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Minimum Time Overtaking Problem of Vehicle Handling Inverse Dynamics Based on Two Kinds of Safe Distances

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Chinese Journal of Mechanical Engineering 2018年第6期31卷 207-216页

作者： You-Qun Zhao Xing-long Zhang Wen-Xin Zhang Fen lin College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics

Overtaking accidents caused by improper operations performed by a driver occur frequently. However, most stud?ies on overtaking safety have neglected research into driver control input. A novel method is proposed to obtain the driver control input during the overtaking process. Meanwhile, to improve the safety of overtaking, two types of safe distances, and the time of the overtaking are considered. Path constraints are established when considering the two types of safe distances. An optimal control model is established to solve the minimum time maneuver under multiple constraints. Using the Gauss pseudospectral method, the optimal control problem is converted into a nonlinear pro?gramming problem, which is then solved through sequential quadratic programming(SQP). In addition, the e ective?ness of the proposed method is verified based on the results of a Carsim simulation. The simulation results show that by adopting an inverse dynamics method to solve the manipulation problem of the vehicle’s minimum overtaking time, the manipulation capability of a vehicle in completing an overtaking safely within the minimum time can be obtained. This method can provide a reference for research into the active safety of manned and unmanned vehicles.

关键词： Handling inverse dynamics Safe distance Overtaking Optimal control Simulation

Cd3(C3N3S3)2 coordination polymer/graphene nanoarchitectures for enhanced photocatalytic H2O2 production under visible light

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Science Bulletin 2017年第9期62卷 610-618页

作者： Jie Xu Zhenye Chen Hongwen Zhang Guibin lin Huaxiang lin Xuxu Wang Jinlin long State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhou 350116China The Institute of Scientific and Industrial Research(SANKEN) Osaka UniversityOsaka 567-0047Japan

For a long time, there has been global concern over the environment and energy problems. Recently, the problems, which have brought about serious effect on the global living condition, have been in the ‘‘spotlight" and given impetus to the universal's efforts to head for the same direction: stem the worst warming and strive for the renewable energy source. Hydrogen peroxide(H_2O_2) is undoubtedly a good choice,which holds the promise as a clean, efficient, safe and transferrable energy carrier. Octahedral coordination polymer, Cd_3(C_3N_3S_3)_2, was found to be a robust photocatalyst for H_2O_2 generation under visible light irradiation. To further improve the H_2O_2 generation efficiency, adhering the octahedron to reduced graphene(rGO) was applied as the strategy herein. The study shows that by adhering Cd_3(C_3N_3S_3)_2to rGO, the formation of H_2O_2 is 2.5-fold enhanced and its deformation is concurrently suppressed. This work not only demonstrates the effectiveness of adhering Cd_3(C_3N_3S_3)_2polymer to rGO for the improvement of the polymer's photocatalytic performance, but also proposes a general way for the fabrication of graphene/coordination compound hybrids for maximizing their synergy.

关键词： Photocatalysis Coordination polymer rGO Cd3(C3N3S3)2 H2O2 generation

Phase,microstructure and compressive properties of refractory high-entropy alloys CrHfNbTaTi and CrHfMoTaTi

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International Journal of Minerals,Metallurgy and Materials 2022年第6期29卷 1231-1236页

作者： Jiaojiao Yi Fuyang Cao Mingqin Xu lin Yang Lu Wang long Zeng Laboratory of Advanced Multicomponent Materials School of Mechanical EngineeringJiangsu University of TechnologyChangzhou 213001China School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China School of Materials Science and Engineering Jiangsu University of TechnologyChangzhou 213001China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

New refractory high-entropy alloys,CrHfNbTaTi and CrHfMoTaTi,derived from the well-known HfNbTaTiZr alloy through principal element substitution were prepared using vacuum arc *** phase components,microstructures,and compressive properties of the alloys in the as-cast state were *** showed that both alloys were composed of BCC and cubic Laves *** terms of mechanical properties,the yield strength increased remarkably from 926 MPa for HfNbTaTiZr to 1258 MPa for CrHfNbTaTi,whereas a promising plastic strain of around 15.0%was retained in *** morphology and composition of the network-shaped interdendritic regions were closely related to the improved mechanical properties due to elemental *** were surrounded by an incompact interdendritic shell after Mo incorporation,which deteriorated yield strength and accelerated brittleness.

关键词： refractory high-entropy alloys phase structure microstructure yield strength plastic strain

Recent advances towards catalytic asymmetric Conia-ene-type reactions

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Chinese Chemical Letters 2021年第3期32卷 954-962页

作者： En-Ze lin Yin Xu Kegong Ji long-Wu Ye College of Chemistry and Pharmacy Northwest A&F UniversityShaanxi Key Laboratory of Natural Products&Chemical BiologyYangling 712100China The Key Laboratory for Chemical Biology of Fujian Province and State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China State Key Laboratory of Organometallic Chemistry Chinese Academy of SciencesShanghai 200032China

Conia-ene reactions,as a type of ene reactions,have not become a remarkable focus until the beginning of21st century,when Lewis acids served as powerful catalysts and found an increasingly broad utilization in this ***,the catalytic Conia-ene reactions have gained great significance in synthetic chemistry due to their high efficiency and atom economy on the construction of valuable cyclic *** the past two decades,the rapid development of transition-metal catalysis and organocatalysis has imposed a profound impact on the exploration of asymmetric Conia-ene *** a result,several strategies have been developed and applied *** on the basis of the catalytic system,this review comprehensively presents a summary of recent progress achieved in this emerging domain,aimed at highlighting the reactions’features,practicalities,and the mechanistic rationale is presented where possible.

关键词： Conia-ene reaction Asymmetric catalysis Transition metals Organocatalysts

Modelling the performance of EPB shield tunnelling using machine and deep learning algorithms

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Geoscience Frontiers 2021年第5期12卷 81-92页

作者： Song-Shun lin Shui-long Shen Ning Zhang Annan Zhou Department of Civil Engineering School of Naval ArchitectureOceanand Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China MOE Key Laboratory of Intelligent Manufacturing Technology College of EngineeringShantou UniversityShantouGuangdong 515063China Discipline of Civil and Infrastructure School of EngineeringRoyal Melbourne Institute of Technology(RMIT)Victoria 3001Australia Shanghai Key Laboratory for Digital Maintenance of Buildings and Infrastructure Shanghai Jiao Tong UniversityShanghai 200240China

This paper introduces an intelligent framework for predicting the advancing speed during earth pressure balance(EPB)shield *** artificial intelligence(AI)models based on machine and deep learning techniques-back-propagation neural network(BPNN),extreme learning machine(ELM),support vector machine(SVM),long-short term memory(LSTM),and gated recurrent unit(GRU)-are *** geological and nine operational parameters that influence the advancing speed are considered.A field case of shield tunnelling in Shenzhen City,China is analyzed using the developed models.A total of 1000 field datasets are adopted to establish intelligent *** prediction performance of the five models is ranked as GRU>LSTM>SVM>ELM>***,the Pearson correlation coefficient(PCC)is adopted for sensitivity *** results reveal that the main thrust(MT),penetration(P),foam volume(FV),and grouting volume(GV)have strong correlations with advancing speed(AS).An empirical formula is constructed based on the high-correlation influential factors and their corresponding field ***,the prediction performances of the intelligent models and the empirical method are *** results reveal that all the intelligent models perform better than the empirical method.

关键词： EPB shield machine Advancing speed prediction Intelligent models Empirical analysis Tunnel excavation

Novel approach for active vibration control of a flexible missile

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Defence Technology（防务技术） 2020年第4期16卷 956-967页

作者： Cheng-long Pan Ji-li Rong Tian-fu Xu Da-lin Xiang School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Norinco Group Aviation Ammunition Research Institute Harbin 150030China Beijing Institute of Astronautical Systems Engineering Beijing 100076China

This paper investigates the feasibility of using an active dynamic vibration absorber(ADVA) for active vibration control of a flexible missile system through *** on the principles of a dynamic vibration absorber(DVA),a ring-type ADVA is first designed to attenuate the elastic vibration of the flexible missile,and the design of the active controller adopts the proportional-integral-derivative(PID)control *** motion equations of a flexible missile with an ADVA,which is subjected to follower thrust at its aft end,are derived using the Lagrangian *** the minimum of the root mean square(RMS) of the lateral displacement response of the center of mass as the objective function,a genetic algorithm(GA) is used to optimize the parameter of the DVA and PID *** numerical calculations show that the ADVA and DVA are effective in suppressing the vibration and provide approximately 41.2% and 17.6% improvement,respectively,compa red with the case of no DVA,The ADVA has better performance than the DVA,When the missile is subjected to follower thrust,the effect of vibration reduction is more effective than the case without follower *** is feasible to reduce vibration and improve the stability of flexible missiles by means of the ADVA.

关键词： Flexible missile PID controller Active dynamic vibration absorber Genetic algorithms

Evaluation of biological effects of three neodymium compounds on silkworm,Bombyx mori

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Journal of Rare Earths 2021年第10期39卷 1289-1299,I0005页

作者： Vivian Andoh Huaiyang Guan lin Ma Weiguo Zhao long Li Guohua Wu College of Biotechnology Jiangsu University of Science and TechnologyZhenjiang 212018China The Sericultural Research Institute Chinese Academy of Agricultural SciencesZhenjiang 212018China

Neodymium(Nd)is one of the most famous members of rare earth elements *** the increasing global demand for Nd,it can inevitably enter the environment and affect the ecological environment through the food chain and other ***,it is very important to study the biological effects of *** this study,the biological effects of 3 kinds of Nd compounds,*** oxide(Nd_(2)O_(3)),neodymium chloride(NdCl3)and neodymium nitrate(Nd(NO_(3))_(3)),were evaluated by using silkworm models through the method of intravascular *** of the three Nd compounds was prepared into 6 groups at different concentrations(40,50,60,70,80,90μg/μL).The results show that within the certain concentration range,Nd compounds show great damage to the growth of silkworms since high death rate is observed:the death rate from Nd2 O3 group is floating between 30%and 80%,the one from NdCl3 group is between 17%and 33%and that from Nd(NO3)3 group is between 23%and 37%.It also reveals that Nd compounds have some negative effects on the body length and weight of ***,the histophysiological study shows that the three Nd compounds cause no obvious negative effects on the cell morphologies in midgut,fat body and silk *** XRD and FTIR spectra show that the secondary and the crystalline structures of silks are not destroyed,the TGA and DTG data exhibit that the thermal stability of silks is not damaged,and the tensile test shows that the mechanical properties of silks are not affected significantly by the intake of Nd *** general,the intake of Nd compounds has significant inhibitory effects on silkworm growth but little negative impact on silk structures or cell morphology,the study can provide useful toxicological data for the safe application of Nd compounds in various fields.

关键词： Nd compounds Bombyx mori Model animal Biological effects Rare earths

Emission control and phase migration of PCDD/Fs in a rotary kiln incinerator:hazardous vs medical waste incineration

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Waste Disposal and Sustainable Energy 2023年第3期5卷 395-406页

作者： Ying Peng Yunfeng Ma Xiaoqing lin Jisheng long Xiaodong Li State Key Laboratory for Clean Energy Utilization Institute for Thermal Power EngineeringZhejiang UniversityHangzhou310027China Shanghai SUS ENVIRONMENT Co. LTDShanghai201703China

This study was carried out in a full-scale(50 t/d)rotary kiln incinerator to explore the removal characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)by different units of air pollution control devices(APCDs),and special interest was focused on the“memory effect”phenomenon of PCDD/Fs in the wet scrubber(WS),which usually caused an undesirable rise in PCDD/F emission *** general removal efficiency of PCDD/Fs by APCDs was 99.4%(from 14.11 at exhaust heat boiler(EHB)outlet to 0.09 ng I-TEQ/Nm^(3)at stack)under medical waste(MW)incineration condition,and 99.2%(from 19.91 to 0.16 ng I-TEQ/Nm^(3))under hazardous waste(HW)incineration *** PCDD/F concentrations in flue gas decreased along the APCDs except for WS,in which the“memory effect”was *** detail,WS largely increased the I-TEQ concentration of gas-phase PCDD/Fs from 0.047 to 0.188 ng I-TEQ/Nm^(3)in the flue gas,and the concentration of particulate-phase PCDD/Fs increased from 0.003 to 0.030 ng I-TEQ/Nm^(3).In addition,this study found that phase migration promoted the accumulation of PCDD/Fs in scrubbing water,and the flow entrainment phenomenon played a great role in causing the“memory effect”.The PCDD/F concentrations of fly ash collected from cyclone and fabric filter(FF)were as high as 4.23 and 6.99 ng I-TEQ/g,respectively,which had exceeded the national landfill limitation(3 ng I-TEQ/g)in *** system balance calculations revealed that APCDs promoted the migration of PCDD/Fs from the gas-phase to the particulate-phase,which caused fly ash to be the main carrier of PCDD/Fs and led to excessive *** results of this study can contribute to the optimized design of combustion conditions and system cleaning for controlling PCDD/F emissions from rotary kiln incinerators.

关键词： Air pollution control devices Wet scrubber Removal efficiency Memory effect Phase migration

PD-YOLO:Colon Polyp Detection Model Based on Enhanced Small-Target Feature Extraction

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Computers, Materials & Continua 2025年第1期82卷 913-928页

作者： Yicong Yu Kaixin lin Jiajun Hong Rong-Guei Tsai Yuanzhi Huang New Engineering Industry College Putian UniversityPutian351100China Engineering Research Center of Big Data Application in Private Health Medicine(Putian University) Fujian Province UniversityPutian351100China Computer College Guangdong University of Science&TechnologyDongguan523668China

In recent years,the number of patientswith colon disease has increased *** polyps are the precursor lesions of colon *** not diagnosed in time,they can easily develop into colon cancer,posing a serious threat to patients’lives and health.A colonoscopy is an important means of detecting colon ***,in polyp imaging,due to the large differences and diverse types of polyps in size,shape,color,etc.,traditional detection methods face the problem of high false positive rates,which creates problems for doctors during the diagnosis *** order to improve the accuracy and efficiency of colon polyp detection,this question proposes a network model suitable for colon polyp detection(PD-YOLO).This method introduces the self-attention mechanism CBAM(Convolutional Block Attention Module)in the backbone layer based on YOLOv7,allowing themodel to adaptively focus on key information and ignore the unimportant *** help themodel do a better job of polyp localization and bounding box regression,add the SPD-Conv(Symmetric Positive Definite Convolution)module to the neck layer and use deconvolution instead of *** results indicate that the PD-YOLO algorithm demonstrates strong robustness in colon polyp *** to the original YOLOv7,on the Kvasir-SEG dataset,PD-YOLO has shown an increase of 5.44 percentage points in AP@0.5,showcasing significant advantages over other mainstream methods.

关键词： Polyp detection YOLOv7 SPD-Conv CBAM deconvolution