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Smith Predictor Based Robust Rapid Tracking Controller

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武汉理工大学学报 2006年第S1期28卷 210-213页

作者： LIU Hongbin,HU Dejin (school of Mechanical Engineering,Shanghai Jiaotong university,Shanghai 20003.,china) school of Mechanical Engineering Shanghai Jiaotong UniversityShanghai 200030China

Precise model is hard to get in real application,a Smith predictor based robust rapid tracking controller for inaccurate model is proposed. Zero phase error feedforward controller which increases system closed-loop dynamics and disturbance observer based Smith feedback control which diminishes model hysteresis and improves stability are integrated. This method is applied in the noncircular machining with piezoelectric ceramic driver. The simulation and experiment show that the performance robustness and stability are well balanced in bandwidth about 200 Hz. The controller can decrease system hysteresis and get good tracking performance for predefined square-wave input signal.

关键词： smith predictor disturbance objection feedforward compensation tracking performance

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由《论语》和《诗论》谈孔子以德论诗

武汉大学学报（人文科学版） 2003年第5期56卷 546-550页

作者：荆雨武汉大学人文科学学院湖北武汉430072

In the Lun Yu , Confucius paid more attention to the understanding and appreciating of The Odes . He considered The Odes as a way of one’s achieving the moral personality. How to understand? There is no illustration in Lun Yu . In Chu Bamboo Slip Shi Lun , Confucius interpreted, from the moral side, some poets of The Odes , such as Guan Ju, Gan Tang, Han Guang and so on.

关键词：孔子德性《诗经》诠释

Aging Precipitation Behavior of 18Cr-16Mn-2Mo-1.1N High Nitrogen Austenitic Stainless Steel and Its Influences on Mechanical Properties

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Journal of Iron and Steel Research International 2012年第8期19卷 43-51页

作者： LI Hua-bing, JIANG Zhou-hua, FENG Hao, MA Qi-feng, ZHAN Dong-ping (school of Materials and Metallurgy, Northeastern university, Shenyang 110819, Liaoning, china) school of Materials and Metallurgy Northeastern University Shenyang Liaoning China

The solution-treated (ST) condition and aging precipitation behavior of 18Cr-16Mn-2Mo-1.1N high nitrogen austenitic stainless steel (HNS) were investigated by optical microscope (OM), scanning electron microscope (SEM), and transmission electron microscope (TEM). The results show that the ST condition of 18Cr-16Mn-2Mo-1.1N HNS with wN above 1% is identified as 1100 ℃ for 90 min, followed by water quenching to make sure the secondary phases completely dissolve into austenitic matrix and prevent the grains coarsening too much. Initial time-temperature-precipitation (TTP) curve of aged 18Cr-16Mn-2Mo-1.1N HNS which starts with precipitation of 0.05% in volume fraction is defined and the 'nose' temperature of precipitation is found to be 850 ℃ with an incubation period of 1 min. Hexagonal intergranular and cellular Cr2N with a=0.478 nm and c=0.444 nm precipitates gradually increase in the isothermal aging treatment. The matrix nitrogen depletion due to the intergranular and a few cellular Cr2N precipitates induces the decay of Vickers hardness, and the increment of cellular Cr2N causes the increase in the values. Impact toughness presents a monotonic decrease and SEM morphologies show the leading brittle intergranular fracture. The ultimate tensile strength (UTS), yield strength (YS) and elongation (El) deteriorate obviously. Stress concentration occurs when the matrix dislocations pile up at the interfaces of precipitation and matrix, and the interfacial dislocations may become precursors to the misfit dislocations, which can form small cleavage facets and accelerate the formation of cracks.

关键词： solution-treated condition aging precipitation behavior time-temperature-precipitation curve high nitrogen austenitic stainless steel mechanical property

A Hammerstein-based Model for Rate-dependent Hysteresis in Piezoelectric Actuator

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A Hammerstein-based Model for Rate-dependent Hysteresis in P...

Practice of and Thoughts on Urban Renovation of Xiamen City Amid Early Modernization (1920-193.)

第24届中国控制与决策会议

作者： Zhenyan Wang 1,2 , Zhen Zhang 1 , Jianqin Mao 1 , Kemin Zhou 3.1.school of Automation Science and Electrical Engineering, Beijing university of Aeronautics and Astronautics, Beijing 100191,china 2. school of Electronical and information Engineering, Taiyuan university of Science and Technology, Taiyuan, 03.024, china 3. school of Electrical Engineering, southwest Jiaotong university, Chengdu, 61003., china

Most smart materials used in engineering applications have rate-dependent hysteresis nonlinearity. In this paper, a Hammerstein-based model is proposed to describe the dynamic characteristics of rate-dependent hysteresis in piezoelectric actuator. A Bouc-Wen model is used to approximate the static nonlinear characteristic while a linear dynamic model is constructed to capture the rate-dependent property of the hysteresis. Firstly, Bouc-Wen model parameters are optimized with particle swarm optimization （PSO） algorithm to model the static hysteresis nonlinearity. Based on this constructed static hysteresis nonlinear model, a recursive least squares （RLS） algorithm is utilized to identify the dynamic linear model parameters of Hammerstein model according to the input-output data with rich frequency information. Finally, the experimental results of applying the proposed method to the modeling of rate-dependent hysteresis in a piezoelectric actuator are presented with a 100Hz sinusoidal scanning signal. The model generation capability is verified in the given frequency range from 1Hz to100Hz when the excitation voltage are 40V, 80V, 120V, respectively.

关键词： Hammerstein Bouc-Wen Rate-dependent Piezoelectric actuator

来源： cnki会议评论

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china City Planning Review 2008年第4期17卷 64-72页

作者： LI Baihao, PhD, Professor, Dean, school of Civil Engineering and Architecture, wuhan university of Technology, wuhan, P. R. china. YAN Xin, postgraduate student of Architecture Design and Theory, school of Civil Engineering and Architecture, wuhan university of Technology, wuhan, P. R. china QIAN Fang

*** on history of urban planning and construction of Xiamen City amid early

关键词： Xiamen modernization overseas destruction sided ne

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公众参与的宪法基础

法学论坛 2011年第4期26卷 100-106页

作者：谢立斌中国政法大学法学院北京100088

学界和实务界往往从提高行政决策的民主性、科学性的角度来看待公众参与制度。然而,在我国的宪法架构下,行政机关已经从人民代表大会获得了民主合法性,无需再诉诸公众参与制度来获得或提高其决策的民主性;行政机关固然应当追求决策的科... 详细信息

学界和实务界往往从提高行政决策的民主性、科学性的角度来看待公众参与制度。然而,在我国的宪法架构下,行政机关已经从人民代表大会获得了民主合法性,无需再诉诸公众参与制度来获得或提高其决策的民主性;行政机关固然应当追求决策的科学性,以确保其行为具有宪法意义上的适当性,但是,公众参与并不必然提高行政决策的科学性。因此,与民主性、科学性有关的宪法条款并不构成公众参与制度的依据。产生于夜警国家时代的自由权是公民防御国家传统侵害的利器;在福利国家时代,为了有效对抗行政决策对公民权利的侵犯,公民可以依据自由权参与行政决策程序。在这种意义上,自由权构成了公众参与制度的宪法基础。

关键词：公众参与民主性科学性自由权夜警国家福利国家

Multi-Residue Determination of Eight Anabolic Steroids by GC-MS in Muscle Tissues from Pigs

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Agricultural Sciences in china 2010年第2期9卷 306-312页

作者： ZENG Dong-ping, LIN Cui-ping, ZENG Zhen-ling, HUANG Xian-hui and HE Li-min Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, south china Agricultural university, Guangzhou 510640, P.R. china Laboratory of Veterinary Pharmacology College of Veterinary Medicine South China Agricultural University Guangzhou 510640 China

A gas chromatography-mass spectrometry （GC-MS） method to determine eight anabolic steroids （diethylstilbestrol, methyltestosterone, norethindrone, 17α-ethynylestradiol, estradiol, 6α-methyl-17α-hydroxy-progesterone, estradiol benzoate, and chlormadinone acetate） was developed. Muscle samples were extracted with liquid-liquid extraction and clean-up was performed in two steps, the extracts obtained were derivatized with heptafluorbutyric （HBF） anhydride and analyzed by GC-MS. In the above method, the linear scope was 2.5-50 μg kg^-1. The range of the recoveries was 78.5-148% for diethylstilbestrol, 70.8-109% for methyltestosterone, 69.8-87.2% for norethindrone, 67.7-120% for 17α-ethynylestradiol, 82.8-103. for estradiol, 70.3.99.2% for 6α-methyl-17α-hydroxy-progesterone, 73.0-104% for estradiol benzoate, and 72.9- 91.8% for chlormadinone acetate. The range of the coefficients of variation within batches was 0.4-12%; the range of the coefficients of variation between batches was 6.4-11%. The limit of detections and the detection capability were 0.99 and 3.3. μg kg^-1 for diethylstilbestrol, 1.05 and 3.50 μg kg^-1 for methyltestosterone, 1.19 and 3.97 μg kg^-1 for norethindrone, 0.94 and 3.13.μg kg^-1 for 17α-ethynylestradiol, 1.45 and 4.83.μg kg^-1 for estradiol, 1.56 and 5.20 μg kg^-1 for 6α-methyl-17α- hydroxy-progesterone, 1.92 and 6.40 μg kg^-1 for estradiol benzoate, and 2.41 and 8.03.μg kg^-1 for chlormadinone acetate, respectively. These results showed that the method was widely available, accurate, and sensitive.

关键词： anabolic steroids GC-MS multi-residue determination pigs

A THREE-DIMENSIONAL DESINGULARIZED HIGH ORDER PANEL METHOD BASED ON NURBS

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Journal of Hydrodynamics 2008年第2期20卷 137-146页

作者： GAO Zhi-liang ZOU Zao-jian State Key Laboratory of Ocean Engineering Shanghai Jiaotong University Shanghai 200030 China school of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200030 China

A desingularized high order panel method based on Non-Uniform Rational B-Spline （NURBS） was developed to deal with three-dimensional potential flow problems. A NURBS surface was used to precisely represent the body geometry. Velocity potential on the body surface was described by the B-spline after the source density distribution on the body surface had been solved. The collocation approach was employed to satisfy the Neurnann boundary condition and Gaussian quadrature points were chosen as both the collocation points and the source points. The singularity was removed by a combined method, so the process of the numerical computation was non-singular. In order to verify the method proposed, the unbounded flow problems of sphere and ellipsoid, the wave-making problem of a submerged ellipsoid were chosen as computational examples. It is shown that the numerical results are in good agreement with analytical solutions and other numerical results in all cases, and sufficient accuracy of numerical solution can be reached with a small number of panels.

关键词： potential flow high order panel method Non-Uniform Rational B-Spline (NURBS) desingularization

Microstructures and corrosion properties of casting in situ Al_3.i-Al composites

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Rare Metals 2010年第1期29卷 78-85页

作者： CHEN Tijun LI Jian HAO Yuan Gansu Key Laboratory of Advanced Nonferrous Materials Lanzhou University of Technology Lanzhou 730050 China school of Material Science and Engineering Xi＇an Shiyou University Xi ＇an 710065 China

The effects of Ti content and the alloying elements of Si and Cu on the microstructures of casting in situ Al3.i-Al composites were investigated. Simultaneously, their corrosion properties were also discussed. The results indicate that the aspect ratios of Al3.i platelets in different Al based composites are different although all of them are in flaky shape. The morphologies of Al3.i phase are not only determined by Ti content, but are also related to the alloying elements. The grain refining role of Al3.i phase in the pure Al and Al-Cu based composites is more effective than that in the Al-Si based composite. The addition of Ti decreases the corrosion resistance of pure Al and Al alloys. The corrosion resistances of the composites are dependent on both the corrosion characteristics of the corresponding matrixes and the distribution of Al3.i platelets.

关键词： metal matrix composite microstructure corrosion resistance alloying element morphology