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The microstructure and texture evolution of tantalum (Ta) during annealing were studied in this work, in addition to simulating and analyzing of the grain boundary motions and their interactions using molecular dynamics simulations (MD). The results showed that the evolution of the recrystallized texture in the surface region of Ta is different from that in the core region. Coincident site lattice (CSL) is significantly related to the grain orientation and thus directly affects the recrystallization texture. MD results showed that the grain boundary mobility rate is higher at low angle grain boundaries (LAGB), which implied that the mobility rate is influenced by the tilt angle. Lower mobility rate of high angle grain boundary (HAGB) possibly caused by a large number of stabilized Σ3 grain boundaries (GBs) between them. It is shown that the inhomogeneous distribution of the recrystallization texture during the annealing process can be possibly attributed to the presence of a large number of Σ3 GBs. • The variation of low-Σ CSL GBs with annealing temperature is similar to the {111} orientation, and the high-Σ CSL GBs change similarly to the {001} orientation. • The formation of {111} texture is mainly controlled by Σ3 and Σ5 GB. • Σ3 GBs of large and stable exist, and even other GBs tend to change towards Σ3 GBs, leading to an increase in the {111} recrystallization texture. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the distributed optimal consensus problem by designing the multi-agent communication systems, where each agent has local access to its own strongly convex utility function. Here, we design two distributed consensus-based optimization algorithms to tackle the optimization problem of multi-agent systems. One is the second-order optimization consensus algorithm, and another is the third-order algorithm. Moreover, the two algorithms can ensure that all agents achieve consensus at a common state which minimizes the sum of the objective function under the assumption that interaction graph is strongly connected and detailed balanced. For each of the proposed algorithms, it can be found that the equilibrium point of the algorithm is the optimal point and it is proved to be asymptotically stable under given conditions. Finally, the performance of the proposed algorithms are verified by two simulations based on an IEEE 14-bus test system and an IEEE 57-bus test system. [ABSTRACT FROM AUTHOR]

In semiconductor integrated circuits, the orientation dependence of the stored energy and texture distribution uniformity of sputtering tantalum targets are critical to the properties of the deposited films which block the diffusion of Cu atoms into the storage cell Si. In this paper, the effect of heating rate on the recrystallization behavior was investigated with the aid of a differential scanning calorimeter (DSC). In addition, the texture and stored energy of deformed tantalum targets with different heat treatments along the thickness direction were characterized using electron backscatter diffraction (EBSD). The results show that the initial temperature of recrystallization rises but the temperature range reduces with the increase of the heating rates. The stored energy of deformed tantalum targets presents various orientation dependencies in different thickness layers. During the heating process, the stored energy difference among the grains with different orientations decreases, but the maximum difference of stored energy in different thicknesses increases inversely. The content of {101} oriented grains increases as the temperature increases, while the content changes of {111} and {001} present a waveform with an opposite trend. • The orientation dependence of the stored energy varies in different layers. • The content of {111} and {001} grains with heating changes in a waveform. • Growth mechanisms of differently oriented sub-grains are different. • {001} recrystallized grains nucleate at grain boundaries of {111} deformed matrix. [ABSTRACT FROM AUTHOR]

This paper investigates the optimal control of uncertain nonlinear systems with external disturbance via adaptive dynamic programming, where two kinds of controllers are introduced and event-driven strategy is used to update the controllers as well as the network weights. One controller is constrained-input, and another is used to offset the external disturbance. Three kinds of neural networks (identifier network, critic network and actor network) are used to approximate the uncertain dynamics, the optimal value, control inputs and external disturbance, respectively. To the best knowledge of the authors, the advantage of this paper is that almost all the existing systems about optimal control via adaptive dynamic programming can be considered as special cases of this system, where the external disturbance is considered. By designing appropriate parameters, the uncertain nonlinear system is asymptotically stable with the event-driven controller. And, under the given learning rates of neural networks, the system state and the estimation error of neural networks are proved to be uniform ultimate boundedness (UUB) via adaptive dynamic programming. Finally, numerical simulation results are presented to verify the theoretical analysis. [ABSTRACT FROM AUTHOR]

In this paper, by considering the development of antivirus software always lags behind the emergence of new virus and the point-to-group information propagation mode, a new computer virus model with point to group and discontinuous anti-virus strategy is presented. To the best of our knowledge, this is the first computer virus model that takes into account the effect of discontinuous anti-virus strategy. The dynamic properties of this model are investigated comprehensively. Specifically, it is found that in the case that the equilibrium is asymptotically stable, the convergence to the equilibrium can actually be achieved in finite time, and the time can be estimated in terms of the model parameters, the initial number of the uninfected computer and latent computer and the initial anti-virus strength, which means the virus in the network can be controlled or eliminated in finite time by increasing the anti-virus strength. Finally, two illustrative examples are also given to support the theoretical results. [ABSTRACT FROM AUTHOR]

This paper concerns the synchronization problem of complex networks with the random switching topologies. By modeling the switching of network topologies as a Markov process, a novel event-triggered synchronization strategy is proposed. Unlike the existing strategies, the event detection of this strategy only works at the network topology switching time instant, which can significantly decrease the communication frequency between nodes and save the network resources. Under this strategy, the synchronization problem of complex network is equivalently converted to the stability of a class of Markovian jump systems with a time-varying delay. By using the Lyapunov–Krasovskii functional method and the weak infinitesimal operation, a sufficient condition for the mean square synchronization of the complex networks subject to Markovian switching topologies is established. Finally, a numerical simulation example is provided to demonstrate the theoretical results. [ABSTRACT FROM AUTHOR]

• Soybean protein isolation (SPI) and thiourea were coated on PA66 fabrics surface. • The LOI value of PA66 fabric was increased to 25.5 from 20.5 by the coating. • The damaged char length of the coated fabric sample was reduced to only 4 cm. • SPI acted in both gas phase and condensed phase during the combustion of the fabric. It has been a big challenge to produce sustainable environmental-friendly flame- retardant synthetic textiles for many years. In this work, soybean protein isolation in association with thiourea was coated on the surface of fibers through a simple pad-dry process in order to prepare flame retardant polyamide 66 (PA66) fabric with reduced environmental hazard and fire risk. The chemical components and the morphology of the treated fabric surface were analyzed by a Fourier transform infrared spectrometer and a scanning electron microscopy respectively. The flammability evaluation by limiting oxygen index (LOI) and vertical burning tests indicated that the LOI value was increased from 20.5–25.5, the damaged char length was reduced to only 4 cm, and the dripping phenomenon was eliminated for the coated PA66 fabric sample by the presence of protein/thiourea. It was demonstrated that the deposited protein/thiourea combination coating significantly improved the fire hazard resistance through affecting the thermal degradation pathway of PA66 fabric. It was proposed that oxygen and flammable gases in the gas phase be diluted by the released H 2 S, NH 3 , H 2 O gases, and compact char formation be promoted by the formed unsaturated double bonds (such as -C = N) during the burning process of PA66-SPI-thiourea samples. It was suggested the sustainable bio-based SPI could be an effective alternative to conventional flame retardants used in textile finishing. [ABSTRACT FROM AUTHOR]

Conventional tillage refers to the tillage process, especially the spring and autumn plowing process in which all the soil surface layer is disturbed, generally tilling approximately 20 cm deep. Conventional tillage is still widely used in sloping land, which leads to serious soil erosion and land degradation. The effect of tillage on soil erosion is defined by Tillage factor (T) in the model. The purpose of this study is to analyze the effect of conventional tillage on soil erosion and to calculate the value of the conventional tillage Factor T. The values of the conventional tillage factor (T value) were calculated for different soil and water conservation zones in China by collecting published literature and plot measurements from unpublished monitoring sites. The results showed that (1) the tillage factors of conventional tillage in China ranged from 0.27 to 0.55, with the largest being the North earth-stony region, the smallest being the Qinghai-Tibet plateau region, and the other six regions, namely, the Northeastern mollisol, the Northern wind erosion, the Northwest Loess Plateau, the South red soil, the Southwestern purple soil and the Southwestern karst region, were 0.34, 0.28, 0.53, 0.37, 0.35 and 0.29, respectively. In the regional soil erosion evaluation, the values can be taken by each of the eight main erosion type regions. (2) In the water erosion area except for the northeast, there is an obvious north south difference in the distribution of the T value, showing a decreasing trend from north to south. In practical use, the T value of the corresponding latitude area can be determined according to the Equation T = 0.2351φ- 0.02225, where φ is the latitude (°). (3) The T values of contour tillage, no-till, and monopoly tillage measures are significantly lower than the T values of conventional tillage, which have significant soil and water conservation benefits. The study initially determined the conventional tillage T values for each water conservation subzone, which can provide basic parameters for soil loss prediction on sloping land. • The t values of 8 subzones are calculated, which can be used in the actual survey. • A formula for calculating t-values is proposed, which can be used for unmeasured areas. • Conventional tillage can reduce soil loss and must be assigned a reasonable value. [ABSTRACT FROM AUTHOR]

Based on the fact that the deposition reactions for electroless Ni–W–P coatings depend on the participation of H 2 PO 2 − , we developed a competitive deposition process that H 2 PO 2 − was controllably assigned to W, P and Ni deposition by the concentration ratio of dual-complexant composed of sodium citrate (NaCit) and lactic acid (Lac), namely NaCit/Lac ratio, and NiSO 4 concentration in plating bath. The impact of the ratio and NiSO 4 concentration on the deposition rate, composition, microstructure, microhardness, adhesion, corrosion resistance and wear resistance of coating was studied. The results indicate that both factors affect W codeposition through changing the deposition rate of Ni. The bath at NaCit/Lac ratio of 1:1 and NiSO 4 concentration of 30–40 g/L accelerates W deposition and Ni deposition, but decelerates P deposition, and thus incorporates more W (6.97–7.02 wt.%) but less P (4.87–5.03 wt.%) in coating. Furthermore, the crystalline structure, nodular morphology, microhardness and adhesion of coating also depend on both factors. The coating plated at different NaCit/Lac ratios and NiSO 4 concentrations demonstrates various corrosion-resistant and wear-resistant performances. [ABSTRACT FROM AUTHOR]

Abstract: The immersion behavior of two different hydroxyapatite (HA) powders before and after sintering was investigated by soaking them in simulated body fluid (SBF) for various periods. The results showed that the mechanism of formation of bone-like apatite on the two HA powders was different due to their different phase composition. Moreover, after being sintered at a proper elevated temperature, the bioactivity of HA powders was increased. [Copyright &y& Elsevier]