Herein, ruthenium (Ru) and iridium (Ir) are introduced to tailor the atomic and electronic structure of self-supported nickel-vanadium (NiV) layered double hydroxide to accelerate water splitting ...kinetics, and the origin of high hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities are analyzed at atomic level. X-ray photoelectron spectroscopy and X-ray absorption near-edge structure spectroscopy studies reveal synergistic electronic interactions among Ni, V, and Ru (Ir) cations. Raman spectra and Fourier and wavelet transform analyses of the extended X-ray absorption fine structure indicate modulated local coordination environments around the Ni and V cations, and the existence of V vacancies. The Debye-Waller factor suggests a severely distorted octahedral V environment caused by the incorporation of Ru and Ir. Theoretical calculations further confirm that Ru or Ir doping could optimize the adsorption energy of intermediates in the Volmer and Heyrovsky steps for HER and accelerate the whole kinetic process for OER.
Here, we describe the synthesis of a novel interwoven NiS/NiS2 structure with an amorphous interface accomplished by carrying out a one-step thermal decomposition of nickel sulfate and thiourea. A ...partial phase transition from NiS2 to NiS induced the amorphous interface in NiS/NiS2 and was expected to separate the H* and H− intermediates onto different interface sites, and to reduce the interfacial energy and charge-transfer resistance as well. When NiS/NiS2 was applied as an electrocatalyst for overall water splitting (OWS), it achieved a geometrical current density of 100 mA cm−2 at a low overpotential of 248 mV for the hydrogen evolution reaction (HER) and 416 mV for the oxygen evolution reaction (OER), obviously superior to those of the single-phase catalysts. In addition, it was also employed as an efficient bifunctional catalyst for OWS, yielding a current density of 10 mA cm−2 at a voltage of 1.62 V.
Virtual power plant (VPP) composed of a large number of distributed energy resources (DERs) has become a regional multienergy aggregation model to realize the large-scale integration of renewable ...energy generation into the grid. Due to the characteristics of centralized management, the existing energy operation mode is difficult to simply apply to distributed energy resources transactions. The decentralization, transparency, contract execution automation and traceability of blockchain technology provide a new solution to the aggregation of decentralized resources and the opacity of transactions in VPP. In this paper, the existing problems of virtual power plants are analyzed, and the virtual power plant trading model is designed, which realizes the transparent benefit distribution and message transmission of virtual power plants. The virtual power plant blockchain network based on blockchain technology in this model solves the DERs coordination problem in VPP and the security and efficiency problems in information transmission. Combined with the actual situation of virtual power plant, the blockchain network collaboration mechanism (BNCM), which is convenient to reach agreement, is designed. Compared with the traditional practical Byzantine fault tolerance (PBFT) consensus algorithm, this mechanism can make DERs reach a consensus quickly. Finally, simulation experiments on the consensus algorithm show that the algorithm can reduce the collaboration time between DERs under the premise of ensuring the same fault tolerance rate and is more suitable for VPP scenarios with a large number of DERs.
The development of cost-effective hydrogen evolution reaction (HER) electrocatalysts based on 3d-transition metal is highly desired but still challenging. Herein, we report on the synthesis of the ...three-dimensional self-supported nickel-oxide-coated cobalt manganese sulfide nanosheets array on carbon cloth (CoMn-S@NiO/CC), which is used as an efficient electrocatalyst for HER in alkaline media. The performance of CoMn-S@NiO/CC is significantly improved through an in situ electrochemical reduction process. The electrochemically activated CoMn-S@NiO/CC (ECA CoMn-S@NiO/CC) drives 100 and 200 mA cm–2 at overpotentials of 232 and 278 mV, respectively, with long-term stability for hydrogen production in 1.0 M KOH. Such high hydrogen evolution activity for ECA CoMn-S@NiO/CC is owed to the incorporation of Co ions, increase in electrochemically active surface area, and the newly formation of amorphous regions on its surface.
Novel (Tb1-xLux)2O3 magneto-optical transparent ceramics were prepared through a solid-solution method via vacuum pre-sintering followed by hot isostatic pressing (HIP). The Lu-containing samples ...were solid-solution phases between Tb2O3 and Lu2O3, which effectively stabilized the phase transition of Tb2O3 during the sintering process. A typical component of (Tb1-xLux)2O3 ceramic with x = 0.5 was selected to study the densification behavior and microstructure evolution in detail. The polished (Tb0.5Lu0.5)2O3 ceramics with a thickness of 3 mm vacuum pre-sintered at 1700 °C under 1.0 × 10−3 Pa combined with HIP post-treatment at 1600 °C showed good magneto-optical property. The Verdet constant measured at 633 nm was -224.33 rad·T−1 m−1, 30% higher than that of Tb3Al5O12 (TAG). However, the in-line transmittance was 73.6% at 633 nm, lower than that of TAG. The (Tb1-xLux)2O3 ceramics will be a promising material for Faraday devices after further improving the optical quality.
The development of low-cost, high-efficiency, and stable bifunctional electrocatalysts toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of paramount importance for ...large-scale water splitting. Here, we develop a new strategy for the first design and synthesis of a NiO@Ni decorated WS2 nanosheet array on carbon cloth (NiO@Ni/WS2/CC) composite. This composite serves as a unique three-dimensional (3D) synergistic electrocatalyst that not only combines the intrinsic properties of individual NiO@Ni and WS2, but also exhibits significantly improved HER and OER activities when compared to that of pure NiO@Ni and WS2. This electrocatalyst possesses Pt-like activity for HER and exhibits better OER performance than that for commercial RuO2, as well as demonstrating superior long-term durability in alkaline media. Furthermore, it enables an alkaline electrolyzer with a current density of 10 mA cm–2 at a cell voltage as 1.42 V, which is the lowest one among all reported values to date. The excellent performance is mainly attributed to the unique 3D configuration and multicomponent synergies among NiO, Ni, and WS2. Our findings provide a new idea to design advanced bifunctional catalysts for water splitting.
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•Ni-WN heterostructure nanowires array on carbon cloth (Ni-WN/CC) was firstly fabricated.•This Ni-WN/CC was directly used as a 3D hydrogen-evolving cathode.•This electrode exhibits ...superior catalytic activity.
Earth-abundant Ni has emerged as an interesting catalytic material toward electrochemical hydrogen evolution reaction (HER) in alkaline media, but developing high-performance Ni-integrated HER catalysts is still a big challenge. Herein, we describe the development of self-standing Ni-tungsten nitride heterostructure nanowires array on conductive carbon cloth (Ni-WN/CC) as a highly efficient 3D hydrogen-evolving cathode in 1.0M KOH with catalytic activity outperforming most reported Pt-free HER catalysts. This Ni-WN/CC electrode exhibits a negligible onset overpotential and a Tafel slope of 71mVdec−1. It demands overpotentials of only 47, 70, and 155mV to drive 10, 20, and 100mAcm−2, respectively, with its activity being maintained for 10h. Such high hydrogen evolution activities are due to electrocatalytic synergistic effects of Ni and WN.
Large-scale personalization is becoming a reality. To ensure market competitiveness and economic benefits, enterprises require rapid response capability and flexible manufacturing operations. ...However, variant design and production line reconfiguration are complicated because it involves the commissioning, replacement, and adaptive integration of equipment and remodification of control systems. Herein, a digital twin-driven production line variant design is presented. As a new technology, the digital twin can realize the parallel control from the physical world to the digital world and accelerate the design process of the production line through a virtual-real linkage. Simultaneously, the actual production line can be simulated to verify the rationality of the design scheme and avoid cost wastage. Four key technologies are described in detail, and a production line variant design platform based on digital twin is built to support rapid production line variant design. Finally, experiments using a smartphone assembly line as an example are performed; the results demonstrate that the proposed method can realize production line variant design and increase production efficiency.
With increasing age, middle-aged and older persons face a series of physical and mental health problems. This study aimed to explore the latent relationships among age, functional disability, ...depression, and life satisfaction. The data were obtained from the Wave 2 (in 2013-2014) and Wave 3 (in 2015-2016) surveys of the China Health and Retirement Longitudinal Study. The analytic sample in the present study included 15,950 individuals aged 45 years and over. The participants answered the same questions concerning depression and life satisfaction in both study waves, and functional disability was measured based on the activities of daily living and instrumental activities of daily living. Age was directly associated with functional disability, life satisfaction, and depression. Functional disability was positively correlated with depression and negatively correlated with life satisfaction. Functional disability strongly mediated the relationships among age, depression, and life satisfaction. Depression and life satisfaction were found to have enduring effects and effects on each other. Additionally, the model revealed a gender difference. Depression in middle-aged people should receive closer attention. Avoiding or improving functional disability may be an effective way to improve life satisfaction and reduce the level of depression in middle-aged and older persons. If prevention work successfully decreases depression, the life dissatisfaction of middle-aged and older people could be improved. Additionally, for the prevention of functional disability and depression and improvement in life satisfaction, gender differences need to be considered.
Abnormal heating of composite insulators on ultra‐high voltage (UHV) transmission lines is widespread under high humidity and heat in southern China. The infrared imaging technology can be used of ...quickly and effectively detect insulators with abnormal heating and determine their defect types. However, it may cause misjudgement when the infrared images are not clear. A super‐resolution reconstruction method of infrared images of composite insulators with abnormal heating based on improved super‐resolution generative adversarial networks (SRGAN) is proposed in this paper, and the dense residual network in SRGAN is perfected by introducing the residual channel attention (ResCA). This method overcomes the problems that the resolution of images reconstructed by traditional methods is not significantly improved, and images are too smooth, and the edge details are easily lost. Compared with the traditional methods, the five reference‐free image quality evaluation indexes of the image reconstructed by the improved SRGAN are increased by −0.73% to 63.84%. Further the effectiveness and superiority of the improved SRGAN are verified by comparing the changes in the distribution of grey values of infrared images before and after reconstruction. Finally, the improved SRGAN is used to perform super‐resolution reconstruction of the low‐resolution infrared image examples.
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