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Dynamics modeling and pressure control of composites tape winding system based on LQSMC

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chinese Journal of Aeronautics 2020年第2期33卷 740-748页

作者： Qi HONG Yaoyao SHI Danni LU The key laboratory of Contemporary Design and Integrated Manufacturing Technology ministry of education Northwestern Polytechnical UniversityXi’an 710072China

Pressure fluctuations during the composite fiber winding process seriously affect the produces compactness strength,fatigue resistance,stress uniformity,and resin *** accuracy of pressure control systems is affected by nonlinear disturbances,such as friction,parameter perturbation,and measurement noise.A robust control algorithm based on linear quadratic optimal control and sliding mode control(LQSMC)is proposed to overcome these *** method is based on the system state space expression and linear quadratic optimal *** state space model of the system is improved by using a Kalman filter and control input for state estimation,and a new sliding surface equation is *** ameliorated control algorithm exhibits good performance and can effectively suppress sliding mode control(SMC)*** and experimental results show that LQSMC offers high control precision,much stronger antiinterference,and robustness,which can effectively improve the positioning and tracking accuracy of a pressure control system compared with linear quadratic optimal control(LQC).The winding pressure control precision is improved by 45%to 50%.The results show that the porosity of composite fiber tape winding products decreased thanks to our method.

关键词： Composites tape winding Dynamics modeling Kalman filter LQSMC Pressure control

Experimental Investigation of Inter-Blade Vortices in a Model Francis Turbine

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chinese Journal of Mechanical Engineering 2017年第4期30卷 854-865页

作者： Demin LIU Xiaobing LIU Yongzhi ZHAO key laboratory of Fluid and Power Machinery of ministry of education Xihua University Dongfang Electric Machinery Co. Ltd

The inter-blade vortex in a Francis turbine becomes one of the main hydraulic factors that are likely to cause blade erosion at deep part load operating con- ditions. However, the causes and the mechanism of inter- blade vortex are still under investigation according to present researches. Thus the causes of inter-blade vortex and the effect of different hydraulic parameters on the inter-blade vortex are investigated experimentally. The whole life cycle of the inter-blade vortex is observed by a high speed camera. The test results illustrate the whole life cycle of the inter-blade vortex from generation to separation and even to fading. It is observed that the inter- blade vortex becomes stronger with the decreasing of flow and head, which leads to pressure fluctuation. Meanwhile, the pressure fluctuations in the vane-less area and the draft tube section become stronger when inter-blade vortices exist in the blade channel. The turbine will be damaged if operating in the inter-blade vortex zone, so its operating range must be far away from that zone. This paper reveals the main cause of the inter-blade vortex which is the larger incidence angle between the inflow angle and theblade angle on the leading edge of the runner at deep part load operating conditions.

关键词： Inter-blade vortex Francis turbine Highspeed photography

Sampled-data modeling and dynamical effect of output-capacitor time-constant for valley voltage-mode controlled buck-boost converter

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chinese Physics B 2017年第11期26卷 515-525页

作者：周述晗周国华曾绍桓冷敏瑞徐顺刚 key laboratory of Magnetic Suspension Technology and Maglev Vehicle of ministry of education School of Electrical Engineering Southwest Jiaotong University

By analyzing the output voltage ripple of a buck-boost converter with large equivalent series resistance（ESR） of output capacitor, one valley voltage-mode controller for buck-boost converter is proposed. Considering the fact that the increasing and decreasing slopes of the inductor current are assumed to be constant during each switching cycle, an especial sampleddata model of valley voltage-mode controlled buck-boost converter is established. Based on this model, the dynamical effect of an output-capacitor time-constant on the valley voltage-mode controlled buck-boost converter is revealed and analyzed via the bifurcation diagrams, the movements of eigenvalues, the Lyapunov exponent spectra, the boundary equations,and the operating-state regions. It is found that with gradual reduction of output-capacitor time-constant, the buck-boost converter in continuous conduction mode（CCM） shows the evolutive dynamic behavior from period-1 to period-2, period-4, period-8, chaos, and invalid state. The stability boundary and the invalidated boundary are derived theoretically by stability analysis, where the stable state of valley voltage-mode controlled buck-boost converter can enter into an unstable state, and the converter can shift from the operation region to a forbidden region. These results verified by time-domain waveforms and phase portraits of both simulation and experiment indicate that the sampled-data model is correct and the time constant of the output capacitor is a critical factor for valley voltage-mode controlled buck-boost converter, which has a significant effect on the dynamics as well as control stability.

关键词： buck-boost converter valley voltage-mode control sampled-data modeling dynamics

Protein adsorption onto diethylaminoethyl dextran modified anion exchanger:Effect of ionic strength and column behavior

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chinese Journal of Chemical Engineering 2018年第2期26卷 259-267页

作者： Shu Bai Lingli Gong Detao Han Yutong Li Linling Yu Yan Sun Department of Biochemical Engineering and key laboratory of Systems Bioengineering of ministry of education School of Chemical Engineering and TechnologyTianjin University

Our previous studies on bovine serum albumin(BSA) adsorption to diethylaminoethyl dextran(DEAE dextran,DexD, grafting-ligand) and DEAE(D, surface-ligand) modified Sepharose FF resins found that all the grafted resins(FF-DexD and FF-D-DexD) exhibited extremely fast uptake rate(effective diffusivity, D_e, D_e/D_O> 1.4),which was six times greater than the ungrafted resins(D_e/D_O 1.1) at the their working/binding IS range. Moreover, the DEAE dextran-FF resin displayed much higher adsorption capacities and De values than commercial ungrafted resin in their working condition. Furthermore, the column results of DEAE dextran-FF resins presented higher dynamic binding capacities than and similar elution ISs with DEAE Sepharose FF to achieve similar(or even higher) recoveries suggest the excellent chromatographic column performance of the DEAE dextran-FF resins. Finally, both high recovery and purity of BSA and γ-globulin could be easily achieved using the typical DEAE dextra

关键词：蛋白质吸附葡聚糖阴离子 Sepharose 修改 DEAE 吸附能力行为

Coriolis Force Effect on Suppression of Neo-Classical Tearing Mode Triggered Explosive Burst in Reversed Magnetic Shear Tokamak Plasmas

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chinese Physics Letters 2021年第4期38卷 75-80页

作者：刘桐魏来王丰王正汹 key laboratory of materials Modification by Beams of the ministry of education School of PhysicsDalian University of TechnologyDalian 116024China

We numerically investigate the Coriolis force effect on the suppression of an explosive burst,triggered by the neo-classical tearing mode,in reversed magnetic shear configuration tokamak plasmas,using a reduced magnetohydrodynamic model,including bootstrap *** works have shown that applying differential poloidal rotation,with rotation shear located near the outer rational surface,is an effective way to suppress an explosive *** comparison with cases where there is no Coriolis force,the amplitude of differential poloidal rotation required to effectively suppress the explosive burst is clearly reduced once the effect of Coriolis force is taken into ***,the effective radial region of the rotation shear location is broadened in cases where the Coriolis force effect is *** rotation with shear located between the radial positions of qminand the outer rational surface always serves to effectively suppress explosive bursts,which we anticipate will reduce operational difficulties in controlling explosive bursts,and will consequently prevent plasma disruption in tokamak experiments.

关键词： rotation effect rational

Identification of a marine woloszynskioid dinoflagellate Biecheleriopsis adriatica and germination of its cysts from southern chinese coasts

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Journal of Environmental Sciences 2018年第4期30卷 246-254页

作者： Wei Kang Zhao-Hui Wang key and Open laboratory of Marina and Estuary Fisheries Ministry of Agriculture of China East China Sea Fisheries Research InstituteChinese Academy of Fishery Sciences College of Life Science and Technology Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education InstitutesJinan University Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering Ministry of Education

A strain of small-sized dinoflagellates, isolated from the culture of sediment incubation collected from the coastal areas in southern China, has been identified under microscopical observation and r DNA sequence. Surface sediments from two sea areas in the southern chinese coastal waters were incubated for 20 and 40 days, and germinated vegetative cells were observed. The cells were identified as species in the Suessiaceae based on the morphological characteristics, ultrastructural features of the cell, as well as its swimming behavior. The studied strain clusters into a well-supported clade together with six sequences of Biecheleriopsis adriatica in the phylogenetic tree based on the large subunit（LSU） rDNA sequence. Therefore, the strain has been identified as B. adriatica based on morphological observation and phylogenetic analysis. B. adriatica was the dominant dinoflagellate species in the germinated phytoplankton community from both sea areas,which contributed 50%–83% to the total germinated dinoflagellates averagely. However,B. adriatica has not been reported in previous phytoplankton surveys, and was probably ignored or misidentified due to its small size and thin wall. The frequent and abundant occurrence of B. adriatica in the germinated phytoplankton community of many sea areas of the southern chinese coastal waters suggests its wide and abundant distribution in these sea areas.

关键词： Biecheleriopsis adriatica Cyst Germination Phylogeny Southern China

Engineering and Application of Pillar[6]arene Functionalized Chiral Surface in Selective Adsorption of R-Adrenaline

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chinese Journal of Chemistry 2022年第8期40卷 925-930页

作者： Ming Cheng Wen Gong Mingxiang Lu Junkai Ma Zhiyan Lu Haibing Li Hubei key laboratory of Wudang Local chinese Medicine Research Department of ChemistrySchool of PharmacyHubei University of MedicineShiyanHubei 442000China Department of Forensic Medicine Zhongnan Hospital of Wuhan UniversityNo.169 East Lake RoadWuchang DistrictWuhanHubei 430071China key laboratory of Pesticide and Chemical Biology(CCNU) Ministry of EducationCollege of ChemistryCentral China Normal UniversityWuhanHubei 430079China Department of Cardiology The Third People's Hospital of Hubei Province Hospital of Hubei ProvinceWuhanHubei 430030China

Chiral properties of biological surface is of importance as they dominate interactions with biomolecules(such as proteins,nucleic acids,hormones)in a living *** by this phenomenon,we designed and constructed a L-/D-N-acetyl-cysteine-pillar[6]arene functionalized Si surface(L-/D-NACP surface)for studying the influence of superficial chirality on selective adsorption of *** fabricated chiral L-/D-NACP surface with consistency in hydrophilia and elementary composition exhibited a strong mirror-symmetric circular dichroism *** the adsorption study,the contact-angle of R-adrenaline droplet on D-NACP surface was more hydrophilic from macroscopical view,and the size and quantity of R-adrenaline aggregation on D-NACP surface was larger than L-NACP surface,implying selective adsorption of R-adrenaline appeared on the D-NACP *** possible mechanism was due to the stronger host-guest interaction between D-NACP and R-adrenaline,which facilitated the selective ***,the D-NACP surface with good selectivity can be used for chiral separation of racemic *** results enhance the under-standing of hormones adsorption affected by surface chirality,and may provide some helpful inspiration for practical application of chiral surface.

关键词： R-Adrenaline Pillararene Chiral surface Molecular recognition Host-guest systems

Enzyme-free Electrochemical Detection of Hydrogen Peroxide Based on the Three-Dimensional Flower-like Cu-based Metal Organic Frameworks and MXene Nanosheets

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chinese Journal of Chemistry 2021年第8期39卷 2181-2187页

作者： Dan Cheng Peipei Li Xiaohua Zhu Meiling Liu Youyu Zhang Yang Liu key laboratory of Chemical Biology&Traditional chinese Medicine Research of ministry of education College of Chemistry and Chemical EngineeringHunan Normal UniversityChangshaHunan 410081China key laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology of ministry of education Department of ChemistryTsinghua UniversityBeijing 100084China

Cu-based metal organic frameworks(MOFs)are regarded as promising sensing materials,which have abundant metal sites,large surface area and simple synthesis *** this work,a novel three-dimensional flower-like Cu-MOF was synthesized,which was combined with ultra-thin MXene nanosheets to construct a novel electrochemical sensor for H_(2)O_(2).

关键词： Metal-organic frameworks MXene Enzyme-free Sensors Hydrogen peroxide

Machining Error Control by Integrating Multivariate Statistical Process Control and Stream of Variations Methodology

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chinese Journal of Aeronautics 2012年第6期25卷 937-947页

作者： WANG Pei ZHANG Dinghua LI Shan CHEN Bing key laboratory of Contemporary Design and Integrated Manufacturing Technology Ministry of Education Northwestern Polyteehnical University Xi'an 710072 China

For aircraft manufacturing industries, the analyses and prediction of part machining error during machining process are very important to control and improve part machining quality. In order to effectively control machining error, the method of integrating multivariate statistical process control （MSPC） and stream of variations （SoV） is proposed. Firstly, machining error is modeled by multi-operation approaches for part machining process. SoV is adopted to establish the mathematic model of the relationship between the error of upstream operations and the error of downstream operations. Here error sources not only include the influence of upstream operations but also include many of other error sources. The standard model and the predicted model about SoV are built respectively by whether the operation is done or not to satisfy different requests during part machining process. Secondly, the method of one-step ahead forecast error （OSFE） is used to eliminate autocorrelativity of the sample data from the SoV model, and the T2 control chart in MSPC is built to realize machining error detection according to the data characteristics of the above error model, which can judge whether the operation is out of control or not. If it is, then feedback is sent to the operations. The error model is modified by adjusting the operation out of control, and continually it is used to monitor operations. Finally, a machining instance containing two operations demonstrates the effectiveness of the machining error control method presented in this paper.

关键词： machining error multivariate statistical process control stream of variations error modeling one-step ahead forecast error error detection