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A 54-year-old woman was admitted to the hospital with a left neck mass. Enhanced CT and ultrasound examinations revealed a lesion in the left sternocleidomastoid muscle. The patient undergone right thyroid lobe resection 8 years ago. Interestingly, the lesion on the sternocleidomastoid muscle, along with the left lobe of the patient’s thyroid, visually appears to form a displaced and complete thyroid in the early Tc-99m-MIBI parathyroid scintigraphy. Combined with Tc-99m-MIBI scintigraphy and abnormal PTH and blood calcium levels, the consideration was given to the lesion in the sternocleidomastoid muscle as an ectopic parathyroid adenoma. Subsequent surgical pathology confirmed this suspicion.

Supercapacitors have attracted tremendous attention due to their merits of excellent cycling stability, remarkable power density and low cost. Nevertheless, the low energy density of supercapacitors has encumbered their further development for practical applications. Development of advanced high-energy supercapacitors is considered to be of crucial importance. In this work, the capacitance of MOF-derived carbon-based supercapacitor is dramatically improved by addition of soluble redox-active LiBr electrolyte additive. The post analysis of this redox-active electrolytes reveal that the Br−/Br2 couple are the main pseudocapacitance contribution in the early cycles stages (

The phase-field model (PFM) is gaining increasing attention in the application of multiphase flows due to its advantages, in which the phase interface is treated as a narrow layer and phase parameters change smoothly and continually at this thin layer. Thus, the construction or tracking of the phase interface can be avoided, and the bulk phase and phase interface can be simulated integrally. PFM provides a useful alternative that does not suffer from problems with either the mass conservation or the accurate computation of surface tension. In this paper, the state of the art of PFM in the numerical modeling and simulation of multiphase flows is comprehensively reviewed. Starting with a brief description of historical developments in the PFM, we continue to take a tour into the basic concepts, fundamental theory, and mathematical models. Then, the commonly used numerical schemes and algorithms for solving the governing systems of PFM in the application of multiphase flows are presented. The various applications and representative results, especially in non-match density scenarios of multiphase flows, are reviewed. The primary challenges and research focus of PFM are analyzed and summarized as well. This review is expected to provide a valuable reference for PFM in the application of multiphase flows.

The double-layer composite electrode has attracted increasing attention in the field of intermediate-temperature solid oxide electrolysis cells (IT-SOEC). To investigate the effects of the cathode diffusion layer (CDL) and cathode functional layer (CFL) structure on performance, a three-dimensional multi-scale IT-SOEC unit model is developed. The model comprehensively considers the detailed mass transfer, electrochemical reaction and heat transfer processes. Meanwhile, percolation theory is adopted to preserve the structural characteristics and material properties of the composite electrode. The mesostructure model and the macroscopic model are coupled in the solution. The effects of the porosity of the CDL, the electrode particle size and the composition of the composite electrode in the CFL on the mass transport process and electrolysis performance of the IT-SOEC unit are analyzed. The results show that the appropriate mass flux and energy consumption in the electrode are obtained with a CDL porosity in the range of 0.3–0.5. The decrease in the electrode particle size is conducive to the improvement of the electrolysis reaction rate. The maximum reaction rate in the CFL increases by 32.64% when the radius of the electrode particle is reduced from 0.5 μm to 0.3 μm. The excellent performance can be obtained when the volume fractions of the electrode phase and electrolyte phase in the CFL tend to be uniform. This study will provide guidance for the performance optimization of IT-SOEC and further promote the development of IT-SOEC hydrogen production technology in engineering applications.

Abstract Dynamic capillarity commonly exists for multiphase flow in porous media, during which fluid viscosity varies and has strong influence. Displacement experiments are conducted on water‐wet, fractured tight rock at in situ pressure and temperature of an oil reservoir via a specially designed apparatus to investigate the effects of fluid viscosity on the dynamic capillarity. The dynamic effect in the matrix is examined through the measurement and calculation of capillary pressure, the dynamic coefficient, and the fluid flow behavior. The results show that with a higher oil viscosity: (a) both the steady and the dynamic capillary pressures reverse their directions more quickly and behave as larger resistances in the matrix; (b) the difference between the steady and the dynamic capillary pressures becomes around 5%‐19% more significant; (c) water saturation changes more slowly corresponding to the lower water relative permeability, while oil relative permeability quickly becomes lower than that during the basic displacement process; and (d) the dynamic coefficient becomes 2‐3 times higher, and the dynamic contact angle becomes 10%‐25% larger, showing a more variable interface. A contact angle advancement coefficient is proposed to identify the significance of contact angle advancement and the competition between capillary pressure and viscous force. The findings of this study can help for better understanding of multiphase flow in tight reservoirs and enhancing oil recovery.

Abstract Sodium molybdate (Na−Mo−O) wrapped by graphene oxide (GO) composites have been prepared via a simple in‐situ precipitation method at room temperature. The composites are mainly constructed with one dimension (1D) ultra‐long sodium molybdate nanorods, which are wrapped by the flexible GO. The introduction of GO is expected to not merely provide more active sites for lithium‐ions storage, but also improve the charge transfer rate of the electrode. The testing electrochemical performances corroborated the standpoint: The Na−Mo−O/GO composites delivers specific capacities of 718 mAh g−1 after 100 cycles at 100 mA g−1, and 570 mAh g−1 after 500 cycles at a high rate of 500 mA g−1; for comparison, the bare Na−Mo−O nanorod shows a severe capacity decay, which deliver only 332 mAh g−1 after 100 cycles at 100 mA g−1. In view of the cost‐efficient and less time‐consuming in synthesis, and one‐step preparation without further treatment, these Na−Mo−O nanorods/GO composites present potential and prospective anodes for LIBs.

It is economical and efficient to use existing natural gas pipelines to transport hydrogen. The fast and accurate prediction of mixing uniformity of hydrogen injection in natural gas pipelines is important for the safety of pipeline transportation and downstream end users. In this study, the computational fluid dynamics (CFD) method was used to investigate the hydrogen injection process in a T-junction natural gas pipeline. The coefficient of variation (COV) of a hydrogen concentration on a pipeline cross section was used to quantitatively characterize the mixing uniformity of hydrogen and natural gas. To quickly and accurately predict the COV, a deep neural network (DNN) model was constructed based on CFD simulation data, and the main influencing factors of the COV including flow velocity, hydrogen blending ratio, gas temperature, flow distance, and pipeline diameter ratio were taken as input nodes of the DNN model. In the model training process, the effects of various parameters on the prediction accuracy of the DNN model were studied, and an accurate DNN architecture was constructed with an average error of 4.53% for predicting the COV. The computational efficiency of the established DNN model was also at least two orders of magnitude faster than that of the CFD simulations for predicting the COV.

Conductive covalent organic frameworks (c-COFs) have been widely used in electrochemical energy storage because of their highly adjustable porosity and modifiable skeletons. Additionally, the fast carrier migration and ion catalysis requirements of micro-electrochemical energy storages (MEESs) are perfectly matched with c-COFs. Therefore, c-COFs show great potential and unlimited prospects in MEESs. However, the main organic component blocks electron conduction, and the internal active sites are difficult to fully utilize, which limits the application of c-COFs. In order to overcome these obstacles, a great deal of research has been conducted on conductivity enhancement. This review first focuses on the exploration of c-COFs in the field of electrical conductivity. Then, the mechanism and explanation of the effect of synthesis on electrical conductivity enhancement are discussed, which emphasizes the range and suitability of c-COFs in MEESs. Finally, the excellent performance characteristics of c-COFs are demonstrated from the MEES perspective, with key points and potential challenges addressed. This review also predicts the direction of development of c-COFs in the future.

The composite electrode structure plays an important role in the optimization of performance of the intermediate-temperature solid oxide electrolysis cell (IT-SOEC). However, the structural influence of the composite electrode on the performance of IT-SOEC is not clear. In this study, we developed a three-dimensional macroscale model coupled with the mesoscale model based on percolation theory. We describe the electrode structure on a mesoscopic scale, looking at the electrochemical reactions, flow, and mass transport inside an IT-SOEC unit with a composite electrode. The accuracy of this multi-scale model was verified by two groups of experimental data. We investigated the effects of operating pressure, volume fraction of the electrode phase, and particle diameter in the composite electrode on electrolysis reaction rate, overpotential, convection/diffusion flux, and hydrogen mole fraction. The results showed that the variation in the volume fraction of the electrode phase had opposite effects on the electrochemical reaction rate and multi-component diffusion inside the composite electrode. Meanwhile, an optimal range of 0.8–1 for the particle diameter ratio was favorable for hydrogen production. The analysis of IT-SOEC with composite electrodes using this multi-scale model enables the subsequent optimization of cell performance and composite electrode structure.

Due to their highly changeable porosity and adaptable skeletons, covalent organic frameworks (COFs) have been frequently used in supercapacitors. Additionally, COFs are a wonderful match for supercapacitors’ requirements for quick carrier migration and ion catalysis. COFs exhibit significant potential and limitless opportunities in electrochemical storage supercapacitors. The applicability of COFs has, nonetheless, been limited because the primary organic component prevents electron conduction and the interior active sites are challenging to fully utilize. The conductivity enhancement of COFs has been the subject of extensive research to solve these challenges. This review begins by outlining the features of COFs in the context of their use in supercapacitors and their methods of synthesis. The application of previously published COF materials in supercapacitors were evaluated including electrode materials and solid-state devices. Finally, essential aspects and potential problems are discussed as the exceptional performance characteristics of COFs are illustrated from a supercapacitor standpoint. This review also forecasts the future of COF-based supercapacitor development.

Single-crystal (SC) layered oxides as cathodes for Li-ion batteries have demonstrated better cycle stability than their polycrystalline (PC) counterparts due to the restrained intergranular cracking formation. However, there are rare reports on comparisons between single-crystal LiMn2O4 (SC-LMO) and polycrystalline LiMn2O4 (PC-LMO) spinel cathodes for Li-ion storage. In this work, the Li-ion storage properties of spinel LiMn2O4 single-crystalline and polycrystalline with similar particle sizes were investigated in a wide voltage window of 2–4.8 V vs. Li/Li+. The SC-LMO cathode exhibited a specific discharge capacity of 178 mA·h·g−1, which was a bit larger than that of the PC-LMO cathode. This is mainly because the SC-LMO cathode showed much higher specific capacity in the 3 V region (Li-ion storage at octahedral sites with cubic to tetragonal phase transition) than the PC-LMO cathode. However, unlike layered-oxide cathodes, the PC-LMO cathode displayed better cycle stability than the SC-LMO cathode. Our studies for the first time demonstrate that the phase transition-induced Mn(II) ion dissolution in the 3 V region rather than cracking formation is the limiting factor for the cycle performance of spinel LiMn2O4 in the wide voltage window.

In the previous researches about the benchmark solutions in the irregular regions, there are some obvious shortcomings, such as small number of computational grids, simple computational domain, small characteristic number, and lack of mixed convection benchmark solution. In order to improve this situation, this article deeply studied the benchmark solutions for two-dimensional fluid flow and heat transfer problems in the irregular regions under the body-fitted coordinate system. Taking the lid-driven flow, natural convection, and mixed convection problems as the research objects and considering the influence of boundary configurations of the computational domains, Reynolds number, Prandtl number, and Grashof number, this article designed three groups of test cases. The program code is first verified through employing the nonlinear multigrid method based on the collocated finite volume method and then the numerical solutions of three test cases with 1024 × 1024 grids and convergence criterion of 10 −14 are obtained to get the benchmark solutions estimated by the Richardson extrapolation method.

The computational efficiency of different composite schemes for the convection terms of the convection-diffusion equations is systematically studied in this paper. They are evaluated by the problems of lid-driven flow and natural convection in a square cavity, within the framework of single-grid and multigrid finite volume methods on collocated grids. For the convection schemes, the computational efficiencies of QUICK scheme and commonly used ten composite schemes (SMART, STOIC, MINMOD, etc.) are compared under the same calculation conditions. The influences of implementation strategy of composite schemes, grid number, Reynolds number and Rayleigh number on the computational efficiency are analyzed. It is found that the computational efficiency of composite schemes is close to that of QUICK scheme without extra calculation burden.

The high-resolution (HR) schemes have been widely used as they can achieve the numerical solution without oscillation and artificial diffusion, especially for convection-dominated problems. However, there still have arguments about the order of accuracy of HR schemes, especially about the extreme value of the solution. In this paper, it is proved that any HR scheme designed in the NVD diagram has second-order accuracy when its combined segments totally locate in the BAIR region. In other words, it has been verified in our study that the segments, which have low-order accuracy when independently employed, have at least second-order accuracy when locate in BAIR region by analysis of two implementation methods of HR scheme and also a number of numerical examples. Meanwhile Richardson extrapolation has been used to estimate the order of accuracy of HR schemes which achieve the same conclusion.

When the conservative governing equation of incompressible fluid flow and heat transfer is discretized by the finite volume method, there are various schemes to deal with the convective term. In this paper, studies on the convective term discretized by two different schemes, named strong and weak conservation schemes, respectively, are presented in detail. With weak conservation scheme, the convective flux at interface is obtained by respective interpolation and subsequent product of primitive variables. With strong conservation scheme, the convective flux is treated as single physical variable for interpolation. The numerical results of two convection heat transfer cases indicate that under the same computation conditions, discretizing the convective term by strong conservation scheme would not only obtain a more accurate solution, but also guarantee the stability of computation and the clear physical meaning of the solution. Especially in the computation regions with sharp gradients, the advantages of strong conservation scheme become more apparent.

The escalating demand for energy storage and catalysis devices in the realm of renewable energy applications has witnessed a rapid surge in recent years, with expectations for continued growth in the foreseeable future. High-entropy oxides, characterized by their diverse atomic configurations, offer notable attributes such as entropy stabilization and redox reactivity, thereby fostering heightened research endeavors within the domain of energy storage and catalysis. This review endeavors to elucidate the entropy-driven mechanisms underpinning high-entropy oxides in the context of energy storage and conversion. Subsequently, it provides a comprehensive exposition of the cutting-edge synthesis strategies and methodologies employed in the fabrication of high-entropy oxides. Moreover, recent advancements in the utilization of high-entropy oxides as cathode/anode materials across a spectrum of energy storage devices, including batteries and supercapacitors, as well as in catalytic systems encompassing photocatalysis and electrocatalysis, are expounded upon. In addition, this review addresses the impending challenges and forthcoming prospects associated with high-entropy oxide electrode materials. Ultimately, it endeavors to offer novel insights aimed at informing the design and implementation of high-entropy oxide electrodes for the advancement of next-generation energy storage and conversion. [ABSTRACT FROM AUTHOR]