Wuhan University of Technology

About: Wuhan University of Technology is a education organization based out in Wuhan, China. It is known for research contribution in the topics: Microstructure & Catalysis. The organization has 40384 authors who have published 36724 publications receiving 575695 citations. The organization is also known as: WUT.

Microstructure and mechanical properties of CoCrFeNiTiAlx high-entropy alloys

Abstract: CoCrFeNiTiAl x ( x values in molar ratio, x = 0, 0.5, 1.0, 1.5 and 2.0) high-entropy alloys were prepared using a vacuum arc melting method. The effects of Al addition on microstructure and mechanical properties were investigated. The results show that only a face-centered cubic (FCC) crystal structure phase is observed in the CoCrFeNiTi alloy. The phase composition transforms to stabilized body-centered cubic (BCC) structure phases and typically cast dendrite structure appears when Al is added. The dendrite region is rich in Co, Ni, Ti and Al elements while the interdendrite region is rich in Fe and Cr elements. Subgrains and nanosized precipitates are observed in the as-cast CoCrFeNiTiAl alloy. These CoCrFeNiTiAl x high-entropy alloys exhibit excellent room-temperature mechanical properties. For CoCrFeNiTiAl 1.0 alloy, the compressive strength and elastic modulus reach as high as 2.28 GPa and 147.6 GPa, respectively. High density of dimple-like structure is observed from the fracture surfaces of the Al 0 alloy, while alloys with Al addition show typical cleavage fractures with river-like patterns and cleavage steps.

Dual modification of graphene by polymeric flame retardant and Ni(OH)2 nanosheets for improving flame retardancy of polypropylene

Abstract: To improve its dispersion and flame retardant efficiency, graphene oxide (GO) is dually modified with polymeric flame retardant and the nanomaterial with catalytic carbonation ability. Via the reactions between oxygen functional groups in GO and P Cl groups in hexachlorocyclotriphosphazene, phosphazene-based flame retardant is grafted to GO. Due to the strong affinity of Ni 2+ with NH 2 groups in this phosphazene flame retardant, the decoration of Ni(OH) 2 nanosheets on the graphene is facilitated. Transmission electron microscopy images confirm good dispersion and exfoliation state of graphene in polypropylene (PP) matrix. The incorporation of functionalized graphene oxide (FGO) results in the reduction of peak heat release rate, total heat release and smoke release of PP during the combustion. Flame mechanism of FGO is concluded according to the results of thermal decomposition and char analysis. This work provides a novel modification strategy for enhancing the dispersion and flame retardant efficiency of graphene.

Layer‐by‐Layer Na3V2(PO4)3 Embedded in Reduced Graphene Oxide as Superior Rate and Ultralong‐Life Sodium‐Ion Battery Cathode

Abstract: Na3V2(PO4)3 (NVP) is regarded as a promising cathode for advanced sodium-ion batteries (SIBs) due to its high theoretical capacity and stable sodium (Na) super ion conductor (NASICON) structure. However, strongly impeded by its low electronic conductivity, the general NVP delivers undesirable rate capacity and fails to meet the demands for quick charge. Herein, a novel and facile synthesis of layer-by-layer NVP@reduced graphene oxide (rGO) nanocomposite is presented through modifying the surface charge of NVP gel precursor. The well-designed layered NVP@rGO with confined NVP nanocrystal in between rGO layers offers high electronic and ionic conductivity as well as stable structure. The NVP@rGO nanocomposite with merely ≈3.0 wt% rGO and 0.5 wt% amorphous carbon, yet exhibits extraordinary electrochemical performance: a high capacity (118 mA h g−1 at 0.5 C attaining the theoretical value), a superior rate capability (73 mA h g−1 at 100 C and even up to 41 mA h g−1 at 200 C), ultralong cyclability (70.0% capacity retention after 15 000 cycles at 50 C), and stable cycling performance and excellent rate capability at both low and high operating temperatures. The proposed method and designed layer-by-layer active nanocrystal@rGO strategy provide a new avenue to create nanostructures for advanced energy storage applications.

Resource Service Composition and Its Optimal-Selection Based on Particle Swarm Optimization in Manufacturing Grid System

Abstract: In distributed manufacturing systems, especially in a manufacturing grid (MGrid) system, there are primarily two kinds of manufacturing tasks (or resource service requests): (1) single resource service request task (SRSRTask), which can be completed by invoking only one resource service, and (2) multi-resource service request task (MRSRTask), which is completed by invoking several resource services in a certain sequence. For an SRSRTask, the system searches the resource services that are qualified for its function requirements and chooses the optimal one to execute it. For an MRSRTask, in addition to the search for all qualified resource services according to each subtask, the system selects one candidate resource service for each subtask. Then the system generates a new composite resource service (CRS) and selects the optimal resource service composite path from all possible paths to execute the task with the given multi-objective (e.g., time minimization, cost minimization, and reliability maximization) and constraints. The above problem is defined as multi-objective MGrid resource service composition and optimal-selection (MO-MRSCOS) problem in this paper. The formulation is presented for an MO-MRSCOS problem to minimize execution time and cost, and maximize the reliability. The basic resource service composite modes (RSCM) for CRS are described, and the principles for translating a complicated RSCM into a simple sequence RSCM are presented for simplifying the resolving process and complexity of MO-MRSCOS. A new MGrid resource service composition and optimal-selection method, based on the principles of particle swarm optimization (PSO), is then proposed. The PSO follows a collaborative population-based search, which models based on the social behavior of bird flocking and fish schooling. The case study demonstrates that the proposed method is useful in solving MO-MRSCOS problems. The experimental results and performance comparison show that the proposed method is both effective and efficient.

Transition‐Metal Phosphides: Activity Origin, Energy‐Related Electrocatalysis Applications, and Synthetic Strategies

Abstract: Developing highly efficient and stable electrocatalysts plays an important role in energy‐related electrocatalysis fields. Transition‐metal phosphides (TMPs) possess a series of advantages, such as high conductivity, earth‐abundance reserves, and good physicochemical properties, therefore arousing wide attention. In this review, the electrochemical activity origin of TMPs, allowing the rational design and construction of phosphides toward various energy‐relevant reactions is first discussed. Subsequently, their unique energy‐related electrocatalysis nature toward hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen oxidation reaction (HOR), carbon dioxide reduction reaction (CO2RR), nitrogen reduction reaction (NRR), urea oxidation reaction (UOR), methanol oxidation reaction (MOR), and others is highlighted. Then, the TMPs’ synthetic strategies are analyzed and summarized systematically. Finally, the existing key issues, countermeasures, and the future challenges of TMPs toward efficient energy‐related electrocatalysis are briefly discussed.