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表达Strep-tag II的重组塞内卡病毒的构建与鉴定
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作者 史家宝 蒙靓 +4 位作者 肖培宇 范峻豪 安同庆 王海伟 于力 《中国预防兽医学报》 CAS CSCD 北大核心 2024年第2期140-146,共7页
为构建表达Strep-tag II的重组塞内卡病毒(SVA),本研究在感染性cDNA克隆p SVA-I212V/S460L的基础上,采用重叠延伸PCR扩增Strep-tag II并采用无缝克隆法将其插入SVA VP1基因C端,构建感染性cDNA克隆,命名为p SVA-Strep,并采用双酶切和测... 为构建表达Strep-tag II的重组塞内卡病毒(SVA),本研究在感染性cDNA克隆p SVA-I212V/S460L的基础上,采用重叠延伸PCR扩增Strep-tag II并采用无缝克隆法将其插入SVA VP1基因C端,构建感染性cDNA克隆,命名为p SVA-Strep,并采用双酶切和测序鉴定正确后,将p SVA-Strep转染BHK-21细胞拯救重组病毒,收集病变细胞上清,并将含有病毒的细胞上清和野生型SVA(SVA-WT)分别感染BHK-21细胞,以未感染病毒的BHK-21细胞作为阴性对照,感染后24 h分别以鼠源SVA VP2蛋白单克隆抗体(MAb)5D10(1∶1000)、鼠源Strep-tag II MAb(1∶2000)作为一抗,以FITC标记的山羊抗小鼠Ig G(1∶2000)为二抗,采用间接免疫荧光试验(IFA)对重组病毒鉴定。IFA结果显示,以鼠源SVA VP2蛋白MAb 5D10为一抗,SVA-WT和重组病毒感染的细胞均出现绿色荧光,以Strep-tag II MAb作为一抗时,仅有重组病毒感染的细胞出现绿色荧光,经SVA-WT感染的BHK-21细胞及阴性对照细胞均无绿色荧光,表明拯救了Strep-tag II标记的重组病毒,并将其命名为r SVA-Strep。将r SVA-Strep在BHK-21细胞中连续传10代,每隔2代采用引物VP1-F/R经PCR鉴定并对第10代重组病毒的VP1基因测序以鉴定r SVA-Strep的遗传稳定性。结果显示,每隔两代的重组病毒经PCR扩增后均出现约780 bp的目的条带,第10代重组病毒扩增的VP1基因测序结果显示Strep-tag II基因仍在重组病毒中,且无基因突变,表明r SVA-Strep的遗传稳定性较强;将SVA-WT和r SVA-Strep分别以MOI 0.01感染BHK-21细胞,在感染后4 h、8 h、12 h、24 h、36 h、48 h和72 h收获病毒测定病毒滴度并绘制生长曲线,结果显示在病毒感染36 h内r SVA-Strep和SVA-WT生长动力学基本一致,表明Strep-tag II的引入在病毒感染36 h内对SVA的复制基本无影响。采用0.2%甲醛充分灭活r SVA-Strep,并利用Strep-TactinRXT Purification纯化试剂盒纯化该灭活病毒,将r SVA-Strep灭活病毒上清加至Strep-Tactin亲和层析柱,分别用不同体积洗脱缓冲液依次洗脱病毒并通过western blot鉴定病毒的纯化效果。对纯化过程中不同洗脱液洗脱病毒的western blot结果显示,不同体积的洗脱液中E1、E2和E3均出现VP0和VP2两条带,且E1和E2的条带最明显,表明洗脱缓冲液的最佳洗脱体积约为2.2 CV;以上结果表明r SVA-Strep可通过Strep-Tactin亲和层析柱一步法纯化。本研究在SVA中插入Strep-tag II标签,为SVA灭活疫苗的快速纯化提供技术手段,也为其他病原的快速纯化方法的建立提供参考。 展开更多
关键词 塞内卡病毒 Strep-tag II 感染性克隆 抗原纯化
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Uncertainty in the seismic performance of semi-active base isolation systems
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作者 Xiaoyue Wang Zhe Qu 《Earthquake Research Advances》 CSCD 2023年第2期62-70,共9页
In a conventional base isolation system,minimizing the seismic responses of the superstructure is always at the cost of increasing the isolator's response.The semi-active control of the isolator has been considere... In a conventional base isolation system,minimizing the seismic responses of the superstructure is always at the cost of increasing the isolator's response.The semi-active control of the isolator has been considered an effective solution to such a dilemma.It tunes the real-time properties of the isolator according to preset rules to further reduce the superstructure's seismic responses without increasing that of the isolator or vice versa.However,the number of ground motion records used to design and validate the controller,i.e.,the preset rules,in existing studies is usually very small and therefore is suspectable if it is adequate to address the significant uncertainty in the shaking of future earthquakes.This paper critically reviews the performance of the proportional-integralderivative(PID),linear-quadratic regulator(LQR),and fuzzy controllers in semi-active base isolation systems with magnetorheological(MR)dampers subjected to highly uncertain ground motion inputs through numerical simulations.The results show that the control performance of the controllers varies significantly with the increasing number of input records,suggesting the necessity of using at least 50 ground motion records to appropriately assess the performance uncertainty of semi-active base isolation systems.More importantly,the superior performance of the optimized controllers is not guaranteed if the system is subjected to ground motions that are new to the controller,even if the controller has been optimized for thousands of existing ground motions.It highlights the need of improving the adaptability of the semi-active systems for uncertain ground motion inputs. 展开更多
关键词 Seismic isolation semi-active control MR damper Control performance UNCERTAINTY
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Joint Modeling of Citation Networks and User Preferences for Academic Tagging Recommender System
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作者 Weiming Huang Baisong Liu Zhaoliang Wang 《Computers, Materials & Continua》 SCIE EI 2024年第6期4449-4469,共21页
In the tag recommendation task on academic platforms,existing methods disregard users’customized preferences in favor of extracting tags based just on the content of the articles.Besides,it uses co-occurrence techniq... In the tag recommendation task on academic platforms,existing methods disregard users’customized preferences in favor of extracting tags based just on the content of the articles.Besides,it uses co-occurrence techniques and tries to combine nodes’textual content for modelling.They still do not,however,directly simulate many interactions in network learning.In order to address these issues,we present a novel system that more thoroughly integrates user preferences and citation networks into article labelling recommendations.Specifically,we first employ path similarity to quantify the degree of similarity between user labelling preferences and articles in the citation network.Then,the Commuting Matrix for massive node pair paths is used to improve computational performance.Finally,the two commonalities mentioned above are combined with the interaction paper labels based on the additivity of Poisson distribution.In addition,we also consider solving the model’s parameters by applying variational inference.Experimental results demonstrate that our suggested framework agrees and significantly outperforms the state-of-the-art baseline on two real datasets by efficiently merging the three relational data.Based on the Area Under Curve(AUC)and Mean Average Precision(MAP)analysis,the performance of the suggested task is evaluated,and it is demonstrated to have a greater solving efficiency than current techniques. 展开更多
关键词 Collaborative filtering citation networks variational inference poisson factorization tag recommendation
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A U-Shaped Network-Based Grid Tagging Model for Chinese Named Entity Recognition
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作者 Yan Xiang Xuedong Zhao +3 位作者 Junjun Guo Zhiliang Shi Enbang Chen Xiaobo Zhang 《Computers, Materials & Continua》 SCIE EI 2024年第6期4149-4167,共19页
Chinese named entity recognition(CNER)has received widespread attention as an important task of Chinese information extraction.Most previous research has focused on individually studying flat CNER,overlapped CNER,or d... Chinese named entity recognition(CNER)has received widespread attention as an important task of Chinese information extraction.Most previous research has focused on individually studying flat CNER,overlapped CNER,or discontinuous CNER.However,a unified CNER is often needed in real-world scenarios.Recent studies have shown that grid tagging-based methods based on character-pair relationship classification hold great potential for achieving unified NER.Nevertheless,how to enrich Chinese character-pair grid representations and capture deeper dependencies between character pairs to improve entity recognition performance remains an unresolved challenge.In this study,we enhance the character-pair grid representation by incorporating both local and global information.Significantly,we introduce a new approach by considering the character-pair grid representation matrix as a specialized image,converting the classification of character-pair relationships into a pixel-level semantic segmentation task.We devise a U-shaped network to extract multi-scale and deeper semantic information from the grid image,allowing for a more comprehensive understanding of associative features between character pairs.This approach leads to improved accuracy in predicting their relationships,ultimately enhancing entity recognition performance.We conducted experiments on two public CNER datasets in the biomedical domain,namely CMeEE-V2 and Diakg.The results demonstrate the effectiveness of our approach,which achieves F1-score improvements of 7.29 percentage points and 1.64 percentage points compared to the current state-of-the-art(SOTA)models,respectively. 展开更多
关键词 Chinese named entity recognition character-pair relation classification grid tagging U-shaped segmentation network
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Differential Expression Analysis of Proteins Regulated by Rare Earth Cerium in Soybean Leaves at Seedling Stage
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作者 Ren Hongyu Zhang Tianren +3 位作者 Miao Yanli Li Haoyang Zhang Shuying Zhang Xingwen 《Journal of Northeast Agricultural University(English Edition)》 CAS 2024年第1期42-52,共11页
This study was to explore the functional mechanism of rare earth regulating soybean leaves and the characteristics and functions of differentially expressed proteins under the regulation of rare earth. In this study, ... This study was to explore the functional mechanism of rare earth regulating soybean leaves and the characteristics and functions of differentially expressed proteins under the regulation of rare earth. In this study, Dongnong 42 was used as material, and 30 mg·L^(-1) CeCl_(3) solution was sprayed on soybean leaves at the seedling stage. Tandem mass tag(TMT) quantitative proteomics technique and bioinformatics analysis were used to identify soybean leaf proteins. A total of 8 510 proteins were identified, and 127 differentially expressed proteins(DEPs) in response to rare earth cerium regulation were identified, among which 64 were upregulated and 63 were down-regulated. The gene ontology(GO) annotation indicated that DEPs were mainly involved in metabolic process, cellular process, response to stimulus, biological regulation, and response to a stimulus;DEPs in cell module categories were mainly involved in cells, cell part, organelle, membrane, membrane part, organelle par, and protein-containing complex;DEPs in molecular functional categories were mainly involved in catalytic activity, binding and antioxidant activity. Kyoto encyclopedia of genes and genomes(KEGG) pathway significantly enriched starch and sucrose metabolism, glycolysis/gluconeogenesis, galactose metabolism, pentose phosphate pathway, and MAPK signaling pathway-plant. These DEPs were mainly involved in photosynthesis, glucose metabolism and stress response. Forty-six differential protein interaction networks were identified by protein interaction network analysis. This experiment provided a reference for studies of the mechanism of rare earth cerium regulating soybean leaf function from the proteomic perspective. 展开更多
关键词 rare earth soybean PROTEOMICS tandem mass tag(TMT)
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Serum proteins differentially expressed in gestational diabetes mellitus assessed using isobaric tag for relative and absolute quantitation proteomics
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作者 Wei-Li Cao Cui-Ping Yu Ling-Li Zhang 《World Journal of Clinical Cases》 SCIE 2024年第8期1395-1405,共11页
BACKGROUND As a well-known fact to the public,gestational diabetes mellitus(GDM)could bring serious risks for both pregnant women and infants.During this important investigation into the linkage between GDM patients a... BACKGROUND As a well-known fact to the public,gestational diabetes mellitus(GDM)could bring serious risks for both pregnant women and infants.During this important investigation into the linkage between GDM patients and their altered expression in the serum,proteomics techniques were deployed to detect the differentially expressed proteins(DEPs)of in the serum of GDM patients to further explore its pathogenesis,and find out possible biomarkers to forecast GDM occurrence.METHODS Subjects were divided into GDM and normal control groups according to the IADPSG diagnostic criteria.Serum samples were randomly selected from four cases in each group at 24-28 wk of gestation,and the blood samples were identified by applying iTRAQ technology combined with liquid chromatography-tandem mass spectrometry.Key proteins and signaling pathways associated with GDM were identified by bioinformatics analysis,and the expression of key proteins in serum from 12 wk to 16 wk of gestation was further verified using enzyme-linked immunosorbent assay (ELISA).RESULTS Forty-seven proteins were significantly differentially expressed by analyzing the serum samples between the GDMgravidas as well as the healthy ones. Among them, 31 proteins were found to be upregulated notably and the rest16 proteins were downregulated remarkably. Bioinformatic data report revealed abnormal expression of proteinsassociated with lipid metabolism, coagulation cascade activation, complement system and inflammatory responsein the GDM group. ELISA results showed that the contents of RBP4, as well as ANGPTL8, increased in the serumof GDM gravidas compared with the healthy ones, and this change was found to initiate from 12 wk to 16 wk ofgestation.CONCLUSION GDM symptoms may involve abnormalities in lipid metabolism, coagulation cascade activation, complementsystem and inflammatory response. RBP4 and ANGPTL8 are expected to be early predictors of GDM. 展开更多
关键词 Gestational diabetes mellitus Liquid chromatography-tandem mass spectrometry Isobaric tag for relative and absolute quantitation PROTEOMICS BIOMARKER
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34.TAG·西海美术馆:面朝大海的艺术长廊
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作者 张路峰 《建筑师》 2024年第2期150-152,共3页
设计:让·努维尔事务所地点:山东青岛西海岸新区时间:2012—2021年规模:17000 m^(2)TAG·西海美术馆位于一座半岛的海边,远离市区^([1,2])。从规划意图看,整个项目由美术馆和艺术工坊两部分组成,但由于工坊部分处于停工状态,艺... 设计:让·努维尔事务所地点:山东青岛西海岸新区时间:2012—2021年规模:17000 m^(2)TAG·西海美术馆位于一座半岛的海边,远离市区^([1,2])。从规划意图看,整个项目由美术馆和艺术工坊两部分组成,但由于工坊部分处于停工状态,艺术社区氛围尚未形成,作为主体建筑的美术馆便成了荒野中的孤独存在,公众可达性较差(图1)。尽管如此,从设计研究角度,这座美术馆仍有许多精彩看点值得关注。 展开更多
关键词 美术馆 让·努维尔 社区氛围 主体建筑 青岛西海岸新区 可达性 艺术长廊 tag
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TAG HEUER 竞速激情
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作者 Chaos 《钟表》 2024年第3期29-31,共3页
继去年以卡莱拉系列Skipper计时码表的精钢版本标志着品牌重返帆船运动与航海领域之后,TAG Heuer泰格豪雅如今欣然发布一款以18K 5N玫瑰金打造的全新版本。金质的Skipper计时码表与精钢版本类似,同样基于2023年前期为纪念卡莱拉系列计... 继去年以卡莱拉系列Skipper计时码表的精钢版本标志着品牌重返帆船运动与航海领域之后,TAG Heuer泰格豪雅如今欣然发布一款以18K 5N玫瑰金打造的全新版本。金质的Skipper计时码表与精钢版本类似,同样基于2023年前期为纪念卡莱拉系列计时码表60周年推出且热销的“玻璃盒”(glassbox)设计,并搭载品牌自制机心Heuer 02(型号:TH20-06),这是一款为帆船赛计时而特别调整的Heuer 02机心。 展开更多
关键词 tag 帆船运动 玫瑰金 航海领域 帆船赛
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Semi-active Sliding Mode Control of Vehicle Suspension with Magneto-rheological Damper 被引量:13
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作者 ZHANG Hailong WANG Enrong +3 位作者 ZHANG Ning MIN Fuhong SUBASH Rakheja SU Chunyi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第1期63-75,共13页
The vehicle semi-active suspension with magneto-theological damper(MRD) has been a hot topic since this decade, in which the robust control synthesis considering load variation is a challenging task. In this paper, ... The vehicle semi-active suspension with magneto-theological damper(MRD) has been a hot topic since this decade, in which the robust control synthesis considering load variation is a challenging task. In this paper, a new semi-active controller based upon the inverse model and sliding mode control (SMC) strategies is proposed for the quarter-vehicle suspension with the magneto-rheological (MR) damper, wherein an ideal skyhook suspension is employed as the control reference model and the vehicle sprung mass is considered as an uncertain parameter. According to the asymptotical stability of SMC, the dynamic errors between the plant and reference systems are used to derive the control damping force acquired by the MR quarter-vehicle suspension system. The proposed modified Bouc-wen hysteretic force-velocity (F-v) model and its inverse model of MR damper, as well as the proposed continuous modulation (CM) filtering algorithm without phase shift are employed to convert the control damping force into the direct drive current of the MR damper. Moreover, the proposed semi-active sliding mode controller (SSMC)-based MR quarter-vehicle suspension is systematically evaluated through comparing the time and frequency domain responses of the sprung and unsprung mass displacement accelerations, suspension travel and the tire dynamic force with those of the passive quarter-vehicle suspension, under three kinds of varied amplitude harmonic, rounded pulse and real-road measured random excitations. The evaluation results illustrate that the proposed SSMC can greatly suppress the vehicle suspension vibration due to uncertainty of the load, and thus improve the ride comfort and handling safety. The study establishes a solid theoretical foundation as the universal control scheme for the adaptive semi-active control of the MR full-vehicle suspension decoupled into four MR quarter-vehicle sub-suspension systems. 展开更多
关键词 magneto-rheological damper vehicle suspension multi-objective performance semi-active sliding mode control FILTERING
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Semi-active control of a cable-stayed bridge under multiple-support excitations 被引量:6
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作者 代泽兵 黄金枝 王红霞 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2004年第3期68-76,共9页
This paper presents a semi-active strategy for seismic protection of a benchmark cable-stayed bridge with consideration of multiple-support excitations. In this control strategy, Magnetorheological (MR) dampers are pr... This paper presents a semi-active strategy for seismic protection of a benchmark cable-stayed bridge with consideration of multiple-support excitations. In this control strategy, Magnetorheological (MR) dampers are proposed as control devices, a LQG-clipped-optimal control algorithm is employed. An active control strategy, shown in previous researches to perform well at controlling the benchmark bridge when uniform earthquake motion was assumed, is also used in this study to control this benchmark bridge with consideration of multiple-support excitations. The performance of active control system is compared to that of the presented semi-active control strategy. Because the MR fluid damper is a con-trollable energy- dissipation device that cannot add mechanical energy to the structural system, the proposed control strategy is fail-safe in that bounded-input, bounded-output stability of the controlled structure is guaranteed. The numerical results demonstrated that the performance of the presented control design is nearly the same as that of the active control system; and that the MR dampers can effectively be used to control seismically excited cable-stayed bridges with multiple-support excitations. 展开更多
关键词 CABLE-STAYED bridge Multiple-support excitation MR damping semi-active control
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Skyhook-based Semi-active Control of Full-vehicle Suspension with Magneto-rheological Dampers 被引量:11
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作者 ZHANG Hailong WANG Enrong +2 位作者 MIN Fuhong SUBASH Rakheja SU Chunyi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第3期498-505,共8页
The control study of vehicle semi-active suspension with magneto-rheological (MR) dampers has been attracted much attention internationally. However, a simple, real time and easy implementing semi-active controller ha... The control study of vehicle semi-active suspension with magneto-rheological (MR) dampers has been attracted much attention internationally. However, a simple, real time and easy implementing semi-active controller has not been proposed for the MR full-vehicle suspension system, and a systematic analysis method has not been established for evaluating the multi-objective suspension performances of MR full-vehicle vertical, pitch and roll motions. For this purpose, according to the 7-degree of freedom (DOF) fullvehicle dynamic system, a generalized 7-DOF MR and passive full-vehicle dynamic model is set up by employing the modified Boucwen hysteretic force-velocity (F-v) model of the MR damper. A semi-active controller is synthesized to realize independent control of the four MR quarter-vehicle sub-suspension systems in the full-vehicle, which is on the basis of the proposed modified skyhook damping scheme of MR quarter-vehicle sub-suspension system. The proposed controller can greatly simplify the controller design complexity of MR full-vehicle suspension and has merits of easy implementation in real application, wherein only absolute velocities of sprung and unsprung masses with reference to the road surface are required to measure in real time when the vehicle is moving. Furthermore, a systematic analysis method is established for evaluating the vertical, pitch and roll motion properties of both MR and passive full-vehicle suspensions in a more realistic road excitation manner, in which the harmonic, rounded pulse and real road measured random signals with delay time are employed as different road excitations inserted on the front and rear two wheels, by considering the distance between front and rear wheels in full-vehicle. The above excitations with different amplitudes are further employed as the road excitations inserted on left and right two wheels for evaluating the roll motion property. The multi-objective suspension performances of ride comfort and handling safety of the proposed MR full-vehicle suspension are thus thoroughly evaluated by comparing with those of the passive full-vehicle suspension. The results show that the proposed controller can ideally improve multiobjective suspension performances of the ride comfort and handling safety. The proposed harmonic, rounded pulse and real road measured random signals with delay time and asymmetric amplitudes are suitable for accurately analyzing the vertical, pitch and roll motion properties of MR full-vehicle suspension system in a more realistic road excitation manner. This research has important theoretical significance for improving application study on the intelligent MR semi-active suspension. 展开更多
关键词 magneto-rheological damper skyhook policy semi-active control multi-objective performances full-vehicle suspension
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SEMI-ACTIVE CONTROL OF VEHICLE SUSPENSION WITH MAGNETO-RHEOLOGICAL DAMPERS:PART Ⅰ——CONTROLLER SYNTHESIS AND EVALUATION 被引量:8
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作者 WANG Enrong YING Liang +2 位作者 WANG Wanjun RAKHEJASubhash SU Chunyi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第1期13-19,共7页
A modified skyhook-based semi-active controller is proposed for implementing an asymmetric control suspension design with symmetric magneto-rheological (MR) dampers. The controller is formulated in current form, whi... A modified skyhook-based semi-active controller is proposed for implementing an asymmetric control suspension design with symmetric magneto-rheological (MR) dampers. The controller is formulated in current form, which is modulated by integrating a continuous modulation and an asymmetric damping force generation algorithms, so as to effectively minimize switching and hysteretic effects from the MR-damper. The proposed controller is implemented with a quarter-vehicle MR-suspension model, and its relative response characteristics are thus evaluated in terms of defined performance measures under varying amplitude harmonic, rounded pulse and random excitations. The sensitivity of the semi-active suspension performance to variations in controller parameters is thoroughly evaluated. The results illustrate that the proposed skyhook-based asymmetric semi-active MR-suspension controller has superior robustness on the system parameter variations, and can achieve desirable multi-objective suspension performance. 展开更多
关键词 Magneto-rheological damper Skyhook damping semi-active control Vehicle suspension
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Semi-Active Control of Wave-Induced Vibration for Offshore Platforms by Use of MR Damper 被引量:8
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作者 李华军 土树青 秘春艳 《China Ocean Engineering》 SCIE EI 2002年第1期33-40,共8页
The objective of the present research is to examine the effectiveness of the lateral vibration control of wave-excited response of offshore platforms with magneto-rheological (MR) damper. In this study, the offshore p... The objective of the present research is to examine the effectiveness of the lateral vibration control of wave-excited response of offshore platforms with magneto-rheological (MR) damper. In this study, the offshore platform is simplified to be a singled degree-of-freedom (SDOF) system by extracting the first vibration mode of the structure. The external 'generalized' wave force is determined with a white noise via a designed filter. A semi-active control method based on optimal control theory is proposed considering that the yield stress of the MR damper can he varied continuously within a certain range. The dynamics of SDOF structure coupled with the MR damper is investigated. Numerical simulation demonstrates that the MR damper with this control strategy can significantly reduce the maximum responses and the root-mean-square (RMS) values. 展开更多
关键词 semi-active control offshore platform vibration reduction wave loading magneto-rheological damper
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Vibration Control of a Composite Beam Using Self-sensing Semi-active Approach 被引量:5
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作者 JI Hongli QIU Jinhao ZHU Kongjun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第5期663-670,共8页
Structural vibration control was an active research area for the past twenty years because of their potential applications in aerospace structures,civil structures,naval structures,etc.Semi-active vibration control me... Structural vibration control was an active research area for the past twenty years because of their potential applications in aerospace structures,civil structures,naval structures,etc.Semi-active vibration control methods based on piezoelectric actuators and synchronized switch damping on inductance(SSDI) techniques attract the attention of many researchers recently due to their advantages over passive and active methods.In the SSDI method,a switch shunt circuit is connected to the piezoelectric patch to shift the phase and amplify the magnitude of the voltage on the piezoelectric patch.The most important issue in SSDI method is to control the switching actions synchronously with the maximum vibration displacement or maximum strain.Hence,usually a displacement sensor is used to measure the vibration displacement or a collocated piezoelectric sensor is needed to measure the strain of the structure near the piezoelectric actuator.A self-sensing SSDI approach is proposed and applied to the vibration control of a composite beam,which avoids using a separate sensor.In the self-sensing technique,the same piezoelectric element functions as both a sensor and an actuator so that the total number of required piezoelectric elements can be reduced.One problem in the self-sensing actuator,which is the same as that in the traditional collocated piezoelectric sensors,is the noise generated in the sensor signal by the impact of voltage inversion,which may cause extra switching actions and deteriorate control performance.In order to prevent the shunt circuit from over-frequent on-and-off actions,a simple switch control algorithm is proposed.The results of control experiments show that the self-sensing SSDI approach combined with the improved switch control algorithm can effectively suppress over-frequent switching actions and gives good control performance by reducing the vibration amplitude by 45%,about 50% improvement from the traditional SSDI with a separate piezoelectric element and a classical switch. 展开更多
关键词 piezoelectric elements synchronized switch damping semi-active control vibration damping SELF-SENSING
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A comparative study of semi-active control strategies for base isolated buildings 被引量:4
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作者 Oliveira F. Morais P. Suleman A. 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2015年第3期487-502,共16页
A comparative analytical study of several control strategies for semi-active(SA) devices installed in baseisolated buildings aiming to reduce earthquake induced vibrations is presented.Three force tracking schemes com... A comparative analytical study of several control strategies for semi-active(SA) devices installed in baseisolated buildings aiming to reduce earthquake induced vibrations is presented.Three force tracking schemes comprising a linear controller plus a 'clipped' algorithm and a nonlinear output feedback controller(NOFC) are considered to tackle this problem.Linear controllers include the integral controller(I),the linear quadratic regulator(LQR) and the model predictive controller(MPC).A single degree-of-freedom system subjected to input accelerograms representative of the Portuguese seismic actions are first used to validate and evaluate the feasibility of these strategies.The obtained results show that structural systems using SA devices can in general outperform those equipped with passive devices for lower fundamental frequency structural systems,namely base-isolated buildings.The effectiveness of the proposed strategies is also evaluated on a 10 storey base-isolated dual frame-wall building.The force tracking scheme with an integral controller outperforms the other three as well as the original structure and the structure equipped with passive devices. 展开更多
关键词 semi-active control integral controller linear qua
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SEMI-ACTIVE CONTROL OF VEHICLE SUSPENSION WITH MAGNETO-RHEOLOGICAL DAMPERS PARTⅡ——EVALUATION OF SUSPENSION PERFORMANCE 被引量:5
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作者 WANG Enrong YING Liang +2 位作者 WANG Wanjun RAKHEJA Subhash SU Chunyi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第2期45-52,共8页
The design and analysis of an intelligent vehicle suspension with MR dampers should address hybrid semi-active control goals, such as rejection of current-switching discontinuity and MR-damper hysteresis, asymmetric d... The design and analysis of an intelligent vehicle suspension with MR dampers should address hybrid semi-active control goals, such as rejection of current-switching discontinuity and MR-damper hysteresis, asymmetric damping from the symmetric MR-damper design, robustness on the vehicle operation parameter uncertainties and consideration of essential multiple suspension goals. Following the proposed skyhook-based asymmetric semi-active controller (Part I ) for achieving the above goals, herein, a set of suspension performance measures and three kinds of varying amplitude harmonic, rounded pulse and really measured random excitations are systematically defined, and the sensitivity of quarter-vehicle MR-suspension performance to variations in operating conditions is thoroughly analyzed. The results illustrate that the proposed skyhook-based semi-active MR-suspension in the asymmetric mode yields relatively superior dynamic responses to meet the multiple suspension performances of ride, rattle space, road-holding and dynamic tire force transmitted to the pavement, and has desirable robustness on variations in operating conditions of vehicle load and speed and the road roughness. 展开更多
关键词 Magneto-rheological damper Asymmetric damping semi-active control Vehicle suspension Multi-objective performance
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Seismic structural control using semi-active tuned mass dampers 被引量:4
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作者 杨润林 周锡元 刘锡荟 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2002年第1期111-118,共8页
This paper focuses on how to determine the instantaneous damping of the semi-active tuned mass damper (SATMD) with continuously variable damping.An off-and-towards-equilibrium (OTE) algorithm is employed to examine th... This paper focuses on how to determine the instantaneous damping of the semi-active tuned mass damper (SATMD) with continuously variable damping.An off-and-towards-equilibrium (OTE) algorithm is employed to examine the control performance of the structure/SATMD system by considering the damping as an assumptive control action.The damping modification of the SATMD is carried out according to the proposed OTE algorithm,which is formulated based on analysis of the structural movement under external excitations,and the measured responses of the structure at every time instant. As examples two numerical simulations of a five-storey and a ten-storey shear structures with a SATMD on the roof are conducted.The effectiveness on vibration reduction of MDOF systems subjected to seismic excitations is discussed.Analysis results show that the behavior of the structure with a SATMD is significantly improved and the feasibility of applying the OTE algorithm to the structural control design of SATMD is also verified. 展开更多
关键词 semi-active TMD seismic structural control MDOF off-and-towards-equilibrium algorithm
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Design approaches for active,semi-active and passive control systems based on analysis of characteristics of active control force 被引量:4
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作者 Ou Jinping Li Hui 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2009年第4期493-506,共14页
In this paper, the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed. The following characteristics are observed: (1) active control can provide significant... In this paper, the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed. The following characteristics are observed: (1) active control can provide significantly superior supplemental damping to a building, but causes a small frequency shift; (2) the linear quadratic regulator (LQR)-based control force is composed of an elastic restoring force component and a damping force component, where the damping force is almost identical to the total control force, however, the elastic restoring force is very small; and (3) the active control forces prevent mction most of the time during the entire control process. These three characteristics imply that active control systems connected to adjacent levels of a building behave like passive damping devices with adjustable parameters, namely damping characteristics in an active control, which is the mechanism used by semi-active control devices to reach similar performance as active control systems. Two indices are defined to quantify the damping characteristics of control forces in active control systems. These two indices can also be used to quantify the capacity of semi-active control to achieve the perfonrlance of active control. Based on the above observations, two principles are founded for optimization of parameters of semi-active control devices and passive dampers. The first is that the maximum output force of a semi-active or passive device to be designed is identical to an active device, called "design principle". The other is the response equivalent principle, which states that the response of a building with semi-active or passive devices is the same as with active devices when the same maximum output force is applied. The design procedure for semi-active control devices and passive dampers is described in detail. Finally, numerical simulations of two benchmark problems is conducted to demonstrate the damping characteristics of active control and investigate the capacity of semi-active control to achieve the same performance as active control. 展开更多
关键词 active control: semi-active control smart control DAMPING design approach
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Performance-based semi-active control algorithm for protecting base isolated buildings from near-fault earthquakes 被引量:3
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作者 Behnam Mehrparvar Taramarz Khoshnoudian 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2012年第1期43-55,共13页
Base isolated structures have been found to be at risk in near-fault regions as a result of long period pulses that may exist in near-source ground motions. Various control strategies, including passive, active and se... Base isolated structures have been found to be at risk in near-fault regions as a result of long period pulses that may exist in near-source ground motions. Various control strategies, including passive, active and semi-active control systems, have been investigated to overcome this problem. This study focuses on the development of a semi-active control algorithm based on several performance levels anticipated from an isolated building during different levels of ground shaking corresponding to various earthquake hazard levels. The proposed performance-based algorithm is based on a modified version of the well-known semi-active skyhook control algorithm. The proposed control algorithm changes the control gain depending on the level of shaking imposed on the structure. The proposed control system has been evaluated using a series of analyses performed on a base isolated benchmark building subjected to seven pairs of scaled ground motion records. Simulation results show that the newly proposed algorithm is effective in improving the structural and nonstructural performance of the building for selected earthquakes. 展开更多
关键词 structural control active control semi-active control base isolation
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Ground target localization algorithm for semi-active laser terminalcorrection projectile 被引量:2
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作者 Xing-long LI Wen-jin YAO +2 位作者 Li-kun ZHU Xiao-ming WANG Ji-yan YU 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2016年第3期234-241,共8页
A target localization algorithm,which uses the measurement information from onboard GPS and onboard laser detector to acquire the target position,is proposed to obtain the accurate position of ground target in real ti... A target localization algorithm,which uses the measurement information from onboard GPS and onboard laser detector to acquire the target position,is proposed to obtain the accurate position of ground target in real time in the trajectory correction process of semi-active laser terminal correction projectile.A target localization model is established according to projectile position,attitude and line-of-sight angle.The effects of measurement errors of projectile position,attitude and line-of-sight angle on localization accuracy at different quadrant elevation angles are analyzed through Monte-Carlo simulation.The simulation results show that the measurement error of line-of-sight angle has the largest influence on the localization accuracy.The localization accuracy decreases with the increase in quadrant elevation angle.However,the maximum localization accuracy is less than 7 m.The proposed algorithm meets the accuracy and real-time requirements of target localization. 展开更多
关键词 semi-active LASER GUIDANCE TERMINAL correction PROJECTILE Target LOCALIZATION LOCALIZATION accuracy
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