Passivity-based non-fragile control for Markovian jump delayed systems via stochastic sampling

<p>This paper studies the problem of non-fragile passive control for Markovian jump delayed systems via stochastic sampling. The Markovian jumping parameters, appearing in the connection weight matrices and in two additive time-varying delay components, are considered to be different. The controller is assumed to have either additive or multiplicative norm-bounded uncertainties. The sampled-data with stochastic sampling is used to design the controller by a discontinuous Lyapunov functional. This functional fully utilises the sawtooth structure characteristics of the sampling input delay. By using the matrix decomposition method and some newly inequalities, sufficient conditions are obtained to guarantee that for all admissible uncertainties the system is robustly stochastically passive. Illustrative examples are provided to show the effectiveness of the results.</p

Structure, Phase Transition, and Controllable Thermal Expansion Behaviors of Sc_2–<i>x</i>Fe_<i>x</i>Mo₃O₁₂

The crystal structures, phase transition, and thermal expansion behaviors of solid solutions of Sc_2–<i>x</i>Fe_<i>x</i>Mo₃O₁₂ (0 ≤ <i>x</i> ≤ 2) have been examined using X-ray diffraction (XRD), neutron powder diffraction (NPD), and differential scanning calorimetry (DSC). At room temperature, samples crystallize in a single orthorhombic structure for the compositions of <i>x</i> < 0.6 and monoclinic for <i>x</i> ≥ 0.6, respectively. DSC results indicate that the phase transition temperature from monoclinic to orthorhombic structure is enhanced by increasing the Fe³⁺ content. High-temperature XRD and NPD results show that Sc_1.3Fe_0.7Mo₃O₁₂ exhibits near zero thermal expansion, and the volumetric coefficients of thermal expansion derived from XRD and NPD are 0.28 × 10^–6 °C^–1 (250–800 °C) and 0.65 × 10^–6 °C^–1 (227–427 °C), respectively. NPD results of Sc₂Mo₃O₁₂ (<i>x</i> = 0) and Sc_1.3Fe_0.7Mo₃O₁₂ (<i>x</i> = 0.7) indicate that Fe substitution for Sc induces reduction of the mean Sc­(Fe)–Mo nonbond distance and the different thermal variations of Sc­(Fe)–O5–Mo2 and Sc­(Fe)–O3–Mo2 bond angles. The correlation between the displacements of oxygen atoms and the variation of unit cell parameters was investigated in detail for Sc₂Mo₃O₁₂

Structure, Magnetism, and Tunable Negative Thermal Expansion in (Hf,Nb)Fe₂ Alloys

Structure, Magnetism, and Tunable Negative Thermal Expansion in (Hf,Nb)Fe₂ Alloy

Zero Thermal Expansion in Magnetic and Metallic Tb(Co,Fe)₂ Intermetallic Compounds

Due to the advantage of invariable length with temperatures, zero thermal expansion (ZTE) materials are intriguing but very rare especially for the metals based compounds. Here, we report a ZTE in the magnetic intermetallic compounds of Tb­(Co,Fe)₂ over a wide temperature range (123–307 K). A negligible coefficient of thermal expansion (α_l = 0.48 × 10^–6 K^–1) has been found in Tb­(Co_1.9Fe_0.1). Tb­(Co,Fe)₂ exhibits ferrimagnetic structure, in which the moments of Tb and Co/Fe are antiparallel alignment along the <i>c</i> axis. The intriguing ZTE property of Tb­(Co,Fe)₂ is formed due to the balance between the negative contribution from the Tb magnetic moment induced spontaneous magnetostriction and the positive role from the normal lattice expansion. The present ZTE intermetallic compounds are also featured by the advantages of wide temperature range, high electrical conductivity, and relatively high thermal conductivity

Zero Thermal Expansion in Magnetic and Metallic Tb(Co,Fe)₂ Intermetallic Compounds

Due to the advantage of invariable length with temperatures, zero thermal expansion (ZTE) materials are intriguing but very rare especially for the metals based compounds. Here, we report a ZTE in the magnetic intermetallic compounds of Tb­(Co,Fe)₂ over a wide temperature range (123–307 K). A negligible coefficient of thermal expansion (α_l = 0.48 × 10^–6 K^–1) has been found in Tb­(Co_1.9Fe_0.1). Tb­(Co,Fe)₂ exhibits ferrimagnetic structure, in which the moments of Tb and Co/Fe are antiparallel alignment along the <i>c</i> axis. The intriguing ZTE property of Tb­(Co,Fe)₂ is formed due to the balance between the negative contribution from the Tb magnetic moment induced spontaneous magnetostriction and the positive role from the normal lattice expansion. The present ZTE intermetallic compounds are also featured by the advantages of wide temperature range, high electrical conductivity, and relatively high thermal conductivity