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Journal of Environmental Sciences 2024年第8期142卷 269-278页

作者： Ying Lu Se wang Yifan shen School of Environmental Science and Engineering Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologyJiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution ControlNanjing University of Information Science and TechnologyNanjing 210044China

The frequent detection of pharmaceutical compounds in the environment has led to a growing awareness,which may pose a major threat to the aquatic *** this study,photodegradation(direct and indirect photolysis)of two different dissociation states of fluoxetine(FLU)was investigated in water,mainly including the determination of photolytic transition states and products,and the mechanisms of indirect photodegradation with·OH,CO_(3)^(*-)and NO_(3)^(*).The main direct photolysis pathways are defluorination and C–C bond *** addition,the indirect photodegradation of FLU in water is mainly through the reactions with·OH and NO_(3)^(*),and the photodegradation reaction with CO_(3)^(*-)is relatively difficult to occur in the water *** results provide a theoretical basis for understanding the phototransformation process of FLU in the water environment and assessing its potential risk.

关键词： Fluoxetine Photochemical mechanism Direct photolysis Free radical reaction DFT

An Asynchronous Variational Integrator for Contact Problems Involving Elastoplastic Solids

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Acta Mechanica Solida Sinica 2024年第2期37卷 305-315页

作者： Zongwu Niu Zixiao wang Yongxing shen University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai200240China School of Agriculture and Biology Shanghai Jiao Tong UniversityShanghai200240China Department of Biostatistics Johns Hopkins Bloomberg School of Public HealthBaltimoreMaryland21205USA

Simulations of contact problems involving at least one plastic solid may be costly due to their strong nonlinearity and requirements of *** this work,we develop an explicit asynchronous variational integrator(AVI)for inelastic non-frictional contact problems involving a plastic *** AVI assigns each element in the mesh an independent time step and updates the solution at the elements and nodes *** asynchrony makes the AVI highly efficient in solving such bi-material *** advantage of the AVI,the constitutive update is locally performed in one element at a time,and contact constraints are also enforced on only one *** time step of the contact element is subdivided into multiple segments,and the fields are updated *** a contact event,only one element involving a few degrees of freedom is considered,leading to high *** proposed formulation is first verified with a pure elastodynamics benchmark and further applied to a contact problem involving an elastoplastic solid with non-associative volumetric *** numerical results indicate that the AVI exhibits excellent energy behaviors and has high computational efficiency.

关键词： Asynchronous variational integrator Plasticity Contact Computational efficiency Finite element method

Investigation of Ce/BEA as a passive NO_(x)adsorber:*** aging deactivation mechanism

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Journal of Rare Earths 2024年第8期42卷 1524-1530,I0004页

作者： Yiying Ding Minghui Yu Xiaojie Yu Meiqing shen Jianqiang wang Jun wang Gurong shen School of Chemical Engineering and Technology Tianjin UniversityTianjin300350China School of Materials Science and Engineering Tianjin UniversityTianjin300350China National Rare Earth Catalysis Research Institute Dongying257000China

Ce/BEA has the potential to be applied as a novel passive NO_(x)absorber(PNA)in the after-treatment of vehicles due to its considerable NO_(x)storage ***,as a vehicle exhaust after-treatment material,it must withstand the test of long-term hydrothermal *** work examined the deactivation mechanism of Ce/BEA during hydrothermal aging.3.0 wt%Ce/BEA was prepared using the ionexchange method,and then subjected to hydrothermal treatment at 650℃with 10%H_(2)O for 1-12 h to obtain samples with different aging *** comparison,the H-BEA support was aged under the same ***-Emmett-Teller(BET)method,X-ray diffraction(XRD),NH_(3)temperature programmed reduction(NH_(3)-TPD),^(27)Al MAS nuclear magnetic resonance(^(27)Al MAS NMR),H_(2)temperature programmed reduction(H_(2)-TPR),and high resolution-transmission electron microscopy(HR-TEM)were performed to characterize the changes in PNA performance,structure,Ce species,and *** HR-TEM and H_(2)-TPR results show that CeO_(x)particles appear after hydrothermal aging,which results from the detachment and aggregation of active Ce *** on the^(27)Al MAS NMR results,we conclude that BEA zeolite dealumination leads to the loss of acidic sites and the transformation of active Ce species on the acidic sites into the less active CeO_(x).This is the primary reason for the hydrothermal aging deactivation of Ce/BEA.

关键词： Passive NO_(x)adsorber Ce/BEA Hydrothermal aging CeO_(x) Dealumination Rare earths

Function-reversible facets enabling SrTiO_(3)nanocrystals for improved photocatalytic hydrogen evolution

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Frontiers in Energy 2024年第1期18卷 101-109页

作者： Bin wang Bei AN Xiaoqian LI Shaohua shen School of Physics Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter(Ministry of Education)Key Laboratory of Shaanxi for Advanced Materials and Mesoscopic PhysicsXi’an Jiaotong UniversityXi’an 710049China International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an 710049China

It has been widely reported that,for faceted nanocrystals,the two adjacent facets with different band levels contribute to promoted charge separation,and provide active sites for photocatalytic reduction and oxidation reaction,*** such cases,only one family of facets can be used for photocatalytic hydrogen ***,by using SrTiO_(3)nanocrystals enclosed by{023}and{001}facets as a model photocatalyst,this paper proposed a strategy to achieve the full-facets-utilization of the nanocrystals for photocatalytic hydrogen via chemically depositing Pt nanoparticles on all *** photo-deposition experiment of CdS provided direct evidence to demonstrate that the{023}facets which were responsible for photooxidation reaction can be function-reversed for photocatalytic hydrogen evolution after depositing Pt nanoparticles,together with the{001}***,the full-facets-utilization led to a much-improved activity for photocatalytic hydrogen,in contrast to those SrTiO_(3)nanocrystals with only{001}facets deposited by Pt nanoparticles via a photo-deposition method.

关键词： SrTiO_(3)nanocrystals crystal facets photocatalysis hydrogen evolution

Investigation of Ce/BEA as a passive NO_(x)adsorber:*** occurrences of cerium and adsorption behavior

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Journal of Rare Earths 2024年第7期42卷 1265-1271,I0003页

作者： Minghui Yu Yiying Ding Xiaojie Yu Siwei Yan Meiqing shen Jianqiang wang Jun wang Gurong shen School of Materials Science and Engineering Tianjin UniversityTianjin300350China School of Chemical Engineering and Technology Tianjin UniversityTianjin300350China National Rare Earth Catalysis Research Institute Dongying257000China

Ce/BEA has great potential as a passive NO_(x)absorber(PNA)to reduce the NO_(x)emissions during the cold start phase especially in diesel engine for its high resistance to CO and suitable NO_(x)desorption temperature ***,as a novel material,its physical and chemical properties still remain *** this work,Ce/BEA was synthesized by ion-exchange method to identify the active species in NO_(x)adsorption,compared with aggregated Ce species in Ce/SiAlO_(x) prepared by impregnation method.X-ray diffraction(XRD),high resolution-transmission electron microscopy(HR-TEM)and aberration-corrected-scanning transmission electron microscopy(AC-STEM)were performed to confirm the isolated single atom formation of Ce species in Ce/***-vis diffraction reflection spectra(DRS)and X-ray photoelectron spectroscopy(XPS)were conducted to find the difference of chemical environment between the isolated Ce species and aggregated *** performance evaluation and temperature programmed reduction of hydrogen(H_(2)-TPR)results show the high NO_(x)storage capacity and active oxygen species quantity in Ce/*** is also found that the main NO_(x)adsorption species are Ce^(4+)-O^(∗)rather than Ce^(3+).NO_(x)-diffuse reflectance infrared Fourier transform spectroscopy(NO_(x)-DRIFTS)confirms that the bidentate nitrite species are the critical NO_(x)adsorption intermediates and the conception of NO_(x)adsorption and desorption processes is proposed.

关键词： Passive NO_(x)absorber Ce/BEA Isolated Ce species Rare earths

Parallel Light Fields: A Perspective and A Framework

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 542-544页

作者： Fei-Yue wang Yu shen IEEE State Key Laboratory for Management and Control of Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of ScienceBeijing 100049

Dear Editor,Light fields give relatively complete description of scenes from perspective of angles and positions of rays. At present time, most of the computer vision algorithms take 2D images as input which are simplified expression of light fields with depth information discarded. In theory, computer vision tasks may achieve better performance as long as complete light fields are acquired.

关键词： computer Framework simplified

Absolute pose estimation of UAV based on large-scale satellite image

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Chinese Journal of Aeronautics 2024年第6期37卷 219-231页

作者： Hanyu wang Qiang shen Zilong DENG Xinyi CAO Xiaokang wang School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

Obtaining absolute pose based on pre-loaded satellite images is one of the important means of autonomous navigation for small Unmanned Aerial Vehicles(UAVs)in Global Navigation Satellite System(GNSS)denied *** of the previous works have tended to build Convolutional Neural Networks(CNNs)to extract features and then directly regress the pose,which will fail when solving the challenges caused by the huge viewpoint and size differences between“UAV-satellite”image pairs in real-world ***,this paper proposes a probability distribution/regression integrated deep model with the attention-guided triple fusion mechanism,which estimates discrete distributions in pose space and three-dimensional vectors in translation *** order to overcome the shortage of the relevant dataset,this paper simulates image datasets captured by UAVs with forward-facing cameras during target searching and autonomous *** effectiveness,superiority,and robustness of the proposed method are verified by simulated datasets and flight tests.

关键词： Satellite imagery Unmanned Aerial Vehicle(UAV) Deep neural networks Vision navigation von Mises-Fisher distribution

Identifying the enhancement mechanism of Al/MoO_(3) reactive multilayered films on the ignition ability of semiconductor bridge using a one-dimensional gas-solid two-phase flow model

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Defence Technology（防务技术） 2024年第3期33卷 168-179页

作者： Jianbing Xu Yuxuan Zhou Yun shen Yueting wang Yinghua Ye Ruiqi shen School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China Micro-Nano Energetic Devices Key Laboratory of MIIT Nanjing 210094China Institute of Space Propulsion Nanjing University of Science and TechnologyNanjing 210094China

Energetic Semiconductor bridge(ESCB)based on reactive multilayered films(RMFs)has a promising application in the miniature and intelligence of initiator and pyrotechnics *** the ignition enhancement mechanism of RMFs on semiconductor bridge(SCB)during the ignition process is crucial for the engineering and practical application of advanced initiator and pyrotechnics *** this study,a one-dimensional(1D)gas-solid two-phase flow ignition model was established to study the ignition process of ESCB to charge particles based on the reactivity of Al/MoO_(3) *** order to fully consider the coupled exothermic between the RMFs and the SCB plasma during the ignition process,the heat release of chemical reaction in RMFs was used as an internal heat source in this *** is found that the exothermal reaction in RMFs improved the ignition performance of *** the process of plasma rapid condensation with heat release,the product of RMFs enhanced the heat transfer process between the gas phase and the solid charge particle,which accelerated the expansion of hot plasma,and heated the solid charge particle as well as gas phase region with low *** addition,it made up for pressure loss in the gas *** the plasma dissipation process,the exothermal chemical reaction in RMFs acted as the main heating source to heat the charge particle,making the surface temperature of the charge particle,gas pressure,and gas temperature rise *** result may yield significant advantages in providing a universal ignition model for miniaturized ignition devices.

关键词： Ignition enhancement mechanism 1D gas-solid two-phase flow Al/MoO_(3)reactive multilayered films Semiconductor bridge Miniaturized ignition device

CMOS-level mega-pixel organic camera chips made of photocrosslinked photovoltaic nanocells

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Science China Materials 2024年第9期67卷 3043-3045页

作者： Yegang Liang Zhuoran wang Guozhen shen School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing100081China

Organic and hybrid optoelectronics have been driving the frontiers in displays,sensing,and energy in recent decades due to their superior performance,low-cost high-yield manufacturing,and new form factor of mechanical flexibility that is promising for lightweight and wearable applications[1-3].However,the inherent vulnerability makes organic semiconductors incompatible with conventional semiconductor microfabrication,posing significant challenges in high density integration to compete with the resolution of conventional image sensors[4].

关键词： frontier driving lightweight

Experimental and numerical study regarding H-steel all-bolted connection steel frame with composite wall boards

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 427-443页

作者： Fan Min Guo Hongchao Li shen.wang Zhenshan wang Huaqiang School of Civil Engineering and Architecture Xi’an University of TechnologyXi’an 710048China State Key Laboratory Base of Eco-Hydraulic Engineering in Arid Area Xi’an University of TechnologyXi’an 710048China

H-steel all-bolted connection steel frame structures with heat preservation and decoration composite wall boards were investigated and the seismic performances of three scaled specimens were *** failure modes,hysteresis curves,bearing capacity,ductility,energy dissipation capacity,stiffness degradation and strain distribution were *** calculation method of structural theoretical internal force was *** results showed that the overall structural seismic performance was better,and the structural ductility met the demands of elastic-plastic inter-story drift angle for seismic *** H-steel weak-axis connection structure obtained better energy dissipation capacity,and its bearing capacity and stiffness were slightly different from the strong-axis *** heat preservation and decoration performance of composite wallboard and the all-bolted connection of the steel frame realized prefabrication during the whole construction *** plastic hinge of the steel beam can be moved outwards because of the L-angles,which effectively avoids stress concentration in joint areas and expands the plastic hinge *** errors between the theoretical structural capacity calculated by the plastic analysis method and the test results were within 2.44%.In addition,structural failure mechanisms and bearing capacities were verified by the finite element(FE)analysis,and the effects of the main parameters on the structures were *** FE verification results were the same as in the *** research results provide theoretical support and technical guidance for the application of thermal insulation and decorative composite wall panels in H-shaped steel all-bolted steel frames.

关键词： composite wall boards all-bolted steel frame H-steel low-cyclic loading failure modes