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Interfacial charge transfer and photocatalytic activity in a reverse designed Bi_(2)O_(3)/TiO_(2)core-shell

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Frontiers in Energy 2021年第3期15卷 732-743页

作者： Sabina Ait ABDELKADER Zhenpeng CUI Abdelghani LAACHACHI Christophe COLBEAU-JUSTIN Mohamed Nawfal GHAZZAL UniversitéParis-Saclay UMR 8000CNRSInstitut de Chimie PhysiqueOrsay 91405France Materials Research and Technology Department(MRT) Luxembourg Institute of Science and Technology(LIST)Käerjeng 4940Luxembourg

In this study,the electronic and photocatalytic properties of core-shell heterojunctions photocatalysts with reversible configuration of TiO_(2)and Bi_(2)O_(3)layers were *** core-shell nanostructure,obtained by efficient control of the sol-gel polymerization and impregnation method of variable precursors of semiconductors,makes it possible to study selectively the role of the interfacial charge transfer in each *** morphological,optical,and chemical composition of the core-shell nanostructures were characterized by high-resolution transmission electron microscopy,UV-visible spectroscopy and X-ray photoelectron *** results show the formation of homogenous TiO_(2)anatase and Bi_(2)O_(3)layers with a thickness of around 10 and 8 nm,*** interfacial charge carrier dynamic was tracked using time resolved microwave conductivity and transition photocurrent *** charge transfer,their density,and lifetime were found to rely on the layout layers in the core-shell *** optimal core-shell design,Bi_(2)O_(3)collects holes from TiO_(2),leaving electrons free to react and increase by 5 times the photocatalytic efficiency toward H2 *** study provides new insight into the importance of the design and elaboration of optimal heterojunction based on the photocatalyst system to improve the photocatalytic activity.

关键词： photocatalysis core-shell heterojunction H2 TiO_(2) Bi_(2)O_(3)

Future Commercial Vehicle Powertrains:Contributions to Sustainable Transportation

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Future Commercial Vehicle Powertrains:Contributions to Susta...

A Virtual Prototyping Approach for Development of PMSM on Real‑Time Platforms: A Case Study on Temperature Sensitivity

FISITA 2012 World Automotive Congress--Volume 3:Future Automotive Powertrains

作者： Heimo Schreier Lukas Walter AVL list GmbH GrazAustria

Objective Already for many years,fuel consumption and operating cost were the major technology drivers for commercial ***,in order to achieve agreed CO goals and to reduce the dependency on crude oil,governments are implementing CO or fuel consumption *** more,reduction of fuel consumption and consequently low operating costs are continuously an important focus for manufacturers and owners of commercial *** powertrain technologies,which will further reduce fuel consumption,are able to combine these three drivers,to reduce CO emission,to reduce the dependency on crude oil and to address the need of lower total cost of ownership of the owners of commercial *** The efficiency of commercial powertrains can be significantly increased in *** potentials for improvement are seen specifically in those technologies,which are able to provide a global optimum of the whole powertrain system,from engine to exhaust aftcrtreatment to cooling system up to transmission and the final *** total a fuel efficiency potential of20%is seen for long haul *** AVL has developed a whole line of technologies,which can be implemented to the commercial powertrain in the future to address the requirements *** individual measures are the optimization of the balance between engine and aftertreatment systems,reduced engine friction by advanced thermal management systems,reduced parasitic losses of the auxiliaries in real life driving cycles,conversion of exhaust energy in driving power,application of new and advanced transmission technologies and shift strategies as well as degrees of electrification of the ***,alternative fuels provide another field of CO friendly technologies as well as reduced operating *** specifically,the availability of local resources drive short term *** paper will compare the individual saving potentials of these technologies,will rate it against criteria

关键词： Commercial powertrain Fuel efficiency CO2 reduction

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Automotive Innovation 2022年第3期5卷 285-298页

作者： René Scheer Yannick Bergheim Simon Aleff Daniel Heintges Niclas Rahner Rafael Gries Jakob Andert Teaching and Research Area Mechatronics in Mobile Propulsion RWTH Aachen UniversityForckenbeckstr.4Aachen 52074Germany DENSO Automotive Deutschland GmbH Friedrich‑List‑Allee 42Wegberg 41844Germany

This paper presents a comprehensive evaluation of system interactions in a battery electric vehicle caused by temperature sensitivity of permanent magnet synchronous machines(PMSM).An analytical model of a PMSM considering iron losses and thermal impact is implemented on a field programmable gate array suitable for hardware-in-the-loop *** the presented virtual prototyping approach,different machine characteristics defined by the design are used to parameterize the analytical *** investigated temperature effect is understood as an interacting influence between machine character-istics and control,which are investigated in terms of torque generation,voltage utilization and efficiency under closed-loop condition in a vehicle *** particular,using a surface permanent magnet rotor and an interior permanent magnet rotor,the performance of both machine designs is analyzed by varying temperature-adjusted feedforward control strategies on the basis of a driving cycle from a *** comparison shows that the machine design with surface-mounted mag-nets is associated with higher temperature *** this case,the temperature consideration in the feedforward control provides a14%loss reduction in closed-loop vehicle test *** can be summarized that the electromagnetic torque is less sensitive to a temperature variation with increasing *** presented development approach demonstrates the impact of interactions in electric powertrains without the need of real prototypes.

关键词： FPGA PMSM Iron loss FEM Spatial harmonics RT-MIL Virtual prototyping Frontloading Closed-

Data-driven diagnosis of high temperature PEM fuel cells based on the electrochemical impedance spectroscopy: Robustness improvement and evaluation

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Journal of Energy Chemistry 2024年第9期96卷 544-558页

作者： Dan Yu Xingjun Li Samuel Simon Araya Simon Lennart Sahlin Vincenzo Liso Department of Energy Aalborg UniversityAalborg 9220Denmark Walker Department of Mechanical Engineering The University of Texas at AustinAustinTX 78712USA Materials Research and Technology Development Luxembourg Institute of Science and Technology(LIST)4422 BelvauxLuxembourg

Utilizing machine learning techniques for data-driven diagnosis of high temperature PEM fuel cells is beneficial and meaningful to the system durability. Nevertheless, ensuring the robustness of diagnosis remains a critical and challenging task in real application. To enhance the robustness of diagnosis and achieve a more thorough evaluation of diagnostic performance, a robust diagnostic procedure based on electrochemical impedance spectroscopy (EIS) and a new method for evaluation of the diagnosis robustness was proposed and investigated in this work. To improve the diagnosis robustness: (1) the degradation mechanism of different faults in the high temperature PEM fuel cell was first analyzed via the distribution of relaxation time of EIS to determine the equivalent circuit model (ECM) with better interpretability, simplicity and accuracy;(2) the feature extraction was implemented on the identified parameters of the ECM and extra attention was paid to distinguishing between the long-term normal degradation and other faults;(3) a Siamese Network was adopted to get features with higher robustness in a new embedding. The diagnosis was conducted using 6 classic classification algorithms—support vector machine (SVM), K-nearest neighbor (KNN), logistic regression (LR), decision tree (DT), random forest (RF), and Naive Bayes employing a dataset comprising a total of 1935 collected EIS. To evaluate the robustness of trained models: (1) different levels of errors were added to the features for performance evaluation;(2) a robustness coefficient (Roubust_C) was defined for a quantified and explicit evaluation of the diagnosis robustness. The diagnostic models employing the proposed feature extraction method can not only achieve the higher performance of around 100% but also higher robustness for diagnosis models. Despite the initial performance being similar, the KNN demonstrated a superior robustness after feature selection and re-embedding by triplet-loss method, which sug

关键词： PEM fuel cell Data-driven diagnosis Robustness improvement and evaluation Electrochemical impedance spectroscopy

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多维模型与高速直喷柴油机的设计和研制

柴油机 1990年第2期12卷 36-42页

作者： W.布郎斯得特吴吉湘 AVL list有限公司

本文叙述了计算流体力学(或多维计算模型)在计算内燃机流动过程方面的应用,特别是AVL如何应用此方法在设计和研制高速直喷柴油机过程中所做的工作,讨论了理论基础和应用多维流体计算所遇到的问题;介绍了已广泛用于汽车工业的计算程序算... 详细信息

本文叙述了计算流体力学(或多维计算模型)在计算内燃机流动过程方面的应用,特别是AVL如何应用此方法在设计和研制高速直喷柴油机过程中所做的工作,讨论了理论基础和应用多维流体计算所遇到的问题;介绍了已广泛用于汽车工业的计算程序算出的典型计算结果,包括缸内进气诱导和压缩涡流的二维和三维计算结果和进气歧管内的流动计算结果。所有这些计算的最重要特征是它们能够给出对复杂物理现象的深入理解,此外这一方法还能够提供通过试验很难或不能得到的重要信息。多维模型即可用于设计阶段评估和各种不同设计方案的分析,又可用于发展研制过程中,通过计算不同边界和运转条件下发动机的性能来揭示共同特征和变化趋势。

关键词：多维模型柴油机高速设计

Reachability-Based Confidence-Aware Probabilistic Collision Detection in Highway Driving

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Engineering 2024年第2期33卷 90-107页

作者： Xinwei Wang Zirui Li Javier Alonso-Mora Meng Wang School of Engineering and Materials Science Queen Mary University of LondonLondon E14NSUK Department of Cognitive Robotics Delft University of TechnologyDelft 2628 CDNetherlands School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Chair of Traffic Process Automation “Friedrich List”Faculty of Transport and Traffic SciencesTU DresdenDresden 01069Germany

Risk assessment is a crucial component of collision warning and avoidance systems for intelligent ***-based formal approaches have been developed to ensure driving safety to accurately detect potential vehicle ***,they suffer from over-conservatism,potentially resulting in false–positive risk events in complicated real-world *** this paper,we combine two reachability analysis techniques,a backward reachable set(BRS)and a stochastic forward reachable set(FRS),and propose an integrated probabilistic collision–detection framework for highway *** this framework,we can first use a BRS to formally check whether a two-vehicle interaction is safe;otherwise,a prediction-based stochastic FRS is employed to estimate the collision probability at each future time ***,the framework can not only identify non-risky events with guaranteed safety but also provide accurate collision risk estimation in safety-critical *** construct the stochastic FRS,we develop a neural network-based acceleration model for surrounding vehicles and further incorporate a confidence-aware dynamic belief to improve the prediction *** experiments were conducted to validate the performance of the acceleration prediction model based on naturalistic highway driving *** efficiency and effectiveness of the framework with infused confidence beliefs were tested in both naturalistic and simulated highway *** proposed risk assessment framework is promising for real-world applications.

关键词： Probabilistic collision detection Confidence awareness Probabilistic acceleration prediction Reachability analysis Risk assessment

Correction to affiliations

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Financial Innovation 2020年第1期6卷 969-970页

作者： Financial Innovation Full list of author information is available at the end of the article

Correction to:Zhang,S.,Xiong,W.,Ni,*** *** of big data to finance:observations on an internet credit Service Company in *** Innovation 1,17(2015)https://***/10.1186/s40854-015-0017-2 There is an error in the Author Details in this article Zhang et al.(2015).The affiliation of Xin Li should be corrected to:Department of Information Systems,City University of Hong Kong,Kowloon Tong,Hong Kong,China Correction to:Ge,L.,Luo,*** rivalry and lending on crowdfunding platforms:an empirical *** Innov 2,17(2016)https://***/10.1186/s40854-016-0035-8 There is an error in the affiliations on Page 1 of this article Ge and Luo(2016).The affiliation of Ling Ge and Xuechen Luo should be corrected to:Department of Information Systems,City University of Hong Kong,Kowloon Tong,Hong Kong,China.

关键词： finance China. Financial

Nonnegative non-redundant tensor decomposition

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Frontiers of Mathematics in China 2013年第1期8卷 41-61页

作者： Olexiy KYRGYZOV Deniz ERDOGMUS Laboratoire d'Outils pour l'Analyse de Donn@es LIST CEA Gif-sur-Yvette F-91911 France Cognitive Systems Lab Department of Electrical and Computer Engineering Northeastern University Boston MA 02115 USA

Nonnegative tensor decomposition allows us to analyze data in their ＇native＇ form and to present results in the form of the sum of rank-1 tensors that does not nullify any parts of the factors. In this paper, we propose the geometrical structure of a basis vector frame for sum-of-rank-1 type decomposition of real-valued nonnegative tensors. The decomposition we propose reinterprets the orthogonality property of the singularvectors of matrices as a geometric constraint on the rank-1 matrix bases which leads to a geometrically constrained singularvector frame. Relaxing the orthogonality requirement, we developed a set of structured-bases that can be utilized to decompose any tensor into a similar constrained sum-of-rank-1 decomposition. The proposed approach is essentially a reparametrization and gives us an upper bound of the rank for tensors. At first, we describe the general case of tensor decomposition and then extend it to its nonnegative form. At the end of this paper, we show numerical results which conform to the proposed tensor model and utilize it for nonnegative data decomposition.

关键词： matrix tensor rank-1 decomposition basis vector frame

Generalization of the Second Order Vector Potential Formulation for Arbitrary Non-Orthogonal Curvilinear Coordinates Systems from the Covariant Form of Maxwell's Equations

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Journal of Electromagnetic Analysis and Applications 2012年第10期4卷 400-409页

作者： Denis Prémel CEA LIST F-91191 Gif sur Yvette CEDEX France.

A great number of semi-analytical models, notably the representation of electromagnetic fields by integral equations are based on the second order vector potential (SOVP) formalism which introduces two scalar potentials in order to obtain analytical expressions of the electromagnetic fields from the two potentials. However, the scalar decomposition is often known for canonical coordinate systems. This paper aims in introducing a specific SOVP formulation dedicated to arbitrary non-orthogonal curvilinear coordinates systems. The electromagnetic field representation which is derived in this paper constitutes the key stone for the development of semi-analytical models for solving some eddy currents moelling problems and electromagnetic radiation problems considering at least two homogeneous media separated by a rough interface. This SOVP formulation is derived from the tensor formalism and Maxwell’s equations written in a non-orthogonal coordinates system adapted to a surface characterized by a 2D arbitrary aperiodic profile.

关键词： Second Order Vector Potential (SOVP) Curvilinear Coordinate System Eddy Current Non-Destructive Testing (ECNDT)