摘要：
Diffusion study of the Ni-Si-V system is significant for the establishment of kinetic database of Ni-based alloys. In this work, the diffusion couple experiment combined with the numerical inverse method was adopted to evaluate the diffusivities and atomic mobilities for the Ni-Si-V fcc phase with high throughput. We prepared 12 fcc Ni-Si-V diffusion couples, which were annealed at 1273, 1373 and 1473 K, and their composition profiles after annealing were then measured by EPMA (Electron Probe Microanalysis). Subsequently, inputting the measured composition profiles as well as the available thermodynamic descriptions into the numerical inverse method incorporated in the CALTPP (CALculation of ThermoPhysical Properties) software, the composition- and temperature-dependent diffusivities and atomic mobilities for the Ni-Si-V fcc phase were simultaneously evaluated. In order to verify the reliability of the present evaluations, the CALTPP-simulated diffusion behaviors such as composition profiles and diffusion paths were compared with the measured ones, demonstrating reasonable agreements with each other. Meanwhile, the high-throughput determinations of diffusivities were confirmed by the ones obtained by the Matano-Kirkaldy method. Furthermore, applying the presently obtained diffusivities and atomic mobilities in combination with thermodynamic descriptions of the Ni-Si-V fcc phase, their diffusion flux, two-dimensional composition profile, activation energy and pre-frequency factor were predicted. It is expected that the presently obtained diffusivities and atomic mobilities of the Ni-Si-V fcc phase can contribute to the establishment of kinetic database of Ni-based alloys for their high-efficiency material design.
摘要：
Titanium (Ti) alloys are widely used in high-tech fields like aerospace and biomedical engineering. Laser additive manufacturing (LAM), as an innovative technology, is the key driver for the development of Ti alloys. Despite the significant advancements in LAM of Ti alloys, there remain challenges that need further research and development efforts. To recap the potential of LAM high-performance Ti alloy, this article systematically reviews LAM Ti alloys with up-to-date information on process, materials, and properties. Several feasible solutions to advance LAM Ti alloys are reviewed, including intelligent process parameters optimization, LAM process innovation with auxiliary fields and novel Ti alloys customization for LAM. The auxiliary energy fields (e.g. thermal, acoustic, mechanical deformation and magnetic fields) can affect the melt pool dynamics and solidification behaviour during LAM of Ti alloys, altering microstructures and mechanical performances. Different kinds of novel Ti alloys customized for LAM, like peritectic alpha-Ti, eutectoid (alpha + beta)-Ti, hybrid (alpha + beta)-Ti, isomorphous beta-Ti and eutectic beta-Ti alloys are reviewed in detail. Furthermore, machine learning in accelerating the LAM process optimization and new materials development is also outlooked. This review summarizes the material properties and performance envelops and benchmarks the research achievements in LAM of Ti alloys. In addition, the perspectives and further trends in LAM of Ti alloys are also highlighted. Substantive review of innovations in methodology, process and materials of AM Ti alloys.Novel titanium alloys designed for laser additive manufacturing.Machine learning assisted alloy design and process optimization.Field-assisted additive manufacturing for titanium alloys fabrications.
作者：
Nie, Mingxing;Zou, Liwei;Cui, Hao;Zhou, Xinhui;Wan, Yaping
期刊：
Electronics,2024年13(2):264- ISSN：2079-9292
通讯作者：
Wan, YP
作者机构：
[Wan, YP; Wan, Yaping; Cui, Hao; Zhou, Xinhui; Nie, Mingxing; Zou, Liwei] Univ South China, Sch Comp Sci, Hengyang 421001, Peoples R China.
通讯机构：
[Wan, YP ] U;Univ South China, Sch Comp Sci, Hengyang 421001, Peoples R China.
关键词：
human activity recognition;LoRa wireless RF signal preprocessing;deep learning;feature extraction;differential signal processing
摘要：
<jats:p>This paper introduces a novel approach for enhancing human activity recognition through the integration of LoRa wireless RF signal preprocessing and deep learning. We tackle the challenge of extracting features from intricate LoRa signals by scrutinizing the unique propagation process of linearly modulated LoRa signals—a critical aspect for effective feature extraction. Our preprocessing technique involves converting intricate data into real numbers, utilizing Short-Time Fourier Transform (STFT) to generate spectrograms, and incorporating differential signal processing (DSP) techniques to augment activity recognition accuracy. Additionally, we employ frequency-to-image conversion for the purpose of intuitive interpretation. In comprehensive experiments covering activity classification, identity recognition, room identification, and presence detection, our carefully selected deep learning models exhibit outstanding accuracy. Notably, ConvNext attains 96.7% accuracy in activity classification, 97.9% in identity recognition, and 97.3% in room identification. The Vision TF model excels with 98.5% accuracy in presence detection. Through leveraging LoRa signal characteristics and sophisticated preprocessing techniques, our transformative approach significantly enhances feature extraction, ensuring heightened accuracy and reliability in human activity recognition.</jats:p>
摘要：
Poly(triazine imide) synthesized by the molten salt route with incorporation of Li+ and Cl- ions (PTI/Li+Cl-) was prepared by rational controlling of the washing extent. The surface transformation of the phase-pure PTI framework incurred by thorough washing has been confirmed by a systematic analysis based on x-ray diffraction, Ultraviolet Raman, atomic force microscope, and x-ray photoelectron spectroscopy measurements. Uranyl ion adsorption experiments further support the surface structural transformation from triazine-unit PTI to heptazine-based graphitic carbon nitride. Efforts on the exploration of PTI material application should be mainly directed toward the waterless fields to give good repeatability. Graphical Abstract The surface transformation of the phase-pure PTI/LiCl from triazine-based structure to heptazine-based g-C3N4 framwork incurred by thorough washing has been detected by a systematic analysis based on XRD, Ultraviolet Raman, AFM and XPS measurements, and further confirmed by uranyl ion adsorption experiments.
摘要：
The phosphinimide materials described in this paper were synthesized by polymerization precipitation. The properties of complexes coordinated with metal ions can be used as adsorbents for the adsorption of radioactive elements by using ligands such as imide and phosphorus groups. Then, the synthetic phosphinimide was characterized in detail by FT-IR, SEM, EDS and XPS, and its morphology and structural changes were studied. In addition, the effects of the material on the removal of uranium(VI) from aqueous solutions at different pH, sorbent doses, contact times, initial concentrations, and temperatures were studied. The experimental data shows that the adsorption process can fit the pseudo-second-order kinetic model well, which is in line with the Langmuir isotherm model. The thermodynamic study of adsorption shows that the adsorption process is a spontaneous endothermic process. In addition, at a temperature of 303.15 K and pH = 6, the maximum adsorption of uranium(VI) by phosphinimide in 25 min can reach 234.6 mg g−1, and a removal rate of 97.75%.
作者机构：
[Liao, S; Liao, Sen; Tang, Tian; Zhang, Lilei; Wang, Guoping] Univ South China, Hengyang, Peoples R China.
通讯机构：
[Liao, S ] U;Univ South China, Hengyang, Peoples R China.
摘要：
Designing metal-organic framework (MOF) materials with high conductivity is crucial for their application in energy storage devices. In this study, a simple process, namely, a one-pot hydrothermal method, was used for simultaneously synthesizing the composite of carbon quantum dots (CQDs) and NiCo-MOF, and the effect of various carbon sources for CQDs was compared. The results showed that it was very necessary to choose an appropriate carbon source for obtaining NiCo-MOF with the expected lower Rs and Rct. Carbon sources significantly affected the morphology of NiCo-MOF, and in turn its specific surface area, pore volume and pore size. Particularly, after introducing CQDs derived from citric acid, the electron cloud density around the metal Co atom in the NiCo-MOF composite became higher, improving electron transfer ability, activating the metal center Co and alleviating polarization. As a result, the obtained NiCo-MOF-CA composite exhibited a capacitance of 1826.8 F g-1 at 1 A g-1, significantly higher than that of NiCo-MOF (1060.3 F g-1). An amplifying circuit model was proposed for explaining the phenomenon. Its cyclic performance also became better, but still left to be further improved. The simple synthesis process might be applied to the preparation of other similar composites. In addition, the conductivity of MOFs was improved by introducing specific conductive additives to alter the electronic structure of the metal atom in active materials, providing an effective strategy for other researchers. By adding carbon dots to NiCo-MOF to enhance its electrochemical properties and screening the materials synthesised from different carbon sources, the composites synthesised from isocitric acid as the carbon source had the best performance.
期刊：
Journal of Radioanalytical and Nuclear Chemistry,2024年:1-18 ISSN：0236-5731
通讯作者：
Nie, Chang-ming;Peng, GW
作者机构：
[Peng, Guo-wen; Guo, Meng-zhen; Xiao, Xi-lin; Wang, Yun; Kong, Xiang-he; Peng, GW; Nie, Chang-ming; Wu, Can-ran; Ouyang, Wen-jun; Nie, CM] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;[Peng, Guo-wen; Guo, Meng-zhen; Xiao, Xi-lin; Wang, Yun; Kong, Xiang-he; Peng, GW; Nie, Chang-ming; Wu, Can-ran; Ouyang, Wen-jun; Nie, CM] Key Lab Hunan Prov Design & Applicat Nat Actinide, Hengyang 421001, Peoples R China.
通讯机构：
[Peng, GW ; Nie, CM] U;Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;Key Lab Hunan Prov Design & Applicat Nat Actinide, Hengyang 421001, Peoples R China.
关键词：
Chiral-at-uranium complex;R/S-O,O-dimethyl-S-[1,2-bis(ethoxycarbonyl)ethyl]thiophosphates (R/S-DBTPs);Complexation;Enantioseparation;Density functional theory (DFT)
摘要：
It's very important to design novel uranium(VI) complexes with enantioselectivity for identification and enantioseparation of chiral pesticides. Enantiomers of O,O-dimethyl-S-[1,2-bis(ethoxycarbonyl)ethyl]thiophosphates(DBTPs) exhibit different biological toxicities. In this work, two novel chiral-at-uranium complexes (uranyl-2-(9-(1H-indazole-1-carbonyl)-1,10-phenanthrolin-2-yl)-1H-inden-1-one (Uranyl-IPIDO) and uranyl-2-(9-(1-oxo-1H-inden-2-yl)-1,10-phenanthrolin-2-yl)naphthalene-1,4-dione (Uranyl-OPND)) were designed to selectively enantioseparate R/S-DBTPs. Based on density functional theory (DFT), complexation behaviors and enantioseparation of Uranyl-IPIDO/Uranyl-OPND with R/S-DBTPs were theoretically investigated. Through analyses of EDA, Delta G, ESP, QTAIM, EDDM, LOL, FMO, MO, IGMH, ETS-NOCV, we found that Uranyl-IPIDO/Uranyl-OPND demonstrated excellent enantioseparation performance for R/S-DBTPs, with separation factors of 110-30526 and enantioselectivity coefficients exceeding 99% in water, butanol, octanol, and propanoic acid.
摘要：
OBJECTIVES: To unravel the heterogeneity and function of microenvironmental neutrophils during intervertebral disc degeneration (IDD). METHODS: Single-cell RNA sequencing (scRNA-seq) was utilized to dissect the cellular landscape of neutrophils in intervertebral disc (IVD) tissues and their crosstalk with nucleus pulposus cells (NPCs). The expression levels of macrophage migration inhibitory factor (MIF) and ACKR3 in IVD tissues were detected. The MIF/ACKR3 axis was identified and its effects on IDD were investigated in vitro and in vivo. RESULTS: We sequenced here 71520 single cells from 5 control and 9 degenerated IVD samples using scRNA-seq. We identified a unique cluster of neutrophils abundant in degenerated IVD tissues that highly expressed MIF and was functionally enriched in extracellular matrix organization (ECMO). Cell-to-cell communication analyses showed that this ECMO-neutrophil subpopulation was closely interacted with an effector NPCs subtype, which displayed high expression of ACKR3. Further analyses revealed that MIF was positively correlated with ACKR3 and functioned via directly binding to ACKR3 on effector NPCs. MIF inhibition attenuated degenerative changes of NPCs and extracellular matrix, which could be partially reversed by ACKR3 overexpression. Clinically, a significant correlation of high MIF/ACKR3 expression with advanced IDD grade was observed. Furthermore, we also found a positive association between MIF(+) ECMO-neutrophil counts and ACKR3(+) effector NPCs density as well as higher expression of the MIF/ACKR3 signaling in areas where these two cell types were neighbors. CONCLUSIONS: These data suggest that ECMO-neutrophil promotes IDD progression by their communication with NPCs via the MIF/ACKR3 axis, which may shed light on therapeutic strategies.
摘要：
This study investigates the structural characteristics of granite in southeastern Hunan Province and their impact on radon exhalation rates. By quantitatively analyzing the main minerals, significant correlations were found between radon exhalation rates and various structural parameters. Notably, biotite particle size positively correlated with radon exhalation, while quartz particle size showed a negative correlation. This research is the first to apply quantitative structural analysis to radon exhalation in granite, providing new insights and methods for future studies and environmental safety standards.
通讯机构：
[Hu, PF ] U;Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.
关键词：
Colloidal gas aphrons;Ion flotation;Uranium -containing wastewater;Cationic surfactant;Uranium species
摘要：
Treatment of uranium-containing wastewater has become an increasingly important research focus with the exploitation and utilization of uranium resources. The introduction of new technologies and continuous updating of existing technologies are the urgent tasks for the treatment of uranium-containing wastewater. Ion flotation is one technology with the potential to address uranium contamination. In this study, the improved ion flotation technique for removing U(VI) from acidic solutions was established by colloidal gas aphrons (CGAs). The CGAs were produced by stirring cetyltrimethylammonium bromide (CTAB) solutions at high speed. Measurements of half-life, gas hold-up, bubble size distribution and zeta potential of CGAs have been performed in this work. In the batch process, as CGAs continued to be added, the uranium removal increased steeply at first then slowly, and finally leveled off. At pH 6, the final uranium removal can reach the highest 99.3 % at an initial uranium concentration of 2.5 mg/L. The effective removal of U(VI) by the CGAs formed by cationic CTAB indicated that U (VI) existed as anionic species under these conditions. It was found that the concentration of carbonate ions in solution increased with the increase of flotation time, which may be caused by the dissolution of carbon dioxide brought in by bubbles. The calculation results of Visual MINTEQ software show that the concentration of carbonate ions generated at pH 6 is sufficient for anionic uranium-carbonate to dominate. In addition, it was found that the size and zeta potential of CGAs all played a significant role in removing U(VI) from the acidic solution.
摘要：
Solute transport in conventional acid leaching of sandstone uranium ores is limited by diffusion and convection, resulting in extended leaching cycles. This study described an electrokinetic-enhanced method for leaching sandstone uranium ore with sulfuric acid and was intended to investigate the impacts of potential gradients on leaching efficiency. Electrokinetic horizontal column leaching experiments were conducted on sandstone uranium ore. After 20 h of leaching, the uranium leaching efficiencies were 54.90 %, 56.36 %, 68.33 %, and 82.04 % for potential gradients of 0, 0.5, 1.0, and 2.0 V/cm, respectively. The uranium leaching efficiency of sandstone at a 2.0 V/cm potential gradient was 27.14 % greater than that at a 0 V/cm potential gradient, and the leaching time was decreased by approximately 40 % at the same uranium leaching efficiency. Analyses of the chemical fraction of uranium, XRD and SEM-EDS showed that the applied potential gradient facilitated solute transport during leaching, thus accelerating the leaching efficiency of adsorbed uranium, tetravalent uranium, and uranium encapsulated in lattices of silicates and primary and secondary minerals in sandstone uranium ores. Therefore, electrokinetic action is excellent for enhancing the effectiveness of sulfuric acid leaching of sandstone uranium ores and has broad application prospects.
摘要：
A novel metal-organic framework (MOF) material, MIL-100(Fe)-DMA, was synthesized using the solvothermal method. The structure of the MOF was characterized using scanning electron microscopy-energy dispersive X-ray spectroscopy, N(2) adsorption-desorption isotherms, X-ray diffraction analysis, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and Mössbauer spectroscopy. Batch adsorption experiments were performed to investigate the effects of initial Sr(2+) and Cs(+) concentrations, adsorption time, pH, and coexisting cations on the adsorption performance of the material. The adsorption mechanism was further elucidated using adsorption kinetics and isotherm models. The results indicated that the adsorption of Sr(2+) and Cs(+) does not significantly affect the MOF material structure. As reaction time and initial ion concentration increased, the adsorption capacity of MIL-100(Fe)-DMA for Sr(2+) and Cs(+) increased rapidly and then gradually reached equilibrium. Optimal adsorption occurred under alkaline conditions, with maximum adsorption capacity observed at pH=8. The adsorption process for Sr(2+) and Cs(+) was well described by the pseudo-second-order kinetic model, the Weber-Morris model, and the Langmuir adsorption isothermal model. The adsorption process was mainly identified as monolayer chemical adsorption, influenced by multiple factors. Characterization combined with density functional theory calculations revealed that the unsaturated carboxylic acid groups on the surface of the MOFs play a crucial role in the interaction with Sr(2+) and Cs(+).
期刊：
Separation and Purification Technology,2024年335:126214 ISSN：1383-5866
通讯作者：
Xie, D
作者机构：
[Li, Suzhe; Tang, Zengming; Yang, Xiaomin] Univ South China, Sch Resource & Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Xie, D; Xie, Dong; Li, Suzhe; Tang, Zengming; Yang, Xiaomin] Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang 421001, Peoples R China.;[Xie, D; Xie, Dong] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Xie, D ] N;Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang 421001, Peoples R China.;Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
摘要：
Finding an inexpensive and efficient porous adsorbent to capture the gaseous radioiodine generated during spent fuel reprocessing has been challenging. Herein, we present a design philosophy for waste control to develop porous carbon for gaseous iodine capture from sewage sludge waste. Among them, the novel in situ etching of polytetrafluoroethylene was employed to improve pore accessibility. The hazards of the conventional preparation of sludge-derived carbon using highly corrosive NaOH and HF solutions were overcome. Polytetrafluoro-ethylene etched porous carbon with large specific surface area (1103 m2/g), interconnected hierarchical porous structure, and excellent hydrophobicity (water contact angle 126.52 degrees), providing efficient adsorption of gaseous iodine in hot (30-150 degrees C) and humid (50-96% relative humidity [RH]) environments. The iodine adsorption of hierarchical porous carbon was tested under static and dynamic conditions, and high records have been achieved. Notably, due to the structural advantage of hydrophobicity, a considerable dynamic adsorption capacity (1746.77 mg/g) was also maintained in a mixed iodine gas stream containing water vapor in a humid (50% RH) hot (75 degrees C) condition. This study is the first to use an in situ etching strategy for polytetrafluoroethylene, which opens a new avenue for converting sludge waste into low-cost porous carbon and provides an attractive option for capturing iodine in hot and humid environments.
摘要：
Indoor and Built Environment, Ahead of Print. <br/>The decommissioning of nuclear facilities and nuclear accidents may release a various amount of radioactive aerosols, which could pose a serious threat to the natural environment and human health. Therefore, there is a need to develop an eco-friendly aerosol suppressant to control the radioactive aerosol. In this paper, carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), rhamnolipid and sophorajaponica glycolipid were selected as the raw material, and the aerosol suppressant was prepared by solution polymerization. The sample was characterized by FTIR, TGA, viscosity, surface tension and contact angle analysis. The results indicated that the grafted reaction was successful. Rhamnolipid and sophorajaponica glycolipid effectively reduced the surface tension of the copolymer solution to 27.7 mN/m, and the contact angle between the polymer solution and experimental dust was decreased to 27.36°. The aerosol sedimentation experiment showed that the suppressant had a significant effect on aerosol. The sedimentation efficiency of concrete aerosols was 87.7%, and the sedimentation efficiency of radioactive aerosols reached 90.8%. It provided an eco-friendly and effective method to quickly and easily control and remove high-concentration radioactive aerosol.
