357页

作者： tingting zhang Shijie zhang Huayi LI Xiangtian ZHAO Research Center of Satellite Technology Harbin Institute of TechnologyHarbin 150080China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

The distributed prescribed-time orbit containment control for the satellite cluster flight with multiple dynamic leaders is *** directed information communication topology between followers is taken into account in the overall *** the satellite mass is assumed to be constant,a distributed prescribed-time orbit containment controller is,firstly,presented to drive the followers into the dynamic convex hull produced by multiple ***,the parameter uncertainty is considered,and a prescribed-time sliding mode estimator is introduced to estimate the desired velocity of each *** on the estimated state,a novel distributed adaptive prescribed-time orbit containment control scheme is *** Lyapunov stability theory is utilized to prove the prescribed-time stability of the closed-loop ***,several numerical simulations and comparison of different control methods are provided to verify the effectiveness and superiority of the proposed control method.

关键词： Satellite cluster Orbit containment control Prescribed-time control Parameter uncertainty Directed communication graph

Bayesian ensemble methods for predicting ground deformation due to tunnelling with sparse monitoring data

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Underground Space 2024年第3期16卷 79-93页

作者： Zilong zhang tingting zhang Xiaozhou Li Daniel Dias School of Civil Engineering Central South UniversityChangshaHunan 410075China Laboratory 3SR Grenoble Alpes UniversityCNRS UMR 5521Grenoble 38000France

Numerous analytical models have been developed to predict ground deformations induced by tunneling,which is a critical issue in tunnel ***,the accuracy of these predictions is often limited by errors and uncertainties resulting from model selection and parameter fittings,given the paucity of monitoring data in field *** paper proposes a novel approach to estimate tunnelling-induced ground deformations by applying Bayesian model averaging to several representative prediction *** accounting for both model and parameter uncertainties,this approach enables more realistic predictions of ground deformations than individual ***,our results indicate that the Gonzalez-Sagaseta model outperforms other models in predicting ground surface settlements,while the Loganathan-Poulos model is most suitable for predicting subsurface vertical and horizontal ***,our analysis reveals that when monitoring data are sparse,model uncertainties may contribute up to 78.7%of the total ***,obtaining sufficient data for parameter fitting is crucial for accurate *** proposed method in this study offers a more realistic and efficient prediction of tunnelling-induced ground deformations.

关键词： Tunnelling-induced ground deformations Sparse data Model uncertainties Bayesian model averaging

Coupled effects of methane monooxygenase and nitrogen source on growth and poly-β-hydroxybutyrate(PHB)production of Methylosinus trichosporium OB3b

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Journal of Environmental Sciences 2017年第2期29卷 49-57页

作者： tingting zhang Jiti Zhou Xiaowei Wang Yu zhang Key Laboratory of Industrial Ecology and Environmental Engineering School of Environmental Sdence and TechnologyDalian University of TechnologyDalian 115024China

The coupled effects of nitrogen source and methane monooxygenase（MMO） on the growth and poly-β-hydroxybutyrate（PHB） accumulation capacity of methanotrophs were *** ammonia-supplied methanotrophs expressing soluble MMO（s MMO） grew at the highest rate, while N2-fixing bacteria expressing particulate MMO（p MMO） grew at the lowest rate. Further study showed that more hydroxylamine and nitrite was formed by ammonia-supplied bacteria containing p MMO, which might cause their slightly lower growth rate. The highest PHB content（51.0%） was obtained under nitrogen-limiting conditions with the inoculation of nitrate-supplied bacteria containing p MMO. Ammoniasupplied bacteria also accumulated a higher content of PHB（45.2%） with the expression of p MMO, while N2-fixing bacteria containing p MMO only showed low PHB production capacity（32.1%）. The maximal PHB contents of bacteria expressing s MMO were low, with no significant change under different nitrogen source conditions. The low MMO activity,low cell growth rate and low PHB production capacity of methanotrophs continuously cultivated with N2 with the expression of p MMO were greatly improved in the cyclic NO3-N2 cultivation regime, indicating that long-term deficiency of nitrogen sources was detrimental to the activity of methanotrophs expressing pMMO.

关键词： Methane Methanotroph PHB Nitrogen source Methane monooxygenase

Enrichments of methanotrophic–heterotrophic cultures with high poly-β-hydroxybutyrate(PHB) accumulation capacities

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Journal of Environmental Sciences 2018年第3期30卷 133-143页

作者： tingting zhang Xiaowei Wang Jiti Zhou Yu zhang Key Laboratory of Industrial Ecology and Environmental Engineering School of Environmental Science and Technology Dalian University of Technology

Methanotrophic–heterotrophic communities were selectively enriched from sewage sludge to obtain a mixed culture with high levels of poly-β-hydroxybutyrate（PHB）accumulation capacity from *** was used as the carbon source,N2as sole nitrogen source,and oxygen and Cu content were *** proved essential for PHB *** cultures enriched with Cu could accumulate high content of PHB（43.2%–45.9%）,while only small amounts of PHB were accumulated by cultures enriched without Cu（11.9%–17.5%）.Batch assays revealed that communities grown with Cu and a higher O2content synthesized more PHB,which had a wider optimal CH4：O2range and produced a high PHB content（48.7%）even though in the presence of *** all methanotrophic–heterotrophic communities,both methanotrophic and heterotrophic populations showed the ability to accumulate *** methane was added as the sole carbon source,heterotrophs dominated with abundances between 77.2%and 85.6%.All methanotrophs detected belonged to type II genera,which formed stable communities with heterotrophs of different PHB production capacities.

关键词： Methanotroph Activated sludge PHB N2-fixation Methane monooxygenase

ADMM-based Distributed State Estimation for Integrated Energy System

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CSEE Journal of Power and Energy Systems 2019年第2期5卷 275-283页

作者： Yaxin Du Wen zhang tingting zhang Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong UniversityJinan 250061China

In order to have an accurate knowledge of system-wide operation states,it is necessary to perform state estimation for the integrated energy system(IES)as the basis of energy man-agement and *** state estimation is practically infeasible for IES due to the unreliability of communication,the barrier on privacy,and the large scale of integrated *** paper proposes a distributed state estimation algorithm based on the alternating direction method of multipliers(ADMM)for IES containing electricity,heat,and natural *** coupling units are taken into full consideration in modeling of IES state estimation to reflect the harmonization of multi *** the basis of bilinear measurement model,the state estimation considering nonlinear measurements can be replaced by an equivalent three-stage problem containing two linear state estimations and an intermediate transformation to avoid non-convex *** three-stage procedure for IES state estimation can be further decoupled over three sub-systems with coordination on coupling units,yielding a fully distributed scheme based on ADMM.A modified ADMM with the self-adjusting penalty parameter is also adopted to enhance the *** results demonstrate the validity and superiority of the proposed algorithm.

关键词： Alternating direction method of multipliers coupling units distributed state estimation integrated energy system