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Investigation on the urea deposit formation and thermal decomposition characteristics in the SCR aftertreatment system of a diesel engine

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Journal of Environmental Sciences 2021年第5期33卷 157-171页

作者： Menghan Li Yao Zhang Jiancheng Yang Xiaori Liu Zhenguo Li Qiang Zhang Tianjin Key Laboratory of Clean Energy and Pollution Control School of Energy and Environmental EngineeringHebei University of TechnologyTianjin 300401China School of Civil and Transportation Engineering Hebei University of TechnologyTianjin 300401China National Engineering Laboratory for Mobile Source Emission Control Technology China Automotive Technology&Research Center Co.Ltd.Tianjin 300300China State Key Laboratory of Engines Tianjin UniversityTianjin 300072China School of Energy and Power Engineering Shandong UniversityJinanShandong 250061China

Selective catalytic reduction is the most efficient and reliable equipment for NOx control in current diesel engines. However, the issue of urea crystallization becomes increasingly serious with the implement of the new emissions standards. In this paper, urea deposit samples collected from engine test bed and tube furnace were characterized by thermogravimetric analysis and Fourier transform-infrared analysis to aid the comprehension of urea deposit formation. Moreover, thermogravimetric tests were conducted to disclose the effects of catalyst on the thermal decomposition processes of urea deposit. The results indicated that less temperature resistant species are formed in the engine test bed than in the tube furnace at conditions with the same temperatures. The main compositions in the World Harmonized Transient Cycle(WHTC) urea deposits are urea, cyanuric acid(CYA) and ammelide, implying that accelerating the decomposition of these species could prevent the accumulation of urea deposit. CuWTi, Cu β and CuZSM catalysts could lead to increased yield of CYA during pure urea thermolysis. Cu β, CuWTi and VWTi catalysts tend to promote the thermolysis of CYA while VWTi has the most significant catalytic effects on the thermal decomposition of ammelide and ammeline.

关键词： Urea deposit Decomposition characteristics Selective catalytic reduction Catalyst Thermolysis

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Sensor lessPMSM control Algorithm for Rim-Driven Thruster Based on Improved PSO 6

Sensor lessPMSM Control Algorithm for Rim-Driven Thruster Ba...

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6th International Conference on transportation Information and Safety, ICTIS 2021

作者： Yang, Zhi Yan, Xinping Ouyang, Wu Hongfen, Bai Reliability Engineering Institute School of Transportation and Logistics Engineering Wuhan University of Technology Wuhan China Wuhan China Shanghai Maritime University Key Laboratory of Transport Industry of Marine Technology and Control Engineering Shanghai China

ISBN: (纸本)9781665497138

Aiming at the chattering and parameter setting problems in the Permanent Magnet Synchronous Motor of Rim-Driven Thruster (RDT), a sensorless control algorithm combining model reference adaptive control (MRAC) and variable structure control (VSC) is presented. An improved particle swarm optimization (PSO) algorithm is used, the integral of the error between the RDT's estimated speed and the given speed's absolute value and time's product is chosen as a performance evaluation function in the algorithm. The cosine change is introduced to the inertia weight in the iterative process of the PSO which realizes the optimization of the adjustable parameters in the observer. The algorithm is verified by means of MATLAB/ Simulink simulation. The simulation results show that compared with the PSO based on the commonly used inertial weight adjustment method, the improved PSO can improve the shortcomings of slow iteration speed and insufficient precision, the sensorless control algorithm based on the improved PSO can reduce the chattering generated in the RDT motor speed and position estimation, the error between the estimated speed and the given speed, and get the rotor estimation speed accurately, the reliability of the algorithm is verified. © 2021 IEEE.

关键词： Speed

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A highly active VOx-MnOx/CeO_(2) for selective catalytic reduction of NO:The balance between redox property and surface acidity

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Journal of Rare Earths 2021年第11期39卷 1370-1381,I0003页

作者： Runnong Yang Zihan Gao Ming Sun Guangying Fu Gao Cheng Wuyuan Liu Xiaobo Yang Xiangyun Zhao Lin Yu Key Laboratory of Clean Chemistry Technology of Guangdong Regular Higher Education Institutions Guangzhou Key Laboratory of Clean Transportation Energy ChemistrySchool of Chemical Engineering and Light IndustryGuangdong University of TechnologyGuangzhou 510006China School of Chemistry Sun Yat-Sen UniversityGuangzhou 510275China Waygreen Technologies Inc.Guangzhou 511441China

Excellent catalysts with low-temperature activity and relatively wide temperature window for selective catalytic reduction of NO with ammonia(NH_(3)-SCR) are highly demanded in view of the practical treatment of ***,we have designed a highly active VOx-MnOx/CeO_(2) material based on the intrinsic requirement of SCR reaction for catalyst,namely redox sites and surface acid *** vanadium oxide and manganese oxide are highly dispersed over the ceria mesosphere via simple incipient wetness *** loading of manganese could introduce acid sites and enhance the redox property remarkably,while the loading of vanadium increases acid sites and weakens redox *** tentatively controlling the appropriate loading ratio of the two components,the optimal catalyst achieves a balance between redox property and surface *** work shed light on the development of new SCR catalyst with superior low temperature activity,wide work temperature window and good hydrothermal stability.

关键词： Redox property Surface acidity Highly active catalyst NH_(3)-SCR Rare earths

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Lacunary silicotungstic heteropoly salts as high-performance catalysts in oxidation of cyclopentene

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Chinese Journal of Chemical engineering 2023年第4期56卷 152-159页

作者： Peiyin Chen Yanxiong Fang Kaihong Xie Yao Chen Yang Liu Hongliang Zuo Weijian Lu Baoyu Liu School of Chemical Engineering and Light Industry Guangdong Provincial Key Laboratory of Plant Resources BiorefineryGuangzhou Key Laboratory of Clean Transportation Energy ChemistryGuangdong University of TechnologyGuangzhou 510006China Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory(Rongjiang Laboratory) Jieyang 515200China Guangdong Xinhuayue Petrochemical Group Stock Company No.18Youcheng 4 RoadMaoming 525000China

The development of polyoxometalates for olefin oxidation is critical to achieving the green chemical process of the C5 fraction further ***-lacunary silicotungstic anions were easily obtained by continuously adjusting the p H instead of the traditional step-by-step method,which exhibited excellent performance in the catalytic oxidation of cyclopentene(CPE)to aldehydes or *** 93.69%CPE conversion and 97.15%total product selectivity(41.38%for glutaraldehyde(GA)and 55.77%for 1,2-cyclopentanediol(1,2-diol)were achieved by using H_(2)O_(2)as the oxidant and acetonitrile as the *** complementary characterization,it was found that the optimized di-lacunary silicotungstic polyoxometalate retained a complete Keggin structure,and exhibited better catalytic activity and stability than the mono-lacunary or saturated silicodecatungstate because it exposed more catalytic active ***,in situ FT-IR spectra was utilized to monitor the reaction process,revealing the formation of the active species W(O_(2))on the di-lacunary silicotungstic polyoxometalate and the intermediate epoxycyclopentane during the catalytic oxidation of cyclopentene.

关键词： Lacunary silicotungstic heteropoly salts Cyclopentene(CPE) Catalytic oxidation Glutaraldehyde(GA) 1,2-Cyclopentanediol(1,2-diol)

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MTPA control of interior fault-tolerant permanent magnet motor for the marine electric propulsion system 6

MTPA control of interior fault-tolerant permanent magnet mot...

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6th International Conference on transportation Information and Safety, ICTIS 2021

作者： Bai, Hongfen Yan, Xinping Ouyang, Wu Reliability Engineering Institute School of Transportation and Logistics Engineering Wuhan University of Technology Wuhan China Shanghai Maritime University Key Laboratory of Transport Industry of Marine Technology and Control Engineering Shanghai China MoST Wuhan China

ISBN: (纸本)9781665497138

In order to improve the torque output capability of interior fault-tolerant permanent magnet motor (IFTPMM) applied in the electric propulsion ships, the maximum torque per ampere (MTPA) is studied. According to the basic equations of the motor in the d-q coordinate system, the Lagrangian multiplier method is proposed to obtain the multi-order equations of d-q axis current and torque. The optimal operating point of the MTPA control is found by MATLAB and the MTPA control is realized. Compared to the control method of $\text{id}=0$, the simulation waveform shows that the MTPA control is more suitable in IFTPMM and the control algorithm has high efficiency and fast dynamic response, which can meet the requirements of electric propulsion ships for propulsion motors. © 2021 IEEE.

关键词： MATLAB

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An Optimal control Based Trajectory Planning Method for Cooperative Merging Maneuvers 3

An Optimal Control Based Trajectory Planning Method for Coop...

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3rd International Symposium on Intelligent Robotics and Systems, ISoIRS 2023

作者： Wang, Qi Ge, Hao Duan, Xuting Zhou, Jianshan School of Transportation Science and Engineering Beihang University State Key Lab of Intelligent Transportation System Beijing Key Laboratory for Cooperative Vehicle Infrastructure Systems and Safety Control State Key Laboratory of Air Traffic Management System and Technology Beijing China Nanjing Research Institute of Electronic Engineering State Key Laboratory of Air Traffic Management System and Technology Nanjing China School of Transportation Science and Engineering Beihang University State Key Lab of Intelligent Transportation System Beijing Key Laboratory for Cooperative Vehicle Infrastructure Systems and Safety Control Beijing China

ISBN: (纸本)9798350339963

Due to the prediction errors and diverse driving styles of surrounding vehicles, traffic congestion and even accidents can occur in the traffic bottleneck area where vehicles merge into the main road. To ensure that connected and automated vehicles (CAVs) can quickly and efficiently merge into the main road, this paper proposes a cooperative trajectory planning method based on optimal control for vehicle cut-in scenarios. A optimal control model is constructed, and a quintic polynomial is used to generate the initial solution of the optimal control problem to accelerate the solution process and improve the success rate. Finally, The obtained merging trajectory is then synchronized with the movement of vehicles on the main road to optimize their actions and ensure a safe merging process. Joint simulation with Robot Operating System (ROS) and RVIZ is utilized, and the results show that the proposed algorithm can quickly obtain cooperative results, the locally successful merging trajectory meets the requirements of smoothness and safety, and if the solution does not allow merging, the merging vehicle is instructed to terminate the execution. © 2023 IEEE.

关键词： Trajectories

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GDKansformer: A group-wise dynamic Kolmogorov–Arnold transformer with multi-view gated attention for pathological image diagnosis

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Expert Systems with Applications 2025年 286卷

作者： Xiaoyan Lu Xun Gong Yuanyuan Chen School of Computing and Artificial Intelligence Southwest Jiaotong University Chengdu 611756 PR China National Engineering Laboratory of Integrated Transportation Big Data Application Technology and Manufacturing Industry Chains Collaboration and Information Support Technology Key Laboratory of Sichuan Province Southwest Jiaotong University Chengdu 611756 PR China Engineering Research Center of Sustainable Urban Intelligent Transportation Ministry of Education Chengdu 611756 PR China Department of Pathology The Third People’s Hospital of Chengdu Affiliated Hospital of Southwest Jiaotong University Chengdu 610031 PR China

Pathological image diagnosis is a fundamental and critical component of precision medicine, playing a pivotal role in clinical decision-making. However, due to the high heterogeneity of pathological images, existing models still face the challenges of insufficient feature representation, poor interpretability, and high computational costs. To address these issues, we propose a novel pathological image diagnosis model called GDKansformer, which integrates the Group-wise Dynamic Kolmogorov–Arnold Network with a Vision Transformer (ViT) architecture. Specifically, this model employs adaptive dynamic fitting and group-wise computation strategies to seamlessly embed an improved Kolmogorov–Arnold Network (KAN) into ViTs, thereby boosting pathological representation and interpretability. The proposed group-wise computation strategy effectively mitigates the distribution overfitting caused by the KAN structure and significantly reduces the computational costs. Furthermore, a Multi-view Gated Attention (MVGA) block comprising pixel-level non-local neighborhoods and adaptive local perception is designed to eliminate redundant non-feature information and enhance contextual interactions, thereby improving the feature discrimination of the model for high heterogeneity data distributions. Experimental results demonstrate that GDKansformer achieves high accuracy with lower parameters, highlighting the significant potential in facilitating pathological diagnosis.

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Microscopic damage and deterioration of carbonaceous slate in cold region subjected to freeze-thaw cycles

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Journal of Rock Mechanics and Geotechnical engineering 2025年

作者： Peichao Zheng Xianjun Tan Zhihao Du Xianhuan Liu Yun Zhou Kai Shen Bo Guan Weizhong Chen State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China University of Chinese Academy of Sciences Beijing 100049 China College of Resources Shandong University of Science and Technology Tai’an 271019 China College of Architecture and Civil Engineering Xi’an University of Science and Technology Xi’an 710054 China Xinjiang Academy of Transportation Sciences Co. Ltd. Urumqi 830000 China Xinjiang Transportation Investment Group Co. Ltd Urumqi 830099 China Key Laboratory of Transport Industry of Highway Engineering Technology in Arid Desert Areas Urumqi 830000 China

Freezing and thawing processes play a crucial role in causing significant deformation and damage to layered soft rocks in cold region due to daily and seasonal temperature fluctuations. However, the frost heave mechanism of the rocks and their mechanical behaviors at the meso-scale still require further investigations. For this, we focused on carbonaceous slate reported in a high-altitude cold region, in terms of mineral composition, content, and microstructure. The strength and failure of mineral grain (MG) interfaces are studied using three-point-bending tests, in order to explore the evolution of mode I fracture toughness and tensile strength with the Dugdale-Barenblatt model and the Weibull distribution model. The results indicate that the damage of slate involves the initiation and propagation of microfracture networks at clay MG interfaces (bedding planes), driven by frost heave pressure at macroscopic and microscopic scales. This process causes the detachment of some MGs, resulting in fracture surfaces with a distinctive pulled-off planar structure. The hydrophilicity of clay MGs, interfacial strengths, and microfracture structures contribute to the freeze-thaw damage. As the number of freeze-thaw cycles increases, the effective area per unit decreases, leading to an exponentially decreasing in mode I fracture toughness and tensile strength at MG interfaces. Approximately 67% strength degradation occurs after 14 freeze-thaw cycles. This provides theoretical basis and experimental methods for better understanding the damage and deterioration behaviors of layered soft rocks in cold region under natural freeze-thaw cycles.

关键词： Freeze-thaw damage Layered soft rocks Tensile strength Mode I fracture toughness Crack propagation

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On the parameterized complexity of minimum/maximum degree vertex deletion on several special graphs

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Frontiers of Computer Science 2023年第4期17卷 97-107页

作者： Jia LI Wenjun LI Yongjie YANG Xueying YANG School of Information Engineering Hunan Industry PolytechnicChangsha 410036China Hunan Provincial Key Laboratory of Intelligent Processing of Big Data on Transportation School of Computer and Communication EngineeringChangsha University of Science and TechnologyChangsha 410015China Chair of Economic Theory Saarland UniversitySaarbrücken 66123Germany

In the minimum degree vertex deletion problem,we are given a graph,a distinguished vertex in the graph,and an integer κ,and the question is whether we can delete at most κ vertices from the graph so that the distinguished vertex has the unique minimum *** maximum degree vertex deletion problem is defined analogously but here we want the distinguished vertex to have the unique maximum *** is known that both problems areΨ-hard and fixed-parameter intractable with respect to some natural *** this paper,we study the(parameterized)complexity of these two problems restricted to split graphs,p-degenerate graphs,and planar *** study provides a comprehensive complexity landscape of the two problems restricted to these special graphs.

关键词： minimum degree maximum degree vertex deletion split graphs planar graphs parameterized complexity

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Enhanced ortho-selective t–butylation of phenol over sulfonic acid functionalized mesopore MTW zeolites

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Chinese Journal of Chemical engineering 2023年第8期60卷 1-7页

作者： Baoyu Liu Feng Xiong Jianwen Zhang Manna Wang Yi Huang Yanxiong Fang Jinxiang Dong School of Chemical Engineering and Light Industry Guangdong Provincial Key Laboratory of Plant Resources BiorefineryGuangzhou Key Laboratory of Clean Transportation Energy ChemistryGuangdong University of TechnologyGuangzhou 510006China Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory(Rongjiang Laboratory) Jieyang 515200China School of Engineering Institute for Materials&ProcessesThe University of EdinburghRobert Stevenson RoadEdinburgh EH93FBUnited Kingdom

Novel organo-inorganic hybrid materials(MTW-x-SO_(3)H) have been fabricated by immobilizing 3-mercap topropyltriethoxysilane onto mesopore MTW zeolites, which is treated via a simple oxidation process with hydrogen peroxide as the oxidant to transform sulfhydryl group into sulfonic acid group. The organic sulfhydryl groups are covalently bonded to the external surface of MTW zeolites through the condensation between siloxane arising from organic fragments with silanol groups on the surface of MTW zeolites, the hybrids contain sulfonic acid group within the external surface of MTW zeolites and an opened mesoporous system in the matrix of MTW zeolites, which provide enough accessible Brùnsted acid sites for the alkylation between phenol with tert-butyl alcohol. Through this methodology it's possible to prepare multifunctional materials where the plenty of mesopores are benefit for the introduction of larger numbers of sulfonic acid groups that contributes to activity during reactions, resulting in high activity(>55%) of MTW-4-SO_(3)H and desired selectivity(>56%) of 2-TBP(2-tert-butyl phenol) in the alkylation between phenol with tert-butyl alcohol.

关键词： MTW Zeolites Acidity Catalysis Alkylation

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