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Stabilization for a Class of Discrete-time Switched Large-scale Systems with Parameter Uncertainties

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International Journal of Automation and computing 2019年第4期16卷 543-552页

作者： chang-chun Sun School of Science Shenyang Jianzhu University

The problem of robust stabilization for a class of discrete-time switched large-scale systems with parameter uncertainties and nonlinear interconnected terms is considered. By using state feedback and Lyapunov function technique, a decentralized switching control approach is put forward to guarantee the solutions of large-scale systems converge to the origin globally. A numerical example and a corresponding simulation result are utilized to verify the effectiveness of the presented approach.

关键词： Switched large-scale systems discrete-time state feedback decentralized control switching law

Design and Analysis for a Three-Rotational-DOF Flight Simulator of Fighter-Aircraft

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Chinese Journal of Mechanical Engineering 2018年第3期31卷 48-59页

作者： chang-chun Zhou Yue-Fa Fang Robot Research Center Beijing Jiaotong University

Most of researchers focused on traditional six degrees of freedom(DOF) Stewart flight simulator,which can not be adaptive in fighter?aircraft flight simulator. A three rotational DOF flight simulator of fighter?aircraft based on dou?ble parallel manipulator and hybrid structure is presented. The flight simulator is composed of two identical 3?RRS(revolute?revolute?spherical) spherical parallel manipulators and one cabin,called Twins. The cabin has an additional independent DOF for 360° continuous rotation,so it can be applied as a flight simulator for a fighter?aircraft to achieve spin maneuvering. Because of the introduction of the hybrid structure and double parallel manipulator of themechanism,the redundancy exists with respect to both kinematics and actuation. Kinematics is carried out and Jaco?bian matrix is established by means of screw theory. The inverse kinematics is given out by the analytical method. 64 groups inverse solutions are showed in a table by permutation. Forward kinematics is solved by an e ectively numeri?cal method. The forward numerical method is realized based on the analytically inverse kinematics and Jacobian matrix. The numerical examples show that the forward numerical method can be used in real?time control. The rollingmotion is considered in forward kinematics and a numerical example is given out. The proposed flight simulator can spin and there are three rotational DOF with a hybrid structure so that the novel flight simulator can be used in the field of the fighter?aircraft for pilots to train.

关键词： Parallel manipulator Hybrid mechanisms Actuation redundancy Flight simulator Kinematics Screw theory Jacobian matrix

Trifluoromethylation of Carbonyl Compounds with Sodium Trifluoroacetate

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Chinese Chemical Letters 2005年第10期16卷 1313-1316页

作者： Ying chang chun CAI School of Chemical Engineering Nanjing University of Science and Technology Nanjing 210094

In the presence of copper （I） halide as catalyst, a variety of carbonyl compounds could be trifluoromethylated with sodium trifluoroacetate to give the corresponding alcohols in moderate to high yields.

关键词： Trifluoromethylation sodium trifluoroacetate carbonyl compounds aldehydes.

lahysiological links of circadian clock and biological clock of aging

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Protein & Cell 2017年第7期8卷 477-488页

作者： Fang Liu Hung-chun chang Institute of Neuroscience State Key Laboratory of Neuroscience Key Laboratory of Primate Neurobiology CAS Center for Excellence in Brain Science and Intelligence Technology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200031 China University of Chinese Academy of Sciences Shanghai 200031 China

Circadian rhythms orchestrate biochemical and physi-ological processes in living organisms to respond the day/night cycle. In mammals, nearly all cells hold self- sustained circadian clocks meanwhile couple the intrinsic rhythms to systemic changes in a hierarchical manner. The suprachiasmatic nucleus （SCN） of the hypothalamus functions as the master pacemaker to initiate daily synchronization according to the photope-riod, in turn determines the phase of peripheral cellular clocks through a variety of signaling relays, including endocrine rhythms and metabolic cycles. With aging, circadian desynchrony occurs at the expense of peripheral metabolic pathologies and central neurode- generative disorders with sleep symptoms, and genetic ablation of circadian genes in model organisms resem- bled the aging-related features. Notably, a number of studies have linked longevity nutrient sensing pathways in modulating circadian clocks. Therapeutic strategies that bridge the nutrient sensing pathways and circadian clock might be rational designs to defy aging.

关键词： circadian rhythms SCN longevity

Overview of Computational Modeling in Nano/Micro Scaled Thin Films Mechanical Properties and Its Applications

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Computer Modeling in Engineering & Sciences 2019年第8期120卷 239-260页

作者： chang-chun Lee Pei-Chen Huang Department of Power Mechanical Engineering National Tsing Hua UniversityNo.101Section 2Kuang-Fu RoadHsinchu 30013Taiwan

This research reviews the application of computational mechanics on the properties of nano/micro scaled thin films,in which the application of different computational methods is *** concept and fundamental theories of concerned applications,material behavior estimations,interfacial delamination behavior,strain engineering,and multilevel modeling are thoroughly ***,an example of an interfacial adhesion estimation is presented to systematically estimate the related mechanical reliability issue in the microelectronic *** presented results show that the peeled mode fracture is the dominant delamination behavior of layered material system,with high stiffness along the bonding ***,the shear mode fracture being dominated as the polymer cover plate with low moduli is *** occurrence of crack advance is also significantly influenced by the interfacial crack length and applied ***,this paper could serve as a guideline of several engineering cases with the assistance of computational mechanics.

关键词： Computational mechanics mechanical responses nano/micro thin films

An Information-Theoretic Approach to Effective Inference for Z-functionals

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Acta Mathematica Sinica,English Series 2009年第11期25卷 1893-1906页

作者： chang chun WU Run Chu ZHANG College of Mathematics and Information Engineering Jiaxing University Jiaxing 314001 P. R. China KLAS and School of Mathematics and Statistics Northeast Normal University Changchun 130024 P. R. China LMPC and School of Mathematical Sciences Nankai University Tianjin 300071 P. R. China

In this paper, through an information-theoretic approach, we construct estimations and confidence intervals of Z-functionals involving finite population and with the presence of auxiliary information. In particular, we give a method of estimating the variance of finite population with known mean. The modified estimates and confidence intervals for Z-functionals can adequately use the auxiliary information, at least not worse than what the standard ones do. A simulation study is presented to assess the performance of the modified estimates for the finite sample case.

关键词： confidence interval finite population modified Z-estimates information-theoretic approach Z-functional

Critical Exponent for the Parabolic Equation u_t=Δu^m + h(t)u^p in a Cone

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Acta Mathematica Sinica,English Series 2012年第8期28卷 1623-1632页

作者： chang chun LIU Song Zhe LIAN Department of Mathematics Jilin University

In this paper, we study the initial-boundary value problem of porous medium equationut = △um ＋ h（t）up in a cone D = （0, ） Ω, where h（t） - t. Let wl denote the smallest Dirichlet eigenvalue for the Laplace-Beltrami operator on Ω and let l denote the positive root cf l2＋（n-2）l = wl. 2（＋1）＋（rn- 1）, then the problem has no global nonnegative solutions We prove that if m 〈 p 〈 m ＋ for any nonnegative u0 unless u0 -= 0; if p 〉 m ＋＋ a（m - 1）, then the problem has global n4-1 solutions for some uo 〉 O.

关键词： Porous medium equation cone critical exponent

Correlation between intrinsic dipole moment and pyroelectric coefficient of Fe-Mg tourmaline

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International Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 105-112页

作者： chang-chun Zhao Li-bing Liao Jie Xing School of Science China University of Geosciences School of Materials Science and Technology China University of Geosciences

Single-crystal X-ray diffraction structural data of four Fe-Mg tourmalines with different Fe contents from Xinjiang, Sichuan, and Yunnan Provinces, China, were collected at room temperature and-100oC. The intrinsic dipole moments of polyhedra and the total intrinsic dipole moment of the unit cell were calculated. By comparing the intrinsic electric dipole moments of the X, Y, Z, T, and B site polyhedra, it is found that the T site polyhedron makes the greatest contribution to the total intrinsic dipole moment. The pyroelectric coefficients of four Fe-Mg tourmalines were experimentally determined, and the influence of intrinsic dipole moments on their pyroelectric properties was inves-tigated. The experimental results show that, compared with the case at room temperature, the intrinsic dipole moments change with the total Fe content at-100oC in a completely different way. With the decrease of temperature, the total intrinsic dipole moments of tourmaline de-crease. Over the same temperature interval, the pyroelectric coefficients increase with the increase in intrinsic dipole moment.

关键词： tourmaline pyroelectricity dipole moment polyhedra

Interaction of Egg-Sphingomyelin with DOPC in Langmuir Monolayers

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Chinese Journal of Chemical Physics 2012年第6期25卷 691-696,I0004页

作者： chang-chun Haoa Run-guang Sun Jing Zhang College of Physics and Information Technology Shaanxi Normal University Xi'an 710052 China College of Food Engineering and Nutritional Science Shaanxi Normal University Xi'an 710062China

Lipid rafts are a dynamic microdomain structure found in recent years, enriched in sphin- golipids, cholesterol and particular proteins. The change of structure and function of lipid rafts could result in many diseases. In this work, the monolayer miscibility behavior of mixed systems of Egg-Sphingomyelin （ESM） with 1, 2-dioleoyl-sn-glycero-3-phosphocholine was in- vestigated in terms of mean surface area per molecule and excess molecular area AAex at certain surface pressure, surface pressure and excess surface pressure Arcex at certain mean molecular area. The stability and compressibility of the mixed monolayers was assessed by the parameters of surface excess Gibbs free energy AGex, excess Helmholtz energy AHex and elasticity. Thermodynamic analysis indicates AAex and ATrex in the binary systems with positive deviations from the ideal behavior, suggesting repulsive interaction. The max- imum of AGex and AHex was at the molar fraction of ESM of 0.6, demonstrating the mixed monolayer was more unstable. The repulsive interaction induced phase separation in the monolayer.

关键词： Monolayer Attractive and repulsive interaction Stability Phase separation