Equal channel angle pressing is recognized for its ability to refine alloy grains and alter grain orientation, thereby achieve better mechanical performance of the magnesium alloy. This study investigates the microstr...
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Equal channel angle pressing is recognized for its ability to refine alloy grains and alter grain orientation, thereby achieve better mechanical performance of the magnesium alloy. This study investigates the microstructures,dynamic recrystallization mechanism, texture development, and mechanical performance of GW94K(Mg–8.7Gd–4.18Y–0.42Zr wt. %) Mg alloy following ECAP-4 passes at 400°C and 3 mm/min. Results show that when high-temperature deformation is undertaken, twin formation is suppressed while dislocation slip is facilitated, increasing dislocation density during deformation. Following ECAP deformation, the sample displayed higher fracture elongation, TYS, and UTS than the as-solutioned GW94K alloy. In particular, the GW94K alloy performed well mechanically after ECAP-4 passes, with an ultimate TYS of 231 MPa, an UTS of 290 MPa, and an elongation of 14.8 %. DDRX and shear bands induce CDRX, both of which are important in plastic deformation. as well as in modifying microstructure and grain orientation during ECAP deformation.
Differing from the statically precipitated grain boundary α(GBα) that holds Burgers Orientation Relationship(BOR) with adjacent β grains, in this work, it was found that over 97.77 % of the dynamically precipitated...
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Differing from the statically precipitated grain boundary α(GBα) that holds Burgers Orientation Relationship(BOR) with adjacent β grains, in this work, it was found that over 97.77 % of the dynamically precipitated GBαs do not hold BOR with either side of the adjacent β grains in hot-forged Ti-652 titanium alloy. The evolution of GBα orientation was decoupled as dynamic precipitation and annihilation, which was quantitatively distinguished by defining three misorientation angles: the deviation form BOR(ω), the misorientation between adjacent β grains(θ) and the misorientation between non-BOR GBαs(θ'). During the entire hot forging, an adequate dynamic precipitation produces piecewise continuous and slender GBαs with ω <10°typically, manifesting as θ <25°but θ'>45°. Oppositely, a sufficient annihilation leads to the dynamic globularization of GBαs and increase of ω with θ≥25°but mainly θ'≤45°. Dynamic precipitation was driven by the intrinsic BOR preference of GBαs, while annihilation attributed to grain growth and rotation caused by accumulated plastic deformation. Deciphering the dynamic precipitation and annihilation of GBα provides a quantitative criterion to tailor microstructures and mechanical properties in the future.
With electric vehicles(EVs) emerging as a primary mode of transportation,ensuring their reliable operation in harsh environments is ***,lithium-ion batteries(LIBs) suffer from severe polarization at low temperatures,l...
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With electric vehicles(EVs) emerging as a primary mode of transportation,ensuring their reliable operation in harsh environments is ***,lithium-ion batteries(LIBs) suffer from severe polarization at low temperatures,limiting their operation in cold *** addition,difficulties in discovering new battery materials have highlighted a growing demand for innovative electrode designs that achieve high performance,even at low temperatu *** address this issue,we prepared a thin,resistive,and patterned carbon interlayer on the anode current *** carbon-patterned layer(CPL) serves as a self-heating layer to efficiently elevate the entire cell temperature,thus improving the rate capability and cyclability at low temperatures while maintaining the performance at room ***,we validated the versatile applicability of CPLs to large-format LIB cells through experimental studies and electrochemo-thermal multiphysics modeling and simulations,with the results confirming 11% capacity enhancement in 21,700 cylindrical cells at a 0.5C-rate and-24℃.We expect this electrode design to offer reliable power delivery in harsh climates,thereby potentially expanding the applications of LIBs.
Premature adiabatic shear localization caused by strain softening is a roadblock for the application of body-centered cubic(BCC)structured high-entropy alloy(HEAs)in the impact field.A micron-scale orthorhombic-phase(...
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Premature adiabatic shear localization caused by strain softening is a roadblock for the application of body-centered cubic(BCC)structured high-entropy alloy(HEAs)in the impact field.A micron-scale orthorhombic-phase(O-phase)strengthened TiZrVNbAl alloy was developed to delay adiabatic shear fail-ure and enhance dynamic *** O-phase can not only reduce the slip length,but also promote the pinning and tangling of the dislocations near the phase *** introduction of the O-phase transformed the strain hardening rate from negative to positive,resulting in a significantly improved dy-namic shear ***,slip transfer across the O-phase via dislocation cutting mechanisms and a reduction of slip band spacing guaranteed dynamic deformation *** from the introduction of the O-phase,the alloy exhibits an excellent stored energy density(～446 J/cm3,surpass the reported BCC-HEAs and typical titanium alloys),a large dynamic fracture strain(～42％)and a con-siderable dynamic specific yield strength(～241 MPa cm3 g-1).The present study presents an effective approach for developing BCC-HEAs with excellent dynamic shear resistance and plasticity.
The prerequisites and peculiarities of the establishment of the Electrical engineering Faculty at Kharkov Technological institute are considered. The main stages of the faculty's development, its contribution to t...
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Aqueous zinc-ion batteries(AZIBs)are gaining attention owing to their affordability,high safety,and high energy density,making them a promising solution for large-scale energy ***,their performance is hampered by the ...
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Aqueous zinc-ion batteries(AZIBs)are gaining attention owing to their affordability,high safety,and high energy density,making them a promising solution for large-scale energy ***,their performance is hampered by the instability of both the anode-electrolyte interface and the cathode-electrolyte *** use of sodium gluconate(SG),an organic sodium salt with multiple hydroxyl groups,as an electrolyte additive is *** and theoretical analyses demonstrate that Na^(+)from SG can intercalate and deintercalate within the associated V_(2)O_(5) cathode during in situ electrochemical *** action supports the layered structure of V_(2)O_(5),prevents structural collapse and phase transitions,and enhances Zn^(2+)diffusion ***,the gluconate anion disrupts the original Zn^(2+)solvation structure,mitigates water-induced side reactions,and suppresses Zn dendrite *** synchronous regulation of both the V_(2)O_(5) cathode and Zn anode by the SG additive leads to considerable performance ***‖Zn symmetric batteries demonstrate a cycle life exceeding 2800 h at 0.5 mA cm^(-2)and 1 mAh cm^(-2).In Zn‖V_(2)O_(5) full batteries,a high specific capacity of 288.92 mAh g^(-1)and capacity retention of 82.29%are maintained over 1000 cycles at a current density of 2 A g^(-1).This multifunctional additive strategy offers a new pathway for the practical application of AZIBs.
Ferroelastic rare earth tantalates（RETaO4） are widely researched as the next-generation thermal barrier coatings（TBCs）,and RETaO4powders are hugely significant for synthesizing their *** current research used chem...
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Ferroelastic rare earth tantalates（RETaO4） are widely researched as the next-generation thermal barrier coatings（TBCs）,and RETaO4powders are hugely significant for synthesizing their *** current research used chemical co-precipitation within an automated experimental device to synthesize RETaO4（RE=Nd,Sm,Gd,Ho,Er） *** device automatically monitored and controlled the solutions' pH,improving the chemical co-precipitation *** crystal structure and microstructure of the RETaO4powders can be controlled by changing the annealing temperature,and the materials undergo an m'-m phase *** m'-RETaO4powders exhibit nano-size grains,while m-RETaO4powders evince micron-size grains,altered by the annealing temperatures.A simultaneous thermal analysis estimates the reversive ferroelastic tetragonal-monoclinic phase transition ***,this research focuses on the synthesis,crystal structures,micro structures,and phase transition of the fabricated RETaO4powders.
The earthquake early warning(EEW) system provides advance notice of potentially damaging ground shaking. In EEW, early estimation of magnitude is crucial for timely rescue operations. A set of thirty-four features is ...
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The earthquake early warning(EEW) system provides advance notice of potentially damaging ground shaking. In EEW, early estimation of magnitude is crucial for timely rescue operations. A set of thirty-four features is extracted using the primary wave earthquake precursor signal and site-specific *** Japan's earthquake magnitude dataset, there is a chance of a high imbalance concerning the earthquakes above strong impact. This imbalance causes a high prediction error while training advanced machine learning or deep learning models. In this work, Conditional Tabular Generative Adversarial Networks(CTGAN), a deep machine learning tool, is utilized to learn the characteristics of the first arrival of earthquake P-waves and generate a synthetic dataset based on this information. The result obtained using actual and mixed(synthetic and actual) datasets will be used for training the stacked ensemble magnitude prediction model, MagPred, designed specifically for this study. There are 13295, 3989, and1710 records designated for training, testing, and validation. The mean absolute error of the test dataset for single station magnitude detection using early three, four, and five seconds of P wave are 0.41, 0.40,and 0.38 MJMA. The study demonstrates that the Generative Adversarial Networks(GANs) can provide a good result for single-station magnitude prediction. The study can be effective where less seismic data is available. The study shows that the machine learning method yields better magnitude detection results compared with the several regression models. The multi-station magnitude prediction study has been conducted on prominent Osaka, Off Fukushima, and Kumamoto earthquakes. Furthermore, to validate the performance of the model, an inter-region study has been performed on the earthquakes of the India or Nepal region. The study demonstrates that GANs can discover effective magnitude estimation compared with non-GAN-based methods. This has a high potential for wid
A complete examination of Large Language Models’strengths,problems,and applications is needed due to their rising use across *** studies frequently focus on single-use situations and lack a comprehensive understandin...
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A complete examination of Large Language Models’strengths,problems,and applications is needed due to their rising use across *** studies frequently focus on single-use situations and lack a comprehensive understanding of LLM architectural performance,strengths,and *** gap precludes finding the appropriate models for task-specific applications and limits awareness of emerging LLM optimization and deployment *** this research,50 studies on 25+LLMs,including GPT-3,GPT-4,Claude 3.5,DeepKet,and hybrid multimodal frameworks like ContextDET and GeoRSCLIP,are thoroughly *** propose LLM application taxonomy by grouping techniques by task focus—healthcare,chemistry,sentiment analysis,agent-based simulations,and multimodal *** methods like parameter-efficient tuning(LoRA),quantumenhanced embeddings(DeepKet),retrieval-augmented generation(RAG),and safety-focused models(GalaxyGPT)are evaluated for dataset requirements,computational efficiency,and performance *** for ethical issues,data limited hallucinations,and KDGI-enhanced fine-tuning like Woodpecker’s post-remedy corrections are *** investigation’s scope,mad,and methods are described,but the primary results are *** work reveals that domain-specialized fine-tuned LLMs employing RAG and quantum-enhanced embeddings performbetter for context-heavy *** medical text normalization,ChatGPT-4 outperforms previous models,while two multimodal frameworks,GeoRSCLIP,increase remote ***-efficient tuning technologies like LoRA have minimal computing cost and similar performance,demonstrating the necessity for adaptive models in multiple *** discover the optimum domain-specific models,explain domain-specific fine-tuning,and present quantum andmultimodal LLMs to address scalability and cross-domain *** framework helps academics and practitioners identify,adapt,and innovate LLMs for different *** work
Thermal Protection System(TPS) with thick tiles, low thermal conductivity, and a short re-entry stage stands as a critical element within reusable aircraft, whose reliability is related to the function and changes wit...
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Thermal Protection System(TPS) with thick tiles, low thermal conductivity, and a short re-entry stage stands as a critical element within reusable aircraft, whose reliability is related to the function and changes with their physical properties, external conditions, and degradation. Meanwhile, due to the limitation of testing resources, epistemic uncertainties stemming from the small samples are present in TPS reliability modeling. However, current TPS reliability modeling methods face challenges in characterizing the relationships among reliability and physical properties, external conditions, degradation, and epistemic uncertainties. Therefore, under the framework of belief reliability theory, a TPS reliability model is constructed, which takes into account the physical principle, external conditions, performance degradation, and epistemic uncertainties. A reliability simulation algorithm is proposed to calculate TPS reliability. Through a case study and comparison analysis, the proposed method is validated as more effective than the existing method. Additionally,reliability sensitivity analysis is conducted to identify the sensitive factors of reliability under the condition of small samples, through which suggestions are provided for TPS functional design and improvement.
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