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•Lithium-vacancies type LLOs are pre-treated by NH4H2PO4.•Surface stable bi-phase coating layers are generated through pretreatment.•LLOs after pretreatment realize stable cycling and ...fast charging successfully.
Li-rich Mn-based layered oxides (LLOs) exhibiting ultrahigh specific capacity larger than 250 mAh g−1 have become the most promising cathode candidate for high energy density lithium-ions batteries (LIBs). Fast charging capability and cycling stability are highly desirable for LIBs so as to satisfy specific application scenarios such as electric vehicles. However, stable cycling and fast charging properties are severely hindered by obstacles including irreversible oxygen release, structural degradation and poor reaction kinetics. In this work, an integrative and facile surface structures constructing strategy to achieve stable cycling and fast charging in LLOs was provided. Oxygen vacancies and double coating layers including lithium phosphate layer and spinel layer were constructed on the surface through ammonium dihydrogen phosphate (NH4H2PO4) pretreatment. The designed material with induced stable bi-phase coating layers delivers a high discharge specific capacity of 284.6 mAh g−1 at 0.1 C with an ultrahigh initial coulombic efficiency of 95.3% and excellent rate performance of 132.2 mAh g−1 at 10 C. Even after 100 cycles, it can display a remarkable capacity of 215.8 mAh g−1 under 1 C/1 C and 205.1 mAh g−1 under 3 C/1 C. The excellent fast charging performance and cycling stability can be attributed to accelerated Li+ transportation rate due to its surface ion conductive layer and surface spinel phase layer, as well as suppressed oxygen release, transition metals dissolution and electrolyte attack resulting from surface oxygen vacancies and dual protective layers.
In this paper, we propose a new constructing approach for a weighted topology of wireless sensor networks (WSNs) based on local-world theory for the Internet of Things (IOT). Based on local-world ...theory, an uneven clustering weighted evolving model of WSNs is designed. The definitions of edge weight and vertex strength take sensor energy, transmission distance, and flow into consideration. The vertex strengths drive the growth of topology; meanwhile, the edge weights change correspondingly. Experimental data demonstrate that the WSN topology we obtain has the property of weighted networks of the IOT: the edge weight, vertex degree, and strength follow a power-law distribution. Related IOT research work shows that weighted WSNs not only share the robustness and fault tolerance of weight-free networks, but also reduce the probability that successive node breakdowns occur; furthermore, they enhance the synchronization of WSNs.
In recent times, with the incremental demand for fully autonomous systems, research interests are observed in learning machine-based intelligent, self-organizing, and evolving controllers. In this ...paper, a new evolving and self-organizing controller, namely generic-controller (G-controller), is proposed. The G-controller works in a fully online mode with minor expert domain knowledge. It is developed by incorporating the sliding mode control (SMC) theory with an advanced incremental learning machine, namely generic evolving neuro-fuzzy inference system. The controller starts operating from scratch with an empty set of fuzzy rule, and therefore, no offline training is required. To cope with the changing dynamic characteristics of the plant, the controller can add or prune the rules on demand. Control law and adaptation laws for the consequent parameters are derived from the SMC algorithm to establish a stable closed-loop system, where the stability of the G-controller is guaranteed by using the Lyapunov function. The uniform asymptotic convergence of tracking error to zero is witnessed through the implication of an auxiliary robustifying control term. In addition, the implementation of the multivariate Gaussian function helps the controller to handle the nonaxis parallel data from the plant and consequently, enhances the robustness against uncertainties and environmental perturbations. Finally, the controller's performance has been evaluated by observing the tracking performance in controlling simulated plants of unmanned aerial vehicle, namely bio-inspired flapping wing micro air vehicle and hexacopter for a variety of trajectories.
Abstract Constructing Complex Words in the Dictionary of Ghazi In linguistics; there are various ways to increase vocabularies in dictionary. One of the ways to increase words is called the ...complex method. Complex words have not been studied until now in Kurdish language. The study is entitled ``Constructing Complex Words in the Dictionary of Ghazi``. It is a bilingual (Kurdish- Arabic) and (Arabic- Kurdish) dictionary. Throughout this research, the researcher tries to show the constructing complex words that have been used in the Kurdish and Arabic language via certain rules. The research utilizes the qualitative method; this research is of immense significance because it has not been conducted enough in Kurdish language especially in the Bahdini Kurdish dictionary. The purpose of this study is revealing how the rules of the complex words were composed or constructed in the dictionary. In addition to that, the study concentrates on divulging the rate of the rules used in constructing the complex words. In other words, the researcher will confirm how each rule for the constructed complex words have been put into use, and he will also show the percentage of these words. The newness of the title of the research is the chief research problem. Hence the researcher will attempt to display the complex words and their rules as well as their percentage in his research, therefore; the results will be unfolded accordingly. Key words: Words, derivation, percentage, Ghazi dictionary, constructing, complex.
Zeolite-loaded noble metal catalysts have demonstrated excellent performance in addressing cold-start automotive exhaust NOx emissions and catalytic oxidation of VOCs applications. Pd and Pt are the ...most commonly used active metals in PNA and VOC catalysts, respectively. However, despite the same metal/zeolite composition, the efficient active sites for PNA and VOC catalysts have been viewed as mainly Pd2+ and Pt0, respectively, both of which are different from each other. As a result, various methods need to be applied to dope Pd and Pt in zeolitic support respectively for different usages. No matter which type of metal species is needed, the common requirement for both PNA and VOC catalysts is that the metal species should be highly dispersed in zeolite support and stay stable. The purpose of this paper is to review the progress of synthetic means of zeolite-coated noble metals (Pd, Pt, etc.) as effective PNA or VOC catalysts. To give a better understanding of the relationship between efficient metal species and the introduced methods, the species that contributed to the NOx adsorption (PNA) and VOCs deep catalytic oxidation were first summarized and compared. Then, based on the above discussion, the detailed construction strategies for different active sites in PNA and VOC catalysts, respectively, were elaborated in terms of synthetic routes, precursor selection, and zeolite carrier requirements. It is hoped that this will contribute to a better understanding of noble metal adsorption/catalysis in zeolites and provide promising strategies for the design of adsorption/catalysts with high activity, selectivity and stability.
The paper introduces noble metal species and active sites in PNA and VOCs catalysts. Then summarizes the impacts of precursors, zeolite properties, and metal introduction methods on active metal site construction in zeolites for these applications. Display omitted
•Pd2+ is the main active site for passive adsorption of NOx on Pd/zeolite.•Pt0 is the main active site for catalytic oxidation of VOCs on Pt/zeolite.•The form of precursor will affect the dispersion of noble metal species.•Zeolite structure, Si/Al ratio, acidity and hydrophobicity and so on will affect the dispersion of noble metals.•The preparation method will affect the distribution, dispersion and morphology of noble metals.
The uses of granular hydrogels to assemble macroscopic bulk hydrogels display numerous distinct advantages. However, prior assembly of bulk hydrogels is accomplished by interparticle linking ...strategy, which compromised mechanical property and thermal stability under hostile conditions. To expand their applications as engineering soft materials, self‐regenerative granular hydrogels via a seamless integrating approach to regenerate bulk hydrogels is highly desirable. Herein, covalent regenerative granular hydrogels (CRHs) are prepared at low‐temperature synthetic conditions and re‐construct bulk seamless hydrogels at high‐temperature aqueous environments. The re‐formed bulk hydrogels display rubber‐like viscoelastic behaviors over a wide range of temperatures from 90 to 150 °C, where the covalent re‐crosslinking reactions homogeneously occurr along the periphery and in the matrix of granular hydrogels, accounting for the increased structural integrity at high temperatures. The bulk hydrogel shows increased elasticity and long‐term thermal integrity at 150 °C for more than six months in the confined fractures. Moreover, regenerative granular CRH‐based bulk hydrogels significantly improve mechanical robustness under destructive pressure. Thus, high temperature water induced regenerative granular hydrogels present the paradigm to treat engineering scenarios such as large fractures for hydraulic fracturing, drilling operation, and disproportionate permeability reduction under extremely hostile conditions during subsurface energy recovery.
Granular hydrogels with self‐regenerative function under high temperature aqueous condition generate void‐free seamless robust bulk hydrogels. The formation of bulk hydrogels occurs in a wide range of temperatures from 90 to 150 °C. The re‐constructed hydrogels show long‐term thermal stability under extremely hostile conditions of 150 °C and high pressure resistance in simulated void space conduits.
Artificial Interphases
In article number 2213510, Ying Bai, Chuan Wu, Ran Zhao, and co‐workers report new insights into artificial interphases between Zn and electrolyte, involving the materials used ...as artificial layers, corresponding protection mechanisms, and construction techniques. Notably, emphasizing the evaluation of different construction strategies of artificial layers in regard of commercialization, which could provide guidance to develop desired artificial interphases for practical applications.
This research aims to describe the students’ metacognitive failure in constructing proof and the scaffolding support. The participants of this qualitative case study were eight preservice mathematics ...teachers of six-semester, State University of Malang. We carried out a test about proof construction problems in Abstract Algebra. Then we verified the data using triangulation of constant comparative method from a test and a task-based interview with the stimulated recall. The results indicated two groups of students in proving strategy. Group I performed “appropriate” syntactic strategy and Group II vice versa. Blindness was experienced by the subject that does not recognize errors detection or the ambiguity of the proof. Mirage occurred when the subject recognizes an error detection on the proper strategy or application of a theorem, then is unable to verify the truth of his work. Misdirection appeared when the subject recognizes a lack of progress, then uses an incomplete or irrelevant concept. Vandalism emerged with no progress or detection of errors of the strategy then the subject performs some irrelevant steps to the issue or uses a misconception. Practically, the teachers can use these results for learning innovations in scaffolding-based proof courses. The scaffolding might need some development and application in supporting students to overcome difficulty in proving mathematical sentences.
This article presents an approach for the automatic semantic segmentation of floorplan images, predicting room boundaries (walls, doors, windows) and semantic labels of room types. A multi-task ...network was designed to represent and learn inherent dependencies by combining a Convolutional Neural Network to generate suitable features with a Graph Convolutional Network (GCN) to capture long-range dependencies. In particular, a Self-Constructing Graph module is applied to automatically induce an input graph for the GCN. Experiments on different datasets demonstrate the superiority and effectiveness of the multi-task network compared to state-of-the-art methods. The accurate results not only allow for subsequent vectorization of the existing floorplans but also for automatic inference of layout graphs including connectivity and adjacency relations. The latter could serve as basis to automatically sample layout graphs for architectural planning and design, predict missing links for unobserved parts for as-built building models and learn important latent topological and architectonic patterns.
•Automatic semantic segmentation of floorplan images of buildings.•Designed multi-task network combining CNN and Graph Convolutional Network (GCN) to capture long-range dependencies.•Applied Self-Constructing Graph module to automatically induce a graph structure.•Experimental results on different datasets demonstrate superiority over state-of-the-art methods.•Automatic inference of layout graphs representing connectivity and adjacency relations.
Rechargeable aqueous zinc-ion batteries are emerged as fascinating “beyond Li-ion” battery technologies for large-scale energy storage due to low cost, high theoretical capacity, high safety and ...environmental friendliness. However, developing cathode materials with outstanding electrochemical performance are prerequisites. Herein, the a-V2O5@Ti3C2Tx heterostructure is prepared by in situ incorporating amorphous V2O5 with Ti3C2Tx MXene to enhance the rechargeable aqueous Zn-ion batteries performance. Benefitting from the distinctive amorphous structure of a-V2O5, outstanding conductivity of Ti3C2Tx MXene and the strong synergistic effect between two components, the a-V2O5@Ti3C2Tx heterostructure presents isotropic ion diffusion paths, plentiful ion storage sites and splendid conductivity. As a consequence, the a-V2O5@Ti3C2Tx heterostructure displays excellent specific capacity of 544 mAh g−1 at 0.5 A g−1 and outstanding rate performance. Particularly, even at a fairly high current density of 30 A g−1, the a-V2O5@Ti3C2Tx heterostructure shows an impressive specific capacity of 135 mAh g−1 along with about 100% coulombic efficiency after 1000 cycles. Furthermore, the mechanism related is expounded via comprehensive characterizations. Therefore, this work offers a way for developing high-performance vanadium-based cathode materials for aqueous zinc-ion batteries.
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•Amorphous V2O5@Ti3C2Tx was fabricated via a simple in situ synthetic method.•Synergistic effect amorphous V2O5 and Ti3C2Tx endows fascinating properties.•The cathode presents outstanding specific capacity and cycling stability.•The mechanisms involved were elucidated via comprehensive characterizations.
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