In practical applications, high-temperature superconducting (HTS) cables or magnets may carry AC with DC bias, such as in superferric magnets, which can increase the AC loss of the cables or magnets. When the DC bias current is high, the resulting high loss can lead to a significant temperature rise in the cable or magnet and may even cause quench. Furthermore, different waveforms of the alternating current also result in different losses and temperature rises. Therefore, it is essential to investigate the AC loss of the cable under different current waveforms and DC bias levels using an electromagnetic-thermal coupling method. In this paper, an electromagnetic-thermal coupling model is used to investigate the AC loss and temperature rise characteristics of four stacked REBCO tapes under four typical current waveforms and various DC bias levels. The actual multilayer structure of REBCO tapes is considered in the numerical simulation, which facilitates the analysis of current distribution among different layers and its contribution to the total loss of the stacked cable. The results show that under zero DC bias or a small DC bias (0.1Idc), the square-wave current yields the largest AC loss, while the triangular-wave current results in the smallest AC loss. The losses generated by the sawtooth and sinusoidal currents are comparable and intermediate between those of the two aforementioned waveforms. When the DC bias current is moderate (0.5Idc) and the amplitude of the alternating current is greater than 0.5Icable, the loss of the cable increases rapidly. The loss generated by the square-wave current is the largest, followed by the sinusoidal current, while the sawtooth and triangular currents produce the smallest losses. When the DC bias current is high (0.9Idc), even a small amplitude alternating current results in high AC loss in the cable.

In some practical applications, such as flux pumps and rotating electrical machines, high-temperature superconducting (HTS) coated conductors carry direct current (DC) and are subjected to alternating background magnetic fields, resulting in dynamic resistance. Dynamic resistance leads to dynamic loss. Furthermore, an alternating background magnetic field induces magnetization loss in the superconducting layer and eddy current loss in the metallic reinforcement layer. These losses will increase the temperature of the HTS tapes, causing a portion of the transport current to be diverted to the metallic reinforcement layer, thereby generating transport losses. Therefore, an electromagnetic-thermal coupling model is required to analyze this comprehensive phenomenon. This paper employs an electromagnetic-thermal coupling model to investigate the dynamic resistance, loss, and temperature rise characteristics of four parallel stacked HTS tapes carrying direct current and exposed to an external alternating magnetic field. Considering that there may be misalignment among the tapes during the practical fabrication of cables, the cable composed of four stacked tapes is categorized into three structures: perfectly stacked cable, obliquely stacked cable and disorderly stacked cable. The results show that misaligned stacked HTS cables exhibit higher self-field critical current compared to perfectly stacked ones. When the misalignment degree is held constant, obliquely stacked cables demonstrate the highest critical current, followed by disorderly stacked cable, while perfectly stacked cables show the lowest. When HTS cables carrying direct DC are placed in an alternating background magnetic field, obliquely stacked cables exhibit the highest dynamic resistance and losses, followed by those of disorderly stacked cables, while perfectly stacked cables demonstrate the lowest.

This study, based on the micro-panel data from the China Family Panel Studies (CFPS) and the digital financial inclusion index at the prefecture level, focuses on the internal mechanisms through which rural e-commerce and digital finance synergistically promote consumption upgrading. Using a multi-period difference-in-differences (DID) approach, this research evaluates the effects of e-commerce demonstration policies and analyzes the transmission pathways through a mediation effect model. The findings reveal that e-commerce demonstration policies significantly enhance consumption upgrading among rural households. Digital finance serves as a crucial mediating variable, amplifying the promotional effect of e-commerce development on consumption upgrading by reducing transaction frictions and optimizing resource allocation. Further heterogeneity analysis indicates that the policies have a more pronounced effect on stimulating consumption upgrading in regions with lower levels of economic development.

Background: Non-gestational Ovarian Choriocarcinoma (NGOC) is an extremely rare and highly malignant ovarian germ cell tumor with nonspecific clinical manifestations, making early diagnosis challenging. At present, detailed reports on the clinical and imaging characteristics of NGOC are scarce. This case report discusses a rare instance of NGOC in a prepubertal adolescent, complemented by a literature review to enhance clinicians' understanding of its presentation, diagnosis, and treatment. Case Presentation: A 10-year-old female with no history of menstruation or sexual activity presented with persistent lower abdominal pain and vaginal bleeding. Preoperative imaging: revealed a large pelvic mass with heterogeneous echogenicity and vascularity. Serum Human Chorionic Gonadotropin (hCG) levels were markedly elevated (>297,000 IU/L).Preoperative Imaging Ultrasonography and CT demonstrated a large, heterogeneous, hypervascular adnexal mass with features of necrosis and cystic changes, suggesting malignancy. Surgical and Pathological: Findings The mass, originating from the right adnexa, was removed via laparotomy. Histopathology confirmed NGOC, supported by immunohistochemistry, showing strong positivity for markers like CD146, CK18, HCG, and HPL, along with a high Ki-67 index (>90%). Conclusion: In young females with no sexual life, significantly elevated HCG levels and imaging findings of a large heterogeneous adnexal mass should raise suspicion for NGOC. Early recognition and multimodal diagnostic approaches, including imaging, biochemical, and pathological assessments, are essential for timely intervention, reducing metastatic risk and improving prognosis. This report contributes to the understanding of NGOC and emphasizes the importance of accurate diagnosis for better patient outcomes.

In light of large annual output and easy gathering, expired foods are regarded as a potential biomass to produce high value-added carbon cathodes in large scale for Zn-ion hybrid supercapacitors (ZIHSCs). Herein, inspired by the composition rich in protein and spongy scaffolding framework, the recycled carbon source of expired waffles is converted into 3D cheese-like hierarchical porous carbon doped by N, O dual-heteroatoms, together with high surface area and ample interconnected multiscale channels, plentiful nano-sized graphene layers plus preferable wettability towards aqueous electrolyte, therefrom making for numerous accessible active sites, fast kinetics and robust 3D network. As a result, the assembled aqueous coin-type ZIHSC device achieves a wondrous capacity of 214.4 mAh g- 1 at 0.1 A g- 1 with a marvelous conserved capacity of 94.7 mAh g- 1 by magnifying the current density to 50 A g- 1 and irresistible energy/power outputs of 171.2 Wh kg-1/42 kW kg- 1 plus an illustrious durability of 95.6 % capacity conservation over 20000 cycles at 20 A g-1. Significantly, the assembled quasi-solid ZIHSC device gives a surprising energy storage capability (a capacity of 154.9 mAh g-1, an energy output of 121.0 Wh kg-1, along with excellent flexibility and a low self-discharge rate of 2.75 mV h-1).

This paper extends the Hu-Zhang element for linear elasticity problems to curved domains, preserving strong symmetry and H(div)-conformity. The non-polynomial structure of the curved Hu-Zhang element makes it difficult to analyze the stability result, which is overcome by establishing a novel inf-sup condition. Optimal convergence rates are achieved for all variables except the stress L^2-error. This suboptimality originates from the fact that the divergence space of the curved Hu-Zhang element is not contained in the discrete displacement space, which is rectified by local p-enrichment in the Hu-Zhang space on curved boundary elements. Some numerical experiments validate the theoretical results.

Diamond/Cu composites are ideal materials for thermal management in high-power electronic devices. The use of W coating can enhance the interfacial bonding of the composites and improve the room temperature thermal performance. However, its high-temperature thermal performance cannot be guaranteed. This study constructs diamond/W-Cu/Cu dual-layer interface structures based on coated W to further optimize the high-temperature thermal performance of the composites. This work synthesized diamond/Cu composites with various interface structures by varying the sintering temperature and time. The results indicate that the W-WC composite interface has a higher thermal conductivity than the W-W2C-WC interface structure, and a peak thermal conductivity of 660 W/(m center dot K) is achieved at an interface structure of 52 nm W-108 nm WC, corresponding to a thermal expansion coefficient of 5.2 ppm/K. A dual-layer interface structure was next constructed. While the results show that the dual-layer interface composites have better high-temperature thermal properties and bonding with the interface. The relative density of the composite was increased by nearly 2.8 % and its thermal conductivity was increased to 698 W/(m center dot K), while the high-temperature thermal conductivity degradation (at 200 degrees C) was reduced from 33.5 % to 29.5 %. Additionally, it achieves a 25 % reduction in high-temperature coefficient of thermal expansion (CTE) and improves thermal stability by 50 %. Its low thermal resistance and high thermal stability provide an innovative solution for the thermal management of high heat flow density electronics.

This study introduces a novel lateral rolling friction additive manufacturing (L-RFAM) using sheet. Process optimization focuses on the lateral deposition orientation, which increases the contact area between the friction tool and the sheet to ensure sufficient heat input for high-quality deposition. Solid-state manufacturing of metal structures is achieved using a milling cutter featuring orthogonal intersecting vertical and horizontal grooves as the tool head. To investigate the material formation mechanism during L-RFAM, the surface morphology, microstructure evolution, and properties of the deposited samples were analyzed. Al-Mg-Si-Sc alloy was successfully fabricated using L-RFAM in this work. The deposited samples exhibited an equiaxed fine-grained microstructure. The ultimate tensile strength (UTS) of the interface bonding zone reached 95 % of that of the base metal, and its elongation (EL) increased by 27.5 %. The tensile strength (UTS) of the additive region decreased by 21.5 %, but its elongation (EL) increased by 50 %. L-RFAM demonstrates significant potential for solid-state additive manufacturing and provides fundamental insights applicable to future applications in material repair, gradient manufacturing, and miniaturization.

Using data from the China Household Finance Survey and a two-way-fixed-effects model, this study explores the impact of digital finance on farmers' average propensity to consume and analyzes the potential risks related to excessive consumption. Results indicate that digital finance significantly enhances farmers' average propensity to consume, facilitating and increasing rural consumption demand. However, digital finance may lead to excessive debt, increasing the potential risks of excessive consumption among farmers. Further analysis reveals that financial literacy plays a moderating role in the influence of digital finance on farmers' consumption propensity. Farmers with lower financial literacy are more susceptible to the promotional effects of digital finance, which may increase the risk of excessive consumption and disproportionate debt. Furthermore, this study offers some policy recommendations for the promotion of digital finance in rural areas.

REBCO coated conductors have a multi-layer structure, and the outer encapsulation layer is generally made of non-magnetic copper material. This paper proposes a new structure of REBCO tape, which replaces the copper layer with magnetic material to explore its transport loss and magnetization loss. The results indicate that copper-encapsulated REBCO tapes have lower transport losses at low currents, while tapes encapsulated with strong magnetic nickel alloy materials have the highest transport losses. At high transport currents, the transport losses of REBCO tapes encapsulated with different materials are almost equal. At low fields, the magnetization loss of the tape encapsulated with strong magnetic nickel alloy is lower, while the magnetization loss of the tape encapsulated with copper is the highest, due to the magnetic shielding effect of the magnetic material. Under high-field conditions, the difference in magnetization loss between magnetic material-encapsulated tapes and copper-encapsulated tapes decreases.

The performance of electrocatalysts in oxygen reduction reactions is crucial for clean energy technologies such as fuel cells and metal-air batteries. Developing highly active and low-cost oxygen reduction catalysts remains a significant challenge. In this work, a silver loaded nitrogen doped graphene sheet (Ag-NGs) nanocomposite with high ORR catalytic performance was synthesized by a microwave plasma technique. XPS analysis reveals that silver nanoparticles preferentially adsorb onto the graphite-nitrogen site structure, resulting in improved catalytic activity for ORR, a conclusion confirmed by first principles calculations. And the incorporation of high-level nitrogen doping into graphene with a pyridine structure also contributes to the improved performance of the ORR catalyst. Moreover, the Ag-NGs nanocomposite not only demonstrates exceptional catalytic activity for the four-electron pathway of oxygen reduction reactions, but also exhibits remarkable stability. This study underscores the potential of the Ag-loaded nitrogen-doped graphene nanocomposite as a promising electrocatalyst for utilization in clean-energy devices.

Graphene/copper composite materials with excellent mechanical and electrical properties are urgently needed in many industrial fields. In this study, we successfully prepared oriented nitrogen-doped graphene-like/copper (NGL/Cu) composite materials with high strength and electrical conductivity. Structural characterization reveals that NGL with a nitrogen content of 5.95(atom)% is uniformly distributed on the surface of flake copper with a good orientation. Through hot-pressing sintering, a layered structure is formed within the copper matrix. The layered structure of NGL has proven effective in load transfer and impeding dislocation slip. Following cold rolling treatment, the NGL/Cu composite material exhibited a tensile strength of 435 MPa, which is 1.94 times higher than that of the pure copper matrix. Additionally, it demonstrated a high electrical conductivity of 95.1% IACS. This high-performance graphene/copper composite material holds promising prospects for achieving enhanced electronic device performance and reliability.

Cables made by HTS tapes usually have anisotropic dependence by magnetic field owing to the inherit anisotropic characteristics in HTS materials. By increasing number of tapes, the perpendicular magnetic field components weaken the critical current of the whole conductor, and also lead to larger AC loss during AC operation. To reduce the AC loss from stacked HTS conductors, this article studies gap optimization schemes between non-twisted stacked HTS tapes. Finite element modeling with performance comparisons for a stacked HTS conductor (10 tapes) using non-uniform schemes is demonstrated. The results indicate that gap optimizations have better impacts in AC loss reduction rather than those direct stacked conductors. Designs using non-twisted configurations would be simpler, cheaper, and more robust. Therefore, the gap optimization method can be used to explore high current design for large-scale HTS applications.

Considering the superiorities of abundance, easy collection, low cost, and nearly constant composition, the wasted A4 papers are deemed as a recyclable and scalable carbon source to fabricate functional carbon materials for Zn-ion hybrid supercapacitors (ZIHSCs), which integrate the supercapacitors' high-power output and batteries' high energy density. Herein, the wasted A4 papers are efficiently converted into an advanced carbon material owning a hierarchical porous structure with a high surface area and interconnected multiscale channels, a graphitic structure, and a good level of N/O codoping. By taking advantage of these features, an express electron/ion transfer pathway, a large accessible surface interface, and a robust architecture are achieved for swift kinetics, numerous active sites, and excellent steadiness to afford a charming Zn2+ storage capability for the aqueous coin-type ZIHSC device (a high capacity of 244 mAh g-1 at 0.1 A g-1 with a capacity conservation of 116.4 mAh g-1 even amplifying the current density by 200 times, a supreme energy density of 190.4 Wh kg-1, a supreme power output of 18 kW kg-1, and an eminent durability of 93.8% over 10,000 cycles at 10 A g-1). Excitingly, the quasi-solid ZIHSC device also bespeaks an enjoyable capacity of 211.7 mAh g-1, a high energy density of 159.3 Wh kg-1, good mechanical flexibility, and a low self-discharge rate. This work puts forward a simple and scalable strategy to enable the wasted A4 paper as a competitive carbon source to construct advanced cathode material for Zn2+ storage.

Large-scale high temperature superconducting (HTS) magnets usually have tens of double/single pancake coil units. The structural optimization and manufacture of the magnet assembly result in varying axial gaps between adjacent pancakes. This brings additional difficulties for inserting the superconducting joints and dealing with the welding factors such as the gap, welding angle and overlapped length. This article presents the simulation modeling and general joint design guideline of a spiral joint scheme for large-scale HTS magnets and other similar applications. An easy-to-implement model has been built to characterize the physical behaviors of joint resistance. This article explores feasible joint design guidance and performance evaluation solutions for largescale applications of HTS magnets having a series of HTS-HTS joints among pancake coils.

This study addresses the urgent problem of developing high-performance metal-based conductor materials capable of adapting to complex working environments. A novel method, called Accumulative Hot Pressing Roll Bonding (AHRB), is proposed for fabricating Cu/Mo/NGs multilayer composite materials. Through repetitive cold rolling and hot-pressing operations, nanoscale metal-based layered materials with thicknesses in the range of hundreds of nanometers are successfully obtained. This material features a multilayered interconnected net structure with Mo2C as the core and CuMo alloy as the framework. The layers are dislocated and connected to each other. The mechanical properties of the materials are significantly improved due to heterogeneous strengthening and grain refinement. The material achieves a tensile strength of 854 MPa, while the conductivity remains stable between 55% similar to 60% IACS. The reaction between NGs and Mo leads to the formation of an Mo2C interface, while the hot-pressing operation promotes the formation of a CuMo diffusion interface. These two interfaces enhance the interlayer forces of the composites, thereby improving the material's integrity. The investigation of Cu/Mo/NGs multilayer composite materials presents a novel approach for alloying refractory metals Mo and Cu, offering promising prospects for future engineering applications.

Background:The rate at which the anticancer drug paclitaxel is cleared from the body markedly impacts its dosage and chemotherapy effectiveness. Importantly, paclitaxel clearance varies among individuals, primarily because of genetic polymorphisms. This metabolic variability arises from a nonlinear process that is influenced by multiple single nucleotide polymorphisms (SNPs). Conventional bioinformatics methods struggle to accurately analyze this complex process and, currently, there is no established efficient algorithm for investigating SNP interactions. Methods:We developed a novel machine-learning approach called GEP-CSIs data mining algorithm. This algorithm, an advanced version of GEP, uses linear algebra computations to handle discrete variables. The GEP-CSI algorithm calculates a fitness function score based on paclitaxel clearance data and genetic polymorphisms in patients with nonsmall cell lung cancer. The data were divided into a primary set and a validation set for the analysis. Results:We identified and validated 1184 three-SNP combinations that had the highest fitness function values. Notably, SERPINA1, ATF3 and EGF were found to indirectly influence paclitaxel clearance by coordinating the activity of genes previously reported to be significant in paclitaxel clearance. Particularly intriguing was the discovery of a combination of three SNPs in genes FLT1, EGF and MUC16. These SNPs-related proteins were confirmed to interact with each other in the protein-protein interaction network, which formed the basis for further exploration of their functional roles and mechanisms. Conclusion:We successfully developed an effective deep-learning algorithm tailored for the nuanced mining of SNP interactions, leveraging data on paclitaxel clearance and individual genetic polymorphisms.

Bi-2223/Ag multifilament superconducting tape has high critical temperature, high critical current, and low loss, which has great application potential in superconducting power devices. However, it is a multifilament structure, and it takes a long time to use the finite element method (FEM) to simulate its electromagnetic and thermal properties. A method called “homogenization” is applied to quickly evaluate the electromagnetic characteristics of multifilament tape under normal alternating current. However, further research is needed to determine the applicability of the homogenization model under fault currents. In this paper, we use the electromagnetic-thermal coupling model to compare and analyze the loss and temperature change of the original model and the homogenization model tape under normal alternating current and fault current. Under normal alternating current, the temperature rise of the tape can be ignored, so the influence of temperature on the loss of the tape can be ignored. At this time, the homogenization model can quickly and effectively evaluate the AC loss of multifilament tape. Under the fault current, when the fault degree is small (Ip/Ic0 is less than 1), the tape temperature rise is not obvious, and the difference between the two models is small. At this time, the homogenization model can still quickly and effectively evaluate the loss of multifilament tape. When the fault degree is large (Ip/Ic0 is greater than 2), the temperature rise of the tape obtained by the two models is significantly different, so the tape loss obtained by the two models is somewhat different. At this time, the homogenization model should be carefully selected to describe the loss of multifilament tape.

The global energy crisis and growing concerns about environmental pollution have spurred researchers to explore eco-friendly methods of generating clean energy. Previous studies have often relied on noble metal catalysts to facilitate oxygen reduction reactions (ORR) in energy production reactions. However, their high cost has limited their widespread adoption, making the development of highly active and affordable ORR catalysts a significant challenge. In this study, a vacuum heat treatment technique was employed to fabricate a cobalt-loaded mesoporous graphene (Co-Gs) nanocomposite. The inclusion of cobalt in graphene enhances the reaction, while the presence of mesoporous graphene provides a larger surface area to accommodate the active sites of Co. This synergistic effect promotes the improvement of catalytic performance. Additionally, the stability and methanol tolerance of Co-Gs nanocomposites is also superior than that of Pt-C. The excellent catalytic performance of the Co-Gs nanocomposite is attributed to a four-electron pathway within the nanocomposite, as demonstrated by electrocatalytic kinetics investigations. Additionally, the interface interaction between the Co nanoparticles and Gs enhances the efficiency of electron transfer, effectively improving the catalytic performance. These findings highlight the potential of Co-loaded graphene nanocomposites as highly efficient and cost-effective electrocatalysts for clean energy application. Superior catalytic performance of Co@mesoporous graphene nanocomposites toward oxygen reduction reaction is attributed to the four-electron transfer occurring during the reaction. image

Due to the anisotropy of high-temperature superconducting (HTS) materials, the stacked HTS conductors in a magnetic field are significantly affected, leading to a substantial reduction of critical current. In order to improve the performance of stacked conductors, we optimized the gap between these stacked tapes. First, we conducted experimental tests with four stacked tapes, and the results indicated that the critical current increased by about 5%. In order to explore the effect of the gap optimization scheme on the current distribution, we set up a model with 10 stacked conductors. Through modeling, it was found that the optimized gap scheme could improve the current distribution and increase the overall current carrying capability. This study provides a feasible optimization scheme for the design of high-current stacked HTS conductors, which can potentially enhance their performance in practical engineering.