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Powder samples of ABO3 perovskite manganites with the composition Pr0.6Sr0.4MxMn1-xO3 (M=Fe, Co, or Ni, 0.00≤x≤0.25) were synthesized using the sol-gel method. X-ray diffraction analyses showed that all three sets of samples had a single phase with an orthorhombic structure. The magnetic moment, μobs, of the samples at 10 K, decreased slowly for x≤0.10, whereas μobs decreased rapidly for x≥0.10. The dependences of μobs on the doping level x for the three series of samples were fitted successfully. In the fitting process, Mn, Fe, Co, and Ni cations were assumed to be trivalent, and the magnetic moment directions of Fe3+, Co3+, and Ni3+ cations were assumed to be canted antiferromagnetically coupled with Mn3+ cations. The cant angle φ decreased with the increase in x for x≤0.10 for Fe- and Ni-doped (x≤0.15 for Co-doped) samples and increased rapidly when x≥0.10 (x≥0.15 for Co-doped) samples. These properties are discussed using an oxygen 2p itinerant electron model, which is very similar to the oxygen 2p hole model proposed by Alexandrov et al. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the correlations of MC4R and MSH2 with adult obesity, a total of 46 patients with early-stage colon cancer were treated in our hospital between February 2008 and February 2009 and were enrolled. PATIENTS AND METHODS: Venous blood was regularly drawn from subjects of the observation group and 48 healthy subjects for 6 years. Expression levels of MC4R and MSH2 genes were tested using quantitative polymerase chain reaction analyses, and the ensuing proteins were determined using enzyme-linked immunosorbent assays and Western blotting and immunohistochemical analyses. Finally, correlations with body mass index (BMI) and the presence of colon cancer were identified using multivariate analyses. RESULTS: Compared with the control group, MSH2 mRNA and protein expression increased significantly over time (p < 0.05) in patients with colon cancer. Moreover, MSH2 expression was correlated with colon cancer progression, and MC4R mRNA and protein expression increase concurrently in comparison with the control group (p < 0.05). Also, the mean BMI among patients with colon cancer was 30.8, whereas that among control subjects was only 21.4. These data indicate a relationship between BMI and colon cancer. CONCLUSIONS: Expression of MSH2 in patients with colon cancer may promote the expression of the obesity gene MC4R, potentially contributing to body weight gains. [ABSTRACT FROM AUTHOR]

The structure, electronic structure, states density and optics properties of the orthorhombic CH3NH3PbI3 perovskite with vacancy at the B sites are calculated by the CASTEP program. The calculated results indicate that the cell volume shrinks with the content of vacancy at the B sites increasing, and the structure has the large degree of distortion from the cubic structure. The band gaps are 1.656, 1.750, 3.077, 3.256 and 4.76 eV, corresponding to , 0.25, 0.50, 0.75 and 1.00, respectively. As an application, the additional absorption peak can be obtained by CH3NH3PbI3 perovskite doped vacancy at the B sites. [ABSTRACT FROM AUTHOR]

Ti-doped Ni0.68Fe2.32O4 spinel ferrite samples with nominal composition Ni0.68−0.8 xTi xFe2.32−0.2 xO4 (0 ≤ x ≤ 0.312) were prepared using conventional ceramic methods. The samples exhibited a single-phase cubic spinel structure. When the doping level had values x > 0.15, a transition temperature, TN, was found, below which the magnetization of the samples decreased with decreasing measurement temperature. This phenomenon indicates that an additional antiferromagnetic structure arises in the traditional spinel phase of ferrites resulted from Ti doping. Therefore, Ti ions appear in the form of Ti3+ and Ti2+ cations that have magnetic moments, rather than as Ti4+ cations without magnetic moment as assumed by many researchers. The dependence of the magnetic moments on the Ti doping level x at 10 K was fitted successfully using our quantum-mechanical potential barrier model proposed earlier. In the fitting process, we assumed that the magnetic moments of the Ti cations were opposite to the direction of the Fe and Ni moments. According to the fitted results, the Ti2+ cations at the [B] sites constitute about 81% of the total Ti content x for all samples, which is close to the content of the Ni2+ cations at the [B] sites (77%). [ABSTRACT FROM AUTHOR]

This article considers the leader-following consensus problem of heterogeneous multi-agent systems. The proposed multi-agent system is consisted of heterogeneous agents where each agents have their own nonlinear dynamic behavior. To overcome difficulty from heterogeneous nonlinear intrinsic dynamics of agents, a fuzzy disturbance observer is adopted. In addition, based on the Lyapunov stability theory, an adaptive control method is used to compensate the observation error caused by the difference between the unknown factor and estimated values. Two numerical examples are given to illustrate the effectiveness of the proposed method. © 2013 Wiley Periodicals, Inc. Complexity 19: 20-31, 2014 [ABSTRACT FROM AUTHOR]

In this paper, we present a method for synchronizing two different chaotic systems that have unknown parameters that are affected by stochastic variations generated by the Wiener process. The parameters are expressed by the sum of their mean values and the white Gaussian noise multiplied by the diffusion matrices. To describe the unknown nonlinear function yielded by Itô's lemma due to the unknown diffusion matrices, a fuzzy logic system is employed. Using adaptive fuzzy control, the response system is synchronized with the drive system within an arbitrarily small error bound. Numerical simulations show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, the problem of adaptive ℋ∞ synchronization for unified chaotic systems with unknown parameter and external disturbance is studied. It is noticed that this unified chaotic system contains the noted Lorentz, Lü and Chen systems. Based on Lyapunov theory and linear matrix inequality (LMI) formulation, the novel feedback controller with adaptive law is established to not only guarantee stable synchronization of both master and slave systems but also reduce the effect of external disturbance to an ℋ∞ norm constraint. A criterion for existence of the controller is given in terms of LMIs. Finally, a numerical example shows the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

A method of computing a new model predictive control (MPC) law for linear parameter varying systems with input constraints is proposed. The proposed method improves feasibility and system performance by deriving a new sufficient condition for the cost monotonicity. The control problem is formulated as a minimisation of the upper bound of finite horizon cost function satisfying the sufficient conditions. The relaxation matrices yield less conservative sufficient condition in terms of linear matrix inequalities so that it allows to design a more robust MPC. A numerical example is included to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

A study of the free energy of the perovskite manganites was performed by fitting experimental results for the temperature dependence of the crystal cell volume using a detailed semiclassical model of the free energy. The fitted results coincide with the experimental results for the samples La1-xCaxMnO3 (x=0.2, 0.25, 0.3, and 0.5). The free energy includes the energy corresponding to thermal vibration of the crystal lattice, the ionic cohesive energy, and additional energies produced by electrical carriers from the double exchange mechanism and the thermal activation of small polarons. [ABSTRACT FROM AUTHOR]

The effects of the vacancy at the B sites on the structural and magnetic properties of perovskite manganites with a nominal composition La0.75Sr0.25Mn1-xO3 (0.0 ≤ x ≤ 0.13), prepared by the sol-gel method, were investigated. X-ray diffraction patterns indicate that there is a ABO3 perovskite structure single phase in the samples with x ≤ 0.08; however, there are second and third phases containing La, except ABO3 perovskite phase, in the samples with x ≥ 0.10. Magnetic measurement indicates that the sample with x = 0.08 has the lowest Curie temperature. By a quantitative phase analysis, we believe that there is a maximum value of vacancy content at the B sites in ABO3 perovskite manganites. [ABSTRACT FROM AUTHOR]

This work investigates the stability and dissipativity problems for neural networks with time-varying delay. By the construction of new augmented Lyapunov-Krasovskii functionals based on integral inequality and the use of zero equality approach, three improved results are proposed in the forms of linear matrix inequalities. And, based on the stability results, the dissipativity analysis for NNs with time-varying delays was investigated. Through some numerical examples, the superiority and effectiveness of the proposed results are shown by comparing the existing works., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)