The decentralized control problem is considered for a class of nonlinear time-varying interconnected systems. Each subsystem is with the dead-zone input and unmodeled dynamics. The interconnections ...are bounded by time-varying nonlinear functions, which relaxes the commonly used linear condition or time-invariant condition. Based on the recursive method, we design a new decentralized finite-time controller such that all the state variables reach zero in finite time. The reaching time is based on the design parameters and initial value of system state. Furthermore, the fixed time stability conditions are given and the constructed controller can guarantee the fixed-time stabilization of the system, in which the reaching time only depends the control design parameters. Finally, simulation results are presented to illustrate the effectiveness of proposed method.
Mitochondria are known to generate approximately 90% of cellular reactive oxygen species (ROS). The imbalance between mitochondrial reactive oxygen species (mtROS) production and removal due to ...overproduction of ROS and/or decreased antioxidants defense activity results in oxidative stress (OS), which leads to oxidative damage that affects several cellular components such as lipids, DNA, and proteins. Since the kidney is a highly energetic organ, it is more vulnerable to damage caused by OS and thus its contribution to the development and progression of chronic kidney disease (CKD). This article aims to review the contribution of mtROS and OS to CKD progression and kidney function deterioration.
In mesoscopic perovskite solar cells, the electron transport layer plays an important role in charge extraction and determines the charge-transport property to attain a superior photovoltaic ...performance. Herein, we report a low-cost, solution-based deposition procedure of decorating graphene quantum dots on the surface of mesoporous TiO2 film, expecting that a more effective electron-transport channel can be formed for the enhancement of solar cell performance, finally, an impressive power conversion efficiency of 20.45% is achieved in the resulting optimized perovskite solar cell. Furthermore, the results of various spectroscopic characterizations including electronic impedance spectroscopy, steady-state and time-resolved photoluminescence spectrum elucidate that the introduction of GQDs on the surface of mesoporous TiO2 film not only enhance the electron extraction but also facilitate the charge transportation at interface between the perovskite and electron transport layer.
Graphene quantum dots were used to decorate the mesoporous TiO2 film, which was employed as the electron-transporting layer for perovskite solar cells, resulting in a maximum PCE of 20.45%. Display omitted
•Graphene quantum dots decorated on the surface of mesoporous film was explored.•The best efficiency of 20.45% was achieved in an optimal PSC.•Graphene quantum dots enhanced the extraction and transportation of electron in PSC.
Permissionless blockchain, as a kind of distributed ledger, has gained considerable attention because of its openness, transparency, decentralization, and immutability. Currently, permissionless ...blockchain has shown a good application prospect in many fields, from the initial cryptocurrency to the Internet of Things (IoT) and Vehicular Ad-Hoc Networking (VANET), which is considered as the beginning of rewriting our digital infrastructure. However, blockchain confronts some privacy risks that hinder its practical applications. Though numerous surveys reviewed the privacy preservation in blockchain, they failed to reveal the latest advances, nor have they been able to conduct a unified standard comprehensive classification of the privacy protection of permissionless blockchain. Therefore, in this paper, we analyze the specific characteristics of permissionless blockchain, summarize the potential privacy threats, and investigate the unique privacy requirements of blockchain. Existing privacy preservation technologies are carefully surveyed and evaluated based on our proposed evaluation criteria. We finally figure out open research issues as well as future research directions from the perspective of privacy issues.
In this paper, we study the problem of output feedback distributed containment control for a class of high-order nonlinear multiagent systems under a fixed undirected graph and a fixed directed ...graph, respectively. Only the output signals of the systems can be measured. The novel reduced order dynamic gain observer is constructed to estimate the unmeasured state variables of the system with the less conservative condition on nonlinear terms than traditional Lipschitz one. Via the backstepping method, output feedback distributed nonlinear controllers for the followers are designed. By means of the novel first virtual controllers, we separate the estimated state variables of different agents from each other. Consequently, the designed controllers show independence on the estimated state variables of neighbors except outputs information, and the dynamics of each agent can be greatly different, which make the design method have a wider class of applications. Finally, a numerical simulation is presented to illustrate the effectiveness of the proposed method.
The porous NiS thin films on Ni foam substrate were fabricated for the first time by an electrodeposition route and then used directly as an anode for lithium-ion batteries, which exhibited larger ...capacity and good cycle stability.
•The porous NiS on Ni foam substrate were fabricated by an electrodeposition route.•NiS/Ni thin films were used as the electrode material in lithium-ion batteries.•The cell fabricated by NiS/Ni exhibited larger capacity and good cycle stability.
Electrodeposition, a convenient approach, has been used for fabricating porous NiS thin films on Ni foam substrate. The obtained NiS/Ni thin films were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and energy dispersive spectrometry. Furthermore, the electrodeposited NiS/Ni thin films were first used as the anode for lithium-ion intercalation and exhibited large capacities and good cycling stability.
The optimal design and effectiveness of three control systems, tuned viscous mass damper (TVMD), tuned inerter damper (TID) and tuned mass damper (TMD), on mitigating the seismic responses of base ...isolated structures, were systematically studied. First, the seismic responses of the base isolated structure with each control system under white noise excitation were obtained. Then, the structural parameter optimizations of the TVMD, TID and TMD were conducted by using three different objectives. The results show that the three control systems were all effective in minimizing the root mean square value of seismic responses, including the base shear of the BIS, the absolute acceleration of structural SDOF, and the relative displacement between the base isolation floor and the foundation. Finally, considering the superstructure as a structural MDOF, a series of time history analyses were performed to investigate the effectiveness and activation sensitivity of the three control systems under far field and near fault seismic excitations. The results show that the effectiveness of TID and TMD with optimized parameters on mitigating the seismic responses of base isolated structures increased as the mass ratio increases, and the effectiveness of TID was always better than TMD with the same mass ratio. The TVMD with a lower mass ratio was more efficient in reducing the seismic response than the TID and TMD. Furthermore, the TVMD, when compared with TMD and TID, had better activation sensitivity and a smaller stroke.
The realistic simulation of the train dynamic loading is essential to the study of the dynamic behaviors and long-term stability of the railway subgrade. Considering the loading intermittence caused ...by the time interval between adjacent trains and the increasing dynamic stress response of the subgrade caused by the increasing axle load and running speed of trains, a series of dynamic triaxial tests with single-stage and multi-stage intermittent cyclic loading were performed. The results show that the existence of the intermittent stage improved the resistance of samples to cyclic loading and thus reduced the permanent strain, and the initial small dynamic stress under multi-stage loading also effectively reduced the accumulation of permanent deformation under the subsequent large dynamic stress. Based on the time-hardening approach, a prediction model for the permanent strain was proposed to consider the influence of loading intermittence and multi-level dynamic stress, and this model can predict the permanent strain under single-stage and multi-stage intermittent cyclic loading well. The research results can provide guidance for further understanding of the deformation characteristics and settlement prediction of railway subgrade under actual train loading.
•Single-stage and multi-stage intermittent cyclic loading tests were conducted.•The influence of loading intermittence and multi-level dynamic stress on the permanent strain were studied.•A prediction model of permanent strain was proposed to consider the loading intermittence and multi-level dynamic stress.•For different deformation behaviors under intermittent loading, the prediction model could obtain good prediction results.
This paper considers the distributed consensus tracking problem for a class of high-order stochastic multiagent systems with uncertain nonlinear functions under a fixed undirected graph. Through the ...recursive method, the novel nonlinear distributed controllers are designed. By constructing a kind of special form for the virtual controller in the first step of recursive design, we realize that the state variables of every agent are separated except the outputs of the adjacency agents. The designed controller of each agent only depends on its own state variables and the outputs of the adjacent multiagents. With the proposed method, it is not required any more that the orders of the agents are same. This makes the designed controller be easier to be implemented and the proposed method be applicable for a wider class of multiagent systems. The efficiency of the design approach is illustrated by a simulation example.
The electron transporting layer plays an important role in charge extraction and transporting procedure for mesoscopic perovskite solar cells. Herein, the TiO2-B nanoparticles are used as an electron ...transporting material in perovskite solar cells for the first time which achieves a high efficiency of 18.83%. Furthermore, the effects of TiO2-B electron transporting layer on the nature of perovskite adsorption layer and the photovoltaic properties of devices are investigated in detail. As a consequence, the high efficiency can be ascribed to perovskite layer with a high crystallinity, resulting in suppressing charge recombination at interfaces, leading to favourable energy level alignment between perovskite and TiO2-B.
TiO2-B nanoparticles were first used as an electron transporting material in perovskite solar cells which achieved a highest efficiency of 18.83%. Display omitted
•TiO2-B nanoparticles were first employed as an ETL material in PSCs.•PSCs based on the TiO2-B ETL layer achieved a best efficiency of 18.83%.•TiO2-B exhibited a favourable energy level alignment with perovskite layer.
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