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A Hybrid Approach to Modeling and Control of Vehicle Height for Electronically Controlled Air Suspension

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Chinese Journal of Mechanical Engineering 2016年第1期29卷 152-162页

作者： SUN Xiaoqiang CAI Yingfeng WANG Shaohua LIU Yanling CHEN Long School of Automotive and Traffic Engineering Jiangsu University Automotive Engineering Research Institute Jiangsu University

The control problems associated with vehicle height adjustment of electronically controlled air suspension （ECAS） still pose theoretical challenges for researchers, which manifest themselves in the publications on this subject over the last years. This paper deals with modeling and control of a vehicle height adjustment system for ECAS, which is an example of a hybrid dynamical system due to the coexistence and coupling of continuous variables and discrete events. A mixed logical dynamical （MLD） modeling approach is chosen for capturing enough details of the vehicle height adjustment process. The hybrid dynamic model is constructed on the basis of some assumptions and piecewise linear approximation for components nonlinearities. Then, the on-off statuses of solenoid valves and the piecewise approximation process are described by propositional logic, and the hybrid system is transformed into the set of linear mixed-integer equalities and inequalities, denoted as MLD model, automatically by HYSDEL. Using this model, a hybrid model predictive controller （HMPC） is tuned based on online mixed-integer quadratic optimization （MIQP）. Two different scenarios are considered in the simulation, whose results verify the height adjustment effectiveness of the proposed approach. Explicit solutions of the controller are computed to control the vehicle height adjustment system in realtime using an offline multi-parametric programming technology （MPT）, thus convert the controller into an equivalent explicit piecewise affine form. Finally, bench experiments for vehicle height lifting, holding and lowering procedures are conducted, which demonstrate that the HMPC can adjust the vehicle height by controlling the on-off statuses of solenoid valves directly. This research proposes a new modeling and control method for vehicle height adjustment of ECAS, which leads to a closed-loop system with favorable dynamical properties.

关键词： electronically controlled air suspension vehicle height control hybrid system mixed logical dynamical,model predictive control

A possible Younger Dryas-type event during Asian monsoonal Termination 3

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science china Earth sciences 2006年第9期49卷 982-990页

作者： CHEN Shitao1, WANG Yongjin1, KONG Xinggong1, LIU Dianbing1, CHENG Hai2 & R.L. Edwards2 1. College of Geography science, Nanjing Normal University, jiangsu Key Laboratory of Environmental Change and Ecological Construction, Nanjing 210097, china 2. Department of Geology and Geophysics, University of Minnesota, Minneapolis MN55455, USA 1. College of Geography science Nanjing Normal University Jiangsu Key Laboratory of Environmental Change and Ecological Construction Nanjing 210097 China 2. Department of Geology and Geophysics University of Minnesota Minneapolis MN 55455 USA

Seven U-Th dates, 560 δ 18O data and microscopic sequences were measured for sta- lagmites from two high-altitude caves in Shennongjia area, Hubei Province. Variations of the de- cadal-resolution stalagmite δ 18O record from Swan Cave (1600 m elevation) reflect large spatial changes in circulation strength and precipitation of Asian monsoon. The evidence comes from a great similarity among the stalagmite δ 18O records from Nanjing, jiangsu Province; Libo, Guizhou Province and here studied area during the last deglaciation, including a part interval of Younger-Dryas event and Bolling-Allerod. A 30-year-resolution stalagmite δ 18O record from Yongxing Cave (1400 m eleva- tion), 70 km away from Swan Cave, reveals a rapid transition of Asian monsoon climate during Ter- mination 3 at about 245±5 kaBP. Based on 3 U-Th dates and about 5000 continuous annual bands, a millennial dry episode has been observed during Asian monsoonal Termination 3 from the Yongxing δ 18O profile. With respect to its structure, duration and transition, the dry reversal, as indicated by our stalagmite δ 18O record, generally agrees with the pattern of the YD event well-expressed in the Chi- nese stalagmite δ 18O records. This YD-type event is characterized by a large decrease in δ 18O value as much as 2.30‰, more than half of the δ 18O excursion between glacial/interglacial periods, and lasts 1371±59 a determined by the annual counting chronology. After this event, the monsoon climate shifted abruptly into the interglacial period within 74±4 a. Our data corroborate the view that the re- peated occurrence of YD-type event was not an “accident”, possibly resulted from the coupling of ice-sheet and oceanic/atmospheric circulations.

关键词： stalagmite, Termination 3, Asian monsoon, YD-type event, Shennongjia, Hubei Province.

A new family of sp3-hybridized carbon phases

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Chinese Physics B 2016年第1期25卷 712-716页

作者：徐宁李建福黄勃龙王保林 Department of Physics Yancheng Institute of Technology.Mcheng 224051.China Department of Physics and Materials science.City University of Hong Kong.Hong Kong China

A new family of superhard carbon allotropes C48（2i ＋ 1 ） is constructed by alternating even 4 and 8 membered rings. These new carbon allotropes are of a spatially antisymmetrical structure, compared with the symmetrical structures of bet- C4, Z-carbon, and P-carbon. Our calculations show that bulk moduli of C48（2i ＋ 1 ） are larger than that of c-BN and smaller than that of cubic-diamond. C48（2i ＋ 1 ） are transparent superhard materials possessing large Vicker hardness comparable to diamoud. This work can help us understand the structural phase transformations of cold-compression graphite and carbon nanotubes.

关键词： low-temperature phase transformation superhard carbon phase

Oxidation of Difluorocarbene by Pyridine N-Oxide and Ensuing Access to Carbamoyl Fluorides

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Chinese Journal of Chemistry 2023年第22期41卷 2981-2987页

作者： Hai-Jun Tang Xue-Min Shi Xiao-Yu Zhu Cheng-Qiang Wang Chao Feng Technical Institute of Fluorochemistry(TiF) Institute of Advanced Synthesis(iAs)State Key Laboratory of Material-Oriented Chemical EngineeringSchool of Chemistry and Moiecular EngineeringNanjing TechUniversity30 South Puzhu RoadNanjingJiangsu211816China

A practical one-pot preparation of carbamoyl fluorides from easily obtained pyridine N-oxide,commercially available secondary amines and synthetically versatile difluorocarbene precursors(Ruppert-Prakash reagent or Chen's reagent)was developed herein,which dexterously resorted to the oxidation of difluorocarbene by external pyridine N-oxide to produce the toxic and gaseous fluorophosgene in *** features of this method include nice functionality tolerance,late-stage modification of drug molecules and the recoveryand recycle of quinoline.

关键词： Difluorocarbene Pyridine N-oxide Fluorophosgene Carbamoyl fluorides Amines Fluorine

Investigate the effects of magnetic fields on the penetration ability of a shaped charge jet at different standoffs

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Defence Technology（防务技术） 2021年第5期17卷 1722-1730页

作者： Bin Ma Zheng-xiang Huang Zhong-wei Guan Xin Jia Xu-dong Zu Qiang-qiang Xiao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China School of Engineering University of LiverpoolLiverpoolL693GQUK

The influence of a magnetic field on the stability of a shaped charge jet is experimentally investigated at standoffs of 490,650 and 800 *** experimental results without and with the magnetic field are compared in terms of the shaped charge jet form,stability and penetration ability.A theoretical model based on one-dimension fluid dynamics is then developed to assess the depth of penetration of the shaped charge at those three standoffs and magnetic *** results show that the penetration capability can be enhanced in more than 70%by the magnetic *** theoretical calculations are compared with the experimental results with reasonably good *** addition,the parameters introduced in the theory are discussed together with the experiments at three standoffs studied.

关键词： Shaped charge jet Stability Penetration Magnetic field Coupling mechanism

Synthesis of poly(pyridine-imide)s and their electronic memory performances

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science china Chemistry 2017年第2期60卷 237-242页

作者： Haifeng Chen Linxin Wu Xiong Xiao Hongliang Wang Jun Jiang Lihua Wang Qingfeng Xu Jianmei Lu College of Chemistry Chemical Engineering and Materials Science Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University Suzhou 215123 China

In this paper,poly(pyridine-imide)s,PI-Ph and PI-Naphth,were successfully synthesised and fabricated for use as memory *** Al/PI-Ph/indium tin oxide(ITO)device showed dynamic random access memory characteristics,whereas Al/PI-Naphth/ITO showed rewritable(FLASH)memory *** of their UV,cyclic voltammograms,and density functional theory,were used to illustrate the different memory *** results show that the stability of electric-field-induced-charge-transfer complexes can affect memory performance.

关键词： poly(pyridine-imide)s memory device charge-transfer

A novel 2D graphene oxide modified α-AgVO_(3) nanorods: Design, fabrication, and enhanced visible-light photocatalytic performance

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Journal of Advanced Ceramics 2022年第2期11卷 308-320页

作者： Jian WU Liangyu LI Xing-ao LI Xin MIN Yan XING New Energy Technology Engineering Lab of jiangsu Province School of ScienceNanjing University of Posts&Telecommunications(NUPT)Nanjing 210023China Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes National Laboratory of Mineral MaterialsSchool of Materials Science and TechnologyChina University of Geosciences(Beijing)Beijing 100083China

Silver vanadates are promising visible-light-responded photocatalysts with suitable bandgap for solar ***,the easy recombination of photogenerated carriers limits their *** overcome this obstacle,a novel 2D graphene oxide(GO)modifiedα-AgVO_(3) nanorods(GO/α-AgVO_(3) )photocatalyst was designed herein to improve the separation of *** GO/α-AgVO_(3) was fabricated through a facile in-situ coprecipitation method at room *** was found that the as-prepared 0.5 wt%GO/α-AgVO_(3) exhibited the most excellent performance for rhodamine B(RhB)decomposition,with an apparent reaction rate constant 18 times higher than that of pureα-AgVO_(3) under visible-light *** light of the first-principles calculations and the hetero junction analysis,the mechanism underpinned the enhanced photocatalytic performance was *** enhanced photocatalytic performance was ascribed to the appropriate bandgap ofα-AgVO_(3) nanorods for visible-light response and efficient separation of photocarriers through GO *** work demonstrates the feasibility of overcoming the easy recombination of photogenerated carriers and provides a valuable GO/α-AgVO_(3) photocatalyst for pollutant degradation.

关键词： α-AgVO_(3) graphene oxide modifiedα-AgVO_(3)nanorods(GO/α-AgVO_(3)) photocatalysis graphene oxide(GO)nanosheets in-situ coprecipitation processing

Electrochemical trepanning with uniform electrolyte flow around the entire blade profile

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Chinese Journal of Aeronautics 2019年第7期32卷 1748-1755页

作者： Dong ZHU Tingyu XUE Xingyan HU Zhouzhi GU College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

In the traditional machining process for diffusers, blades are easily deformed, and methods suffer from high tool wear and low efficiency. Electrochemical machining(ECM) possesses unique advantages when applied to these difficult-to-machine materials. In the ECM process, theflow field plays a crucial role. Here, an electrolyte flow mode that supplies uniform flow around the entire blade profile was adopted for electrochemical trepanning of diffusers. Various flow rates were employed to obtain the optimal flow field. Simulations were conducted using ANSYS software, and results indicated that increasing the flow rate substantially afforded a more uniform flowfield. A series of experiments was then performed, and results revealed that increasing the flow rate greatly improved both the machining efficiency and the surface quality of the diffusers. The maximum feeding rate of the cathode reached 4 mm/min, the blade taper of the concave part decreased to 0.02, and the blade roughness was reduced to 1.216 lm. The results of this study demonstrated the high feasibility of this method and its potential for machining other complex components for engineering applications.

关键词： Diffuser Electrochemical machining Flow Roughness Taper

Test Data Generation for Multiple Paths Based on Local Evolution

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Chinese Journal of Electronics 2015年第1期24卷 46-51页

作者： YAO Xiangjuan GONG Dunwei WANG Wenliang College of science China University of Mining and Technology School of Information and Electrical Engineering China University of Mining and Technology

Generating test data by genetic algorithms is a promising research direction in software testing, among which path coverage is an important test method. The efficiency of test data generation for multi-path coverage needs to be further improved. We propose a test data generation method for multi-path coverage based on a genetic algorithm with local evolution. The mathematical model is established for all target paths, while in the algorithm the individuals are evolved locally according to different objective functions. We can improve the utilization efficiency of test data. The computation cost can be reduced by using fitness functions of different granularity in different phases of the algorithm.

关键词： Test data generation Path coverage Genetic algorithm Local evolution.