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Event-triggered tracking control for a class of nonholonomic systems in chained form

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Science China(Information Sciences) 2023年第7期66卷 147-161页

作者： Liang XU Youfeng SU he cai Center for Discrete Mathematics and Theoretical Computer Science Fuzhou University College of Computer and Data Science Fuzhou University School of Automation Science and Engineering South China University of Technology

In this study, the event-triggered asymptotic tracking control problem is considered for a class of nonholonomic systems in chained form for the time-varying reference input. First, to eliminate the ripple phenomenon caused by the imprecise compensation of the time-varying reference input, a novel time-varying event-triggered piecewise continuous control law and a triggering mechanism with a time-varying triggering function are developed. Second, an explicit integral input-to-state stable Lyapunov function is constructed for the time-varying closed-loop system regarding the sampling error as the external input. The origin of the closed-loop system is shown to be uniformly globally asymptotically stable for any global exponential decaying threshold signals, which in turn rules out the Zeno behavior. Moreover, infinitely fast sampling can be avoided by appropriately tuning the exponential convergence rate of the threshold signal. A numerical simulation example is provided to illustrate the proposed control approach.

关键词： event-triggered nonholonomic systems strict Lyapunov function tracking integral input-to-state stable

An overview on the distributed internal model approach and its applications

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Control Theory and Technology 2024年第3期22卷 345-359页

作者： Youfeng Su he cai Jie Huang College of Computer and Data Science Fuzhou UniversityFuzhou 350116China School of Automation Science and Engineering South China University of TechnologyGuangzhou 510641China Department of Mechanical and Automation Engineering The Chinese University of Hong KongShatinHong KongChina

The cooperative output regulation problem has been studied by two approaches:the distributed observer(DO)approach and the distributed internal model(DIM)approach,*** of these two approaches has its own merits and ***,we presented an overview on the cooperative output regulation problem by the DO *** paper further surveys the cooperative output regulation problem by the DIM *** first summarize the constructions and the roles of two different versions of the internal models:the distributed p-copy internal model and the distributed canonical internal ***,we describe an integrated framework that combines the DO approach and the DIM *** and variants of the DIM and their applications will also be highlighted.

关键词： Cooperative output regulation Distributed p-copy internal model Distributed canonical internal model Integrated approach

Study on terahertz spectra of SO_2 and H_2S

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Science China(Physics,Mechanics & Astronomy) 2013年第4期56卷 685-690页

作者： cai he WANG Dong SheN JingLing Beijing Key Laboratory for Terahertz Spectroscopy and Imaging Key Laboratory of Terahertz Optoelectronics Ministry of Education Department of Physics Capital Normal University Beijing Institute of Environment Features

The spectral characteristics of air pollution gas sulfur dioxide and hydrogen sulfide has been studied experimentally and theo-retically in the range of 0.2-2.6 THz. The gases absorption spectra of sulfur dioxide and hydrogen sulfide, as measured by terahertz Time-Domain Spectroscopy (THz-TDS) technique, show equi-spaced absorption peaks. The peak intervals are varied for different gas and may relate with the molecule structures and rotation modes. We have calculated the intervals of rotational transition frequency according to the gases molecule structure and the rotational modes. The results are consistent with experimental results which confirm the suggestion that the absorption is coming from the molecular rotational transition. The study suggests a technique to detect air pollutants by THz-TDS and the rotational modes of gas molecules.

关键词： spectroscopy terahertz wave rotational mode gas molecule

Abundance and biomass of heterotrophic microbes in the Kongsfjorden, Svalbard

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Acta Oceanologica Sinica 2005年第6期24卷 143-152页

作者： JIANG Xiaodong he Jianfeng cai Minghong State Oceanic Administration Key Laboratory for Polar Science Polar Research Institute of China Shanghai 200136 China State Oceanic Administration Key Laboratory for Polar Science Polar Research Institute of China Shanghai 200136 China State Oceanic Administration Key Laboratory for Polar Science Polar Research Institute of China Shanghai 200136 China

Abundance and biomass of heterotrophic microbes were investigated usingepifluorescense microscopy in August 2004 along a transect in the Kongsfjorden, a glacial fjord inthe high arctic, located in the north-western part of Svalbard. A bacterial abundance was low atouter fjord stations (on average 2.29 x 10~8 ind./dm^3) and was higher at inner fjord stations (onaverage 3.52 x 10~8 ind./dm^3).The biomass of bacteria ranged from 3.69 to 8.01 mg/m^*** abundanceof bacteria was low at the surface of water(0 m), whereas the higher abundances often occurred atdepths of 30～50 *** abundance of heterotrophic flagellates varied from 2.785 to 8.891 x 10~4 ind./dm^3. The assemblage was numerically dominated by less than 5 μm heterotrophic flagellates(78.67%～94.80%).The biomass of heterotrophic flagellates varied from 0.37 to 2.30 mg/m^*** meanbiomass distribution for all stations was 4.91% for less than 5 μm heterotrophic flagellates,86.74% for 6～20 μm flagellates and 8.35% for greater than 20 μm sized *** low biomassof heterotrophic flagellates often occurred at the surface of water (0 m),while the maximum valueof biomass occurred at different depths. The biomass of total heterotrophic microbial communityranged from 4.20 to 10.03 mg/m^*** mean biomass distribution for all stations was 82.58% forbacteria, 15.77% for flagellates and 1.66% for ciliates.

关键词： abundance biomass bacteria flagellate kongsfjorden

Fast Algorithm for Maneuvering Target Detection in SAR Imagery Based on Gridding and Fusion of Texture Features

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Geo-Spatial Information Science 2011年第3期14卷 169-176页

作者： YUAN Zhan he You cai Fuqing Research Institute of Information Fusion Technology Naval Aeronautical and Astronautical University 128 Erma Road Yantai264001 China

Designing detection algorithms with high efficiency for Synthetic Aperture Radar(SAR) imagery is essential for the operator SAR Automatic Target Recognition(ATR) *** work abandons the detection strategy of visiting every pixel in SAR imagery as done in many traditional detection algorithms,and introduces the gridding and fusion idea of different texture fea-tures to realize fast target *** first grids the original SAR imagery,yielding a set of grids to be classified into clutter grids and target grids,and then calculates the texture features in each *** fusing the calculation results,the target grids containing potential maneuvering targets are *** dual threshold segmentation technique is imposed on target grids to obtain the regions of *** fused texture features,including local statistics features and Gray-Level Co-occurrence Matrix(GLCM),are *** efficiency and superiority of our proposed algorithm were tested and verified by comparing with existing fast de-tection algorithms using real SAR *** results obtained from the experiments indicate the promising practical application val-ue of our study.

关键词： synthetic aperture radar imagery target detection texture feature gridding gray-level co-occurrence matrix fusion

Association of aphid life stages using DNA sequences： A case study of tribe Eriosomatini （hemiptera： Aphididae Pemphiginae）

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Insect Science 2008年第6期15卷 545-551页

作者： he-cai Zhang Dong Zhang Ge-Xia Qiao Institute of Zoology Chinese Academy of Sciences Beijing henan Normal University Xinxiang Henan Province Graduate University of the Chinese Academy of Sciences Beijing China

Association of aphid life stages based on a portion of COI sequence was applied in Eriosomatini. Three aphid specimens, nos. 17496, 19265a, and 19265b collected on Gramineae roots all clustered with Tetraneura chinensis Mordvilko with strong support. The average pairwise p-distance among the four taxa was 0.001 （range, 0.000-0.002）, and that among all the ingroup taxa was 0.065 （range, 0.000-0.141）. This indicated that nos. 17496 and 19265 b were the secondary-host morphs of T. chinensis. In this paper the secondary host morph of T. chinensis is described for the first time. With the identification of more species＇ secondary-host morphs, aphids identification based on this morph will be made easily.

关键词： COI sequence Eriosomatini primary host morph secondary host morph Tetraneura chinensis

N-heterocyclic Carbenes Catalyzed Phospho-Aldol Reaction of Aldehydes

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Chinese Journal of Chemistry 2013年第12期31卷 1573-1576页

作者： Lin he Zhihua cai Xiaowei Ma Guangfen Du Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan and School of Chemistry and Chemical Engineering Shihezi University Xinjiang 832000 China

An efficient phospho-aldol reaction of aldehydes catalyzed by N-heterocyclic carbenes （NHCs） has been developed. With 10 mol% stable NHC 1,3-bis（2,6-diisopropylphenyl）imidazol-2-ylidene, various aldehydes reacted with dialkylphosphites smoothly to provide a-hydroxy phosphonates in 59%--99% yield. In this process, NHC was assumed to function as a carbon-centered bronsted base.

关键词： N-heterocyclic carbenes phosphite aldehyde phospho-aldol reaction a-hydroxy phosphonate

Biocatalytic synthesis of (R)-(-)-mandelic acid from racemic mandelonitrile by a newly isolated nitrilase-producer Alcaligenes sp. ECU0401

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Chinese Chemical Letters 2007年第6期18卷 677-680页

作者： Yu cai he Jian he Xu Yi Xu Li Ming Ouyang Jiang Pan Laboratory of Biocatalysis and Bioprocessing State Key Laboratory of Bioreactor Engineering East China University of Science and Technology Shanghai 200237 China

By using acetonitrile as the sole nitrogen source, a microbial strain with high nitrilase activity, named as Alcaligenes sp. ECU0401, was newly isolated from soil, which could enantioselectively transform racemic mand... 详细信息

关键词： Mandelonitrile Nitrilase (R)-()-Mandelic acid Screening Alcaligenes sp. ECU0401

Influence of pontic design of anterior fixed dental prosthesis on speech: A clinical case study

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World Journal of Clinical Cases 2021年第36期9卷 11276-11284页

作者： Jia Wan he cai Tong Wang Jun-Yu Chen Institute of Science and Technology for Brain-inspired Intelligence Fudan UniversityShanghai 200433China Department of Prosthodontics State Key Laboratory of Oral DiseasesNational Clinical Research Center for Oral DiseasesWest China Hospital of StomatologySichuan UniversityChengdu 610041Sichuan ProvinceChina

BACKGROUND The pontic design of fixed dental prostheses(FDPs)is strongly associated with the phonetic function,and the phonetic function of anterior FDPs with different pontic designs remains *** To investigate the immediate and short-term influence of pontic design of anterior FDPs on Chinese speech in a clinical case using objective acoustic *** Two FDPs with two types of pontic design(saddle pontic and modified ridge lap pontic)were fabricated for one patient with maxillary anterior teeth *** acoustic analysis of patient’s articulation was conducted immediately after wearing the FDPs and 1 wk after wearing these *** The effect of FDP on Chinese vowels(/a/,/o/,/e/,/i/,/u/,and/ü/)was insignificant,because the recovery of vowel distortion occurred within 1 wk for both ***(/f/,/s/,and/sh/)of eight Chinese fricative consonants were found to have obvious distortions,and the/s/sound distortion last for more than 1 wk for the patient wearing FDP with modified ridge lap pontic *** The influence of anterior FDP on articulation of Chinese vowels is insignificant,while the articulation of Chinese fricative consonants is more *** fabricating anterior FDPs for patients with speech related professions,saddle pontic design can be an alternative option compared with modified ridge lap pontic design.

关键词： Fixed dental prostheses Acoustic analysis Phonetic function Pontic design Clinical case study